fix(logging): 日志写入改用 output_dir 并避免重复初始化

- 日志目录改为 get_output_dir()/logs/...（兼容 WECHAT_TOOL_DATA_DIR）
- 清理/关闭旧 handlers，避免重复输出和 Windows 文件锁
- get_logger/get_log_file_path 未初始化时自动 setup_logging
- 新增 tests/test_logging_config_data_dir.py

desktop/scripts/installer-custom.nsh

@@ -14,6 +14,34 @@
 
 Var WDA_InstallDirPage
 
+!macro customInit
+  ; Safety: older versions created an `output` junction inside the install directory that points to the
+  ; per-user AppData `output` folder. Some uninstall/update flows may traverse that junction and delete
+  ; real user data. Remove it as early as possible during install/update.
+  Call WDA_RemoveLegacyOutputLink
+!macroend
+
+!macro customInstall
+  ; Provide a safe, non-junction way for users to locate the real per-user output directory.
+  ; The actual data is NOT stored inside $INSTDIR (it is wiped on update/reinstall).
+  ; `open-output.cmd` uses %APPDATA% so it works for the current user.
+  FileOpen $0 "$INSTDIR\output-location.txt" w
+  FileWrite $0 "WeChatDataAnalysis output folder (per user):$\r$\n%APPDATA%\\${APP_PACKAGE_NAME}\\output$\r$\n"
+  FileClose $0
+
+  FileOpen $1 "$INSTDIR\open-output.cmd" w
+  ; NSIS escaping: use $\" to output a literal quote character into the .cmd file.
+  FileWrite $1 "@echo off$\r$\nexplorer $\"%APPDATA%\\${APP_PACKAGE_NAME}\\output$\"$\r$\n"
+  FileClose $1
+!macroend
+
+Function WDA_RemoveLegacyOutputLink
+  ; $INSTDIR is usually the full install directory. Be defensive and also try the nested path
+  ; in case the installer is running before electron-builder appends "\${APP_FILENAME}".
+  RMDir "$INSTDIR\output"
+  RMDir "$INSTDIR\${APP_FILENAME}\output"
+FunctionEnd
+
 !macro customPageAfterChangeDir
   ; Add a confirmation page after the directory picker so users clearly see
   ; the final install location (includes the app sub-folder).
@@ -90,6 +118,10 @@ Var /GLOBAL WDA_DeleteUserData
 !macro customUnInit
   ; Default: keep user data (also applies to silent uninstall / update uninstall).
   StrCpy $WDA_DeleteUserData "0"
+
+  ; Safety: if an older build created an `output` junction inside the install dir, remove it early so
+  ; directory cleanup can't traverse it and delete the real per-user output folder.
+  RMDir "$INSTDIR\output"
 !macroend
 
 !macro customUnWelcomePage

desktop/src/main.cjs

@@ -123,6 +123,68 @@ function isPortAvailable(port, host) {
   });
 }
 
+function getEphemeralPort(host) {
+  return new Promise((resolve) => {
+    try {
+      const srv = net.createServer();
+      srv.unref();
+      srv.once("error", () => resolve(null));
+      srv.listen({ port: 0, host }, () => {
+        const addr = srv.address();
+        const p = addr && typeof addr === "object" ? Number(addr.port) : null;
+        srv.close(() => resolve(Number.isInteger(p) ? p : null));
+      });
+    } catch {
+      resolve(null);
+    }
+  });
+}
+
+async function chooseAvailablePort(preferredPort, host) {
+  const preferred = parsePort(preferredPort);
+  if (preferred != null && (await isPortAvailable(preferred, host))) return preferred;
+
+  // Keep the port close to the user's expectation when possible.
+  if (preferred != null) {
+    for (let i = 1; i <= 50; i += 1) {
+      const cand = preferred + i;
+      if (cand > 65535) break;
+      if (await isPortAvailable(cand, host)) return cand;
+    }
+  }
+
+  // Fall back to an OS-chosen ephemeral port.
+  const random = await getEphemeralPort(host);
+  if (random != null && (await isPortAvailable(random, host))) return random;
+
+  return null;
+}
+
+async function ensureBackendPortAvailableOnStartup() {
+  // Avoid surprising behavior in dev: the frontend dev server expects a stable backend port.
+  if (!app.isPackaged) return getBackendPort();
+
+  const bindHost = getBackendBindHost();
+  const currentPort = getBackendPort();
+  const ok = await isPortAvailable(currentPort, bindHost);
+  if (ok) return currentPort;
+
+  const chosen = await chooseAvailablePort(currentPort, bindHost);
+  if (chosen == null) {
+    logMain(`[main] backend port unavailable: ${currentPort} host=${bindHost}; failed to find a free port`);
+    return currentPort;
+  }
+
+  try {
+    setBackendPortSetting(chosen);
+    logMain(`[main] backend port ${currentPort} unavailable; switched to ${chosen}`);
+  } catch (err) {
+    logMain(`[main] failed to persist backend port ${chosen}: ${err?.message || err}`);
+  }
+
+  return getBackendPort();
+}
+
 function resolveDataDir() {
   if (resolvedDataDir) return resolvedDataDir;
 
@@ -163,7 +225,11 @@ function getExeDir() {
 
 function ensureOutputLink() {
   // Users often expect an `output/` folder near the installed exe. We keep the real data
-  // in the per-user data dir, and (when possible) create a Windows junction next to the exe.
+  // in the per-user data dir.
+  //
+  // NOTE: We intentionally avoid creating a junction/symlink inside the install directory.
+  // Some uninstall/update flows may traverse reparse points and delete the target directory,
+  // causing data loss (the install dir is removed on every update/reinstall).
   if (!app.isPackaged) return;
 
   const exeDir = getExeDir();
@@ -171,26 +237,56 @@ function ensureOutputLink() {
   if (!exeDir || !dataDir) return;
 
   const target = path.join(dataDir, "output");
-  const linkPath = path.join(exeDir, "output");
+  const legacyLinkPath = path.join(exeDir, "output");
 
-  // If the target doesn't exist yet, create it so the link points somewhere real.
+  // Ensure the real output dir exists.
   try {
     fs.mkdirSync(target, { recursive: true });
   } catch {}
 
-  // If something already exists at linkPath, do not overwrite it.
+  // Best-effort: remove a legacy junction/symlink at `exeDir/output` so uninstallers can't
+  // accidentally traverse it and delete the real per-user output directory.
   try {
-    if (fs.existsSync(linkPath)) return;
+    const st = fs.lstatSync(legacyLinkPath);
+    if (st.isSymbolicLink()) {
+      try {
+        fs.unlinkSync(legacyLinkPath);
+        logMain(`[main] removed legacy output link: ${legacyLinkPath}`);
+      } catch (err) {
+        logMain(`[main] failed to remove legacy output link: ${err?.message || err}`);
+      }
+    } else if (st.isDirectory()) {
+      const entries = fs.readdirSync(legacyLinkPath);
+      if (Array.isArray(entries) && entries.length === 0) {
+        // Remove an empty real directory to reduce confusion (it will be recreated by the backend if needed).
+        fs.rmdirSync(legacyLinkPath);
+      } else {
+        // Do not overwrite non-empty directories to avoid data loss.
+        // Note: data stored here will be wiped on update/reinstall.
+        logMain(
+          `[main] output dir exists in install dir (not a link): ${legacyLinkPath}. real data dir output: ${target}`
+        );
+      }
+    } else {
+      logMain(`[main] output path exists and is not a directory/link: ${legacyLinkPath}`);
+    }
   } catch {
-    return;
+    // Doesn't exist yet.
   }
 
+  // Best-effort: drop a helper file next to the exe so users can find the real data.
+  // This avoids the data-loss risks of using junctions/symlinks under the install directory.
   try {
-    fs.symlinkSync(target, linkPath, "junction");
-    logMain(`[main] created output link: ${linkPath} -> ${target}`);
-  } catch (err) {
-    logMain(`[main] failed to create output link: ${err?.message || err}`);
-  }
+    const p = path.join(exeDir, "output-location.txt");
+    const text = `WeChatDataAnalysis data directory\n\nOutput folder:\n${target}\n`;
+    fs.writeFileSync(p, text, { encoding: "utf8" });
+  } catch {}
+
+  try {
+    const p = path.join(exeDir, "open-output.cmd");
+    const text = `@echo off\r\nexplorer \"${target}\"\r\n`;
+    fs.writeFileSync(p, text, { encoding: "utf8" });
+  } catch {}
 }
 
 function getMainLogPath() {
@@ -990,6 +1086,16 @@ async function waitForBackend({ timeoutMs, healthUrl } = {}) {
   const startedAt = Date.now();
   // eslint-disable-next-line no-constant-condition
   while (true) {
+    // If the backend process died, fail fast (otherwise we'd wait for the full timeout).
+    if (!backendProc) {
+      throw new Error(`Backend process exited before becoming ready: ${url}`);
+    }
+    if (backendProc.exitCode != null) {
+      throw new Error(
+        `Backend process exited (code=${backendProc.exitCode} signal=${backendProc.signalCode || "null"}): ${url}`
+      );
+    }
+
     try {
       const code = await httpGet(url);
       if (code >= 200 && code < 500) return;
@@ -1254,6 +1360,30 @@ function registerWindowIpc() {
     }
   });
 
+  ipcMain.handle("app:getOutputDir", () => {
+    const dir = resolveDataDir();
+    if (!dir) return "";
+    return path.join(dir, "output");
+  });
+
+  ipcMain.handle("app:openOutputDir", async () => {
+    const dir = resolveDataDir();
+    if (!dir) throw new Error("无法定位数据目录");
+    const outDir = path.join(dir, "output");
+    try {
+      fs.mkdirSync(outDir, { recursive: true });
+    } catch {}
+    try {
+      const err = await shell.openPath(outDir);
+      if (err) throw new Error(err);
+      return { success: true, path: outDir };
+    } catch (e) {
+      const message = e?.message || String(e);
+      logMain(`[main] openOutputDir failed: ${message}`);
+      throw new Error(message);
+    }
+  });
+
   ipcMain.handle("app:checkForUpdates", async () => {
     return await checkForUpdatesInternal();
   });
@@ -1272,6 +1402,11 @@ function registerWindowIpc() {
     }
 
     try {
+      // Safety: remove legacy `output` junctions in the install dir before triggering the NSIS update/uninstall.
+      // Some uninstall flows may traverse reparse points and delete the real per-user output directory.
+      try {
+        ensureOutputLink();
+      } catch {}
       autoUpdater.quitAndInstall(false, true);
       return { success: true };
     } catch (err) {
@@ -1312,15 +1447,41 @@ async function main() {
   registerWindowIpc();
   registerDebugShortcuts();
 
-  // Resolve/create the data dir early so we can log reliably and (optionally) place a link
+  // Resolve/create the data dir early so we can log reliably and place helper files
   // next to the installed exe for easier access.
   resolveDataDir();
   ensureOutputLink();
+  await ensureBackendPortAvailableOnStartup();
 
   logMain(`[main] app.isPackaged=${app.isPackaged} argv=${JSON.stringify(process.argv)}`);
 
   startBackend();
-  await waitForBackend({ timeoutMs: 30_000 });
+  try {
+    await waitForBackend({ timeoutMs: 30_000 });
+  } catch (err) {
+    // In some environments a specific port may be blocked/reserved (WSAEACCES) or taken.
+    // Best-effort: pick a new port and retry once so the app can still start.
+    if (app.isPackaged) {
+      const prevPort = getBackendPort();
+      const bindHost = getBackendBindHost();
+      const nextPort = await chooseAvailablePort(prevPort + 1, bindHost);
+      if (nextPort != null && nextPort !== prevPort) {
+        logMain(`[main] backend not ready on port ${prevPort}; retrying on ${nextPort}`);
+        try {
+          setBackendPortSetting(nextPort);
+          await restartBackend({ timeoutMs: 30_000 });
+          logMain(`[main] backend retry succeeded on port ${nextPort}`);
+        } catch (retryErr) {
+          logMain(`[main] backend retry failed: ${retryErr?.stack || String(retryErr)}`);
+          throw retryErr;
+        }
+      } else {
+        throw err;
+      }
+    } else {
+      throw err;
+    }
+  }
 
   const win = createMainWindow();
   mainWindow = win;

desktop/src/preload.cjs

@@ -19,6 +19,10 @@ contextBridge.exposeInMainWorld("wechatDesktop", {
 
   chooseDirectory: (options = {}) => ipcRenderer.invoke("dialog:chooseDirectory", options),
 
+  // Data/output folder helpers
+  getOutputDir: () => ipcRenderer.invoke("app:getOutputDir"),
+  openOutputDir: () => ipcRenderer.invoke("app:openOutputDir"),
+
   // Auto update
   getVersion: () => ipcRenderer.invoke("app:getVersion"),
   checkForUpdates: () => ipcRenderer.invoke("app:checkForUpdates"),

frontend/components/SettingsDialog.vue

@@ -142,6 +142,24 @@
               <div v-if="desktopBackendPortError" class="text-xs text-red-600 whitespace-pre-wrap -mt-1.5">
                 {{ desktopBackendPortError }}
               </div>
+
+              <div class="flex flex-col gap-1.5 sm:flex-row sm:items-center sm:justify-between">
+                <div class="min-w-0 flex-1">
+                  <div class="text-[13px] font-medium text-[#222]">output 目录</div>
+                  <div class="mt-0.5 text-[11px] text-[#909090] break-words">{{ desktopOutputDirText }}</div>
+                </div>
+                <button
+                  type="button"
+                  class="shrink-0 rounded-[6px] border border-[#e2e2e2] bg-white px-2 py-1 text-[12px] text-[#222] transition hover:bg-[#f9f9f9] disabled:cursor-not-allowed disabled:opacity-50"
+                  :disabled="!isDesktopEnv || desktopOutputDirLoading"
+                  @click="onDesktopOpenOutputDir"
+                >
+                  打开 output
+                </button>
+              </div>
+              <div v-if="desktopOutputDirError" class="text-xs text-red-600 whitespace-pre-wrap -mt-1.5">
+                {{ desktopOutputDirError }}
+              </div>
             </div>
           </section>
 
@@ -288,6 +306,15 @@ const desktopBackendPortApplying = ref(false)
 const desktopBackendPortError = ref('')
 const desktopBackendPortDefault = ref(10392)
 
+const desktopOutputDir = ref('')
+const desktopOutputDirLoading = ref(false)
+const desktopOutputDirError = ref('')
+const desktopOutputDirText = computed(() => {
+  if (!isDesktopEnv.value) return '仅桌面端可用'
+  const v = String(desktopOutputDir.value || '').trim()
+  return v || '—'
+})
+
 const switchTrackClass = (enabled, disabled = false) => {
   if (disabled) return enabled ? 'bg-[#07b75b] opacity-50 cursor-not-allowed' : 'bg-[#d0d0d0] opacity-50 cursor-not-allowed'
   return enabled ? 'bg-[#07b75b] hover:brightness-95' : 'bg-[#d0d0d0] hover:brightness-95'
@@ -437,6 +464,36 @@ const refreshDesktopBackendPort = async () => {
   }
 }
 
+const refreshDesktopOutputDir = async () => {
+  if (!process.client || typeof window === 'undefined') return
+  if (!window.wechatDesktop?.getOutputDir) return
+  desktopOutputDirLoading.value = true
+  desktopOutputDirError.value = ''
+  try {
+    const v = await window.wechatDesktop.getOutputDir()
+    desktopOutputDir.value = String(v || '').trim()
+  } catch (e) {
+    desktopOutputDirError.value = e?.message || '读取 output 目录失败'
+  } finally {
+    desktopOutputDirLoading.value = false
+  }
+}
+
+const onDesktopOpenOutputDir = async () => {
+  if (!process.client || typeof window === 'undefined') return
+  if (!window.wechatDesktop?.openOutputDir) return
+  desktopOutputDirLoading.value = true
+  desktopOutputDirError.value = ''
+  try {
+    const res = await window.wechatDesktop.openOutputDir()
+    if (res?.path) desktopOutputDir.value = String(res.path || '').trim()
+  } catch (e) {
+    desktopOutputDirError.value = e?.message || '打开 output 目录失败'
+  } finally {
+    desktopOutputDirLoading.value = false
+  }
+}
+
 const applyDesktopBackendPort = async () => {
   if (!process.client || typeof window === 'undefined') return
   const raw = String(desktopBackendPortInput.value || '').trim()
@@ -567,6 +624,7 @@ onMounted(async () => {
     void desktopUpdate.initListeners()
     await refreshDesktopAutoLaunch()
     await refreshDesktopCloseBehavior()
+    await refreshDesktopOutputDir()
   }
 
   await nextTick()

src/wechat_decrypt_tool/api.py

@@ -10,8 +10,13 @@ from starlette.exceptions import HTTPException as StarletteHTTPException
 from starlette.responses import FileResponse
 from starlette.staticfiles import StaticFiles
 
-from . import __version__ as APP_VERSION
 from .logging_config import setup_logging, get_logger
+
+# 初始化日志系统
+setup_logging()
+logger = get_logger(__name__)
+
+from . import __version__ as APP_VERSION
 from .path_fix import PathFixRoute
 from .chat_realtime_autosync import CHAT_REALTIME_AUTOSYNC
 from .routers.chat import router as _chat_router
@@ -30,10 +35,6 @@ from .routers.wrapped import router as _wrapped_router
 from .sns_stage_timing import add_sns_stage_timing_headers
 from .wcdb_realtime import WCDB_REALTIME, shutdown as _wcdb_shutdown
 
-# 初始化日志系统
-setup_logging()
-logger = get_logger(__name__)
-
 app = FastAPI(
     title="微信数据库解密工具",
     description="现代化的微信数据库解密工具，支持微信信息检测和数据库解密功能",

src/wechat_decrypt_tool/logging_config.py

@@ -53,9 +53,9 @@ class WeChatLogger:
         return cls._instance
     
     def __init__(self):
-        if not self._initialized:
-            self.setup_logging()
-            WeChatLogger._initialized = True
+        # Lazy-init in `setup_logging()` / accessors to avoid double-initialization when
+        # callers instantiate the manager and then call `setup_logging()` again.
+        pass
     
     def setup_logging(self, log_level: str = "INFO"):
         """设置日志配置"""
@@ -66,7 +66,9 @@ class WeChatLogger:
 
         # 创建日志目录
         now = datetime.now()
-        log_dir = Path("output/logs") / str(now.year) / f"{now.month:02d}" / f"{now.day:02d}"
+        from .app_paths import get_output_dir
+
+        log_dir = get_output_dir() / "logs" / str(now.year) / f"{now.month:02d}" / f"{now.day:02d}"
         log_dir.mkdir(parents=True, exist_ok=True)
         
         # 设置日志文件名
@@ -77,6 +79,10 @@ class WeChatLogger:
         root_logger = logging.getLogger()
         for handler in root_logger.handlers[:]:
             root_logger.removeHandler(handler)
+            try:
+                handler.close()
+            except Exception:
+                pass
         
         # 配置日志格式
         # 文件格式（无颜色）
@@ -109,22 +115,48 @@ class WeChatLogger:
         
         # 只为uvicorn日志器添加文件处理器，保持其原有的控制台处理器（带颜色）
         uvicorn_logger = logging.getLogger("uvicorn")
+        for handler in uvicorn_logger.handlers[:]:
+            if isinstance(handler, logging.FileHandler):
+                uvicorn_logger.removeHandler(handler)
+                try:
+                    handler.close()
+                except Exception:
+                    pass
         uvicorn_logger.addHandler(file_handler)
         uvicorn_logger.setLevel(level)
 
         # 只为uvicorn.access日志器添加文件处理器
         uvicorn_access_logger = logging.getLogger("uvicorn.access")
+        for handler in uvicorn_access_logger.handlers[:]:
+            if isinstance(handler, logging.FileHandler):
+                uvicorn_access_logger.removeHandler(handler)
+                try:
+                    handler.close()
+                except Exception:
+                    pass
         uvicorn_access_logger.addHandler(file_handler)
         uvicorn_access_logger.setLevel(level)
 
         # 只为uvicorn.error日志器添加文件处理器
         uvicorn_error_logger = logging.getLogger("uvicorn.error")
+        for handler in uvicorn_error_logger.handlers[:]:
+            if isinstance(handler, logging.FileHandler):
+                uvicorn_error_logger.removeHandler(handler)
+                try:
+                    handler.close()
+                except Exception:
+                    pass
         uvicorn_error_logger.addHandler(file_handler)
         uvicorn_error_logger.setLevel(level)
 
         # 配置FastAPI日志器
         fastapi_logger = logging.getLogger("fastapi")
-        fastapi_logger.handlers = []
+        for handler in fastapi_logger.handlers[:]:
+            fastapi_logger.removeHandler(handler)
+            try:
+                handler.close()
+            except Exception:
+                pass
         fastapi_logger.addHandler(file_handler)
         fastapi_logger.addHandler(console_handler)
         fastapi_logger.setLevel(level)
@@ -136,6 +168,8 @@ class WeChatLogger:
         logger.info(f"日志文件: {self.log_file}")
         logger.info(f"日志级别: {logging.getLevelName(level)}")
         logger.info("=" * 60)
+
+        WeChatLogger._initialized = True
         
         return self.log_file
     
@@ -145,6 +179,8 @@ class WeChatLogger:
     
     def get_log_file_path(self) -> Path:
         """获取当前日志文件路径"""
+        if not hasattr(self, "log_file"):
+            self.setup_logging()
         return self.log_file
 
 
@@ -157,10 +193,14 @@ def setup_logging(log_level: str = "INFO") -> Path:
 def get_logger(name: str) -> logging.Logger:
     """获取日志器的便捷函数"""
     logger_manager = WeChatLogger()
+    if not WeChatLogger._initialized:
+        logger_manager.setup_logging()
     return logger_manager.get_logger(name)
 
 
 def get_log_file_path() -> Path:
     """获取当前日志文件路径的便捷函数"""
     logger_manager = WeChatLogger()
+    if not WeChatLogger._initialized:
+        logger_manager.setup_logging()
     return logger_manager.get_log_file_path()

tests/test_logging_config_data_dir.py

@@ -0,0 +1,63 @@
+import os
+import sys
+import unittest
+import importlib
+from pathlib import Path
+from tempfile import TemporaryDirectory
+
+
+ROOT = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(ROOT / "src"))
+
+
+def _close_logging_handlers() -> None:
+    # Close handlers to avoid Windows temp dir cleanup failures (FileHandler holds a lock).
+    import logging
+
+    for logger_name in ("", "uvicorn", "uvicorn.access", "uvicorn.error", "fastapi"):
+        lg = logging.getLogger(logger_name)
+        for h in lg.handlers[:]:
+            try:
+                h.close()
+            except Exception:
+                pass
+            try:
+                lg.removeHandler(h)
+            except Exception:
+                pass
+
+
+class TestLoggingConfigDataDir(unittest.TestCase):
+    def setUp(self):
+        self._prev_data_dir = os.environ.get("WECHAT_TOOL_DATA_DIR")
+        self._td = TemporaryDirectory()
+        os.environ["WECHAT_TOOL_DATA_DIR"] = self._td.name
+
+        import wechat_decrypt_tool.app_paths as app_paths
+        import wechat_decrypt_tool.logging_config as logging_config
+
+        importlib.reload(app_paths)
+        importlib.reload(logging_config)
+
+        self.logging_config = logging_config
+
+    def tearDown(self):
+        _close_logging_handlers()
+
+        if self._prev_data_dir is None:
+            os.environ.pop("WECHAT_TOOL_DATA_DIR", None)
+        else:
+            os.environ["WECHAT_TOOL_DATA_DIR"] = self._prev_data_dir
+        self._td.cleanup()
+
+    def test_setup_logging_uses_wechat_tool_data_dir(self):
+        log_file = self.logging_config.setup_logging()
+
+        base = Path(self._td.name) / "output" / "logs"
+        self.assertTrue(log_file.is_relative_to(base))
+        self.assertTrue(log_file.exists())
+
+
+if __name__ == "__main__":
+    unittest.main()
+