// ============================================================
// data_gateway/index.js - 对外 API 数据网关主入口
// 暴露两个路由：
//   POST /api/v1/ingest/:skillId    外部数据写入（公网，需 API Key）
//   GET  /api/v1/data/:skillId/query 内部数据读取（localhost 或 Internal Token）
// ============================================================
const { logJSON } = require('../logger')
const { verifyApiKey, listEnabledSkills, requireLocalOnly, requireInternalOnly } = require('./auth')
const { insert, upsertLatest, queryLatest, queryList, queryByTimeRange, count } = require('./store')
const { loadSkillConfig } = require('./auth')
const { bindRoutes: bindExternalStorageRoutes } = require('./skills/external_storage')
const { bindRoutes: bindEmailSenderRoutes } = require('./skills/email_sender')
const { bindRoutes: bindPrivateClipboardRoutes } = require('./skills/private_clipboard')

const setNoCache = (res) => {
  try {
    res.set('Cache-Control', 'no-store, no-cache, must-revalidate, proxy-revalidate')
    res.set('Pragma', 'no-cache')
    res.set('Expires', '0')
  } catch {}
}

// ============================================================
// 安全工具函数
// ============================================================

// 原型污染防护：移除 __proto__、constructor、prototype 等危险键
const PROTO_KEYS = new Set(['__proto__', 'constructor', 'prototype', '__defineGetter__', '__defineSetter__', '__lookupGetter__', '__lookupSetter__', '__proto__'])
const sanitizeObject = (obj, depth = 0) => {
  if (depth > 10) return {} // 防止无限递归
  if (obj === null || typeof obj !== 'object') return obj
  if (Array.isArray(obj)) return obj.map(item => sanitizeObject(item, depth + 1))
  const clean = {}
  for (const [key, val] of Object.entries(obj)) {
    if (PROTO_KEYS.has(key)) continue
    clean[key] = sanitizeObject(val, depth + 1)
  }
  return clean
}

// 全局错误处理：隐藏详细堆栈，避免泄露路径和技术栈
const errorHandler = (err, req, res, _next) => {
  try { logJSON('data_gateway.error', { path: req.path, error: String(err.message || err) }, 'data_gateway') } catch {}
  if (!res.headersSent) {
    res.status(500).json({ ok: false, error: 'internal_error' })
  }
}

// Ingest 接口速率限制：同一 IP 每分钟最多 60 次请求
const ingestRateLimit = new Map()
const INGEST_MAX_PER_MIN = 60
const INGEST_WINDOW_MS = 60 * 1000
const checkIngestRate = (ip) => {
  const rec = ingestRateLimit.get(ip)
  if (!rec || Date.now() - rec.start > INGEST_WINDOW_MS) {
    ingestRateLimit.set(ip, { start: Date.now(), count: 1 })
    return { ok: true }
  }
  rec.count++
  if (rec.count > INGEST_MAX_PER_MIN) {
    const waitSec = Math.ceil((rec.start + INGEST_WINDOW_MS - Date.now()) / 1000)
    return { ok: false, retryAfter: Math.max(1, waitSec) }
  }
  return { ok: true }
}
// 每分钟清理一次
setInterval(() => {
  const now = Date.now()
  for (const [ip, rec] of ingestRateLimit.entries()) {
    if (now - rec.start > INGEST_WINDOW_MS + 10000) ingestRateLimit.delete(ip)
  }
}, 60000)

const SOURCE_MAX_LEN = 255
const DATA_MAX_BYTES = 10 * 1024 // 10KB

const bindRoutes = (app) => {
  // ============================================================
  // 外部存储 skill（第三方 OSS 读写）
  // 路由挂载在 /api/v1/skills/external_storage/*
  // ============================================================
  try {
    bindExternalStorageRoutes(app)
  } catch (e) {
    console.error(`[data_gateway] Failed to bind external_storage routes: ${e.message}`)
  }

  // ============================================================
  // 邮件发送 skill（对外发邮件）
  // 路由挂载在 /api/v1/ingest/email_sender/*
  // ============================================================
  try {
    bindEmailSenderRoutes(app)
  } catch (e) {
    console.error(`[data_gateway] Failed to bind email_sender routes: ${e.message}`)
  }

  // ============================================================
  // 私人剪贴板 skill（对外写入剪贴板）
  // 路由挂载在 /api/v1/ingest/private_clipboard/*
  // ============================================================
  try {
    bindPrivateClipboardRoutes(app)
  } catch (e) {
    console.error(`[data_gateway] Failed to bind private_clipboard routes: ${e.message}`)
  }

  // ============================================================
  // 外部写入接口（公网暴露）
  // POST /api/v1/ingest/:skillId
  // Headers: X-API-Id, X-API-Key
  // Body: { "source": "...", "data": { ... } }
  // ============================================================
  app.post('/api/v1/ingest/:skillId', (req, res) => {
    setNoCache(res)
    const skillId = String(req.params.skillId || '').trim()
    if (!skillId) return res.status(400).json({ ok: false, error: 'missing skill id' })

    const auth = verifyApiKey(req)
    if (!auth.ok) {
      try { logJSON('data_gateway.auth.fail', { skillId, error: auth.error, ip: req.ip }, 'data_gateway') } catch {}
      return res.status(401).json({ ok: false, error: auth.error })
    }

    // 速率限制
    const clientIp = req.ip || req.connection.remoteAddress || 'unknown'
    const rateCheck = checkIngestRate(clientIp)
    if (!rateCheck.ok) {
      return res.status(429).json({ ok: false, error: '请求过于频繁，请在 ' + rateCheck.retryAfter + ' 秒后重试' })
    }

    const body = req.body || {}
    let source = String(body.source || '').trim()
    let data = body.data

    // source 长度限制
    if (source.length > SOURCE_MAX_LEN) {
      return res.status(400).json({ ok: false, error: 'source 超过长度限制（' + SOURCE_MAX_LEN + ' 字符）' })
    }

    // 如果没有 data 字段，将整个 body 视为 data（排除 source）
    if (data === undefined) {
      const bodyData = { ...body }
      delete bodyData.source
      data = Object.keys(bodyData).length > 0 ? bodyData : body
    }

    // data 类型验证：必须是对象
    if (typeof data !== 'object' || data === null || Array.isArray(data)) {
      return res.status(400).json({ ok: false, error: 'data 必须是 JSON 对象' })
    }

    // data 大小限制
    const dataBytes = Buffer.byteLength(JSON.stringify(data), 'utf8')
    if (dataBytes > DATA_MAX_BYTES) {
      return res.status(413).json({ ok: false, error: 'data 超过大小限制（' + Math.round(DATA_MAX_BYTES / 1024) + 'KB）' })
    }

    // 原型污染防护
    data = sanitizeObject(data)

    const record = insert(skillId, { source, data })
    try { logJSON('data_gateway.ingest.ok', { skillId, source, recordId: record.id }, 'data_gateway') } catch {}
    return res.json({ ok: true, id: record.id, created_at: record.created_at })
  })

  // ============================================================
  // 内部读取接口（本机直连，或带 Internal Token 的受保护读取）
  // GET /api/v1/data/:skillId/query?mode=latest|list&limit=100&offset=0
  // Headers: X-Internal-Token, X-Skill-Id
  // ============================================================
  app.get('/api/v1/data/:skillId/query', requireInternalOnly, (req, res) => {
    setNoCache(res)
    const skillId = String(req.params.skillId || '').trim()
    if (!skillId) return res.status(400).json({ ok: false, error: 'missing skill id' })

    const mode = String(req.query.mode || 'latest').trim()
    const limit = parseInt(req.query.limit, 10) || 100
    const offset = parseInt(req.query.offset, 10) || 0
    const source = req.query.source || null
    const start = req.query.start || null
    const end = req.query.end || null

    try {
      if (mode === 'list') {
        if (start || end) {
          const result = queryByTimeRange(skillId, { start, end, limit })
          return res.json({ ok: true, ...result })
        }
        const result = queryList(skillId, { limit, offset, source })
        return res.json({ ok: true, ...result })
      }

      // mode === 'latest'（默认）
      const row = queryLatest(skillId)
      if (!row) return res.json({ ok: true, rows: [], total: 0 })
      return res.json({ ok: true, rows: [row], total: 1 })
    } catch (e) {
      try { logJSON('data_gateway.query.error', { skillId, error: String(e.message || e) }, 'data_gateway') } catch {}
      return res.status(500).json({ ok: false, error: String(e.message || e) })
    }
  })

  // ============================================================
  // 管理接口：列出所有已启用的 skill（仅 localhost）
  // GET /api/v1/data/skills
  // ============================================================
  app.get('/api/v1/data/skills', requireLocalOnly, (req, res) => {
    setNoCache(res)
    const skills = listEnabledSkills()
    const result = skills.map(s => {
      const cfg = loadSkillConfig(s.id)
      return {
        id: s.id,
        name: s.name,
        mode: String(cfg && cfg.mode || 'append'),
        record_count: count(s.id)
      }
    })
    res.json({ ok: true, skills: result })
  })

  // 全局错误处理：统一返回简洁错误，隐藏堆栈和路径信息
  app.use(errorHandler)
}

module.exports = { bindRoutes, listEnabledSkills, loadSkillConfig }