import WebSocket from 'ws'
import { getDefaultAgentId } from '@/app/api/nova-config'
import { HTTPClient } from '@/http'

const novaClient = new HTTPClient({
  baseURL: process.env.NOVA_BASE_URL,
  headers: {
    'Content-Type': 'application/json',
    'Tenant-Id': process.env.NOVA_TENANT_ID!,
    'Authorization': process.env.NOVA_ACCESS_KEY!,
  },
})

interface BotArtifact {
  path: string
  fileName: string
  taskId?: string
}

interface UserConnection {
  ws: WebSocket
  conversationId: string
  lastActivity: number
  idleTimer: ReturnType<typeof setTimeout> | null
  heartbeatTimer: ReturnType<typeof setTimeout> | null
  pendingResolve: ((text: string) => void) | null
  pendingReject: ((error: Error) => void) | null
  responseTexts: Map<string, string>
  artifacts: BotArtifact[]
}

const connections = new Map<string, UserConnection>()

let totalMessages = 0
let totalResponseTime = 0
let responseCount = 0

const IDLE_TIMEOUT = 5 * 60 * 1000
const RESPONSE_TIMEOUT = 10 * 60 * 1000
const HEARTBEAT_INTERVAL = 20 * 1000

function buildWssUrl(conversationId: string): string {
  const baseUrl = process.env.NOVA_BASE_URL!
  const wssBase = baseUrl.replace('https://', 'wss://').replace('http://', 'ws://')
  const authorization = process.env.NOVA_ACCESS_KEY
  const tenantId = process.env.NOVA_TENANT_ID
  return `${wssBase}/v1/super_agent/chat/completions?Authorization=${authorization}&X-Locale=zh&X-Region=CN&Tenant-Id=${tenantId}&conversation_id=${conversationId}`
}

function extractText(obj: unknown): string {
  if (typeof obj === 'string') return obj
  if (obj && typeof obj === 'object') {
    const o = obj as Record<string, unknown>
    if (typeof o.text === 'string') return o.text
    if (o.content) return extractText(o.content)
  }
  return ''
}

interface DirFileItem {
  file_name?: string
  path?: string
}

const extractDirFileList = (payload: unknown): DirFileItem[] => {
  if (Array.isArray(payload)) return payload
  if (!payload || typeof payload !== 'object') return []
  const obj = payload as Record<string, unknown>
  if (Array.isArray(obj.data)) return obj.data as DirFileItem[]
  return []
}

const resolvePathByName = (files: DirFileItem[], fileName?: string): string | null => {
  if (!fileName) return null
  const normalizedName = fileName.trim().startsWith('/upload/') ? fileName.slice('/upload/'.length) : fileName.trim()
  if (!normalizedName) return null

  const expectedSegment = `upload/${normalizedName}`
  const matched = files.find(item => {
    if (typeof item.file_name !== 'string' || !item.file_name) return false
    return item.file_name.includes(expectedSegment)
  })

  return matched?.path || null
}

const toAbsoluteHttpUrl = (value: unknown): string | null => {
  if (typeof value !== 'string' || !value) return null
  if (value.startsWith('http://') || value.startsWith('https://')) return value
  return null
}

async function resolveArtifactUrls(artifacts: BotArtifact[], defaultTaskId: string): Promise<{ fileName: string; url: string }[]> {
  const results: { fileName: string; url: string }[] = []

  // Create a Map with a composite key to keep uniqueness
  const uniqueArtifacts = new Map<string, BotArtifact>()
  for (const artifact of artifacts) {
    const key = artifact.path || artifact.fileName
    if (!uniqueArtifacts.has(key)) {
      uniqueArtifacts.set(key, artifact)
    }
  }

  for (const artifact of uniqueArtifacts.values()) {
    try {
      const taskId = artifact.taskId || defaultTaskId
      let resolvedPath = artifact.path

      if (taskId && resolvedPath) {
        const dirFilesResponse = await novaClient.post<unknown>(
          '/v1/super_agent/chat/get_dir_file',
          { task_id: taskId }
        )
        const dirFiles = extractDirFileList(dirFilesResponse)
        const matchedPath = resolvePathByName(dirFiles, artifact.fileName)
        if (matchedPath) {
          resolvedPath = matchedPath
        }
      }

      const response = await novaClient.post<string>('/v1/super_agent/chat/oss_url', {
        file_path: resolvedPath,
        task_id: taskId,
      })

      const signedUrl = toAbsoluteHttpUrl(response)
      const fallback = toAbsoluteHttpUrl(artifact.path)
      const finalUrl = signedUrl || fallback

      if (finalUrl) {
        results.push({ fileName: artifact.fileName, url: finalUrl })
      }
    } catch (err) {
      console.error(`[Nova Bridge] 解析附件 URL 失败 (${artifact.fileName}):`, err)
    }
  }

  return results
}

function startHeartbeat(conn: UserConnection): void {
  stopHeartbeat(conn)
  conn.heartbeatTimer = setInterval(() => {
    if (conn.ws.readyState === WebSocket.OPEN) {
      conn.ws.send(JSON.stringify({ message_type: 'ping' }))
    }
  }, HEARTBEAT_INTERVAL)
}

function stopHeartbeat(conn: UserConnection): void {
  if (conn.heartbeatTimer) {
    clearInterval(conn.heartbeatTimer)
    conn.heartbeatTimer = null
  }
}

function resetIdleTimer(userId: string, conn: UserConnection): void {
  if (conn.idleTimer) {
    clearTimeout(conn.idleTimer)
  }
  conn.idleTimer = setTimeout(() => {
    closeConnection(userId)
  }, IDLE_TIMEOUT)
}

function closeConnection(userId: string): void {
  const conn = connections.get(userId)
  if (!conn) return
  stopHeartbeat(conn)
  if (conn.idleTimer) clearTimeout(conn.idleTimer)
  if (conn.ws.readyState === WebSocket.OPEN || conn.ws.readyState === WebSocket.CONNECTING) {
    conn.ws.close(1000)
  }
  connections.delete(userId)
}

function createConnection(userId: string, conversationId: string): Promise<UserConnection> {
  return new Promise((resolve, reject) => {
    const wsUrl = buildWssUrl(conversationId)
    const ws = new WebSocket(wsUrl)

    const conn: UserConnection = {
      ws,
      conversationId,
      lastActivity: Date.now(),
      idleTimer: null,
      heartbeatTimer: null,
      pendingResolve: null,
      pendingReject: null,
      responseTexts: new Map(),
      artifacts: [],
    }

    const connectTimeout = setTimeout(() => {
      ws.close()
      reject(new Error('WebSocket 连接超时'))
    }, 10000)

    ws.on('open', () => {
      clearTimeout(connectTimeout)
      ws.send(JSON.stringify({
        message_type: 'switch_conversation',
        conversation_id: conversationId,
      }))
      connections.set(userId, conn)
      startHeartbeat(conn)
      resetIdleTimer(userId, conn)
      resolve(conn)
    })

    ws.on('message', async (raw: Buffer) => {
      const data = raw.toString()
      try {
        const parsed = JSON.parse(data)

        if (parsed?.data?.message_type === 'pong' || parsed?.message_type === 'pong') {
          return
        }

        const event = parsed?.data
        if (!event) return

        if (event.role === 'assistant' && event.event_type !== 'tool_call') {
          const text = extractText(event.content)
          if (text && event.event_id) {
            conn.responseTexts.set(event.event_id, text)
          }

          // 提取附件
          if (event.content && typeof event.content === 'object') {
            const content = event.content as Record<string, any>
            const taskId = event.task_id as string | undefined

            if (content.attachments) {
              const arr = Array.isArray(content.attachments) ? content.attachments : [content.attachments]
              arr.forEach((att: any) => {
                if (att?.file_name) {
                  conn.artifacts.push({ path: att.path || att.file_url || att.file_id || '', fileName: att.file_name, taskId })
                }
              })
            }
            if (content.attachment_files && Array.isArray(content.attachment_files)) {
              content.attachment_files.forEach((file: any) => {
                if (file?.file_name) {
                  conn.artifacts.push({ path: file.path || file.url || '', fileName: file.file_name, taskId })
                }
              })
            }
            if (content.files && Array.isArray(content.files)) {
              content.files.forEach((file: any) => {
                const fileName = file.name || file.file_name
                if (fileName) {
                  conn.artifacts.push({ path: file.path || file.url || file.id || '', fileName, taskId })
                }
              })
            }
          }
        }

        const taskStatus = (event.task_status ?? event.event_status) as string | undefined
        if (taskStatus === 'success' || taskStatus === 'completed') {
          if (conn.pendingResolve) {
            let fullText = Array.from(conn.responseTexts.values()).join('\n')
            
            // 拼接附件 URL 到 Markdown 中
            if (conn.artifacts.length > 0) {
              const resolvedUrls = await resolveArtifactUrls(conn.artifacts, conn.conversationId)
              const imageExts = new Set(['png', 'jpg', 'jpeg', 'gif', 'webp', 'svg'])
              
              const attachmentsText = resolvedUrls.map(att => {
                const ext = att.fileName.split('.').pop()?.toLowerCase() || ''
                if (imageExts.has(ext)) {
                  // 图片直接渲染 Markdown 图片语法
                  return `![${att.fileName}](${att.url})`
                } else {
                  // 文件渲染为普通链接
                  return `[${att.fileName}](${att.url})`
                }
              }).join('\n\n')
              
              if (attachmentsText) {
                fullText = fullText ? `${fullText}\n\n${attachmentsText}` : attachmentsText
              }
            }

            conn.pendingResolve(fullText)
            conn.pendingResolve = null
            conn.pendingReject = null
            conn.responseTexts.clear()
            conn.artifacts = []
          }
        } else if (taskStatus === 'failed' || taskStatus === 'error') {
          if (conn.pendingReject) {
            conn.pendingReject(new Error('Nova 任务失败'))
            conn.pendingResolve = null
            conn.pendingReject = null
            conn.responseTexts.clear()
            conn.artifacts = []
          }
        }
      } catch {
        // 忽略解析失败的消息
      }
    })

    ws.on('error', (err) => {
      clearTimeout(connectTimeout)
      console.error(`[Nova Bridge] WebSocket 错误 (用户: ${userId}):`, err.message)
      if (conn.pendingReject) {
        conn.pendingReject(new Error('WebSocket 连接错误'))
        conn.pendingResolve = null
        conn.pendingReject = null
      }
    })

    ws.on('close', () => {
      stopHeartbeat(conn)
      connections.delete(userId)
      if (conn.pendingReject) {
        conn.pendingReject(new Error('WebSocket 连接关闭'))
        conn.pendingResolve = null
        conn.pendingReject = null
      }
    })
  })
}

async function getConnection(userId: string, conversationId: string): Promise<UserConnection> {
  const existing = connections.get(userId)
  if (existing && existing.ws.readyState === WebSocket.OPEN) {
    existing.lastActivity = Date.now()
    resetIdleTimer(userId, existing)
    return existing
  }
  if (existing) {
    closeConnection(userId)
  }
  return createConnection(userId, conversationId)
}

export async function sendMessageAndWaitResponse(
  userId: string,
  conversationId: string,
  content: string,
  uploadFileIds?: string[],
): Promise<string> {
  const conn = await getConnection(userId, conversationId)

  conn.responseTexts.clear()
  conn.artifacts = []
  totalMessages++
  const sendTime = Date.now()

  const agentId = getDefaultAgentId()

  return new Promise((resolve, reject) => {
    const timeout = setTimeout(() => {
      if (conn.pendingReject) {
        conn.pendingReject(new Error('响应超时'))
        conn.pendingResolve = null
        conn.pendingReject = null
        conn.responseTexts.clear()
      }
    }, RESPONSE_TIMEOUT)

    conn.pendingResolve = (text: string) => {
      clearTimeout(timeout)
      totalResponseTime += Date.now() - sendTime
      responseCount++
      resolve(text)
    }
    conn.pendingReject = (err: Error) => {
      clearTimeout(timeout)
      reject(err)
    }

    const message = JSON.stringify({
      message_type: 'chat',
      conversation_id: conversationId,
      agent_id: agentId,
      content,
      upload_file_ids: uploadFileIds,
    })

    try {
      conn.ws.send(message)
    } catch (err) {
      clearTimeout(timeout)
      conn.pendingResolve = null
      conn.pendingReject = null
      reject(err)
    }
  })
}

export function closeAllConnections(): void {
  for (const userId of connections.keys()) {
    closeConnection(userId)
  }
}

/**
 * Close only connections whose key starts with `${platform}:`.
 * Each bot should call this in stopBot() instead of closeAllConnections()
 * so that stopping one bot doesn't break other bots' connections.
 */
export function closeConnectionsForPlatform(platform: string): void {
  const prefix = `${platform}:`
  for (const key of connections.keys()) {
    if (key.startsWith(prefix)) {
      closeConnection(key)
    }
  }
}

export function getStats() {
  return {
    activeConnections: connections.size,
    totalMessages,
    averageResponseTime: responseCount > 0 ? Math.round(totalResponseTime / responseCount) : 0,
  }
}