feat(chat): 聊天页支持日历定位/卡片解析/HTML导出分页

- 新增 /api/chat/messages/daily_counts 与 /api/chat/messages/anchor，用于月度热力图与按日/首条定位\n- messages/around 支持跨 message 分片定位，定位更稳定\n- 新增 /api/chat/chat_history/resolve 与 /api/chat/appmsg/resolve，合并转发/链接卡片可按 server_id 补全\n- 新增 /api/chat/media/favicon，并补齐 link 本地缩略图处理\n- HTML 导出支持分页加载（html_page_size），避免大聊天单文件卡顿\n- tests: 覆盖 heatmap/anchor、favicon 缓存、HTML 分页导出

frontend/assets/css/tailwind.css

@@ -786,6 +786,128 @@
     @apply px-3 py-3 border-b border-gray-100;
   }
 
+  /* 时间侧边栏（按日期定位） */
+  .time-sidebar {
+    @apply w-[420px] h-full flex flex-col bg-white border-l border-gray-200 flex-shrink-0;
+  }
+
+  .time-sidebar-header {
+    @apply flex items-center justify-between px-4 py-3 border-b border-gray-200 bg-gray-50;
+  }
+
+  .time-sidebar-title {
+    @apply flex items-center gap-2 text-sm font-medium text-gray-800;
+  }
+
+  .time-sidebar-close {
+    @apply p-1.5 text-gray-500 hover:text-gray-700 hover:bg-gray-200 rounded-md transition-colors;
+  }
+
+  .time-sidebar-body {
+    @apply flex-1 overflow-y-auto min-h-0;
+  }
+
+  .time-sidebar-status {
+    @apply px-4 py-2 text-xs text-gray-600 border-b border-gray-100;
+  }
+
+  .time-sidebar-status-error {
+    @apply text-red-600;
+  }
+
+  .calendar-header {
+    @apply flex items-center justify-between px-4 py-3;
+  }
+
+  .calendar-nav-btn {
+    @apply p-1.5 text-gray-500 hover:text-gray-700 hover:bg-gray-100 rounded-md transition-colors disabled:opacity-50 disabled:cursor-not-allowed;
+  }
+
+  .calendar-month-label {
+    @apply text-sm font-medium text-gray-800;
+  }
+
+  .calendar-month-label-selects {
+    @apply flex items-center gap-2;
+  }
+
+  .calendar-ym-select {
+    @apply text-xs px-2 py-1 rounded-md border border-gray-200 bg-white text-gray-800 hover:border-gray-300 focus:outline-none focus:ring-2 focus:ring-[#03C160]/20 disabled:opacity-60 disabled:cursor-not-allowed;
+  }
+
+  .calendar-weekdays {
+    @apply grid grid-cols-7 gap-1 px-4 pt-1;
+  }
+
+  .calendar-weekday {
+    @apply text-[11px] text-gray-400 text-center py-1;
+  }
+
+  .calendar-grid {
+    @apply grid grid-cols-7 gap-1 px-4 pb-4;
+  }
+
+  .calendar-day {
+    @apply h-9 rounded-md flex items-center justify-center text-xs font-medium transition-colors border border-gray-200 bg-white disabled:cursor-not-allowed;
+  }
+
+  .calendar-day-outside {
+    @apply bg-transparent border-transparent;
+  }
+
+  .calendar-day-empty {
+    @apply bg-gray-100 text-gray-400 border-gray-100;
+  }
+
+  .calendar-day-selected {
+    /* Keep background as-is (heatmap), but emphasize with a ring/outline. */
+    box-shadow: 0 0 0 2px rgba(3, 193, 96, 0.85);
+    border-color: rgba(3, 193, 96, 0.95) !important;
+  }
+
+  .calendar-day-l1 {
+    background: rgba(3, 193, 96, 0.12);
+    border-color: rgba(3, 193, 96, 0.18);
+    color: #065f46;
+  }
+
+  .calendar-day-l2 {
+    background: rgba(3, 193, 96, 0.24);
+    border-color: rgba(3, 193, 96, 0.28);
+    color: #065f46;
+  }
+
+  .calendar-day-l3 {
+    background: rgba(3, 193, 96, 0.38);
+    border-color: rgba(3, 193, 96, 0.40);
+    color: #064e3b;
+  }
+
+  .calendar-day-l4 {
+    background: rgba(3, 193, 96, 0.55);
+    border-color: rgba(3, 193, 96, 0.55);
+    color: #053d2e;
+  }
+
+  .calendar-day-l1:hover,
+  .calendar-day-l2:hover,
+  .calendar-day-l3:hover,
+  .calendar-day-l4:hover {
+    filter: brightness(0.98);
+  }
+
+  .calendar-day-number {
+    @apply select-none;
+  }
+
+  .time-sidebar-actions {
+    @apply px-4 pb-4;
+  }
+
+  .time-sidebar-action-btn {
+    @apply w-full text-xs px-3 py-2 rounded-md bg-[#03C160] text-white hover:bg-[#02a650] transition-colors disabled:opacity-60 disabled:cursor-not-allowed;
+  }
+
   /* 整合搜索框样式 */
   .search-input-combined {
     @apply flex items-center bg-white border-2 border-gray-200 rounded-lg overflow-hidden transition-all duration-200;

frontend/composables/useApi.js

@@ -180,6 +180,46 @@ export const useApi = () => {
     return await request(url)
   }
 
+  // 聊天记录日历热力图：某月每日消息数
+  const getChatMessageDailyCounts = async (params = {}) => {
+    const query = new URLSearchParams()
+    if (params && params.account) query.set('account', params.account)
+    if (params && params.username) query.set('username', params.username)
+    if (params && params.year != null) query.set('year', String(params.year))
+    if (params && params.month != null) query.set('month', String(params.month))
+    const url = '/chat/messages/daily_counts' + (query.toString() ? `?${query.toString()}` : '')
+    return await request(url)
+  }
+
+  // 聊天记录定位锚点：某日第一条 / 会话最早一条
+  const getChatMessageAnchor = async (params = {}) => {
+    const query = new URLSearchParams()
+    if (params && params.account) query.set('account', params.account)
+    if (params && params.username) query.set('username', params.username)
+    if (params && params.kind) query.set('kind', String(params.kind))
+    if (params && params.date) query.set('date', String(params.date))
+    const url = '/chat/messages/anchor' + (query.toString() ? `?${query.toString()}` : '')
+    return await request(url)
+  }
+
+  // 解析嵌套合并转发聊天记录（通过 server_id）
+  const resolveNestedChatHistory = async (params = {}) => {
+    const query = new URLSearchParams()
+    if (params && params.account) query.set('account', params.account)
+    if (params && params.server_id != null) query.set('server_id', String(params.server_id))
+    const url = '/chat/chat_history/resolve' + (query.toString() ? `?${query.toString()}` : '')
+    return await request(url)
+  }
+
+  // 解析卡片/小程序等 App 消息（通过 server_id）
+  const resolveAppMsg = async (params = {}) => {
+    const query = new URLSearchParams()
+    if (params && params.account) query.set('account', params.account)
+    if (params && params.server_id != null) query.set('server_id', String(params.server_id))
+    const url = '/chat/appmsg/resolve' + (query.toString() ? `?${query.toString()}` : '')
+    return await request(url)
+  }
+
   // 朋友圈时间线
   const listSnsTimeline = async (params = {}) => {
     const query = new URLSearchParams()
@@ -295,6 +335,7 @@ export const useApi = () => {
         output_dir: data.output_dir == null ? null : String(data.output_dir || '').trim(),
         allow_process_key_extract: !!data.allow_process_key_extract,
         download_remote_media: !!data.download_remote_media,
+        html_page_size: data.html_page_size != null ? Number(data.html_page_size) : 1000,
         privacy_mode: !!data.privacy_mode,
         file_name: data.file_name || null
       }
@@ -408,6 +449,10 @@ export const useApi = () => {
     buildChatSearchIndex,
     listChatSearchSenders,
     getChatMessagesAround,
+    getChatMessageDailyCounts,
+    getChatMessageAnchor,
+    resolveNestedChatHistory,
+    resolveAppMsg,
     listSnsTimeline,
     listSnsMediaCandidates,
     saveSnsMediaPicks,

src/wechat_decrypt_tool/chat_export_service.py

@@ -541,6 +541,11 @@ body { background: #EDEDED; }
 .wce-chat-title { font-size: 16px; font-weight: 500; color: #111827; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
 .wce-filter-select { font-size: 12px; padding: 6px 8px; border: 0; border-radius: 8px; background: transparent; color: #374151; }
 .wce-message-container { flex: 1; overflow: auto; padding: 16px; min-height: 0; }
+.wce-pager { display: flex; align-items: center; justify-content: center; gap: 12px; padding: 6px 0 12px; }
+.wce-pager-btn { font-size: 12px; padding: 6px 10px; border-radius: 8px; border: 1px solid #e5e7eb; background: #fff; color: #374151; cursor: pointer; }
+.wce-pager-btn:hover { background: #f9fafb; }
+.wce-pager-btn:disabled { opacity: 0.6; cursor: not-allowed; }
+.wce-pager-status { font-size: 12px; color: #6b7280; }
 
 /* Single session item (middle column). */
 .wce-session-item { display: flex; align-items: center; gap: 12px; padding: 0 12px; height: 80px; border-bottom: 1px solid #f3f4f6; background: #DEDEDE; text-decoration: none; color: inherit; }
@@ -838,6 +843,140 @@ _HTML_EXPORT_JS = r"""
     return obj
   }
 
+  const readPageMeta = () => {
+    const el = document.getElementById('wcePageMeta')
+    const obj = safeJsonParse(el ? el.textContent : '')
+    if (!obj || typeof obj !== 'object') return null
+    return obj
+  }
+
+  const initPagedMessageLoading = () => {
+    const meta = readPageMeta()
+    if (!meta) return
+
+    const totalPages = Number(meta.totalPages || 0)
+    if (!Number.isFinite(totalPages) || totalPages <= 1) return
+
+    const initialPage = Number(meta.initialPage || totalPages || 1)
+    const padWidth = Number(meta.padWidth || 0) || 0
+    const prefix = String(meta.pageFilePrefix || 'pages/page-')
+    const suffix = String(meta.pageFileSuffix || '.js')
+
+    const container = document.getElementById('messageContainer')
+    const list = document.getElementById('wceMessageList') || container
+    const pager = document.getElementById('wcePager')
+    const btn = document.getElementById('wceLoadPrevBtn')
+    const status = document.getElementById('wceLoadPrevStatus')
+    if (!container || !list || !pager || !btn) return
+
+    try { pager.style.display = '' } catch {}
+
+    const loaded = new Set()
+    loaded.add(initialPage)
+    let nextPage = initialPage - 1
+    let loading = false
+
+    const setStatus = (text) => {
+      try { if (status) status.textContent = String(text || '') } catch {}
+    }
+
+    const updateUi = (overrideText) => {
+      if (overrideText != null) {
+        setStatus(overrideText)
+        try { btn.disabled = false } catch {}
+        return
+      }
+      if (nextPage < 1) {
+        setStatus('已到底')
+        try { btn.disabled = true } catch {}
+        return
+      }
+      if (loading) {
+        setStatus('加载中...')
+        try { btn.disabled = true } catch {}
+        return
+      }
+      setStatus('点击加载更早消息')
+      try { btn.disabled = false } catch {}
+    }
+
+    const pageSrc = (n) => {
+      const num = padWidth > 0 ? String(n).padStart(padWidth, '0') : String(n)
+      return prefix + num + suffix
+    }
+
+    window.__WCE_PAGE_QUEUE__ = window.__WCE_PAGE_QUEUE__ || []
+    window.__WCE_PAGE_LOADED__ = (pageNo, html) => {
+      const n = Number(pageNo)
+      if (!Number.isFinite(n) || n < 1) return
+      if (loaded.has(n)) return
+      loaded.add(n)
+
+      try {
+        const prevH = container.scrollHeight
+        const prevTop = container.scrollTop
+        list.insertAdjacentHTML('afterbegin', String(html || ''))
+        const newH = container.scrollHeight
+        container.scrollTop = prevTop + (newH - prevH)
+      } catch {
+        try { list.insertAdjacentHTML('afterbegin', String(html || '')) } catch {}
+      }
+
+      loading = false
+      nextPage = n - 1
+      try { applyMessageTypeFilter() } catch {}
+      try { updateSessionMessageCount() } catch {}
+      updateUi()
+    }
+
+    // Flush any queued pages (should be rare, but keeps behavior robust).
+    try {
+      const q = window.__WCE_PAGE_QUEUE__
+      if (Array.isArray(q) && q.length) {
+        const items = q.slice(0)
+        q.length = 0
+        items.forEach((it) => {
+          try {
+            if (it && it.length >= 2) window.__WCE_PAGE_LOADED__(it[0], it[1])
+          } catch {}
+        })
+      }
+    } catch {}
+
+    const requestLoad = () => {
+      if (loading) return
+      if (nextPage < 1) return
+      const n = nextPage
+
+      loading = true
+      updateUi()
+
+      const s = document.createElement('script')
+      s.async = true
+      s.src = pageSrc(n)
+      s.onerror = () => {
+        loading = false
+        updateUi('加载失败，可重试')
+      }
+      try { document.body.appendChild(s) } catch {
+        loading = false
+        updateUi('加载失败，可重试')
+      }
+    }
+
+    btn.addEventListener('click', () => requestLoad())
+
+    let lastScrollAt = 0
+    container.addEventListener('scroll', () => {
+      const now = Date.now()
+      if (now - lastScrollAt < 200) return
+      lastScrollAt = now
+      if (container.scrollTop < 120) requestLoad()
+    })
+
+    updateUi()
+  }
+
   const isMaybeMd5 = (value) => /^[0-9a-f]{32}$/i.test(String(value || '').trim())
   const pickFirstMd5 = (...values) => {
     for (const v of values) {
@@ -926,28 +1065,90 @@ _HTML_EXPORT_JS = r"""
 
     const getText = (node, tag) => {
       try {
-        const el = node.getElementsByTagName(tag)?.[0]
+        if (!node) return ''
+        const els = Array.from(node.getElementsByTagName(tag) || [])
+        const direct = els.find((el) => el && el.parentNode === node)
+        const el = direct || els[0]
         return String(el?.textContent || '').trim()
       } catch {
         return ''
       }
     }
 
+    const getDirectChildXml = (node, tag) => {
+      try {
+        if (!node) return ''
+        const children = Array.from(node.children || [])
+        const el = children.find((c) => String(c?.tagName || '').toLowerCase() === String(tag || '').toLowerCase())
+        if (!el) return ''
+
+        const raw = String(el.textContent || '').trim()
+        if (raw && raw.startsWith('<') && raw.endsWith('>')) return raw
+
+        if (typeof XMLSerializer !== 'undefined') {
+          return new XMLSerializer().serializeToString(el)
+        }
+      } catch {}
+      return ''
+    }
+
+    const getAnyXml = (node, tag) => {
+      try {
+        if (!node) return ''
+        const els = Array.from(node.getElementsByTagName(tag) || [])
+        const direct = els.find((el) => el && el.parentNode === node)
+        const el = direct || els[0]
+        if (!el) return ''
+
+        const raw = String(el.textContent || '').trim()
+        if (raw && raw.startsWith('<') && raw.endsWith('>')) return raw
+        if (typeof XMLSerializer !== 'undefined') return new XMLSerializer().serializeToString(el)
+      } catch {}
+      return ''
+    }
+
+    const sameTag = (el, tag) => String(el?.tagName || '').toLowerCase() === String(tag || '').toLowerCase()
+
+    const closestAncestorByTag = (node, tag) => {
+      const lower = String(tag || '').toLowerCase()
+      let cur = node
+      while (cur) {
+        if (cur.nodeType === 1 && String(cur.tagName || '').toLowerCase() === lower) return cur
+        cur = cur.parentNode
+      }
+      return null
+    }
+
     const root = doc?.documentElement
     const isChatRoom = String(getText(root, 'isChatRoom') || '').trim() === '1'
     const title = getText(root, 'title')
     const desc = getText(root, 'desc') || getText(root, 'info')
 
-    const items = Array.from(doc.getElementsByTagName('dataitem') || [])
-    const parsed = items.map((node, idx) => {
-      const datatype = String(node.getAttribute('datatype') || '').trim()
-      const dataid = String(node.getAttribute('dataid') || '').trim() || String(idx)
+    const datalist = (() => {
+      try {
+        const all = Array.from(doc.getElementsByTagName('datalist') || [])
+        const top = root ? all.find((el) => closestAncestorByTag(el, 'recorditem') === root) : null
+        return top || all[0] || null
+      } catch {
+        return null
+      }
+    })()
+
+    const itemNodes = (() => {
+      if (datalist) return Array.from(datalist.children || []).filter((el) => sameTag(el, 'dataitem'))
+      return Array.from(root?.children || []).filter((el) => sameTag(el, 'dataitem'))
+    })()
+
+    const parsed = itemNodes.map((node, idx) => {
+      const datatype = String(node.getAttribute('datatype') || getText(node, 'datatype') || '').trim()
+      const dataid = String(node.getAttribute('dataid') || getText(node, 'dataid') || '').trim() || String(idx)
 
       const sourcename = getText(node, 'sourcename')
       const sourcetime = getText(node, 'sourcetime')
       const sourceheadurl = normalizeChatHistoryUrl(getText(node, 'sourceheadurl'))
       const datatitle = getText(node, 'datatitle')
       const datadesc = getText(node, 'datadesc')
+      const link = normalizeChatHistoryUrl(getText(node, 'link') || getText(node, 'dataurl') || getText(node, 'url'))
       const datafmt = getText(node, 'datafmt')
       const duration = getText(node, 'duration')
 
@@ -961,6 +1162,7 @@ _HTML_EXPORT_JS = r"""
       const fromnewmsgid = getText(node, 'fromnewmsgid')
       const srcMsgLocalid = getText(node, 'srcMsgLocalid')
       const srcMsgCreateTime = getText(node, 'srcMsgCreateTime')
+      const nestedRecordItem = getAnyXml(node, 'recorditem') || getDirectChildXml(node, 'recorditem') || getText(node, 'recorditem')
 
       let content = datatitle || datadesc
       if (!content) {
@@ -975,7 +1177,11 @@ _HTML_EXPORT_JS = r"""
       const imageFormats = new Set(['jpg', 'jpeg', 'png', 'gif', 'webp', 'bmp', 'heic', 'heif'])
 
       let renderType = 'text'
-      if (datatype === '4' || String(duration || '').trim() || fmt === 'mp4') {
+      if (datatype === '17') {
+        renderType = 'chatHistory'
+      } else if (datatype === '5' || link) {
+        renderType = 'link'
+      } else if (datatype === '4' || String(duration || '').trim() || fmt === 'mp4') {
         renderType = 'video'
       } else if (datatype === '47' || datatype === '37') {
         renderType = 'emoji'
@@ -990,6 +1196,23 @@ _HTML_EXPORT_JS = r"""
         renderType = 'emoji'
       }
 
+      let outTitle = ''
+      let outUrl = ''
+      let recordItem = ''
+      if (renderType === 'chatHistory') {
+        outTitle = datatitle || content || '聊天记录'
+        content = datadesc || ''
+        recordItem = nestedRecordItem
+      } else if (renderType === 'link') {
+        outTitle = datatitle || content || ''
+        outUrl = link || externurl || ''
+        // datadesc can be an invisible filler; only keep as description when meaningful.
+        const cleanDesc = String(datadesc || '').replace(/[\\u3164\\u2800]/g, '').trim()
+        const cleanTitle = String(outTitle || '').replace(/[\\u3164\\u2800]/g, '').trim()
+        if (!cleanDesc || (cleanTitle && cleanDesc === cleanTitle)) content = ''
+        else content = String(datadesc || '').trim()
+      }
+
       return {
         id: dataid,
         datatype,
@@ -1009,6 +1232,9 @@ _HTML_EXPORT_JS = r"""
         srcMsgLocalid,
         srcMsgCreateTime,
         renderType,
+        title: outTitle,
+        recordItem,
+        url: outUrl,
         content
       }
     })
@@ -1028,15 +1254,64 @@ _HTML_EXPORT_JS = r"""
     if (!modal || !titleEl || !closeBtn || !emptyEl || !listEl) return
 
     const mediaIndex = readMediaIndex()
+    let historyStack = []
+    let currentState = null
+    let backBtn = null
+
+    const updateBackVisibility = () => {
+      if (!backBtn) return
+      const show = Array.isArray(historyStack) && historyStack.length > 0
+      try { backBtn.classList.toggle('hidden', !show) } catch {}
+    }
+
+    // Add a back button next to the title (created at runtime to avoid changing the HTML template).
+    try {
+      const header = titleEl.parentElement
+      if (header) {
+        const wrap = document.createElement('div')
+        wrap.className = 'flex items-center gap-2 min-w-0'
+
+        backBtn = document.createElement('button')
+        backBtn.type = 'button'
+        backBtn.className = 'p-2 rounded hover:bg-black/5 flex-shrink-0 hidden'
+        try { backBtn.setAttribute('aria-label', '返回') } catch {}
+        try { backBtn.setAttribute('title', '返回') } catch {}
+        backBtn.innerHTML = '<svg class="w-5 h-5 text-gray-700" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M15 19l-7-7 7-7" /></svg>'
+
+        header.insertBefore(wrap, titleEl)
+        wrap.appendChild(backBtn)
+        wrap.appendChild(titleEl)
+      }
+    } catch {}
 
     const close = () => {
       try { modal.classList.add('hidden') } catch {}
       try { modal.style.display = 'none' } catch {}
       try { modal.setAttribute('aria-hidden', 'true') } catch {}
       try { document.body.style.overflow = '' } catch {}
-      try { titleEl.textContent = '合并消息' } catch {}
+      try { titleEl.textContent = '聊天记录' } catch {}
       try { listEl.textContent = '' } catch {}
       try { emptyEl.style.display = '' } catch {}
+      historyStack = []
+      currentState = null
+      updateBackVisibility()
+    }
+
+    const buildChatHistoryState = (payload) => {
+      const title = String(payload?.title || '聊天记录').trim() || '聊天记录'
+      const xml = String(payload?.recordItem || '').trim()
+      const parsed = parseChatHistoryRecord(xml)
+      const info = (parsed && parsed.info) ? parsed.info : { isChatRoom: false }
+      let records = (parsed && Array.isArray(parsed.items)) ? parsed.items : []
+
+      if (!records.length) {
+        const lines = Array.isArray(payload?.fallbackLines)
+          ? payload.fallbackLines
+          : String(payload?.content || '').trim().split(/\r?\n/).map((x) => String(x || '').trim()).filter(Boolean)
+        records = lines.map((line, idx) => ({ id: String(idx), renderType: 'text', content: line, sourcename: '', sourcetime: '' }))
+      }
+
+      return { title, info, records }
     }
 
     const renderRecordRow = (rec, info) => {
@@ -1102,7 +1377,123 @@ _HTML_EXPORT_JS = r"""
       const serverId = String(rec?.fromnewmsgid || '').trim()
       const serverMd5 = resolveServerMd5(mediaIndex, serverId)
 
-      if (rt === 'video') {
+      if (rt === 'chatHistory') {
+        const card = document.createElement('div')
+        card.className = 'wechat-chat-history-card wechat-special-card msg-radius'
+
+        const chBody = document.createElement('div')
+        chBody.className = 'wechat-chat-history-body'
+
+        const chTitle = document.createElement('div')
+        chTitle.className = 'wechat-chat-history-title'
+        chTitle.textContent = String(rec?.title || '聊天记录')
+        chBody.appendChild(chTitle)
+
+        const raw = String(rec?.content || '').trim()
+        const lines = raw ? raw.split(/\r?\n/).map((x) => String(x || '').trim()).filter(Boolean).slice(0, 4) : []
+        if (lines.length) {
+          const preview = document.createElement('div')
+          preview.className = 'wechat-chat-history-preview'
+          for (const line of lines) {
+            const el = document.createElement('div')
+            el.className = 'wechat-chat-history-line'
+            el.textContent = line
+            preview.appendChild(el)
+          }
+          chBody.appendChild(preview)
+        }
+
+        card.appendChild(chBody)
+
+        const bottom = document.createElement('div')
+        bottom.className = 'wechat-chat-history-bottom'
+        const label = document.createElement('span')
+        label.textContent = '聊天记录'
+        bottom.appendChild(label)
+        card.appendChild(bottom)
+
+        const nestedXml = String(rec?.recordItem || '').trim()
+        if (nestedXml) {
+          card.classList.add('cursor-pointer')
+          card.addEventListener('click', (ev) => {
+            try { ev.preventDefault() } catch {}
+            try { ev.stopPropagation() } catch {}
+            openNestedChatHistory(rec)
+          })
+        }
+
+        body.appendChild(card)
+      } else if (rt === 'link') {
+        const href = normalizeChatHistoryUrl(rec?.url) || normalizeChatHistoryUrl(rec?.externurl)
+        const heading = String(rec?.title || '').trim() || content || href || '链接'
+        const desc = String(rec?.content || '').trim()
+
+        const thumbMd5 = pickFirstMd5(rec?.fullmd5, rec?.thumbfullmd5, rec?.md5)
+        let previewUrl = resolveMd5Any(mediaIndex, thumbMd5)
+        if (!previewUrl && serverMd5) previewUrl = resolveMd5Any(mediaIndex, serverMd5)
+        if (!previewUrl) previewUrl = resolveRemoteAny(mediaIndex, rec?.externurl, rec?.cdnurlstring, rec?.encrypturlstring)
+
+        const card = document.createElement(href ? 'a' : 'div')
+        card.className = 'wechat-link-card wechat-special-card msg-radius cursor-pointer'
+        if (href) {
+          card.href = href
+          card.target = '_blank'
+          card.rel = 'noreferrer noopener'
+        }
+        try { card.style.textDecoration = 'none' } catch {}
+        try { card.style.outline = 'none' } catch {}
+
+        const linkContent = document.createElement('div')
+        linkContent.className = 'wechat-link-content'
+
+        const linkInfo = document.createElement('div')
+        linkInfo.className = 'wechat-link-info'
+        const titleEl = document.createElement('div')
+        titleEl.className = 'wechat-link-title'
+        titleEl.textContent = heading
+        linkInfo.appendChild(titleEl)
+        if (desc) {
+          const descEl = document.createElement('div')
+          descEl.className = 'wechat-link-desc'
+          descEl.textContent = desc
+          linkInfo.appendChild(descEl)
+        }
+        linkContent.appendChild(linkInfo)
+
+        if (previewUrl) {
+          const thumb = document.createElement('div')
+          thumb.className = 'wechat-link-thumb'
+          const img = document.createElement('img')
+          img.src = previewUrl
+          img.alt = heading || '链接预览'
+          img.className = 'wechat-link-thumb-img'
+          try { img.referrerPolicy = 'no-referrer' } catch {}
+          thumb.appendChild(img)
+          linkContent.appendChild(thumb)
+        }
+
+        card.appendChild(linkContent)
+
+        const fromRow = document.createElement('div')
+        fromRow.className = 'wechat-link-from'
+        const fromText = (() => {
+          const f0 = String(rec?.from || '').trim()
+          if (f0) return f0
+          try { return href ? (new URL(href).hostname || '') : '' } catch { return '' }
+        })()
+        const fromAvatarText = fromText ? (Array.from(fromText)[0] || '') : ''
+        const fromAvatar = document.createElement('div')
+        fromAvatar.className = 'wechat-link-from-avatar'
+        fromAvatar.textContent = fromAvatarText || '\u200B'
+        const fromName = document.createElement('div')
+        fromName.className = 'wechat-link-from-name'
+        fromName.textContent = fromText || '\u200B'
+        fromRow.appendChild(fromAvatar)
+        fromRow.appendChild(fromName)
+        card.appendChild(fromRow)
+
+        body.appendChild(card)
+      } else if (rt === 'video') {
         const videoMd5 = pickFirstMd5(rec?.fullmd5, rec?.md5)
         const thumbMd5 = pickFirstMd5(rec?.thumbfullmd5) || videoMd5
         let videoUrl = resolveMd5Any(mediaIndex, videoMd5)
@@ -1202,20 +1593,11 @@ _HTML_EXPORT_JS = r"""
       return row
     }
 
-    const openFromCard = (card) => {
-      const title = String(card?.getAttribute('data-title') || '合并消息').trim() || '合并消息'
-      const b64 = String(card?.getAttribute('data-record-item-b64') || '').trim()
-      const xml = decodeBase64Utf8(b64)
-      const parsed = parseChatHistoryRecord(xml)
-      const info = (parsed && parsed.info) ? parsed.info : { isChatRoom: false }
-      let records = (parsed && Array.isArray(parsed.items)) ? parsed.items : []
-
-      if (!records.length) {
-        const lines = Array.from(card.querySelectorAll('.wechat-chat-history-line') || [])
-          .map((el) => String(el?.textContent || '').trim())
-          .filter(Boolean)
-        records = lines.map((line, idx) => ({ id: String(idx), renderType: 'text', content: line, sourcename: '', sourcetime: '' }))
-      }
+    const applyChatHistoryState = (state) => {
+      currentState = state
+      const title = String(state?.title || '聊天记录').trim() || '聊天记录'
+      const info = state?.info || { isChatRoom: false }
+      const records = Array.isArray(state?.records) ? state.records : []
 
       try { titleEl.textContent = title } catch {}
       try { listEl.textContent = '' } catch {}
@@ -1231,6 +1613,45 @@ _HTML_EXPORT_JS = r"""
         }
       }
 
+      updateBackVisibility()
+    }
+
+    const openNestedChatHistory = (rec) => {
+      const xml = String(rec?.recordItem || '').trim()
+      if (!xml) return
+      if (currentState) {
+        historyStack = [...historyStack, currentState]
+      }
+      const state = buildChatHistoryState({
+        title: String(rec?.title || '聊天记录'),
+        recordItem: xml,
+        content: String(rec?.content || ''),
+      })
+      applyChatHistoryState(state)
+    }
+
+    if (backBtn) {
+      backBtn.addEventListener('click', (ev) => {
+        try { ev.preventDefault() } catch {}
+        if (!Array.isArray(historyStack) || !historyStack.length) return
+        const prev = historyStack[historyStack.length - 1]
+        historyStack = historyStack.slice(0, -1)
+        applyChatHistoryState(prev)
+      })
+    }
+
+    const openFromCard = (card) => {
+      const title = String(card?.getAttribute('data-title') || '聊天记录').trim() || '聊天记录'
+      const b64 = String(card?.getAttribute('data-record-item-b64') || '').trim()
+      const xml = decodeBase64Utf8(b64)
+      const lines = Array.from(card.querySelectorAll('.wechat-chat-history-line') || [])
+        .map((el) => String(el?.textContent || '').trim())
+        .filter(Boolean)
+
+      historyStack = []
+      const state = buildChatHistoryState({ title, recordItem: xml, fallbackLines: lines })
+      applyChatHistoryState(state)
+
       try { modal.classList.remove('hidden') } catch {}
       try { modal.style.display = 'flex' } catch {}
       try { modal.setAttribute('aria-hidden', 'false') } catch {}
@@ -1269,6 +1690,7 @@ _HTML_EXPORT_JS = r"""
     initSessionSearch()
     initVoicePlayback()
     initChatHistoryModal()
+    initPagedMessageLoading()
 
     const select = document.getElementById('messageTypeFilter')
     if (select) {
@@ -1469,6 +1891,7 @@ class ChatExportManager:
         output_dir: Optional[str],
         allow_process_key_extract: bool,
         download_remote_media: bool,
+        html_page_size: int = 1000,
         privacy_mode: bool,
         file_name: Optional[str],
     ) -> ExportJob:
@@ -1493,6 +1916,7 @@ class ChatExportManager:
                 "outputDir": str(output_dir or "").strip(),
                 "allowProcessKeyExtract": bool(allow_process_key_extract),
                 "downloadRemoteMedia": bool(download_remote_media),
+                "htmlPageSize": int(html_page_size) if int(html_page_size or 0) > 0 else int(html_page_size or 0),
                 "privacyMode": bool(privacy_mode),
                 "fileName": str(file_name or "").strip(),
             },
@@ -1544,6 +1968,12 @@ class ChatExportManager:
         allow_process_key_extract = bool(opts.get("allowProcessKeyExtract"))
         download_remote_media = bool(opts.get("downloadRemoteMedia"))
         privacy_mode = bool(opts.get("privacyMode"))
+        try:
+            html_page_size = int(opts.get("htmlPageSize") or 1000)
+        except Exception:
+            html_page_size = 1000
+        if html_page_size < 0:
+            html_page_size = 0
 
         media_kinds_raw = opts.get("mediaKinds") or []
         media_kinds: list[MediaKind] = []
@@ -1898,6 +2328,7 @@ class ChatExportManager:
                             session_items=session_items,
                             download_remote_media=remote_download_enabled,
                             remote_written=remote_written,
+                            html_page_size=html_page_size,
                             start_time=st,
                             end_time=et,
                             want_types=want_types,
@@ -2045,6 +2476,7 @@ class ChatExportManager:
                         "mediaKinds": media_kinds,
                         "allowProcessKeyExtract": allow_process_key_extract,
                         "downloadRemoteMedia": bool(download_remote_media),
+                        "htmlPageSize": int(html_page_size) if export_format == "html" else None,
                         "privacyMode": privacy_mode,
                     },
                     "stats": {
@@ -3110,6 +3542,7 @@ def _write_conversation_html(
     session_items: list[dict[str, Any]],
     download_remote_media: bool,
     remote_written: dict[str, str],
+    html_page_size: int = 1000,
     start_time: Optional[int],
     end_time: Optional[int],
     want_types: Optional[set[str]],
@@ -3499,7 +3932,7 @@ def _write_conversation_html(
         ("emoji", "表情"),
         ("video", "视频"),
         ("voice", "语音"),
-        ("chatHistory", "合并消息"),
+        ("chatHistory", "聊天记录"),
         ("transfer", "转账"),
         ("redPacket", "红包"),
         ("file", "文件"),
@@ -3509,10 +3942,46 @@ def _write_conversation_html(
         ("voip", "通话"),
     ]
 
+    page_size = 0
+    try:
+        page_size = int(html_page_size or 0)
+    except Exception:
+        page_size = 0
+    if page_size < 0:
+        page_size = 0
+
     # NOTE: write to a temp file first to avoid zip interleaving writes.
     with tempfile.TemporaryDirectory(prefix="wechat_chat_export_") as tmp_dir:
         tmp_path = Path(tmp_dir) / "messages.html"
-        with open(tmp_path, "w", encoding="utf-8", newline="\n") as tw:
+        pages_frag_dir = Path(tmp_dir) / "pages_fragments"
+        page_frag_paths: list[Path] = []
+        paged_old_page_paths: list[Path] = []
+        paged_total_pages = 1
+        paged_pad_width = 4
+        with open(tmp_path, "w", encoding="utf-8", newline="\n") as hw:
+            class _WriteProxy:
+                def __init__(self, default_target):
+                    self._default = default_target
+                    self._target = default_target
+
+                def set_target(self, target) -> None:
+                    self._target = target or self._default
+
+                def write(self, s: str) -> Any:
+                    return self._target.write(s)
+
+                def flush(self) -> None:
+                    try:
+                        if self._target is not self._default:
+                            self._target.flush()
+                    except Exception:
+                        pass
+                    try:
+                        self._default.flush()
+                    except Exception:
+                        pass
+
+            tw = _WriteProxy(hw)
             tw.write("<!doctype html>\n")
             tw.write('<html lang="zh-CN">\n')
             tw.write("<head>\n")
@@ -3688,6 +4157,55 @@ def _write_conversation_html(
             tw.write("        </div>\n")
 
             tw.write('        <div id="messageContainer" class="wce-message-container flex-1 overflow-y-auto p-4 min-h-0">\n')
+            tw.write('          <div id="wcePager" class="wce-pager" style="display:none">\n')
+            tw.write('            <button id="wceLoadPrevBtn" type="button" class="wce-pager-btn">加载更早消息</button>\n')
+            tw.write('            <span id="wceLoadPrevStatus" class="wce-pager-status"></span>\n')
+            tw.write("          </div>\n")
+            tw.write('          <div id="wceMessageList">\n')
+
+            page_fp = None
+            page_fp_path: Optional[Path] = None
+            page_no = 1
+            page_msg_count = 0
+
+            def _open_page_fp() -> Any:
+                nonlocal page_fp, page_fp_path
+                pages_frag_dir.mkdir(parents=True, exist_ok=True)
+                page_fp_path = pages_frag_dir / f"page_{page_no}.htmlfrag"
+                page_fp = open(page_fp_path, "w", encoding="utf-8", newline="\n")
+                return page_fp
+
+            def _close_page_fp() -> None:
+                nonlocal page_fp, page_fp_path
+                if page_fp is None:
+                    page_fp_path = None
+                    return
+                try:
+                    page_fp.flush()
+                except Exception:
+                    pass
+                try:
+                    page_fp.close()
+                except Exception:
+                    pass
+                if page_fp_path is not None:
+                    page_frag_paths.append(page_fp_path)
+                page_fp = None
+                page_fp_path = None
+                tw.set_target(hw)
+
+            def _mark_exported() -> None:
+                nonlocal exported, page_no, page_msg_count
+                exported += 1
+                with lock:
+                    job.progress.messages_exported += 1
+                    job.progress.current_conversation_messages_exported = exported
+                if page_size > 0:
+                    page_msg_count += 1
+                    if page_msg_count >= page_size:
+                        _close_page_fp()
+                        page_no += 1
+                        page_msg_count = 0
 
             sender_alias_map: dict[str, int] = {}
             prev_ts = 0
@@ -3755,6 +4273,11 @@ def _write_conversation_html(
                 if ts and ((prev_ts == 0) or (abs(ts - prev_ts) >= 300)):
                     show_divider = True
 
+                if page_size > 0:
+                    if page_fp is None:
+                        _open_page_fp()
+                    tw.set_target(page_fp)
+
                 if show_divider:
                     divider_text = _format_session_time(ts)
                     if divider_text:
@@ -3770,10 +4293,7 @@ def _write_conversation_html(
                     tw.write(f'              <div class="px-3 py-1 text-xs text-[#9e9e9e]">{esc_text(msg.get("content") or "")}</div>\n')
                     tw.write("            </div>\n")
                     tw.write("          </div>\n")
-                    exported += 1
-                    with lock:
-                        job.progress.messages_exported += 1
-                        job.progress.current_conversation_messages_exported = exported
+                    _mark_exported()
                     if ts:
                         prev_ts = ts
                     continue
@@ -4186,7 +4706,7 @@ def _write_conversation_html(
 
                         tw.write("                  </div>\n")
                 elif rt == "chatHistory":
-                    title = str(msg.get("title") or "").strip() or "合并消息"
+                    title = str(msg.get("title") or "").strip() or "聊天记录"
                     record_item = str(msg.get("recordItem") or "").strip()
                     record_item_b64 = ""
                     if record_item:
@@ -4260,7 +4780,7 @@ def _write_conversation_html(
                             tw.write(f'                        <div class="wechat-chat-history-line">{esc_text(line)}</div>\n')
                         tw.write("                      </div>\n")
                     tw.write("                    </div>\n")
-                    tw.write('                    <div class="wechat-chat-history-bottom"><span>合并消息</span></div>\n')
+                    tw.write('                    <div class="wechat-chat-history-bottom"><span>聊天记录</span></div>\n')
                     tw.write("                  </div>\n")
                 elif rt == "transfer":
                     received = is_transfer_received(msg)
@@ -4328,18 +4848,56 @@ def _write_conversation_html(
                 tw.write("            </div>\n")
                 tw.write("          </div>\n")
 
-                exported += 1
-                with lock:
-                    job.progress.messages_exported += 1
-                    job.progress.current_conversation_messages_exported = exported
+                _mark_exported()
                 if ts:
                     prev_ts = ts
 
                 if scanned % 500 == 0 and job.cancel_requested:
                     raise _JobCancelled()
 
+            if page_size > 0:
+                _close_page_fp()
+                paged_total_pages = max(1, len(page_frag_paths))
+                paged_pad_width = max(4, len(str(paged_total_pages)))
+                if page_frag_paths:
+                    paged_old_page_paths = list(page_frag_paths[:-1])
+                    tw.set_target(hw)
+                    try:
+                        tw.write(page_frag_paths[-1].read_text(encoding="utf-8"))
+                    except Exception:
+                        try:
+                            tw.write(page_frag_paths[-1].read_text(encoding="utf-8", errors="ignore"))
+                        except Exception:
+                            pass
+                else:
+                    paged_old_page_paths = []
+                    tw.set_target(hw)
+
+            # Close message list + container
+            tw.set_target(hw)
             tw.write("          </div>\n")
             tw.write("        </div>\n")
+
+            if page_size > 0 and paged_total_pages > 1:
+                page_meta = {
+                    "schemaVersion": 1,
+                    "pageSize": int(page_size),
+                    "totalPages": int(paged_total_pages),
+                    "initialPage": int(paged_total_pages),
+                    "totalMessages": int(exported),
+                    "padWidth": int(paged_pad_width),
+                    "pageFilePrefix": "pages/page-",
+                    "pageFileSuffix": ".js",
+                    "inlinedPages": [int(paged_total_pages)],
+                }
+                try:
+                    page_meta_payload = json.dumps(page_meta, ensure_ascii=False)
+                except Exception:
+                    page_meta_payload = "{}"
+                page_meta_payload = page_meta_payload.replace("</", "<\\/")
+                tw.write(f'<script type="application/json" id="wcePageMeta">{page_meta_payload}</script>\n')
+
+            tw.write("      </div>\n")
             tw.write("    </div>\n")
             tw.write("  </div>\n")
             tw.write("</div>\n")
@@ -4357,7 +4915,7 @@ def _write_conversation_html(
             )
             tw.write('  <div class="w-[92vw] max-w-[560px] max-h-[80vh] bg-white rounded-xl shadow-xl overflow-hidden flex flex-col" role="dialog" aria-modal="true">\n')
             tw.write('    <div class="px-4 py-3 bg-neutral-100 border-b border-gray-200 flex items-center justify-between">\n')
-            tw.write('      <div id="chatHistoryModalTitle" class="text-sm text-[#161616] truncate">合并消息</div>\n')
+            tw.write('      <div id="chatHistoryModalTitle" class="text-sm text-[#161616] truncate">聊天记录</div>\n')
             tw.write('      <button type="button" id="chatHistoryModalClose" class="p-2 rounded hover:bg-black/5" aria-label="关闭" title="关闭">\n')
             tw.write('        <svg class="w-5 h-5 text-gray-700" fill="none" stroke="currentColor" viewBox="0 0 24 24">\n')
             tw.write('          <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M6 18L18 6M6 6l12 12"/>\n')
@@ -4365,7 +4923,7 @@ def _write_conversation_html(
             tw.write("      </button>\n")
             tw.write("    </div>\n")
             tw.write('    <div class="flex-1 overflow-auto bg-white">\n')
-            tw.write('      <div id="chatHistoryModalEmpty" class="text-sm text-gray-500 text-center py-10">没有可显示的合并消息</div>\n')
+            tw.write('      <div id="chatHistoryModalEmpty" class="text-sm text-gray-500 text-center py-10">没有可显示的聊天记录</div>\n')
             tw.write('      <div id="chatHistoryModalList"></div>\n')
             tw.write("    </div>\n")
             tw.write("  </div>\n")
@@ -4377,6 +4935,39 @@ def _write_conversation_html(
 
         zf.write(str(tmp_path), arcname)
 
+        if page_size > 0 and paged_old_page_paths:
+            for page_no, frag_path in enumerate(paged_old_page_paths, start=1):
+                try:
+                    frag_text = frag_path.read_text(encoding="utf-8")
+                except Exception:
+                    try:
+                        frag_text = frag_path.read_text(encoding="utf-8", errors="ignore")
+                    except Exception:
+                        frag_text = ""
+
+                try:
+                    frag_json = json.dumps(frag_text, ensure_ascii=False)
+                except Exception:
+                    frag_json = json.dumps("", ensure_ascii=False)
+
+                num = str(page_no).zfill(int(paged_pad_width or 4))
+                arc_js = f"{conv_dir}/pages/page-{num}.js"
+                js_payload = (
+                    "(() => {\n"
+                    f"  const pageNo = {int(page_no)};\n"
+                    f"  const html = {frag_json};\n"
+                    "  try {\n"
+                    "    const fn = window.__WCE_PAGE_LOADED__;\n"
+                    "    if (typeof fn === 'function') fn(pageNo, html);\n"
+                    "    else {\n"
+                    "      const q = (window.__WCE_PAGE_QUEUE__ = window.__WCE_PAGE_QUEUE__ || []);\n"
+                    "      q.push([pageNo, html]);\n"
+                    "    }\n"
+                    "  } catch {}\n"
+                    "})();\n"
+                )
+                zf.writestr(arc_js, js_payload)
+
     return exported
 
 

src/wechat_decrypt_tool/routers/chat.py

@@ -5,6 +5,7 @@ import asyncio
 import json
 import time
 import threading
+from datetime import datetime, timedelta
 from os import scandir
 from pathlib import Path
 from typing import Any, Optional
@@ -452,6 +453,33 @@ def _resolve_decrypted_message_table(account_dir: Path, username: str) -> Option
     return None
 
 
+def _local_month_range_epoch_seconds(*, year: int, month: int) -> tuple[int, int]:
+    """Return [start, end) range as epoch seconds for local time month boundaries.
+
+    Notes:
+    - Uses local midnight boundaries (not +86400 * days) to stay DST-safe.
+    - Returned timestamps are integers (seconds).
+    """
+
+    start = datetime(int(year), int(month), 1)
+    if int(month) == 12:
+        end = datetime(int(year) + 1, 1, 1)
+    else:
+        end = datetime(int(year), int(month) + 1, 1)
+    return int(start.timestamp()), int(end.timestamp())
+
+
+def _local_day_range_epoch_seconds(*, date_str: str) -> tuple[int, int, str]:
+    """Return [start, end) range as epoch seconds for local date boundaries.
+
+    Returns the normalized `YYYY-MM-DD` date string as the 3rd element.
+    """
+
+    d0 = datetime.strptime(str(date_str or "").strip(), "%Y-%m-%d")
+    d1 = d0 + timedelta(days=1)
+    return int(d0.timestamp()), int(d1.timestamp()), d0.strftime("%Y-%m-%d")
+
+
 def _pick_message_db_for_new_table(account_dir: Path, username: str) -> Optional[Path]:
     """Pick a target decrypted sqlite db to place a new Msg_<md5> table.
 
@@ -3126,6 +3154,27 @@ def _postprocess_full_messages(
                             base_url
                             + f"/api/chat/media/video?account={quote(account_dir.name)}&file_id={quote(video_file_id)}&username={quote(username)}"
                         )
+            elif rt == "link":
+                # Some appmsg link cards (notably Bilibili shares) carry a non-HTTP `<thumburl>` payload
+                # (often an ASN.1-ish hex blob). The actual preview image is typically saved as:
+                #   msg/attach/{md5(conv_username)}/.../Img/{local_id}_{create_time}_t.dat
+                # Expose it via the existing image endpoint using file_id.
+                thumb_url = str(m.get("thumbUrl") or "").strip()
+                if thumb_url and (not thumb_url.lower().startswith(("http://", "https://"))):
+                    try:
+                        lid = int(m.get("localId") or 0)
+                    except Exception:
+                        lid = 0
+                    try:
+                        ct = int(m.get("createTime") or 0)
+                    except Exception:
+                        ct = 0
+                    if lid > 0 and ct > 0:
+                        file_id = f"{lid}_{ct}"
+                        m["thumbUrl"] = (
+                            base_url
+                            + f"/api/chat/media/image?account={quote(account_dir.name)}&file_id={quote(file_id)}&username={quote(username)}"
+                        )
             elif rt == "voice":
                 if str(m.get("serverId") or ""):
                     sid = int(m.get("serverId") or 0)
@@ -4090,6 +4139,182 @@ def _collect_chat_messages(
     return merged, has_more_any, sender_usernames, quote_usernames, pat_usernames
 
 
+@router.get("/api/chat/messages/daily_counts", summary="获取某月每日消息数（热力图）")
+def get_chat_message_daily_counts(
+    username: str,
+    year: int,
+    month: int,
+    account: Optional[str] = None,
+):
+    username = str(username or "").strip()
+    if not username:
+        raise HTTPException(status_code=400, detail="Missing username.")
+    try:
+        y = int(year)
+        m = int(month)
+    except Exception:
+        raise HTTPException(status_code=400, detail="Invalid year or month.")
+    if m < 1 or m > 12:
+        raise HTTPException(status_code=400, detail="Invalid month.")
+
+    try:
+        start_ts, end_ts = _local_month_range_epoch_seconds(year=y, month=m)
+    except Exception:
+        raise HTTPException(status_code=400, detail="Invalid year or month.")
+
+    account_dir = _resolve_account_dir(account)
+    db_paths = _iter_message_db_paths(account_dir)
+
+    counts: dict[str, int] = {}
+
+    for db_path in db_paths:
+        conn = sqlite3.connect(str(db_path))
+        try:
+            try:
+                table_name = _resolve_msg_table_name(conn, username)
+                if not table_name:
+                    continue
+                quoted_table = _quote_ident(table_name)
+                rows = conn.execute(
+                    "SELECT strftime('%Y-%m-%d', CAST(create_time AS INTEGER), 'unixepoch', 'localtime') AS day, "
+                    "COUNT(*) AS c "
+                    f"FROM {quoted_table} "
+                    "WHERE CAST(create_time AS INTEGER) >= ? AND CAST(create_time AS INTEGER) < ? "
+                    "GROUP BY day",
+                    (int(start_ts), int(end_ts)),
+                ).fetchall()
+                for day, c in rows:
+                    k = str(day or "").strip()
+                    if not k:
+                        continue
+                    try:
+                        vv = int(c or 0)
+                    except Exception:
+                        vv = 0
+                    if vv <= 0:
+                        continue
+                    counts[k] = int(counts.get(k, 0)) + vv
+            except Exception:
+                continue
+        finally:
+            conn.close()
+
+    total = int(sum(int(v) for v in counts.values())) if counts else 0
+    max_count = int(max(counts.values())) if counts else 0
+
+    return {
+        "status": "success",
+        "account": account_dir.name,
+        "username": username,
+        "year": int(y),
+        "month": int(m),
+        "counts": counts,
+        "total": total,
+        "max": max_count,
+    }
+
+
+@router.get("/api/chat/messages/anchor", summary="获取定位锚点（某日第一条/会话顶部）")
+def get_chat_message_anchor(
+    username: str,
+    kind: str,
+    account: Optional[str] = None,
+    date: Optional[str] = None,
+):
+    username = str(username or "").strip()
+    if not username:
+        raise HTTPException(status_code=400, detail="Missing username.")
+
+    kind_norm = str(kind or "").strip().lower()
+    if kind_norm not in {"day", "first"}:
+        raise HTTPException(status_code=400, detail="Invalid kind.")
+
+    date_norm: Optional[str] = None
+    start_ts: Optional[int] = None
+    end_ts: Optional[int] = None
+    if kind_norm == "day":
+        if not date:
+            raise HTTPException(status_code=400, detail="Missing date.")
+        try:
+            start_ts, end_ts, date_norm = _local_day_range_epoch_seconds(date_str=str(date))
+        except Exception:
+            raise HTTPException(status_code=400, detail="Invalid date.")
+
+    account_dir = _resolve_account_dir(account)
+    db_paths = _iter_message_db_paths(account_dir)
+
+    best_key: Optional[tuple[int, int, int]] = None
+    best_anchor_id = ""
+    best_create_time = 0
+
+    for db_path in db_paths:
+        conn = sqlite3.connect(str(db_path))
+        try:
+            try:
+                table_name = _resolve_msg_table_name(conn, username)
+                if not table_name:
+                    continue
+                quoted_table = _quote_ident(table_name)
+
+                if kind_norm == "first":
+                    row = conn.execute(
+                        "SELECT local_id, CAST(create_time AS INTEGER) AS create_time, "
+                        "COALESCE(CAST(sort_seq AS INTEGER), 0) AS sort_seq "
+                        f"FROM {quoted_table} "
+                        "ORDER BY CAST(create_time AS INTEGER) ASC, COALESCE(CAST(sort_seq AS INTEGER), 0) ASC, local_id ASC "
+                        "LIMIT 1"
+                    ).fetchone()
+                else:
+                    row = conn.execute(
+                        "SELECT local_id, CAST(create_time AS INTEGER) AS create_time, "
+                        "COALESCE(CAST(sort_seq AS INTEGER), 0) AS sort_seq "
+                        f"FROM {quoted_table} "
+                        "WHERE CAST(create_time AS INTEGER) >= ? AND CAST(create_time AS INTEGER) < ? "
+                        "ORDER BY CAST(create_time AS INTEGER) ASC, COALESCE(CAST(sort_seq AS INTEGER), 0) ASC, local_id ASC "
+                        "LIMIT 1",
+                        (int(start_ts or 0), int(end_ts or 0)),
+                    ).fetchone()
+
+                if not row:
+                    continue
+                try:
+                    local_id = int(row[0] or 0)
+                    create_time = int(row[1] or 0)
+                    sort_seq = int(row[2] or 0)
+                except Exception:
+                    continue
+                if local_id <= 0:
+                    continue
+
+                key = (int(create_time), int(sort_seq), int(local_id))
+                if (best_key is None) or (key < best_key):
+                    best_key = key
+                    best_create_time = int(create_time)
+                    best_anchor_id = f"{db_path.stem}:{table_name}:{local_id}"
+            except Exception:
+                continue
+        finally:
+            conn.close()
+
+    if not best_anchor_id:
+        return {
+            "status": "empty",
+            "anchorId": "",
+        }
+
+    resp: dict[str, Any] = {
+        "status": "success",
+        "account": account_dir.name,
+        "username": username,
+        "kind": kind_norm,
+        "anchorId": best_anchor_id,
+        "createTime": int(best_create_time),
+    }
+    if date_norm is not None:
+        resp["date"] = date_norm
+    return resp
+
+
 @router.get("/api/chat/messages", summary="获取会话消息列表")
 def list_chat_messages(
     request: Request,
@@ -5055,6 +5280,23 @@ def list_chat_messages(
                             base_url
                             + f"/api/chat/media/video?account={quote(account_dir.name)}&file_id={quote(video_file_id)}&username={quote(username)}"
                         )
+            elif rt == "link":
+                thumb_url = str(m.get("thumbUrl") or "").strip()
+                if thumb_url and (not thumb_url.lower().startswith(("http://", "https://"))):
+                    try:
+                        lid = int(m.get("localId") or 0)
+                    except Exception:
+                        lid = 0
+                    try:
+                        ct = int(m.get("createTime") or 0)
+                    except Exception:
+                        ct = 0
+                    if lid > 0 and ct > 0:
+                        file_id = f"{lid}_{ct}"
+                        m["thumbUrl"] = (
+                            base_url
+                            + f"/api/chat/media/image?account={quote(account_dir.name)}&file_id={quote(file_id)}&username={quote(username)}"
+                        )
             elif rt == "voice":
                 if str(m.get("serverId") or ""):
                     sid = int(m.get("serverId") or 0)
@@ -5955,6 +6197,7 @@ async def get_chat_messages_around(
         raise HTTPException(status_code=400, detail="Missing username.")
     if not anchor_id:
         raise HTTPException(status_code=400, detail="Missing anchor_id.")
+
     if before < 0:
         before = 0
     if after < 0:
@@ -5967,7 +6210,7 @@ async def get_chat_messages_around(
     parts = str(anchor_id).split(":", 2)
     if len(parts) != 3:
         raise HTTPException(status_code=400, detail="Invalid anchor_id.")
-    anchor_db_stem, anchor_table_name, anchor_local_id_str = parts
+    anchor_db_stem, anchor_table_name_in, anchor_local_id_str = parts
     try:
         anchor_local_id = int(anchor_local_id_str)
     except Exception:
@@ -5980,14 +6223,15 @@ async def get_chat_messages_around(
     message_resource_db_path = account_dir / "message_resource.db"
     base_url = str(request.base_url).rstrip("/")
 
-    target_db: Optional[Path] = None
+    anchor_db_path: Optional[Path] = None
     for p in db_paths:
         if p.stem == anchor_db_stem:
-            target_db = p
+            anchor_db_path = p
             break
-    if target_db is None:
+    if anchor_db_path is None:
         raise HTTPException(status_code=404, detail="Anchor database not found.")
 
+    # Open resource DB once (optional), and reuse for all message DBs.
     resource_conn: Optional[sqlite3.Connection] = None
     resource_chat_id: Optional[int] = None
     try:
@@ -6004,21 +6248,106 @@ async def get_chat_messages_around(
         resource_conn = None
         resource_chat_id = None
 
-    conn = sqlite3.connect(str(target_db))
-    conn.row_factory = sqlite3.Row
+    # Resolve anchor message tuple from its DB.
+    anchor_ct = 0
+    anchor_ss = 0
+    anchor_table_name = str(anchor_table_name_in or "").strip()
+    anchor_row: Optional[sqlite3.Row] = None
+    anchor_packed_select = "NULL AS packed_info_data, "
     try:
-        table_name = str(anchor_table_name).strip()
-        if not table_name:
+        conn_a = sqlite3.connect(str(anchor_db_path))
+        conn_a.row_factory = sqlite3.Row
+        try:
+            if not anchor_table_name:
+                try:
+                    anchor_table_name = _resolve_msg_table_name(conn_a, username) or ""
+                except Exception:
+                    anchor_table_name = ""
+            if not anchor_table_name:
                 raise HTTPException(status_code=404, detail="Anchor table not found.")
 
             # Normalize table name casing if needed
             try:
-            trows = conn.execute("SELECT name FROM sqlite_master WHERE type='table'").fetchall()
+                trows = conn_a.execute("SELECT name FROM sqlite_master WHERE type='table'").fetchall()
                 lower_to_actual = {str(x[0]).lower(): str(x[0]) for x in trows if x and x[0]}
-            table_name = lower_to_actual.get(table_name.lower(), table_name)
+                anchor_table_name = lower_to_actual.get(anchor_table_name.lower(), anchor_table_name)
             except Exception:
                 pass
 
+            quoted_table_a = _quote_ident(anchor_table_name)
+            has_packed_info_data = False
+            try:
+                cols = conn_a.execute(f"PRAGMA table_info({quoted_table_a})").fetchall()
+                has_packed_info_data = any(str(c[1] or "").strip().lower() == "packed_info_data" for c in cols)
+            except Exception:
+                has_packed_info_data = False
+            anchor_packed_select = (
+                "m.packed_info_data AS packed_info_data, " if has_packed_info_data else "NULL AS packed_info_data, "
+            )
+
+            sql_anchor_with_join = (
+                "SELECT "
+                "m.local_id, m.server_id, m.local_type, m.sort_seq, m.real_sender_id, m.create_time, "
+                "m.message_content, m.compress_content, "
+                + anchor_packed_select
+                + "n.user_name AS sender_username "
+                f"FROM {quoted_table_a} m "
+                "LEFT JOIN Name2Id n ON m.real_sender_id = n.rowid "
+                "WHERE m.local_id = ? "
+                "LIMIT 1"
+            )
+            sql_anchor_no_join = (
+                "SELECT "
+                "m.local_id, m.server_id, m.local_type, m.sort_seq, m.real_sender_id, m.create_time, "
+                "m.message_content, m.compress_content, "
+                + anchor_packed_select
+                + "'' AS sender_username "
+                f"FROM {quoted_table_a} m "
+                "WHERE m.local_id = ? "
+                "LIMIT 1"
+            )
+
+            conn_a.text_factory = bytes
+            try:
+                anchor_row = conn_a.execute(sql_anchor_with_join, (anchor_local_id,)).fetchone()
+            except Exception:
+                anchor_row = conn_a.execute(sql_anchor_no_join, (anchor_local_id,)).fetchone()
+
+            if anchor_row is None:
+                raise HTTPException(status_code=404, detail="Anchor message not found.")
+
+            anchor_ct = int(anchor_row["create_time"] or 0)
+            anchor_ss = int(anchor_row["sort_seq"] or 0) if anchor_row["sort_seq"] is not None else 0
+        finally:
+            conn_a.close()
+    finally:
+        pass
+
+    anchor_id_canon = f"{anchor_db_stem}:{anchor_table_name}:{anchor_local_id}"
+
+    merged: list[dict[str, Any]] = []
+    sender_usernames_all: list[str] = []
+    quote_usernames_all: list[str] = []
+    pat_usernames_all: set[str] = set()
+    is_group = bool(username.endswith("@chatroom"))
+
+    for db_path in db_paths:
+        conn: Optional[sqlite3.Connection] = None
+        try:
+            conn = sqlite3.connect(str(db_path))
+            conn.row_factory = sqlite3.Row
+
+            table_name = ""
+            if db_path.stem == anchor_db_stem:
+                table_name = anchor_table_name
+            else:
+                try:
+                    table_name = _resolve_msg_table_name(conn, username) or ""
+                except Exception:
+                    table_name = ""
+            if not table_name:
+                continue
+
             my_wxid = account_dir.name
             my_rowid = None
             try:
@@ -6041,53 +6370,37 @@ async def get_chat_messages_around(
             packed_select = (
                 "m.packed_info_data AS packed_info_data, " if has_packed_info_data else "NULL AS packed_info_data, "
             )
-        sql_anchor_with_join = (
-            "SELECT "
-            "m.local_id, m.server_id, m.local_type, m.sort_seq, m.real_sender_id, m.create_time, "
-            "m.message_content, m.compress_content, "
-            + packed_select
-            + "n.user_name AS sender_username "
-            f"FROM {quoted_table} m "
-            "LEFT JOIN Name2Id n ON m.real_sender_id = n.rowid "
-            "WHERE m.local_id = ? "
-            "LIMIT 1"
-        )
-        sql_anchor_no_join = (
-            "SELECT "
-            "m.local_id, m.server_id, m.local_type, m.sort_seq, m.real_sender_id, m.create_time, "
-            "m.message_content, m.compress_content, "
-            + packed_select
-            + "'' AS sender_username "
-            f"FROM {quoted_table} m "
-            "WHERE m.local_id = ? "
-            "LIMIT 1"
-        )
 
-        conn.text_factory = bytes
-
-        try:
-            anchor_row = conn.execute(sql_anchor_with_join, (anchor_local_id,)).fetchone()
-        except Exception:
-            anchor_row = conn.execute(sql_anchor_no_join, (anchor_local_id,)).fetchone()
-
-        if anchor_row is None:
-            raise HTTPException(status_code=404, detail="Anchor message not found.")
-
-        anchor_ct = int(anchor_row["create_time"] or 0)
-        anchor_ss = int(anchor_row["sort_seq"] or 0) if anchor_row["sort_seq"] is not None else 0
+            # Stable cross-db ordering: (create_time, sort_seq, db_stem, local_id)
+            stem = db_path.stem
+            if stem < anchor_db_stem:
+                tie_before = "1"
+                tie_before_params: tuple[Any, ...] = ()
+                tie_after = "0"
+                tie_after_params: tuple[Any, ...] = ()
+            elif stem > anchor_db_stem:
+                tie_before = "0"
+                tie_before_params = ()
+                tie_after = "1"
+                tie_after_params = ()
+            else:
+                tie_before = "m.local_id < ?"
+                tie_before_params = (int(anchor_local_id),)
+                tie_after = "m.local_id > ?"
+                tie_after_params = (int(anchor_local_id),)
 
             where_before = (
                 "WHERE ("
                 "m.create_time < ? "
                 "OR (m.create_time = ? AND COALESCE(m.sort_seq, 0) < ?) "
-            "OR (m.create_time = ? AND COALESCE(m.sort_seq, 0) = ? AND m.local_id <= ?)"
+                f"OR (m.create_time = ? AND COALESCE(m.sort_seq, 0) = ? AND {tie_before})"
                 ")"
             )
             where_after = (
                 "WHERE ("
                 "m.create_time > ? "
                 "OR (m.create_time = ? AND COALESCE(m.sort_seq, 0) > ?) "
-            "OR (m.create_time = ? AND COALESCE(m.sort_seq, 0) = ? AND m.local_id >= ?)"
+                f"OR (m.create_time = ? AND COALESCE(m.sort_seq, 0) = ? AND {tie_after})"
                 ")"
             )
 
@@ -6139,42 +6452,68 @@ async def get_chat_messages_around(
                 "LIMIT ?"
             )
 
-        params_before = (anchor_ct, anchor_ct, anchor_ss, anchor_ct, anchor_ss, anchor_local_id, int(before) + 1)
-        params_after = (anchor_ct, anchor_ct, anchor_ss, anchor_ct, anchor_ss, anchor_local_id, int(after) + 1)
+            # Always fetch anchor row from anchor DB, but don't include anchor itself in before/after queries.
+            anchor_rows: list[sqlite3.Row] = []
+            if db_path.stem == anchor_db_stem:
+                if anchor_row is None:
+                    raise HTTPException(status_code=404, detail="Anchor message not found.")
+                anchor_rows = [anchor_row]
 
+            conn.text_factory = bytes
+
+            before_rows: list[sqlite3.Row] = []
+            if int(before) > 0:
+                params_before = (
+                    int(anchor_ct),
+                    int(anchor_ct),
+                    int(anchor_ss),
+                    int(anchor_ct),
+                    int(anchor_ss),
+                    *tie_before_params,
+                    int(before) + 1,
+                )
                 try:
                     before_rows = conn.execute(sql_before_with_join, params_before).fetchall()
                 except Exception:
                     before_rows = conn.execute(sql_before_no_join, params_before).fetchall()
 
+            after_rows: list[sqlite3.Row] = []
+            if int(after) > 0:
+                params_after = (
+                    int(anchor_ct),
+                    int(anchor_ct),
+                    int(anchor_ss),
+                    int(anchor_ct),
+                    int(anchor_ss),
+                    *tie_after_params,
+                    int(after) + 1,
+                )
                 try:
                     after_rows = conn.execute(sql_after_with_join, params_after).fetchall()
                 except Exception:
                     after_rows = conn.execute(sql_after_no_join, params_after).fetchall()
 
+            # Dedup rows by message id within this DB.
             seen_ids: set[str] = set()
             combined: list[sqlite3.Row] = []
-        for rr in list(before_rows) + list(after_rows):
+            for rr in list(before_rows) + list(anchor_rows) + list(after_rows):
                 lid = int(rr["local_id"] or 0)
-            mid = f"{target_db.stem}:{table_name}:{lid}"
+                mid = f"{db_path.stem}:{table_name}:{lid}"
                 if mid in seen_ids:
                     continue
                 seen_ids.add(mid)
                 combined.append(rr)
 
-        merged: list[dict[str, Any]] = []
-        sender_usernames: list[str] = []
-        quote_usernames: list[str] = []
-        pat_usernames: set[str] = set()
-        is_group = bool(username.endswith("@chatroom"))
+            if not combined:
+                continue
 
             _append_full_messages_from_rows(
                 merged=merged,
-            sender_usernames=sender_usernames,
-            quote_usernames=quote_usernames,
-            pat_usernames=pat_usernames,
+                sender_usernames=sender_usernames_all,
+                quote_usernames=quote_usernames_all,
+                pat_usernames=pat_usernames_all,
                 rows=combined,
-            db_path=target_db,
+                db_path=db_path,
                 table_name=table_name,
                 username=username,
                 account_dir=account_dir,
@@ -6183,21 +6522,104 @@ async def get_chat_messages_around(
                 resource_conn=resource_conn,
                 resource_chat_id=resource_chat_id,
             )
-
-        return_messages = merged
+        except HTTPException:
+            raise
+        except Exception:
+            # Skip broken DBs / missing tables gracefully.
+            continue
         finally:
+            if conn is not None:
+                try:
                     conn.close()
+                except Exception:
+                    pass
+
     if resource_conn is not None:
         try:
             resource_conn.close()
         except Exception:
             pass
 
+    # Global dedupe + sort.
+    if merged:
+        seen_ids2: set[str] = set()
+        deduped: list[dict[str, Any]] = []
+        for m in merged:
+            mid = str(m.get("id") or "").strip()
+            if mid and mid in seen_ids2:
+                continue
+            if mid:
+                seen_ids2.add(mid)
+            deduped.append(m)
+        merged = deduped
+
+    def sort_key_global(m: dict[str, Any]) -> tuple[int, int, str, int]:
+        cts = int(m.get("createTime") or 0)
+        sseq = int(m.get("sortSeq") or 0)
+        lid = int(m.get("localId") or 0)
+        mid = str(m.get("id") or "")
+        stem2 = ""
+        try:
+            stem2 = mid.split(":", 1)[0] if ":" in mid else ""
+        except Exception:
+            stem2 = ""
+        return (cts, sseq, stem2, lid)
+
+    merged.sort(key=sort_key_global, reverse=False)
+
+    anchor_index_all = -1
+    for i, m in enumerate(merged):
+        if str(m.get("id") or "") == str(anchor_id_canon):
+            anchor_index_all = i
+            break
+    if anchor_index_all < 0:
+        # Fallback: ignore table casing differences when matching anchor.
+        for i, m in enumerate(merged):
+            mid = str(m.get("id") or "")
+            p2 = mid.split(":", 2)
+            if len(p2) != 3:
+                continue
+            if p2[0] != anchor_db_stem:
+                continue
+            try:
+                if int(p2[2] or 0) == int(anchor_local_id):
+                    anchor_index_all = i
+                    break
+            except Exception:
+                continue
+
+    if anchor_index_all < 0:
+        # Should not happen because we always include the anchor row, but keep defensive.
+        anchor_index_all = 0
+
+    start = max(0, int(anchor_index_all) - int(before))
+    end = min(len(merged), int(anchor_index_all) + int(after) + 1)
+    return_messages = merged[start:end]
+    anchor_index = int(anchor_index_all) - start if 0 <= anchor_index_all < len(merged) else -1
+
+    # Postprocess only the returned window to keep it fast.
+    sender_usernames_win = [str(m.get("senderUsername") or "").strip() for m in return_messages if str(m.get("senderUsername") or "").strip()]
+    quote_usernames_win = [str(m.get("quoteUsername") or "").strip() for m in return_messages if str(m.get("quoteUsername") or "").strip()]
+    pat_usernames_win: set[str] = set()
+    try:
+        for m in return_messages:
+            if int(m.get("type") or 0) != 266287972401:
+                continue
+            raw = str(m.get("_rawText") or "")
+            if not raw:
+                continue
+            template = _extract_xml_tag_text(raw, "template")
+            if not template:
+                continue
+            pat_usernames_win.update({mm.group(1) for mm in re.finditer(r"\$\{([^}]+)\}", template) if mm.group(1)})
+    except Exception:
+        pat_usernames_win = set()
+
     _postprocess_full_messages(
         merged=return_messages,
-        sender_usernames=sender_usernames,
-        quote_usernames=quote_usernames,
-        pat_usernames=pat_usernames,
+        sender_usernames=sender_usernames_win,
+        quote_usernames=quote_usernames_win,
+        pat_usernames=pat_usernames_win,
         account_dir=account_dir,
         username=username,
         base_url=base_url,
@@ -6205,24 +6627,235 @@ async def get_chat_messages_around(
         head_image_db_path=head_image_db_path,
     )
 
-    def sort_key(m: dict[str, Any]) -> tuple[int, int, int]:
-        sseq = int(m.get("sortSeq") or 0)
-        cts = int(m.get("createTime") or 0)
-        lid = int(m.get("localId") or 0)
-        return (cts, sseq, lid)
-
-    return_messages.sort(key=sort_key, reverse=False)
-    anchor_index = -1
-    for i, m in enumerate(return_messages):
-        if str(m.get("id") or "") == str(anchor_id):
-            anchor_index = i
-            break
-
     return {
         "status": "success",
         "account": account_dir.name,
         "username": username,
-        "anchorId": anchor_id,
+        "anchorId": anchor_id_canon,
         "anchorIndex": anchor_index,
         "messages": return_messages,
     }
+
+
+@router.get("/api/chat/chat_history/resolve", summary="解析嵌套合并转发聊天记录（通过 server_id）")
+async def resolve_nested_chat_history(
+    request: Request,
+    server_id: int,
+    account: Optional[str] = None,
+):
+    """Resolve a nested merged-forward chat history item (datatype=17) to its full recordItem XML.
+
+    Some nested records inside a merged-forward recordItem only carry pointers like `fromnewmsgid` (server_id),
+    while the full recordItem exists in the original app message (local_type=49, appmsg type=19) stored elsewhere.
+    WeChat can open it by looking up the original message; we do the same here.
+    """
+    if not server_id:
+        raise HTTPException(status_code=400, detail="Missing server_id.")
+
+    account_dir = _resolve_account_dir(account)
+    db_paths = _iter_message_db_paths(account_dir)
+    base_url = str(request.base_url).rstrip("/")
+    found_appmsg = False
+
+    for db_path in db_paths:
+        conn: Optional[sqlite3.Connection] = None
+        try:
+            conn = sqlite3.connect(str(db_path))
+            conn.row_factory = sqlite3.Row
+            conn.text_factory = bytes
+
+            try:
+                table_rows = conn.execute(
+                    # Some DBs use `Msg_...` (capital M). Use LOWER() to keep matching even if
+                    # `PRAGMA case_sensitive_like=ON` is set.
+                    "SELECT name FROM sqlite_master WHERE type='table' AND lower(name) LIKE 'msg_%'"
+                ).fetchall()
+            except Exception:
+                table_rows = []
+
+            # With `conn.text_factory = bytes`, sqlite_master.name comes back as bytes.
+            # Decode it to the real table name, otherwise we'd end up querying a non-existent
+            # table like "b'Msg_...'" and never find the message.
+            table_names = [_decode_sqlite_text(r[0]).strip() for r in table_rows if r and r[0]]
+            for table_name in table_names:
+                quoted = _quote_ident(table_name)
+                try:
+                    row = conn.execute(
+                        f"""
+                        SELECT local_id, server_id, local_type, create_time, message_content, compress_content
+                        FROM {quoted}
+                        -- WeChat v4 can pack appmsg subtype into the high 32 bits of local_type:
+                        --   local_type = base_type + (app_subtype << 32)
+                        -- so a chatHistory appmsg can be 49 + (19<<32), not exactly 49.
+                        WHERE server_id = ? AND (local_type & 4294967295) = 49
+                        LIMIT 1
+                        """,
+                        (int(server_id),),
+                    ).fetchone()
+                except Exception:
+                    row = None
+
+                if row is None:
+                    continue
+
+                found_appmsg = True
+                raw_text = _decode_message_content(row["compress_content"], row["message_content"]).strip()
+                if not raw_text:
+                    continue
+
+                # If the stored payload is a zstd frame but we couldn't decode it into XML, it's
+                # almost always because the optional `zstandard` dependency isn't installed.
+                try:
+                    blob = row["message_content"]
+                    if isinstance(blob, memoryview):
+                        blob = blob.tobytes()
+                    if isinstance(blob, (bytes, bytearray)) and bytes(blob).startswith(b"\x28\xb5\x2f\xfd"):
+                        lower = raw_text.lower()
+                        if "<appmsg" not in lower and "<msg" not in lower:
+                            raise HTTPException(
+                                status_code=500,
+                                detail="Failed to decode zstd-compressed message_content. Please install `zstandard` and restart the backend.",
+                            )
+                except HTTPException:
+                    raise
+                except Exception:
+                    pass
+
+                parsed = _parse_app_message(raw_text)
+                if not isinstance(parsed, dict):
+                    continue
+
+                if str(parsed.get("renderType") or "") != "chatHistory":
+                    # Found an app message, but not a merged-forward chat history.
+                    continue
+
+                record_item = str(parsed.get("recordItem") or "").strip()
+                if not record_item:
+                    continue
+
+                return {
+                    "status": "success",
+                    "serverId": int(server_id),
+                    "title": str(parsed.get("title") or "").strip(),
+                    "content": str(parsed.get("content") or "").strip(),
+                    "recordItem": record_item,
+                    "baseUrl": base_url,
+                }
+        finally:
+            if conn is not None:
+                try:
+                    conn.close()
+                except Exception:
+                    pass
+
+    if found_appmsg:
+        raise HTTPException(status_code=404, detail="Target message is not a chat history.")
+    raise HTTPException(status_code=404, detail="Message not found for server_id.")
+
+
+@router.get("/api/chat/appmsg/resolve", summary="解析卡片/小程序等 App 消息（通过 server_id）")
+async def resolve_app_message(
+    request: Request,
+    server_id: int,
+    account: Optional[str] = None,
+):
+    """Resolve an app message (base local_type=49) by server_id.
+
+    This is mainly used by merged-forward recordItem dataitems that only contain pointers like
+    `fromnewmsgid` (server_id). WeChat can open the original card by looking up the appmsg in
+    message DBs; we do the same and return the parsed appmsg fields.
+    """
+    if not server_id:
+        raise HTTPException(status_code=400, detail="Missing server_id.")
+
+    account_dir = _resolve_account_dir(account)
+    db_paths = _iter_message_db_paths(account_dir)
+    base_url = str(request.base_url).rstrip("/")
+
+    found_appmsg = False
+    for db_path in db_paths:
+        conn: Optional[sqlite3.Connection] = None
+        try:
+            conn = sqlite3.connect(str(db_path))
+            conn.row_factory = sqlite3.Row
+            conn.text_factory = bytes
+
+            try:
+                table_rows = conn.execute(
+                    "SELECT name FROM sqlite_master WHERE type='table' AND lower(name) LIKE 'msg_%'"
+                ).fetchall()
+            except Exception:
+                table_rows = []
+
+            table_names = [_decode_sqlite_text(r[0]).strip() for r in table_rows if r and r[0]]
+            for table_name in table_names:
+                quoted = _quote_ident(table_name)
+                try:
+                    row = conn.execute(
+                        f"""
+                        SELECT local_id, server_id, local_type, create_time, message_content, compress_content
+                        FROM {quoted}
+                        WHERE server_id = ? AND (local_type & 4294967295) = 49
+                        LIMIT 1
+                        """,
+                        (int(server_id),),
+                    ).fetchone()
+                except Exception:
+                    row = None
+
+                if row is None:
+                    continue
+
+                found_appmsg = True
+                raw_text = _decode_message_content(row["compress_content"], row["message_content"]).strip()
+                if not raw_text:
+                    continue
+
+                # Same zstd guard as chat_history/resolve.
+                try:
+                    blob = row["message_content"]
+                    if isinstance(blob, memoryview):
+                        blob = blob.tobytes()
+                    if isinstance(blob, (bytes, bytearray)) and bytes(blob).startswith(b"\x28\xb5\x2f\xfd"):
+                        lower = raw_text.lower()
+                        if "<appmsg" not in lower and "<msg" not in lower:
+                            raise HTTPException(
+                                status_code=500,
+                                detail="Failed to decode zstd-compressed message_content. Please install `zstandard` and restart the backend.",
+                            )
+                except HTTPException:
+                    raise
+                except Exception:
+                    pass
+
+                parsed = _parse_app_message(raw_text)
+                if not isinstance(parsed, dict):
+                    continue
+
+                # Return a stable, explicit shape for the frontend.
+                return {
+                    "status": "success",
+                    "serverId": int(server_id),
+                    "renderType": str(parsed.get("renderType") or "text"),
+                    "title": str(parsed.get("title") or "").strip(),
+                    "content": str(parsed.get("content") or "").strip(),
+                    "url": str(parsed.get("url") or "").strip(),
+                    "thumbUrl": str(parsed.get("thumbUrl") or "").strip(),
+                    "coverUrl": str(parsed.get("coverUrl") or "").strip(),
+                    "from": str(parsed.get("from") or "").strip(),
+                    "fromUsername": str(parsed.get("fromUsername") or "").strip(),
+                    "linkType": str(parsed.get("linkType") or "").strip(),
+                    "linkStyle": str(parsed.get("linkStyle") or "").strip(),
+                    "size": str(parsed.get("size") or "").strip(),
+                    "baseUrl": base_url,
+                }
+        finally:
+            if conn is not None:
+                try:
+                    conn.close()
+                except Exception:
+                    pass
+
+    if found_appmsg:
+        raise HTTPException(status_code=404, detail="App message decode failed.")
+    raise HTTPException(status_code=404, detail="Message not found for server_id.")

src/wechat_decrypt_tool/routers/chat_export.py

@@ -59,6 +59,10 @@ class ChatExportCreateRequest(BaseModel):
         False,
         description="HTML 导出时允许联网下载链接/引用缩略图等远程媒体（提高离线完整性）",
     )
+    html_page_size: int = Field(
+        1000,
+        description="HTML 导出分页大小（每页消息数）；<=0 表示禁用分页（单文件，打开大聊天可能很卡）",
+    )
     privacy_mode: bool = Field(
         False,
         description="隐私模式导出：隐藏会话/用户名/内容，不打包头像与媒体",
@@ -83,6 +87,7 @@ async def create_chat_export(req: ChatExportCreateRequest):
         output_dir=req.output_dir,
         allow_process_key_extract=req.allow_process_key_extract,
         download_remote_media=req.download_remote_media,
+        html_page_size=req.html_page_size,
         privacy_mode=req.privacy_mode,
         file_name=req.file_name,
     )

src/wechat_decrypt_tool/routers/chat_media.py

@@ -1019,6 +1019,171 @@ async def proxy_image(url: str):
     return resp
 
 
+def _origin_favicon_url(page_url: str) -> str:
+    """Best-effort favicon URL for a given page URL (origin + /favicon.ico)."""
+    u = str(page_url or "").strip()
+    if not u:
+        return ""
+    try:
+        p = urlparse(u)
+    except Exception:
+        return ""
+    if not p.scheme or not p.netloc:
+        return ""
+    return f"{p.scheme}://{p.netloc}/favicon.ico"
+
+
+def _resolve_final_url_for_favicon(page_url: str) -> str:
+    """Resolve final URL for redirects (used for favicon host inference)."""
+    u = str(page_url or "").strip()
+    if not u:
+        return ""
+
+    headers = {
+        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120 Safari/537.36",
+        "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
+    }
+
+    # Prefer HEAD (no body). Some hosts reject HEAD; fall back to GET+stream.
+    try:
+        r = requests.head(u, headers=headers, timeout=10, allow_redirects=True)
+        try:
+            final = str(getattr(r, "url", "") or "").strip()
+            return final or u
+        finally:
+            try:
+                r.close()
+            except Exception:
+                pass
+    except Exception:
+        pass
+
+    try:
+        r = requests.get(u, headers=headers, timeout=10, allow_redirects=True, stream=True)
+        try:
+            final = str(getattr(r, "url", "") or "").strip()
+            return final or u
+        finally:
+            try:
+                r.close()
+            except Exception:
+                pass
+    except Exception:
+        return u
+
+
+@router.get("/api/chat/media/favicon", summary="获取网站 favicon（用于链接卡片来源头像）")
+async def get_favicon(url: str):
+    page_url = html.unescape(str(url or "")).strip()
+    if not page_url:
+        raise HTTPException(status_code=400, detail="Missing url.")
+    if not _is_safe_http_url(page_url):
+        raise HTTPException(status_code=400, detail="Invalid url (only public http/https allowed).")
+
+    # Resolve redirects first (e.g. b23.tv -> www.bilibili.com), so cached favicons are hit early.
+    final_url = _resolve_final_url_for_favicon(page_url)
+    candidates: list[str] = []
+    for u in (final_url, page_url):
+        fav = _origin_favicon_url(u)
+        if fav and fav not in candidates:
+            candidates.append(fav)
+
+    proxy_account = "_favicon"
+    max_bytes = 512 * 1024  # favicons should be small; protect against huge downloads.
+
+    for cand in candidates:
+        if not _is_safe_http_url(cand):
+            continue
+        source_url = normalize_avatar_source_url(cand)
+
+        cache_entry = get_avatar_cache_url_entry(proxy_account, source_url) if is_avatar_cache_enabled() else None
+        cache_file = avatar_cache_entry_file_exists(proxy_account, cache_entry)
+        if cache_entry and cache_file and avatar_cache_entry_is_fresh(cache_entry):
+            logger.info(f"[avatar_cache_hit] kind=favicon account={proxy_account} url={source_url}")
+            touch_avatar_cache_entry(proxy_account, cache_key_for_avatar_url(source_url))
+            headers = build_avatar_cache_response_headers(cache_entry)
+            return FileResponse(
+                str(cache_file),
+                media_type=str(cache_entry.get("media_type") or "application/octet-stream"),
+                headers=headers,
+            )
+
+        # Download favicon bytes (best-effort)
+        headers = {
+            "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120 Safari/537.36",
+            "Accept": "image/avif,image/webp,image/apng,image/*,*/*;q=0.8",
+        }
+        r = None
+        try:
+            r = requests.get(source_url, headers=headers, timeout=20, stream=True, allow_redirects=True)
+            if int(getattr(r, "status_code", 0) or 0) != 200:
+                continue
+
+            ct = str((getattr(r, "headers", {}) or {}).get("Content-Type") or "").strip()
+            try:
+                cl = int((getattr(r, "headers", {}) or {}).get("content-length") or 0)
+            except Exception:
+                cl = 0
+            if cl and cl > max_bytes:
+                raise HTTPException(status_code=413, detail="Remote favicon too large.")
+
+            chunks: list[bytes] = []
+            total = 0
+            for chunk in r.iter_content(chunk_size=64 * 1024):
+                if not chunk:
+                    continue
+                chunks.append(chunk)
+                total += len(chunk)
+                if total > max_bytes:
+                    raise HTTPException(status_code=413, detail="Remote favicon too large.")
+            data = b"".join(chunks)
+        except HTTPException:
+            raise
+        except Exception:
+            continue
+        finally:
+            if r is not None:
+                try:
+                    r.close()
+                except Exception:
+                    pass
+
+        if not data:
+            continue
+
+        payload, media_type, _ext = _detect_media_type_and_ext(data)
+        if media_type == "application/octet-stream" and ct:
+            try:
+                mt = ct.split(";")[0].strip()
+                if mt.startswith("image/"):
+                    media_type = mt
+            except Exception:
+                pass
+
+        if not str(media_type or "").startswith("image/"):
+            continue
+
+        if is_avatar_cache_enabled():
+            entry, out_path = write_avatar_cache_payload(
+                proxy_account,
+                source_kind="url",
+                source_url=source_url,
+                payload=payload,
+                media_type=media_type,
+                ttl_seconds=AVATAR_CACHE_TTL_SECONDS,
+            )
+            if entry and out_path:
+                logger.info(f"[avatar_cache_download] kind=favicon account={proxy_account} url={source_url}")
+                headers = build_avatar_cache_response_headers(entry)
+                return FileResponse(str(out_path), media_type=media_type, headers=headers)
+
+        resp = Response(content=payload, media_type=media_type)
+        resp.headers["Cache-Control"] = f"public, max-age={AVATAR_CACHE_TTL_SECONDS}"
+        return resp
+
+    raise HTTPException(status_code=404, detail="favicon not found.")
+
+
 @router.post("/api/chat/media/emoji/download", summary="下载表情消息资源到本地 resource")
 async def download_chat_emoji(req: EmojiDownloadRequest):
     md5 = str(req.md5 or "").strip().lower()

tests/test_chat_export_html_paging.py

@@ -0,0 +1,221 @@
+import os
+import json
+import hashlib
+import sqlite3
+import sys
+import unittest
+import zipfile
+import importlib
+from pathlib import Path
+from tempfile import TemporaryDirectory
+
+
+ROOT = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(ROOT / "src"))
+
+
+class TestChatExportHtmlPaging(unittest.TestCase):
+    def _reload_export_modules(self):
+        import wechat_decrypt_tool.app_paths as app_paths
+        import wechat_decrypt_tool.chat_helpers as chat_helpers
+        import wechat_decrypt_tool.media_helpers as media_helpers
+        import wechat_decrypt_tool.chat_export_service as chat_export_service
+
+        importlib.reload(app_paths)
+        importlib.reload(chat_helpers)
+        importlib.reload(media_helpers)
+        importlib.reload(chat_export_service)
+        return chat_export_service
+
+    def _seed_contact_db(self, path: Path, *, account: str, username: str) -> None:
+        conn = sqlite3.connect(str(path))
+        try:
+            conn.execute(
+                """
+                CREATE TABLE contact (
+                    username TEXT,
+                    remark TEXT,
+                    nick_name TEXT,
+                    alias TEXT,
+                    local_type INTEGER,
+                    verify_flag INTEGER,
+                    big_head_url TEXT,
+                    small_head_url TEXT
+                )
+                """
+            )
+            conn.execute(
+                """
+                CREATE TABLE stranger (
+                    username TEXT,
+                    remark TEXT,
+                    nick_name TEXT,
+                    alias TEXT,
+                    local_type INTEGER,
+                    verify_flag INTEGER,
+                    big_head_url TEXT,
+                    small_head_url TEXT
+                )
+                """
+            )
+            conn.execute(
+                "INSERT INTO contact VALUES (?, ?, ?, ?, ?, ?, ?, ?)",
+                (account, "", "Me", "", 1, 0, "", ""),
+            )
+            conn.execute(
+                "INSERT INTO contact VALUES (?, ?, ?, ?, ?, ?, ?, ?)",
+                (username, "", "Friend", "", 1, 0, "", ""),
+            )
+            conn.commit()
+        finally:
+            conn.close()
+
+    def _seed_session_db(self, path: Path, *, username: str) -> None:
+        conn = sqlite3.connect(str(path))
+        try:
+            conn.execute(
+                """
+                CREATE TABLE SessionTable (
+                    username TEXT,
+                    is_hidden INTEGER,
+                    sort_timestamp INTEGER
+                )
+                """
+            )
+            conn.execute(
+                "INSERT INTO SessionTable VALUES (?, ?, ?)",
+                (username, 0, 1735689600),
+            )
+            conn.commit()
+        finally:
+            conn.close()
+
+    def _seed_message_db(self, path: Path, *, account: str, username: str, total: int) -> None:
+        conn = sqlite3.connect(str(path))
+        try:
+            conn.execute("CREATE TABLE Name2Id (rowid INTEGER PRIMARY KEY, user_name TEXT)")
+            conn.execute("INSERT INTO Name2Id(rowid, user_name) VALUES (?, ?)", (1, account))
+            conn.execute("INSERT INTO Name2Id(rowid, user_name) VALUES (?, ?)", (2, username))
+
+            table_name = f"msg_{hashlib.md5(username.encode('utf-8')).hexdigest()}"
+            conn.execute(
+                f"""
+                CREATE TABLE {table_name} (
+                    local_id INTEGER,
+                    server_id INTEGER,
+                    local_type INTEGER,
+                    sort_seq INTEGER,
+                    real_sender_id INTEGER,
+                    create_time INTEGER,
+                    message_content TEXT,
+                    compress_content BLOB
+                )
+                """
+            )
+
+            # Generate lots of plain text messages with unique markers.
+            rows = []
+            base_ts = 1735689600
+            for i in range(1, total + 1):
+                marker = f"MSG{i:04d}"
+                real_sender_id = 1 if (i % 2 == 0) else 2
+                rows.append((i, 100000 + i, 1, i, real_sender_id, base_ts + i, marker, None))
+
+            conn.executemany(
+                f"INSERT INTO {table_name} (local_id, server_id, local_type, sort_seq, real_sender_id, create_time, message_content, compress_content) "
+                "VALUES (?, ?, ?, ?, ?, ?, ?, ?)",
+                rows,
+            )
+            conn.commit()
+        finally:
+            conn.close()
+
+    def _prepare_account(self, root: Path, *, account: str, username: str, total: int) -> Path:
+        account_dir = root / "output" / "databases" / account
+        account_dir.mkdir(parents=True, exist_ok=True)
+        self._seed_contact_db(account_dir / "contact.db", account=account, username=username)
+        self._seed_session_db(account_dir / "session.db", username=username)
+        self._seed_message_db(account_dir / "message_0.db", account=account, username=username, total=total)
+        return account_dir
+
+    def _create_job(self, manager, *, account: str, username: str, html_page_size: int):
+        job = manager.create_job(
+            account=account,
+            scope="selected",
+            usernames=[username],
+            export_format="html",
+            start_time=None,
+            end_time=None,
+            include_hidden=False,
+            include_official=False,
+            include_media=False,
+            media_kinds=[],
+            message_types=[],
+            output_dir=None,
+            allow_process_key_extract=False,
+            download_remote_media=False,
+            html_page_size=html_page_size,
+            privacy_mode=False,
+            file_name=None,
+        )
+
+        # Export is async (thread). Allow enough time for a few thousand messages + zip writes.
+        for _ in range(600):
+            latest = manager.get_job(job.export_id)
+            if latest and latest.status in {"done", "error", "cancelled"}:
+                return latest
+            import time as _time
+
+            _time.sleep(0.05)
+        self.fail("export job did not finish in time")
+
+    def test_html_export_paging_inlines_latest_page_only(self):
+        with TemporaryDirectory() as td:
+            root = Path(td)
+            account = "wxid_test"
+            username = "wxid_friend"
+
+            total_messages = 2300
+            page_size = 1000
+            self._prepare_account(root, account=account, username=username, total=total_messages)
+
+            prev_data = os.environ.get("WECHAT_TOOL_DATA_DIR")
+            try:
+                os.environ["WECHAT_TOOL_DATA_DIR"] = str(root)
+                svc = self._reload_export_modules()
+                job = self._create_job(
+                    svc.CHAT_EXPORT_MANAGER,
+                    account=account,
+                    username=username,
+                    html_page_size=page_size,
+                )
+                self.assertEqual(job.status, "done", msg=job.error)
+
+                self.assertTrue(job.zip_path and job.zip_path.exists())
+                with zipfile.ZipFile(job.zip_path, "r") as zf:
+                    names = set(zf.namelist())
+
+                    html_path = next((n for n in names if n.endswith("/messages.html")), "")
+                    self.assertTrue(html_path, msg="missing messages.html")
+                    html_text = zf.read(html_path).decode("utf-8", errors="ignore")
+
+                    # Paging UI + meta should exist for multi-page exports.
+                    self.assertIn('id="wcePageMeta"', html_text)
+                    self.assertIn('id="wcePager"', html_text)
+                    self.assertIn('id="wceMessageList"', html_text)
+                    self.assertIn('id="wceLoadPrevBtn"', html_text)
+
+                    # Latest page is inlined; earliest page should not be present in messages.html.
+                    self.assertIn("MSG2300", html_text)
+                    self.assertNotIn("MSG0001", html_text)
+
+                    conv_dir = html_path.rsplit("/", 1)[0]
+                    page1_js = f"{conv_dir}/pages/page-0001.js"
+                    self.assertIn(page1_js, names)
+                    page1_text = zf.read(page1_js).decode("utf-8", errors="ignore")
+                    self.assertIn("MSG0001", page1_text)
+            finally:
+                if prev_data is None:
+                    os.environ.pop("WECHAT_TOOL_DATA_DIR", None)
+                else:
+                    os.environ["WECHAT_TOOL_DATA_DIR"] = prev_data

tests/test_chat_media_favicon.py

@@ -0,0 +1,133 @@
+import os
+import sqlite3
+import sys
+import unittest
+import importlib
+from pathlib import Path
+from tempfile import TemporaryDirectory
+from unittest.mock import patch
+
+
+ROOT = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(ROOT / "src"))
+
+
+class _FakeResponse:
+    def __init__(self, *, status_code: int = 200, headers: dict | None = None, url: str = "", body: bytes = b""):
+        self.status_code = int(status_code)
+        self.headers = dict(headers or {})
+        self.url = str(url or "")
+        self._body = bytes(body or b"")
+
+    def iter_content(self, chunk_size: int = 64 * 1024):
+        yield self._body
+
+    def close(self) -> None:
+        return None
+
+
+class TestChatMediaFavicon(unittest.TestCase):
+    def test_chat_media_favicon_caches(self):
+        from fastapi import FastAPI
+        from fastapi.testclient import TestClient
+
+        # 1x1 PNG (same as other avatar cache tests)
+        png = bytes.fromhex(
+            "89504E470D0A1A0A"
+            "0000000D49484452000000010000000108060000001F15C489"
+            "0000000D49444154789C6360606060000000050001A5F64540"
+            "0000000049454E44AE426082"
+        )
+
+        with TemporaryDirectory() as td:
+            root = Path(td)
+
+            prev_data = None
+            prev_cache = None
+            try:
+                prev_data = os.environ.get("WECHAT_TOOL_DATA_DIR")
+                prev_cache = os.environ.get("WECHAT_TOOL_AVATAR_CACHE_ENABLED")
+                os.environ["WECHAT_TOOL_DATA_DIR"] = str(root)
+                os.environ["WECHAT_TOOL_AVATAR_CACHE_ENABLED"] = "1"
+
+                import wechat_decrypt_tool.app_paths as app_paths
+                import wechat_decrypt_tool.avatar_cache as avatar_cache
+                import wechat_decrypt_tool.routers.chat_media as chat_media
+
+                importlib.reload(app_paths)
+                importlib.reload(avatar_cache)
+                importlib.reload(chat_media)
+
+                def fake_head(url, **_kwargs):
+                    # Pretend short-link resolves to bilibili.
+                    return _FakeResponse(
+                        status_code=200,
+                        headers={},
+                        url="https://www.bilibili.com/video/BV1Au4tzNEq2",
+                        body=b"",
+                    )
+
+                def fake_get(url, **_kwargs):
+                    u = str(url or "")
+                    if "www.bilibili.com/favicon.ico" in u:
+                        return _FakeResponse(
+                            status_code=200,
+                            headers={"Content-Type": "image/png", "content-length": str(len(png))},
+                            url=u,
+                            body=png,
+                        )
+                    return _FakeResponse(
+                        status_code=404,
+                        headers={"Content-Type": "text/html"},
+                        url=u,
+                        body=b"",
+                    )
+
+                app = FastAPI()
+                app.include_router(chat_media.router)
+                client = TestClient(app)
+
+                with patch("wechat_decrypt_tool.routers.chat_media.requests.head", side_effect=fake_head) as mock_head, patch(
+                    "wechat_decrypt_tool.routers.chat_media.requests.get", side_effect=fake_get
+                ) as mock_get:
+                    resp = client.get("/api/chat/media/favicon", params={"url": "https://b23.tv/au68guF"})
+                    self.assertEqual(resp.status_code, 200)
+                    self.assertTrue(resp.headers.get("content-type", "").startswith("image/"))
+                    self.assertEqual(resp.content, png)
+
+                    # Second call should hit disk cache (no extra favicon download).
+                    resp2 = client.get("/api/chat/media/favicon", params={"url": "https://b23.tv/au68guF"})
+                    self.assertEqual(resp2.status_code, 200)
+                    self.assertEqual(resp2.content, png)
+
+                    self.assertGreaterEqual(mock_head.call_count, 1)
+                    self.assertEqual(mock_get.call_count, 1)
+
+                cache_db = root / "output" / "avatar_cache" / "favicon" / "avatar_cache.db"
+                self.assertTrue(cache_db.exists())
+
+                conn = sqlite3.connect(str(cache_db))
+                try:
+                    row = conn.execute(
+                        "SELECT source_kind, source_url, media_type FROM avatar_cache_entries WHERE source_kind = 'url' LIMIT 1"
+                    ).fetchone()
+                    self.assertIsNotNone(row)
+                    self.assertEqual(str(row[0] or ""), "url")
+                    self.assertIn("favicon.ico", str(row[1] or ""))
+                    self.assertTrue(str(row[2] or "").startswith("image/"))
+                finally:
+                    conn.close()
+            finally:
+                if prev_data is None:
+                    os.environ.pop("WECHAT_TOOL_DATA_DIR", None)
+                else:
+                    os.environ["WECHAT_TOOL_DATA_DIR"] = prev_data
+                if prev_cache is None:
+                    os.environ.pop("WECHAT_TOOL_AVATAR_CACHE_ENABLED", None)
+                else:
+                    os.environ["WECHAT_TOOL_AVATAR_CACHE_ENABLED"] = prev_cache
+
+
+if __name__ == "__main__":
+    unittest.main()
+

tests/test_chat_message_calendar_heatmap.py

@@ -0,0 +1,292 @@
+import hashlib
+import sqlite3
+import sys
+import unittest
+from datetime import datetime
+from pathlib import Path
+from tempfile import TemporaryDirectory
+from unittest.mock import patch
+
+
+ROOT = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(ROOT / "src"))
+
+
+from wechat_decrypt_tool.routers import chat as chat_router
+
+
+def _msg_table_name(username: str) -> str:
+    md5_hex = hashlib.md5(username.encode("utf-8")).hexdigest()
+    return f"Msg_{md5_hex}"
+
+
+def _seed_message_db(path: Path, *, username: str, rows: list[tuple[int, int]]) -> None:
+    """rows: [(create_time, sort_seq), ...]"""
+    table = _msg_table_name(username)
+    conn = sqlite3.connect(str(path))
+    try:
+        conn.execute(
+            f"""
+            CREATE TABLE "{table}"(
+                local_id INTEGER PRIMARY KEY AUTOINCREMENT,
+                create_time INTEGER,
+                sort_seq INTEGER
+            )
+            """
+        )
+        for create_time, sort_seq in rows:
+            conn.execute(
+                f'INSERT INTO "{table}"(create_time, sort_seq) VALUES (?, ?)',
+                (int(create_time), int(sort_seq)),
+            )
+        conn.commit()
+    finally:
+        conn.close()
+
+
+def _seed_message_db_full(path: Path, *, username: str, rows: list[tuple[int, int, str]]) -> None:
+    """rows: [(create_time, sort_seq, text), ...] - minimal schema for /api/chat/messages/around."""
+
+    table = _msg_table_name(username)
+    conn = sqlite3.connect(str(path))
+    try:
+        conn.execute(
+            f"""
+            CREATE TABLE "{table}"(
+                local_id INTEGER PRIMARY KEY AUTOINCREMENT,
+                server_id INTEGER,
+                local_type INTEGER,
+                sort_seq INTEGER,
+                real_sender_id INTEGER,
+                create_time INTEGER,
+                message_content TEXT,
+                compress_content BLOB
+            )
+            """
+        )
+        for create_time, sort_seq, text in rows:
+            conn.execute(
+                f'INSERT INTO "{table}"(server_id, local_type, sort_seq, real_sender_id, create_time, message_content, compress_content) '
+                "VALUES (?, ?, ?, ?, ?, ?, ?)",
+                (0, 1, int(sort_seq), 0, int(create_time), str(text), None),
+            )
+        conn.commit()
+    finally:
+        conn.close()
+
+
+def _seed_contact_db_minimal(path: Path) -> None:
+    conn = sqlite3.connect(str(path))
+    try:
+        conn.execute(
+            """
+            CREATE TABLE contact (
+                username TEXT,
+                remark TEXT,
+                nick_name TEXT,
+                alias TEXT,
+                big_head_url TEXT,
+                small_head_url TEXT
+            )
+            """
+        )
+        conn.execute(
+            """
+            CREATE TABLE stranger (
+                username TEXT,
+                remark TEXT,
+                nick_name TEXT,
+                alias TEXT,
+                big_head_url TEXT,
+                small_head_url TEXT
+            )
+            """
+        )
+        conn.commit()
+    finally:
+        conn.close()
+
+
+class TestChatMessageCalendarHeatmap(unittest.TestCase):
+    def test_daily_counts_aggregates_per_day_and_respects_month_range(self):
+        with TemporaryDirectory() as td:
+            account_dir = Path(td) / "acc"
+            account_dir.mkdir(parents=True, exist_ok=True)
+
+            username = "wxid_test_user"
+
+            ts_jan31_23 = int(datetime(2026, 1, 31, 23, 0, 0).timestamp())
+            ts_feb01_10 = int(datetime(2026, 2, 1, 10, 0, 0).timestamp())
+            ts_feb14_12 = int(datetime(2026, 2, 14, 12, 0, 0).timestamp())
+
+            _seed_message_db(
+                account_dir / "message.db",
+                username=username,
+                rows=[
+                    (ts_jan31_23, 0),
+                    (ts_feb01_10, 5),
+                    (ts_feb01_10, 2),
+                    (ts_feb14_12, 0),
+                ],
+            )
+
+            with patch.object(chat_router, "_resolve_account_dir", return_value=account_dir):
+                resp = chat_router.get_chat_message_daily_counts(
+                    username=username,
+                    year=2026,
+                    month=2,
+                    account="acc",
+                )
+
+            self.assertEqual(resp.get("status"), "success")
+            self.assertEqual(resp.get("username"), username)
+            self.assertEqual(resp.get("year"), 2026)
+            self.assertEqual(resp.get("month"), 2)
+
+            counts = resp.get("counts") or {}
+            self.assertEqual(counts.get("2026-02-01"), 2)
+            self.assertEqual(counts.get("2026-02-14"), 1)
+            self.assertIsNone(counts.get("2026-01-31"))
+
+            self.assertEqual(resp.get("total"), 3)
+            self.assertEqual(resp.get("max"), 2)
+
+    def test_anchor_day_picks_earliest_by_create_time_then_sort_seq_then_local_id(self):
+        with TemporaryDirectory() as td:
+            account_dir = Path(td) / "acc"
+            account_dir.mkdir(parents=True, exist_ok=True)
+
+            username = "wxid_test_user"
+
+            ts_jan31_23 = int(datetime(2026, 1, 31, 23, 0, 0).timestamp())
+            ts_feb01_10 = int(datetime(2026, 2, 1, 10, 0, 0).timestamp())
+
+            _seed_message_db(
+                account_dir / "message.db",
+                username=username,
+                rows=[
+                    (ts_jan31_23, 0),  # local_id = 1
+                    (ts_feb01_10, 5),  # local_id = 2
+                    (ts_feb01_10, 2),  # local_id = 3  <- expected (sort_seq smaller)
+                ],
+            )
+
+            with patch.object(chat_router, "_resolve_account_dir", return_value=account_dir):
+                resp = chat_router.get_chat_message_anchor(
+                    username=username,
+                    kind="day",
+                    account="acc",
+                    date="2026-02-01",
+                )
+
+            self.assertEqual(resp.get("status"), "success")
+            self.assertEqual(resp.get("kind"), "day")
+            self.assertEqual(resp.get("date"), "2026-02-01")
+            anchor_id = str(resp.get("anchorId") or "")
+            self.assertTrue(anchor_id.startswith("message:"), anchor_id)
+            self.assertTrue(anchor_id.endswith(":3"), anchor_id)
+
+    def test_anchor_first_picks_global_earliest(self):
+        with TemporaryDirectory() as td:
+            account_dir = Path(td) / "acc"
+            account_dir.mkdir(parents=True, exist_ok=True)
+
+            username = "wxid_test_user"
+
+            ts_jan31_23 = int(datetime(2026, 1, 31, 23, 0, 0).timestamp())
+            ts_feb01_10 = int(datetime(2026, 2, 1, 10, 0, 0).timestamp())
+
+            _seed_message_db(
+                account_dir / "message.db",
+                username=username,
+                rows=[
+                    (ts_feb01_10, 2),  # local_id = 1
+                    (ts_jan31_23, 0),  # local_id = 2, but earlier create_time -> should win even if local_id bigger
+                ],
+            )
+
+            with patch.object(chat_router, "_resolve_account_dir", return_value=account_dir):
+                resp = chat_router.get_chat_message_anchor(
+                    username=username,
+                    kind="first",
+                    account="acc",
+                )
+
+            self.assertEqual(resp.get("status"), "success")
+            self.assertEqual(resp.get("kind"), "first")
+            anchor_id = str(resp.get("anchorId") or "")
+            self.assertTrue(anchor_id.startswith("message:"), anchor_id)
+            self.assertTrue(anchor_id.endswith(":2"), anchor_id)
+
+    def test_anchor_day_empty_returns_empty_status(self):
+        with TemporaryDirectory() as td:
+            account_dir = Path(td) / "acc"
+            account_dir.mkdir(parents=True, exist_ok=True)
+
+            username = "wxid_test_user"
+            ts_feb01_10 = int(datetime(2026, 2, 1, 10, 0, 0).timestamp())
+
+            _seed_message_db(account_dir / "message.db", username=username, rows=[(ts_feb01_10, 0)])
+
+            with patch.object(chat_router, "_resolve_account_dir", return_value=account_dir):
+                resp = chat_router.get_chat_message_anchor(
+                    username=username,
+                    kind="day",
+                    account="acc",
+                    date="2026-02-02",
+                )
+
+            self.assertEqual(resp.get("status"), "empty")
+            self.assertEqual(resp.get("anchorId"), "")
+
+    def test_around_can_span_multiple_message_dbs_for_pagination(self):
+        from fastapi import FastAPI
+        from fastapi.testclient import TestClient
+
+        with TemporaryDirectory() as td:
+            account_dir = Path(td) / "acc"
+            account_dir.mkdir(parents=True, exist_ok=True)
+
+            username = "wxid_test_user"
+            table = _msg_table_name(username)
+
+            # Anchor in message.db, next message in message_1.db
+            _seed_message_db_full(
+                account_dir / "message.db",
+                username=username,
+                rows=[(1000, 0, "A")],  # local_id=1
+            )
+            _seed_message_db_full(
+                account_dir / "message_1.db",
+                username=username,
+                rows=[(2000, 0, "B")],  # local_id=1
+            )
+            _seed_contact_db_minimal(account_dir / "contact.db")
+
+            app = FastAPI()
+            app.include_router(chat_router.router)
+            client = TestClient(app)
+
+            with patch.object(chat_router, "_resolve_account_dir", return_value=account_dir):
+                resp = client.get(
+                    "/api/chat/messages/around",
+                    params={
+                        "account": "acc",
+                        "username": username,
+                        "anchor_id": f"message:{table}:1",
+                        "before": 0,
+                        "after": 10,
+                    },
+                )
+
+            self.assertEqual(resp.status_code, 200, resp.text)
+            data = resp.json()
+            self.assertEqual(data.get("status"), "success")
+            self.assertEqual(data.get("username"), username)
+            self.assertEqual(data.get("anchorId"), f"message:{table}:1")
+            self.assertEqual(data.get("anchorIndex"), 0)
+
+            msgs = data.get("messages") or []
+            self.assertEqual(len(msgs), 2)
+            self.assertEqual(msgs[0].get("id"), f"message:{table}:1")
+            self.assertEqual(msgs[1].get("id"), f"message_1:{table}:1")