//! 对话管理 — load/list/new/switch/delete/rename/archive + 侧栏折叠态
//!
//! 耦合:
//! - 多处调 useAiEvents.notifyConversationChanged
//! - newConversation/switchConversation 写 appSettings 持久化活跃会话 id

import { aiApi } from '@/api'
import { useAppSettingsStore } from '@/stores/appSettings'
import { state } from '@/stores/ai'
import { notifyConversationChanged } from './useAiEvents'
import { persistUiState } from './useAiPanel'
import { setStreaming } from './streamingGuard'
import { nextMsgId, getConvState, clearConvStreamState, startApprovalTimer } from './aiShared'
import { t } from '@/i18n/i18n-helpers'
import type { AiConversationDetail, AiMessage, AiToolCallInfo } from '@/api/types'

const appSettings = useAppSettingsStore()

/** 拉取会话列表;首次加载时若 appSettings 仍有有效 active-conv 且当前无活跃对话则恢复 */
async function loadConversations() {
  try {
    state.conversations = await aiApi.listConversations()
    // 虚拟项保底:活跃会话未落库(懒创建——首条消息前 DB 无记录)时,侧栏显示虚拟占位项。
    // 后端 ai_conversation_create 仅生成 id 存内存不落库,首条消息发送后 save_conversation 才写库。
    // 此处 active 会话不在 DB 列表时补一个虚拟项,实现「点新建立即出现在侧栏,不发消息不落库」。
    // 首条消息落库后 AiCompleted/AiError 触发的 loadConversations 拉到同 id 真实记录,虚拟项被替代无重复。
    if (state.activeConversationId
      && !state.conversations.some(c => c.id === state.activeConversationId)) {
      const now = String(Date.now())
      state.conversations.unshift({
        id: state.activeConversationId,
        title: null,
        provider_id: null,
        model: null,
        archived: false,
        pinned: false,
        prompt_tokens: 0,
        completion_tokens: 0,
        created_at: now,
        updated_at: now,
      })
    }
    // 恢复上次活跃对话(仅在首次加载、ID 仍有效且当前无活跃对话时)
    const pending = appSettings.get<string | null>('df-ai-active-conv', null)
    if (pending && !state.activeConversationId && state.conversations.some(c => c.id === pending)) {
      await switchConversation(pending)
    }
  } catch (e) {
    // UX-260617-08:网络抖动/IPC 断开时原静默失败,列表可能突空用户不知原因。
    // 此处保留旧列表(赋值语句抛出,旧 state.conversations 不被覆盖)+ 推错误气泡反馈。
    // 仅首次加载(state.conversations 为空)时推气泡,避免拉取/侧栏刷新重试时反复弹错。
    console.error('[AI] 加载会话列表失败:', e)
    if (state.conversations.length === 0) {
      state.messages.push({
        id: `load-conv-fail-${nextMsgId()}`,
        role: 'assistant',
        content: t('ai.loadConvFail'),
        isError: true,
        timestamp: Date.now(),
      } as AiMessage)
      notifyConversationChanged()
    }
  }
}

/** 新建空对话并切过去 */
async function newConversation() {
  const result = await aiApi.createConversation()
  state.activeConversationId = result.id
  void appSettings.set('df-ai-active-conv', result.id)
  state.messages = []
  state.currentText = ''
  state.pendingApprovals = []
  setStreaming(false, { reason: 'newConversation' })
  // F-09 决策e(真并发):newConversation 对齐 switchConversation 并行语义——旧 conv 后台 loop 继续,
  // 不清 generatingConvs(保留旧 conv 生成态跟踪,侧栏显双会话生成,AiCompleted/AiError 按
  // conversation_id 正确收尾旧 conv)。原 state.generatingConvs.clear() 是 A 路线 F-260616-09
  // 单 loop 软隔离遗留,真并发下致后台生成前端丢失跟踪,废弃。
  // queue 清空防旧会话排队消息带进新会话 drain;agentRound 复位 0;searchQuery 清空防新会话
  // 侧栏被旧搜索过滤。此三项均为新 conv 本地视图复位(非跨 conv 跟踪),保留。
  state.queue = []
  state.agentRound = 0
  state.searchQuery = ''
  await loadConversations()
  notifyConversationChanged()
}

// 切换 token:快速连点 A→B 时,后返回的 A 响应按 token 丢弃,防 messages 错配(FR-R1)
let _latestSwitchId = 0

/** 切换到指定会话:加载历史消息(含 tool_calls 回填 + tool_result 映射 + pending 审批恢复) */
export async function switchConversation(id: string) {
  const mySwitchId = ++_latestSwitchId
  // 允许生成中切换:后台继续生成,事件按 conversation_id 路由不污染当前视图
  let detail: AiConversationDetail
  try {
    detail = await aiApi.switchConversation(id)
  } catch {
    // 对话不存在(已删除/未落库的虚 ID)→ 创建新对话替代
    console.warn('[AI] switchConversation 失败,创建新对话:', id)
    const created = await aiApi.createConversation()
    if (mySwitchId !== _latestSwitchId) return
    void appSettings.set('df-ai-active-conv', created.id)
    // 用新对话 id 重走后续逻辑
    detail = { id: created.id, title: null, messages: '[]' }
    state.messages = []
    notifyConversationChanged()
    void loadConversations()
    return
  }
  // 过期响应丢弃(用户已切到别的对话,防 A 后返回覆盖 B)
  if (mySwitchId !== _latestSwitchId) return
  state.activeConversationId = id
  void appSettings.set('df-ai-active-conv', id)
  // P1#6 技术债审查(2026-06-21):streaming 是全局单值,切到非生成会话需按目标 conv 生成态重算,
  // 否则残留 stop 按钮(ChatInput.vue:88 v-if=streaming)→ 点击 store.stopChat 传 activeConversationId
  // 发错会话。对齐 newConversation 复位语义;目标在后台生成时保留 true(stop/流式显示正确)。
  // 根治归 F-09 B 路线:streaming 改 per-conv 态。此处为 A 路线过渡补丁。
  // 批4 双轨收口:读 getConvState(enum 真相源)派生,替代旧 generatingConvs.has。
  // 桥接语义:has(id)=true 等价于 conv_state∈{generating,stopping,compressed}(非终止三态)。
  const targetCs = getConvState(id)
  const targetGen = targetCs === 'generating' || targetCs === 'stopping' || targetCs === 'compressed'
  setStreaming(targetGen, { convId: id, reason: 'switchConversation-recompute' })

  try {
    const rawMsgs = typeof detail.messages === 'string'
      ? JSON.parse(detail.messages)
      : detail.messages

    // 构建 tool_call_id → tool_result 映射，用于回填工具执行结果
    const toolResultMap = new Map<string, string>()
    for (const m of rawMsgs) {
      if (m.role === 'tool' && m.tool_call_id) {
        toolResultMap.set(m.tool_call_id, m.content || '')
      }
    }

    state.messages = rawMsgs
      // 过滤 tool 消息 + truncated 软删消息(UX-09:编辑某条 user 后其后消息标 truncated,
      // 保留 DB 可追溯但从视图移除;前端无 status 字段故按原始 JSON 字段过滤)
      .filter((m: any) => m.role !== 'tool' && m.status !== 'truncated')
      .map((m: any, i: number) => ({
        id: `loaded-${i}`,
        role: m.role,
        content: m.content || '',
        model: m.model,
        // 用后端持久化的真实时间(BUG-260618-01);老数据无 timestamp 字段回退 Date.now()
        timestamp: typeof m.timestamp === 'number' ? m.timestamp : Date.now(),
        // F-260614-05 Phase 2b: 透传 parts(多模态 Image 片)。后端序列化的 ContentPart[]
        // 含 type:'text'|'image' discriminator + url/base64/media_type/alt 字段,
        // 此处原样透传供 AiChat.vue 用户气泡渲染 <img>(base64 模式持久化层已替换占位 Text 片,
        // 故历史 parts 通常仅含 url 模式 Image 或纯 Text)。
        parts: Array.isArray(m.parts) && m.parts.length > 0 ? m.parts : undefined,
        // F-15 阶段2: 透传 status(archived_segment/compressed/null|active),
        // 供 AiChat.vue 按 status 折叠分组渲染。types.ts 未含此字段(不在本任务白名单),
        // 经 as any 透传,消费方 AiChat.vue 同样 cast 读取,类型闭环在两端。
        status: m.status,
        toolCalls: m.tool_calls?.map((tc: any): AiToolCallInfo => {
          // 逐条容错:单条坏 arguments 仅降级为空对象,不影响整条对话回填
          let args: unknown = {}
          const rawArgs = tc.function?.arguments
          if (typeof rawArgs === 'string') {
            try {
              args = rawArgs ? JSON.parse(rawArgs) : {}
            } catch {
              args = {}
            }
          } else if (rawArgs && typeof rawArgs === 'object') {
            args = rawArgs
          }
          return {
            id: tc.id,
            name: tc.function?.name || '',
            args,
            status: 'completed' as const,
            result: toolResultMap.get(tc.id),
          }
        }),
      }))
  } catch (e) {
    // UX-260617-08:历史消息解析/映射失败原仅 state.messages=[] → 切换后空白用户不知原因。
    // 改为推错误气泡提示 + 控制台日志(保留 state.messages 不再清空,避免空白无反馈)。
    console.error('[AI] 切换对话历史消息解析失败:', e)
    state.messages.push({
      id: `switch-conv-fail-${nextMsgId()}`,
      role: 'assistant',
      content: t('ai.switchConvFail'),
      isError: true,
      timestamp: Date.now(),
    } as AiMessage)
  }

  // 加载历史对话 token 总量(来自 DB summary);切换对话清空实时值
  const conv = state.conversations.find(c => c.id === id)
  if (conv && conv.prompt_tokens != null && conv.completion_tokens != null) {
    state.convTokenTotal = {
      prompt: conv.prompt_tokens,
      completion: conv.completion_tokens,
      total: conv.prompt_tokens + conv.completion_tokens,
    }
  } else {
    state.convTokenTotal = null
  }
  state.lastTokenUsage = null

  state.currentText = ''
  // 恢复该对话积压的待审批:重启后后端从审计表重建了 pending_approvals,
  // 此处查回并把对应 toolCard.status 置 pending_approval,使审批卡片重新可见
  // 阶段4:按 IPC 返的 kind 渲染——'path' 类显 once/always/deny(tc.kind='path' + 推 path/dir 文案),
  // 'risk' 类显 approve/reject(tc.kind='risk'/缺省)。对齐阶段3b 统一审批模型(两 kind 都可恢复)。
  try {
    const pending = await aiApi.pendingToolCalls(id)
    // 第二 await 后二次比对:切换 A→B 期间避免用 A 的 pending 覆写 B 的 pendingApprovals
    if (mySwitchId !== _latestSwitchId) return
    if (pending.length) {
      // kind 索引:tool_call_id → kind('risk'/'path'),供恢复 tc/pendingApprovals 按类型渲染
      const pendingKindMap = new Map(pending.map(p => [p.tool_call_id, p.kind]))
      const pendingIds = new Set(pending.map(p => p.tool_call_id))
      const restored: AiToolCallInfo[] = []
      for (const m of state.messages) {
        for (const tc of (m.toolCalls || [])) {
          if (pendingIds.has(tc.id)) {
            tc.status = 'pending_approval'
            const kind = pendingKindMap.get(tc.id) ?? 'risk'
            tc.kind = kind
            // path 类审批:从 tc.args.path 推 path/dir 文案(后端 IPC 仅返 kind,无 dir/path;
            // 此处从工具参数派生,供 ToolCard 审批提示展示)。缺 path 参数的 path 类回退空。
            if (kind === 'path') {
              const p = (tc.args as { path?: string } | null)?.path
              tc.path = p
              tc.dir = p ?? undefined
              tc.reason = t('aiChat.dirAuthHint', { tool: tc.name, path: p ?? '' })
            }
            restored.push({
              id: tc.id,
              name: tc.name,
              args: tc.args,
              status: 'pending_approval',
              kind,
              path: tc.path,
              dir: tc.dir,
              reason: tc.reason,
            })
            // 重新启动审批计时器(APPROVAL_TIMEOUT_MS=Infinity 已决策,不会超时自动拒绝,
            // 启动仅用于计时器注册一致性,保持与 AiApprovalRequired 事件处理对称)
            startApprovalTimer(tc.id, tc.name, kind)
          }
        }
      }
      state.pendingApprovals = restored
    } else {
      state.pendingApprovals = []
    }
  } catch {
    state.pendingApprovals = []
  }
}

/** 删除会话;若删的是当前活跃会话则清空消息+移除活跃 id 持久化 */
async function deleteConversation(id: string) {
  await aiApi.deleteConversation(id)
  // F-09 per-conv:清该会话的 stream state(streaming/currentText),防 convStreamStates Map 无限增长
  // (与 convStates/待审批等 per-conv 资源同款会话级清理语义)。
  clearConvStreamState(id)
  if (state.activeConversationId === id) {
    state.activeConversationId = null
    void appSettings.remove('df-ai-active-conv')
    state.messages = []
  }
  await loadConversations()
  notifyConversationChanged()
}

/** 重命名会话(后端 + 本地侧栏摘要同步) */
async function renameConversation(id: string, title: string) {
  await aiApi.renameConversation(id, title)
  // 本地同步更新侧栏摘要标题
  const conv = state.conversations.find(c => c.id === id)
  if (conv) conv.title = title
  notifyConversationChanged()
}

/** 归档/取消归档(后端 + 本地侧栏分组同步) */
async function archiveConversation(id: string, archived: boolean) {
  await aiApi.archiveConversation(id, archived)
  // 本地同步归档态(侧栏立即移入/移出归档分组)
  const conv = state.conversations.find(c => c.id === id)
  if (conv) conv.archived = archived
  notifyConversationChanged()
}

/** 置顶/取消置顶(后端 + 本地侧栏排序同步;UX-17) */
async function setPinnedConversation(id: string, pinned: boolean) {
  await aiApi.setPinnedConversation(id, pinned)
  // 本地同步置顶态(排序 computed 读 pinned,立即重排)
  const conv = state.conversations.find(c => c.id === id)
  if (conv) conv.pinned = pinned
  notifyConversationChanged()
}

/** 折叠/展开归档分组 */
function toggleArchivedFold() {
  state.archivedCollapsed = !state.archivedCollapsed
  persistUiState()
}

/** 折叠/展开时间分组(today/yesterday/earlier) */
function toggleGroupFold(key: string) {
  state.foldedGroups[key] = !state.foldedGroups[key]
  persistUiState()
}

/** 展开/收起侧栏(会话列表) */
function toggleSidebar() {
  state.sidebarOpen = !state.sidebarOpen
  persistUiState()
}

export function useAiConversations() {
  return {
    loadConversations,
    newConversation,
    switchConversation,
    deleteConversation,
    renameConversation,
    archiveConversation,
    setPinnedConversation,
    toggleArchivedFold,
    toggleGroupFold,
    toggleSidebar,
  }
}

export { loadConversations }