/**
 * AI 智能助手 API
 * 支持自然语言查询用户数据
 */

import { NextRequest, NextResponse } from "next/server"
import { getMongoClient, intelligentSearch, queryFullProfile, getDatabaseStats } from "@/lib/mongodb"

// 消息类型
interface ChatMessage {
  role: "user" | "assistant" | "system"
  content: string
  timestamp?: string
  data?: any
}

// 解析用户意图
function parseIntent(message: string): { type: string; query?: string; params?: any } {
  const msg = message.trim().toLowerCase()
  
  // 查询手机号
  const phoneMatch = message.match(/(?:查|查询|搜索|找)?[：:\s]*(\+?86)?1[3-9]\d{9}/g)
  if (phoneMatch) {
    const phone = phoneMatch[0].replace(/[查询搜索找：:\s]/g, '').replace(/^\+?86/, '')
    return { type: "query_phone", query: phone }
  }
  
  // 查询 QQ
  const qqMatch = message.match(/(?:qq|QQ)[：:\s]*(\d{5,11})|(\d{5,11})\s*(?:qq|QQ)/i)
  if (qqMatch) {
    return { type: "query_qq", query: qqMatch[1] || qqMatch[2] }
  }
  
  // 系统状态
  if (msg.includes("状态") || msg.includes("统计") || msg.includes("总量")) {
    return { type: "system_status" }
  }
  
  // RFM 分析
  if (msg.includes("rfm") || msg.includes("估值") || msg.includes("价值")) {
    return { type: "rfm_analysis" }
  }
  
  // 高价值用户
  if (msg.includes("高价值") || msg.includes("top") || msg.includes("排行")) {
    const limitMatch = msg.match(/(\d+)/)
    return { type: "high_value_users", params: { limit: limitMatch ? parseInt(limitMatch[1]) : 10 } }
  }
  
  // 帮助
  if (msg.includes("帮助") || msg.includes("help") || msg === "?") {
    return { type: "help" }
  }
  
  // 通用搜索
  return { type: "search", query: message }
}

// 格式化用户数据
function formatUserData(user: any): string {
  if (!user) return "未找到用户信息"
  
  const lines: string[] = []
  
  if (user.name) lines.push(`👤 姓名: ${user.name}`)
  if (user.phone_masked) lines.push(`📱 手机: ${user.phone_masked}`)
  if (user.qq) lines.push(`💬 QQ: ${user.qq}`)
  if (user.gender) lines.push(`⚧ 性别: ${user.gender}`)
  if (user.age_range) lines.push(`📅 年龄段: ${user.age_range}`)
  if (user.province || user.city) lines.push(`📍 地区: ${user.province || ''}${user.city || ''}`)
  if (user.evaluation_score || user.user_evaluation_score) {
    lines.push(`⭐ 估值分: ${user.evaluation_score || user.user_evaluation_score}`)
  }
  if (user.user_level) lines.push(`🏆 等级: ${user.user_level}`)
  if (user.carrier) lines.push(`📶 运营商: ${user.carrier}`)
  if (user.tags && user.tags.length > 0) lines.push(`🏷️ 标签: ${user.tags.join(', ')}`)
  
  return lines.join('\n')
}

// 处理 AI 聊天
async function processChat(message: string): Promise<ChatMessage> {
  const startTime = Date.now()
  const intent = parseIntent(message)
  
  try {
    switch (intent.type) {
      case "query_phone": {
        const result = await queryFullProfile(intent.query!)
        if (result.valuation || result.qqPhone) {
          const user = {
            ...result.valuation,
            qq: result.qqPhone?.qq,
            carrier: result.qqPhone?.运营商
          }
          return {
            role: "assistant",
            content: `🎯 手机号 ${intent.query} 查询结果:\n\n${formatUserData(user)}\n\n⏱️ 查询耗时: ${Date.now() - startTime}ms`,
            data: result
          }
        } else {
          return {
            role: "assistant",
            content: `❌ 未找到手机号 ${intent.query} 的相关信息\n\n💡 提示: 请检查手机号是否正确（11位数字）`
          }
        }
      }
      
      case "query_qq": {
        const client = await getMongoClient()
        const qqDb = client.db("KR_腾讯")
        let qqDoc = await qqDb.collection("QQ+手机").findOne({ qq: intent.query })
        if (!qqDoc) {
          qqDoc = await qqDb.collection("QQ+手机").findOne({ qq: parseInt(intent.query!) })
        }
        
        if (qqDoc) {
          const phone = qqDoc.phone || qqDoc.手机号
          let userInfo = `🎯 QQ ${intent.query} 查询结果:\n\n`
          userInfo += `💬 QQ: ${qqDoc.qq}\n`
          userInfo += `📱 手机: ${phone ? phone.toString().replace(/(\d{3})\d{4}(\d{4})/, '$1****$2') : '未知'}\n`
          userInfo += `📊 QQ评分: ${qqDoc.QQ号评分 || 'N/A'}\n`
          userInfo += `📊 手机评分: ${qqDoc.手机号评分 || 'N/A'}\n`
          userInfo += `📍 地区: ${qqDoc.省份 || ''}${qqDoc.地区 || ''}\n`
          userInfo += `📶 运营商: ${qqDoc.运营商 || 'N/A'}\n`
          userInfo += `\n⏱️ 查询耗时: ${Date.now() - startTime}ms`
          
          return {
            role: "assistant",
            content: userInfo,
            data: qqDoc
          }
        } else {
          return {
            role: "assistant",
            content: `❌ 未找到 QQ ${intent.query} 的相关信息`
          }
        }
      }
      
      case "system_status": {
        const stats = await getDatabaseStats()
        return {
          role: "assistant",
          content: `📊 神射手系统状态\n\n` +
            `🟢 连接状态: ${stats.connected ? '正常' : '异常'}\n` +
            `📁 数据库数: ${stats.databases?.length || 0} 个\n` +
            `📄 总记录数: ${(stats.totalDocuments / 1e8).toFixed(2)} 亿条\n` +
            `💾 总数据量: ${(stats.totalSize / 1e9).toFixed(2)} GB\n` +
            `⏱️ 响应延迟: ${stats.latency}ms`,
          data: stats
        }
      }
      
      case "rfm_analysis": {
        const client = await getMongoClient()
        const db = client.db("KR")
        const pipeline = [
          { $group: { _id: "$user_level", count: { $sum: 1 } } },
          { $sort: { count: -1 } }
        ]
        const results = await db.collection("用户估值").aggregate(pipeline).toArray()
        
        let content = `📈 RFM 用户分布统计\n\n`
        let total = 0
        results.forEach(r => {
          const level = r._id || '未分级'
          content += `${level}: ${(r.count / 10000).toFixed(1)}万\n`
          total += r.count
        })
        content += `\n📊 总用户数: ${(total / 10000).toFixed(1)}万`
        content += `\n⏱️ 统计耗时: ${Date.now() - startTime}ms`
        
        return {
          role: "assistant",
          content,
          data: results
        }
      }
      
      case "high_value_users": {
        const limit = intent.params?.limit || 10
        const client = await getMongoClient()
        const db = client.db("KR")
        const users = await db.collection("用户估值")
          .find({ user_evaluation_score: { $exists: true } })
          .sort({ user_evaluation_score: -1 })
          .limit(limit)
          .toArray()
        
        let content = `🏆 高价值用户 TOP${limit}\n\n`
        users.forEach((u, i) => {
          const phone = u.phone?.replace(/(\+?86)?(\d{3})\d{4}(\d{4})/, '$2****$3') || '***'
          content += `${i + 1}. ${u.name || '未知'} (${phone}) - 估值: ${u.user_evaluation_score}\n`
        })
        content += `\n⏱️ 查询耗时: ${Date.now() - startTime}ms`
        
        return {
          role: "assistant",
          content,
          data: users
        }
      }
      
      case "help": {
        return {
          role: "assistant",
          content: `🎯 神射手 AI 助手使用指南\n\n` +
            `📱 查询手机号:\n   "查 13800138000" 或 "13800138000"\n\n` +
            `💬 查询 QQ:\n   "28533368 qq" 或 "qq 28533368"\n\n` +
            `📊 系统状态:\n   "系统状态" 或 "统计"\n\n` +
            `📈 RFM 分析:\n   "RFM分析" 或 "用户估值"\n\n` +
            `🏆 高价值用户:\n   "高价值用户 TOP10"\n\n` +
            `💡 数据覆盖: 20亿+用户，207GB数据`
        }
      }
      
      case "search":
      default: {
        // 尝试智能搜索
        const result = await intelligentSearch(intent.query || message, { limit: 5 })
        if (result.total > 0) {
          let content = `🔍 搜索结果 (共${result.total}条)\n\n`
          result.users.slice(0, 5).forEach((u, i) => {
            content += `${i + 1}. ${u.name || '未知'} - ${u.city || ''} - 估值: ${u.user_evaluation_score || 'N/A'}\n`
          })
          content += `\n⏱️ 查询耗时: ${Date.now() - startTime}ms`
          return {
            role: "assistant",
            content,
            data: result
          }
        } else {
          return {
            role: "assistant",
            content: `🤔 我不太理解 "${message}"\n\n` +
              `💡 你可以尝试:\n` +
              `- 查询手机号: "查 13800138000"\n` +
              `- 查询QQ: "28533368 qq"\n` +
              `- 输入 "帮助" 查看更多功能`
          }
        }
      }
    }
  } catch (error: any) {
    console.error("AI Chat 错误:", error)
    return {
      role: "assistant",
      content: `⚠️ 查询出错: ${error.message}\n\n请稍后重试或检查数据库连接`
    }
  }
}

/**
 * POST /api/ai-chat
 * AI 对话接口
 */
export async function POST(request: NextRequest) {
  try {
    const body = await request.json()
    const { message, history = [] } = body
    
    if (!message || !message.trim()) {
      return NextResponse.json({
        success: false,
        error: "消息不能为空"
      }, { status: 400 })
    }
    
    const response = await processChat(message)
    response.timestamp = new Date().toLocaleTimeString("zh-CN", { hour: "2-digit", minute: "2-digit" })
    
    return NextResponse.json({
      success: true,
      response
    })
    
  } catch (error: any) {
    console.error("AI Chat API 错误:", error)
    return NextResponse.json({
      success: false,
      error: error.message,
      response: {
        role: "assistant",
        content: `⚠️ 服务暂时不可用: ${error.message}`,
        timestamp: new Date().toLocaleTimeString("zh-CN", { hour: "2-digit", minute: "2-digit" })
      }
    }, { status: 500 })
  }
}

/**
 * GET /api/ai-chat
 * 获取 AI 助手状态
 */
export async function GET() {
  try {
    const stats = await getDatabaseStats()
    return NextResponse.json({
      status: "online",
      model: "神射手 AI v1.0",
      capabilities: ["用户查询", "QQ查询", "RFM分析", "智能搜索"],
      database: {
        connected: stats.connected,
        totalUsers: stats.totalDocuments,
        latency: stats.latency
      }
    })
  } catch (error: any) {
    return NextResponse.json({
      status: "degraded",
      error: error.message
    })
  }
}