package plugin

import (
	"context"
	"encoding/json"
	"net/http"
	"net/url"
	"strings"
	"time"

	managedaccess "billing/internal/access"
)

type readOnlyManagedKeyDTO struct {
	ID                string          `json:"id"`
	Name              string          `json:"name"`
	MaskedSecret      string          `json:"masked_secret"`
	Status            string          `json:"status"`
	RouteMode         string          `json:"route_mode"`
	UpstreamAccountID string          `json:"upstream_account_id,omitempty"`
	AllModels         bool            `json:"all_models"`
	ShowInStats       bool            `json:"show_in_stats"`
	Models            []string        `json:"models"`
	Billing           billingStateDTO `json:"billing"`
}

func (a *App) readOnlyResponse(query url.Values) ManagementResponse {
	switch strings.TrimSpace(query.Get("view")) {
	case "keys":
		return a.readOnlyManagedKeys(query.Get("include_archived") == "1")
	case "usage":
		return a.readOnlyUsageResponse(query)
	case "usage-summary":
		return a.usageDashboardResponse()
	case "prices":
		return a.listPrices()
	case "price-catalog":
		return a.searchPriceCatalog(query)
	case "upstreams":
		return a.readOnlyUpstreamAccounts()
	case "model-suggestions":
		return a.modelSuggestions()
	case "key-stats":
		return a.readOnlyManagedKeyStats(strings.TrimSpace(query.Get("id")))
	case "events":
		return a.businessEvents(query)
	default:
		return managementError(http.StatusBadRequest, "invalid_view", "只读资源类型不存在")
	}
}

func (a *App) readOnlyUsageResponse(query url.Values) ManagementResponse {
	limited := url.Values{"page": {"1"}, "page_size": {"50"}}
	response := a.usageResponse(limited)
	if response.StatusCode != http.StatusOK {
		return response
	}
	var payload usageListResponse
	if err := json.Unmarshal(response.Body, &payload); err != nil {
		return managementError(http.StatusInternalServerError, "response_error", "无法生成只读请求明细")
	}
	redactUsageItems(payload.Records)
	return jsonManagementResponse(http.StatusOK, payload)
}

func (a *App) readOnlyManagedKeyStats(id string) ManagementResponse {
	response := a.managedKeyStats(id)
	if response.StatusCode != http.StatusOK {
		return response
	}
	var payload managedKeyStatsResponse
	if err := json.Unmarshal(response.Body, &payload); err != nil {
		return managementError(http.StatusInternalServerError, "response_error", "无法生成只读 Key 统计")
	}
	redactUsageItems(payload.Recent)
	return jsonManagementResponse(http.StatusOK, payload)
}

func redactUsageItems(items []usageListItem) {
	for index := range items {
		items[index].APIKey = ""
	}
}

func (a *App) readOnlyManagedKeys(includeArchived bool) ManagementResponse {
	store, ok := a.currentStore()
	if !ok {
		return managementError(http.StatusServiceUnavailable, "database_unavailable", "Key 数据库尚未初始化")
	}
	keys, err := store.ListManagedKeys(context.Background(), includeArchived)
	if err != nil {
		return managementError(http.StatusInternalServerError, "database_error", err.Error())
	}
	items := make([]readOnlyManagedKeyDTO, 0, len(keys))
	for _, key := range keys {
		state, stateErr := store.BillingState(context.Background(), key.ID, time.Now().UTC())
		if stateErr != nil {
			return managementError(http.StatusInternalServerError, "database_error", stateErr.Error())
		}
		items = append(items, readOnlyManagedKeyDTO{
			ID: key.ID, Name: key.Name, MaskedSecret: maskManagedSecret(key.Secret), Status: key.Status,
			RouteMode: key.RouteMode, UpstreamAccountID: key.UpstreamAccountID,
			AllModels: key.AllModels, ShowInStats: key.ShowInStats, Models: key.Models, Billing: billingStateResponse(state),
		})
	}
	return jsonManagementResponse(http.StatusOK, map[string]any{"keys": items})
}

func (a *App) readOnlyUpstreamAccounts() ManagementResponse {
	store, ok := a.currentStore()
	if !ok {
		return managementError(http.StatusServiceUnavailable, "database_unavailable", "上游账号数据库尚未初始化")
	}
	accounts, err := store.ListUpstreamAccounts(context.Background())
	if err != nil {
		return managementError(http.StatusInternalServerError, "database_error", err.Error())
	}
	return jsonManagementResponse(http.StatusOK, map[string]any{"accounts": accounts})
}

func maskManagedSecret(secret string) string {
	characters := []rune(secret)
	if len(characters) < 6 {
		return "******"
	}
	return string(characters[:2]) + "******" + string(characters[len(characters)-4:])
}

func billingStateResponse(state managedaccess.BillingState) billingStateDTO {
	return billingStateDTO{
		QuotaUSD: formatMicros(state.QuotaMicros), SpentUSD: formatMicros(state.SpentMicros),
		LifetimeSpentUSD: formatMicros(state.LifetimeSpentMicros),
		BalanceUSD:       formatMicros(state.BalanceMicros), ResetPeriod: state.ResetPeriod,
		NextResetAt: state.NextResetAt, MaxConcurrency: state.MaxConcurrency,
		ActiveRequests: state.ActiveRequests, CycleStartedAt: state.CycleStartedAt,
	}
}