'use strict'
const cfg = require('./config')
const { log, json, parseBody, nbiRequest, deepGetValue } = require('./helpers')
const { summarizeDevice } = require('./device-extractors')
const createHostsHandler = require('./device-hosts')

const deviceCache = new Map()
const hostsDbCache = new Map()
const MAX_HISTORY = 60
let pollerTimer = null, lastPollAt = null, pollCount = 0, dbPool = null, dbReady = false
const serialAliases = new Map()

function getPool () {
  if (dbPool) return dbPool
  if (!cfg.CACHE_DB_URL) return null
  const { Pool } = require('pg')
  dbPool = new Pool({ connectionString: cfg.CACHE_DB_URL, max: 3 })
  dbPool.on('error', e => log('Cache DB pool error:', e.message))
  return dbPool
}

async function initCacheDb () {
  const pool = getPool()
  if (!pool) { log('No CACHE_DB_URL — device cache is memory-only'); return }
  try {
    await pool.query(`CREATE TABLE IF NOT EXISTS device_cache (serial TEXT PRIMARY KEY, summary JSONB NOT NULL DEFAULT '{}', previous JSONB, history JSONB NOT NULL DEFAULT '[]', updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW())`)
    await pool.query(`CREATE TABLE IF NOT EXISTS hosts_cache (serial TEXT PRIMARY KEY, data JSONB NOT NULL DEFAULT '{}', updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW())`)
    await pool.query(`CREATE TABLE IF NOT EXISTS device_events (id SERIAL PRIMARY KEY, serial TEXT NOT NULL, event TEXT NOT NULL, reason TEXT, details JSONB, created_at TIMESTAMPTZ NOT NULL DEFAULT NOW())`)
    await pool.query(`CREATE TABLE IF NOT EXISTS modem_diagnostic_cache (serial TEXT PRIMARY KEY, diagnostic JSONB NOT NULL DEFAULT '{}', updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW())`)
    await pool.query(`CREATE INDEX IF NOT EXISTS idx_device_events_serial ON device_events (serial, created_at DESC)`)
    const { rows } = await pool.query('SELECT serial, summary, previous, history, updated_at FROM device_cache')
    for (const row of rows) {
      deviceCache.set(row.serial, {
        summary: row.summary, previous: row.previous,
        updatedAt: row.updated_at?.toISOString() || new Date().toISOString(),
        history: Array.isArray(row.history) ? row.history : [],
      })
    }
    const hostsRows = await pool.query('SELECT serial, data, updated_at FROM hosts_cache')
    for (const row of hostsRows.rows) hostsDbCache.set(row.serial, { data: row.data, updatedAt: row.updated_at?.toISOString() })
    dbReady = true
    log(`Device cache loaded from DB: ${rows.length} devices, ${hostsRows.rows.length} hosts entries`)
  } catch (e) { log('Failed to init cache DB:', e.message) }
}

function createDebouncedWriter (table, serialize) {
  const pending = new Set()
  let timer = null
  async function flush () {
    timer = null
    if (!dbReady || !pending.size) return
    const pool = getPool()
    if (!pool) return
    const keys = [...pending]
    pending.clear()
    for (const key of keys) {
      const data = serialize(key)
      if (!data) continue
      try { await pool.query(data.sql, data.params) } catch (e) { log(`DB write error (${table}) for ${key}: ${e.message}`) }
    }
  }
  return function schedule (key) {
    pending.add(key)
    if (!timer) timer = setTimeout(flush, 2000)
  }
}

const scheduleDbWrite = createDebouncedWriter('device_cache', serial => {
  const entry = deviceCache.get(serial)
  if (!entry) return null
  return {
    sql: `INSERT INTO device_cache (serial, summary, previous, history, updated_at) VALUES ($1, $2, $3, $4, NOW()) ON CONFLICT (serial) DO UPDATE SET summary = EXCLUDED.summary, previous = EXCLUDED.previous, history = EXCLUDED.history, updated_at = NOW()`,
    params: [serial, JSON.stringify(entry.summary), JSON.stringify(entry.previous), JSON.stringify(entry.history)],
  }
})

const scheduleHostsDbWrite = createDebouncedWriter('hosts_cache', serial => {
  const entry = hostsDbCache.get(serial)
  if (!entry) return null
  return {
    sql: `INSERT INTO hosts_cache (serial, data, updated_at) VALUES ($1, $2, NOW()) ON CONFLICT (serial) DO UPDATE SET data = EXCLUDED.data, updated_at = NOW()`,
    params: [serial, JSON.stringify(entry.data)],
  }
})

async function logDeviceEvent (serial, event, reason, details) {
  if (!dbReady) return
  const pool = getPool()
  if (!pool) return
  try { await pool.query('INSERT INTO device_events (serial, event, reason, details) VALUES ($1, $2, $3, $4)', [serial, event, reason || null, details ? JSON.stringify(details) : null]) } catch (e) { log(`Event log error for ${serial}: ${e.message}`) }
}

const DISCONNECT_REASONS = [
  [/dying.?gasp/i, 'Dying Gasp (power failure)'],
  [/LOS/i, 'LOS (loss of signal)'],
  [/LOF/i, 'LOF (loss of frame)'],
]

async function fetchDisconnectReason (deviceId) {
  if (!deviceId) return null
  try {
    const r = await nbiRequest(`/faults/?query=${encodeURIComponent(`device = "${deviceId}"`)}`)
    const faults = Array.isArray(r.data) ? r.data : []
    if (!faults.length) return null
    faults.sort((a, b) => (b.timestamp || '').localeCompare(a.timestamp || ''))
    const msg = (faults[0].detail?.message || faults[0].message || faults[0].code || '').toString()
    for (const [re, label] of DISCONNECT_REASONS) { if (re.test(msg)) return label }
    return msg ? msg.slice(0, 200) : null
  } catch { return null }
}

async function getDeviceEvents (serial, limit = 50) {
  if (!dbReady) return []
  const pool = getPool()
  if (!pool) return []
  try {
    const { rows } = await pool.query('SELECT id, serial, event, reason, details, created_at FROM device_events WHERE serial = $1 ORDER BY created_at DESC LIMIT $2', [serial, limit])
    return rows
  } catch { return [] }
}

function cacheDevice (summary) {
  if (!summary?.serial) return
  const existing = deviceCache.get(summary.serial)
  const now = new Date().toISOString()
  const snapshot = {
    ts: now,
    online: summary.lastInform ? (Date.now() - new Date(summary.lastInform).getTime()) < 900000 : false,
    rxPower: summary.rxPower, txPower: summary.txPower,
    wifiClients: summary.wifi?.totalClients || 0, hostsCount: summary.hostsCount,
    uptime: summary.uptime, ip: summary.ip,
  }
  const history = existing?.history || []
  const last = history[history.length - 1]
  if (!last || last.online !== snapshot.online || last.wifiClients !== snapshot.wifiClients || last.rxPower !== snapshot.rxPower || last.ip !== snapshot.ip || (Date.now() - new Date(last.ts).getTime()) > 60000) {
    history.push(snapshot)
    if (history.length > MAX_HISTORY) history.shift()
  }
  if (existing) {
    existing.summary = summary
    existing.previous = existing.summary
    existing.updatedAt = now
  } else {
    deviceCache.set(summary.serial, { summary, previous: null, updatedAt: now, history })
  }
  scheduleDbWrite(summary.serial)
}

function aliasSerial (alias, realSerial) {
  if (!alias || !realSerial || alias === realSerial) return
  serialAliases.set(alias, realSerial)
  const entry = deviceCache.get(realSerial)
  if (entry) deviceCache.set(alias, entry)
}

function getCacheEntry (serial) {
  let entry = deviceCache.get(serial)
  if (entry) return entry
  const real = serialAliases.get(serial)
  if (!real) return null
  entry = deviceCache.get(real)
  if (entry) deviceCache.set(serial, entry)
  return entry || null
}

function cacheHosts (serial, data) {
  if (!serial || !data) return
  hostsDbCache.set(serial, { data, updatedAt: new Date().toISOString() })
  scheduleHostsDbWrite(serial)
}

function getCachedHosts (serial) { return hostsDbCache.get(serial) || null }
function getCached (serial) { return getCacheEntry(serial) || null }

function getCacheStats () {
  const entries = []
  for (const [serial, entry] of deviceCache) {
    const lastInform = entry.summary?.lastInform ? new Date(entry.summary.lastInform) : null
    entries.push({
      serial, online: lastInform ? (Date.now() - lastInform.getTime()) < 600000 : false,
      model: `${entry.summary?.manufacturer || ''} ${entry.summary?.model || ''}`.trim(),
      wifiClients: entry.summary?.wifi?.totalClients || 0,
      updatedAt: entry.updatedAt, historyPoints: entry.history?.length || 0,
    })
  }
  return {
    devices: deviceCache.size, hostsEntries: hostsDbCache.size, lastPollAt, pollCount, dbReady,
    entries: entries.sort((a, b) => (b.online ? 1 : 0) - (a.online ? 1 : 0)),
  }
}

const FAST_PROJECTION = '_id,_lastInform,InternetGatewayDevice.DeviceInfo.SerialNumber,Device.DeviceInfo.SerialNumber'

async function pollOnlineStatus () {
  if (!cfg.GENIEACS_NBI_URL) return
  // Pause gate — admin toggle via /admin/pollers. Skip silently-ish when
  // paused so the log doesn't spam every 5 minutes.
  if (require('./poller-control').isPaused('device')) {
    if ((pollCount % 12) === 0) log('Device poll: skipped (paused via /admin/pollers)')
    pollCount++
    return
  }
  const startMs = Date.now()
  const { httpRequest } = require('./helpers')
  const allDevices = []
  let skip = 0
  const pageSize = 1000
  try {
    while (true) {
      const r = await httpRequest(cfg.GENIEACS_NBI_URL, `/devices/?projection=${FAST_PROJECTION}&limit=${pageSize}&skip=${skip}`, { timeout: 30000 })
      const page = Array.isArray(r.data) ? r.data : []
      if (!page.length) break
      allDevices.push(...page)
      skip += page.length
      if (page.length < pageSize || allDevices.length >= 10000) break
      // Pause between pages to avoid overwhelming GenieACS
      await new Promise(resolve => setTimeout(resolve, 500))
    }
  } catch (e) { log(`Poll fetch error (skip=${skip}): ${e.message} — processing ${allDevices.length} devices`) }

  let count = 0
  const now = Date.now()
  for (const d of allDevices) {
    try {
      const serial = (deepGetValue(d, 'InternetGatewayDevice.DeviceInfo.SerialNumber') || deepGetValue(d, 'Device.DeviceInfo.SerialNumber') || '').toString()
        || (d._id ? decodeURIComponent(d._id.split('-').slice(2).join('-')) : '')
      if (!serial) continue

      const lastInform = d._lastInform ? new Date(d._lastInform).getTime() : 0
      const online = lastInform ? (now - lastInform) < 900000 : false

      const existing = deviceCache.get(serial)
      if (existing) {
        const wasOnline = existing.history?.length ? existing.history[existing.history.length - 1].online : null
        if (wasOnline !== null && wasOnline !== online) {
          if (!online) fetchDisconnectReason(d._id).then(reason => logDeviceEvent(serial, 'offline', reason, { lastInform: d._lastInform, deviceId: d._id }))
          else logDeviceEvent(serial, 'online', null, { lastInform: d._lastInform, deviceId: d._id })
        }
        existing.summary.lastInform = d._lastInform || null
        existing.summary._id = d._id
        if (d._tags) existing.summary.tags = d._tags
        const snapshot = { ts: new Date().toISOString(), online }
        const history = existing.history
        const last = history[history.length - 1]
        if (!last || last.online !== online || (now - new Date(last.ts).getTime()) > 60000) {
          history.push(snapshot)
          if (history.length > MAX_HISTORY) history.shift()
        }
        existing.updatedAt = new Date().toISOString()
        scheduleDbWrite(serial)
      } else {
        deviceCache.set(serial, {
          summary: { _id: d._id, serial, lastInform: d._lastInform || null },
          previous: null, updatedAt: new Date().toISOString(),
          history: [{ ts: new Date().toISOString(), online }],
        })
      }
      count++
    } catch {}
  }
  lastPollAt = new Date().toISOString()
  pollCount++
  log(`Device poll: ${count} devices in ${Date.now() - startMs}ms (poll #${pollCount})`)
}

async function fetchDeviceDetails (serial) {
  const existing = getCacheEntry(serial)
  const acsId = existing?.summary?._id
  const projection = 'DeviceID,InternetGatewayDevice,Device,_lastInform,_lastBootstrap,_registered,_tags'

  if (acsId) {
    try {
      const r = await nbiRequest(`/devices/${encodeURIComponent(acsId)}`)
      if (r.status === 200 && r.data) {
        const s = summarizeDevice(r.data)
        if (s.serial) cacheDevice(s)
        return s
      }
    } catch (e) { log(`On-demand fetch error for ${serial}: ${e.message}`) }
    return existing?.summary || null
  }

  try {
    let devices = []
    let q = JSON.stringify({ 'DeviceID.SerialNumber._value': serial })
    let r = await nbiRequest(`/devices/?query=${encodeURIComponent(q)}&projection=${projection}`)
    devices = Array.isArray(r.data) ? r.data : []

    if (!devices.length && serial.startsWith('TPLG')) {
      const formatted = serial.slice(4).toUpperCase().match(/.{2}/g).join(':')
      q = JSON.stringify({ 'Device.DeviceInfo.X_TP_MACAddress._value': { '$regex': formatted + '$' } })
      r = await nbiRequest(`/devices/?query=${encodeURIComponent(q)}&projection=${projection}`)
      devices = Array.isArray(r.data) ? r.data : []
    }

    // Raisecom RCMG → try tag + UserName in GenieACS
    if (!devices.length && serial.startsWith('RCMG')) {
      try {
        q = JSON.stringify({ '_tags': serial })
        r = await nbiRequest(`/devices/?query=${encodeURIComponent(q)}&projection=${projection}`)
        devices = Array.isArray(r.data) ? r.data : []
        if (!devices.length) {
          q = JSON.stringify({ 'InternetGatewayDevice.X_CT-COM_UserInfo.UserName._value': serial })
          r = await nbiRequest(`/devices/?query=${encodeURIComponent(q)}&projection=${projection}`)
          devices = Array.isArray(r.data) ? r.data : []
        }
        if (devices.length) log(`Device ${serial} found via RCMG tag/UserName`)
      } catch (e) { log(`RCMG lookup failed for ${serial}: ${e.message}`) }
    }

    if (!devices.length) {
      q = JSON.stringify({ '_id': { '$regex': serial } })
      r = await nbiRequest(`/devices/?query=${encodeURIComponent(q)}&projection=${projection}`)
      devices = Array.isArray(r.data) ? r.data : []
    }

    if (devices.length) {
      const s = summarizeDevice(devices[0])
      if (s.serial) {
        cacheDevice(s)
        if (s.serial !== serial) aliasSerial(serial, s.serial)
      }
      log(`Device ${serial} found via ACS search → ${devices[0]._id}`)
      return s
    }
  } catch (e) { log(`ACS search error for ${serial}: ${e.message}`) }

  log(`Device ${serial} not found in ACS`)
  return null
}

function startPoller (intervalMs = 300000) {
  initCacheDb().then(() => {
    setTimeout(async () => {
      try { await pollOnlineStatus() } catch (e) { log('Initial poll error:', e.message, e.stack) }
      pollerTimer = setInterval(async () => {
        try { await pollOnlineStatus() } catch (e) { log('Poll error:', e.message) }
      }, intervalMs)
    }, 5000)
  }).catch(e => log('Cache DB init failed:', e.message))
  log(`Device cache poller scheduled every ${intervalMs / 1000}s (online status only, details on-demand)`)
}

function stopPoller () { if (pollerTimer) { clearInterval(pollerTimer); pollerTimer = null } }

const handleHosts = createHostsHandler({ nbiRequest, json, deviceCache, cacheHosts, getCachedHosts })

function findSerialByDeviceId (deviceId) {
  for (const [s, entry] of deviceCache) {
    if (entry.summary?._id === deviceId) return s
  }
  return null
}

async function handle (req, res, method, path, url) {
  if (!cfg.GENIEACS_NBI_URL) return json(res, 503, { error: 'GenieACS NBI not configured' })

  try {
    const parts = path.replace('/devices', '').split('/').filter(Boolean)

    if (parts[0] === 'cache-stats' && method === 'GET') return json(res, 200, getCacheStats())

    if (parts[0] === 'events' && method === 'GET') {
      const serial = url.searchParams.get('serial')
      if (!serial) return json(res, 400, { error: 'Provide serial parameter' })
      return json(res, 200, await getDeviceEvents(serial, Math.min(parseInt(url.searchParams.get('limit') || '50', 10), 200)))
    }

    if (parts[0] === 'poll' && method === 'POST') {
      pollOnlineStatus().then(() => log('Manual poll completed')).catch(e => log('Manual poll error:', e.message))
      return json(res, 200, { ok: true, message: 'Poll triggered' })
    }

    if (parts[0] === 'summary' && method === 'GET') {
      const fiveMinAgo = new Date(Date.now() - 5 * 60 * 1000).toISOString()
      const result = await nbiRequest('/devices/?projection=DeviceID,_lastInform,_tags&limit=10000')
      const devices = Array.isArray(result.data) ? result.data : []
      const stats = { total: devices.length, online: 0, offline: 0, models: {} }
      for (const d of devices) {
        const model = d.DeviceID?.ProductClass?._value || 'Unknown'
        const isOnline = d._lastInform && new Date(d._lastInform).toISOString() > fiveMinAgo
        isOnline ? stats.online++ : stats.offline++
        if (!stats.models[model]) stats.models[model] = { total: 0, online: 0 }
        stats.models[model].total++
        if (isOnline) stats.models[model].online++
      }
      return json(res, 200, stats)
    }

    if (parts[0] === 'lookup' && method === 'GET') {
      const serial = url.searchParams.get('serial'), mac = url.searchParams.get('mac')
      const forceRefresh = url.searchParams.get('refresh') === '1'
      if (!serial && !mac) return json(res, 400, { error: 'Provide serial or mac parameter' })

      if (serial && !forceRefresh) {
        const cached = getCacheEntry(serial)
        if (cached?.summary && cached.summary.wifi !== undefined) return json(res, 200, [cached.summary])
        for (const [, entry] of deviceCache) {
          if (entry.summary?._id && entry.summary.wifi !== undefined) {
            const s = entry.summary
            if (s._id?.includes(serial) || s.mac === serial) return json(res, 200, [s])
          }
        }
      }

      const projection = 'DeviceID,InternetGatewayDevice,Device,_lastInform,_lastBootstrap,_registered,_tags'
      let devices = []

      if (serial) {
        let q = JSON.stringify({ 'DeviceID.SerialNumber._value': serial })
        let r = await nbiRequest(`/devices/?query=${encodeURIComponent(q)}&projection=${projection}`)
        devices = Array.isArray(r.data) ? r.data : []

        if (!devices.length && serial.startsWith('TPLG')) {
          q = JSON.stringify({ 'Device.Optical.Interface.1.GponAuth.GponSn._value': { '$regex': serial.slice(4).toUpperCase() + '$' } })
          r = await nbiRequest(`/devices/?query=${encodeURIComponent(q)}&projection=${projection}`)
          devices = Array.isArray(r.data) ? r.data : []
        }
        if (!devices.length) {
          q = JSON.stringify({ '_id': { '$regex': serial } })
          r = await nbiRequest(`/devices/?query=${encodeURIComponent(q)}&projection=${projection}`)
          devices = Array.isArray(r.data) ? r.data : []
        }
        // Raisecom RCMG → resolve via OLT coords (slot/port/ontid) → SNMP WAN IP → GenieACS
        if (!devices.length && serial.startsWith('RCMG')) {
          try {
            // 1. Try GenieACS tag match
            q = JSON.stringify({ '_tags': serial })
            r = await nbiRequest(`/devices/?query=${encodeURIComponent(q)}&projection=${projection}`)
            devices = Array.isArray(r.data) ? r.data : []
            if (devices.length) { log(`Lookup ${serial}: found via tag`); }

            // 2. Try GenieACS UserName field (older Raisecom firmware stores RCMG here)
            if (!devices.length) {
              q = JSON.stringify({ 'InternetGatewayDevice.X_CT-COM_UserInfo.UserName._value': serial })
              r = await nbiRequest(`/devices/?query=${encodeURIComponent(q)}&projection=${projection}`)
              devices = Array.isArray(r.data) ? r.data : []
              if (devices.length) log(`Lookup ${serial}: found via UserName`)
            }

            // 3. Resolve current WAN IP via OLT SNMP coords → search GenieACS by IP
            if (!devices.length) {
              const oltIp = url.searchParams.get('olt_ip')
              const slot = url.searchParams.get('olt_slot')
              const port = url.searchParams.get('olt_port')
              const ontid = url.searchParams.get('olt_ontid')
              if (oltIp && slot && port && ontid) {
                const { getManageIp } = require('./olt-snmp')
                const mgmt = await getManageIp(null, { oltIp, slot: parseInt(slot), port: parseInt(port), ontId: parseInt(ontid) })
                if (mgmt?.manageIp) {
                  q = JSON.stringify({ 'InternetGatewayDevice.WANDevice.1.WANConnectionDevice.1.WANIPConnection.1.ExternalIPAddress._value': mgmt.manageIp })
                  r = await nbiRequest(`/devices/?query=${encodeURIComponent(q)}&projection=${projection}`)
                  devices = Array.isArray(r.data) ? r.data : []
                  if (devices.length) log(`Lookup ${serial}: found via OLT SNMP ${oltIp} ${slot}/${port}/${ontid} → IP ${mgmt.manageIp}`)
                }
              }
            }
          } catch (e) { log(`RCMG lookup error for ${serial}: ${e.message}`) }
        }
      } else if (mac) {
        const cleanMac = mac.replace(/[:-]/g, '').toUpperCase()
        const q = JSON.stringify({ '$or': [
          { 'InternetGatewayDevice.WANDevice.1.WANEthernetInterfaceConfig.MACAddress._value': mac },
          { 'Device.Ethernet.Interface.1.MACAddress._value': mac },
          { 'Device.DeviceInfo.X_TP_MACAddress._value': { '$regex': cleanMac.slice(-6) } },
        ]})
        const r = await nbiRequest(`/devices/?query=${encodeURIComponent(q)}&projection=${projection}`)
        devices = Array.isArray(r.data) ? r.data : []
      }

      const summaries = devices.map(summarizeDevice)
      summaries.forEach(s => {
        cacheDevice(s)
        if (serial && s.serial && s.serial !== serial) deviceCache.set(serial, deviceCache.get(s.serial))
      })
      return json(res, 200, summaries)
    }

    if (parts[0] === 'cache' && method === 'GET') {
      const serial = url.searchParams.get('serial')
      if (serial) {
        const cached = getCached(serial)
        if (!cached) return json(res, 404, { error: 'Not in cache' })
        return json(res, 200, { serial, summary: cached.summary, previous: cached.previous, updatedAt: cached.updatedAt, history: cached.history })
      }
      return json(res, 200, getCacheStats())
    }

    if (parts[0] === 'faults' && parts.length === 1 && method === 'GET') {
      const r = await nbiRequest('/faults/')
      return json(res, r.status, r.data)
    }

    if (!parts.length && method === 'GET') {
      const limit = url.searchParams.get('limit') || '50', skip = url.searchParams.get('skip') || '0'
      const query = url.searchParams.get('query') || ''
      const projection = url.searchParams.get('projection') || 'DeviceID,_lastInform,_tags'
      const sort = url.searchParams.get('sort') || '{"_lastInform":-1}'
      let nbiPath = `/devices/?projection=${encodeURIComponent(projection)}&limit=${limit}&skip=${skip}&sort=${encodeURIComponent(sort)}`
      if (query) nbiPath += `&query=${encodeURIComponent(query)}`
      const result = await nbiRequest(nbiPath)
      const devices = Array.isArray(result.data) ? result.data : []
      if (projection === 'DeviceID,_lastInform,_tags') {
        return json(res, 200, devices.map(d => ({
          _id: d._id, serial: d.DeviceID?.SerialNumber?._value || '',
          manufacturer: d.DeviceID?.Manufacturer?._value || '', model: d.DeviceID?.ProductClass?._value || '',
          oui: d.DeviceID?.OUI?._value || '', lastInform: d._lastInform || null, tags: d._tags || [],
        })))
      }
      return json(res, 200, devices.map(summarizeDevice))
    }

    const deviceId = decodeURIComponent(parts[0])
    const sub = parts[1] || null

    if (!sub && method === 'GET') {
      const r = await nbiRequest(`/devices/?query=${encodeURIComponent(`_id = "${deviceId}"`)}&projection=DeviceID,InternetGatewayDevice,Device,_lastInform,_lastBootstrap,_registered,_tags`)
      const devs = Array.isArray(r.data) ? r.data : []
      if (!devs.length) return json(res, 404, { error: 'Device not found' })
      return json(res, 200, summarizeDevice(devs[0]))
    }

    if (sub === 'tasks' && method === 'POST') {
      const body = await parseBody(req)
      const connReq = url.searchParams.get('connection_request') !== null
      let p = `/devices/${encodeURIComponent(deviceId)}/tasks`
      if (connReq) p += '?connection_request'
      const timeout = url.searchParams.get('timeout')
      if (timeout) p += (connReq ? '&' : '?') + `timeout=${timeout}`
      const r = await nbiRequest(p, 'POST', body)
      return json(res, r.status, r.data)
    }

    if (sub === 'tasks' && method === 'GET') {
      const r = await nbiRequest(`/tasks/?query=${encodeURIComponent(`device = "${deviceId}"`)}`)
      return json(res, r.status, r.data)
    }

    if (sub === 'hosts' && method === 'GET') {
      if (!url.searchParams.has('refresh')) {
        const serial = findSerialByDeviceId(deviceId)
        if (serial) {
          const cached = getCachedHosts(serial)
          if (cached?.data) return json(res, 200, cached.data)
        }
      }
      return handleHosts(res, deviceId)
    }

    if (sub === 'faults' && method === 'GET') {
      const r = await nbiRequest(`/faults/?query=${encodeURIComponent(`device = "${deviceId}"`)}`)
      return json(res, r.status, r.data)
    }

    if (sub === 'events' && method === 'GET') {
      const serial = findSerialByDeviceId(deviceId)
      if (!serial) return json(res, 404, { error: 'Device not found in cache' })
      return json(res, 200, await getDeviceEvents(serial, Math.min(parseInt(url.searchParams.get('limit') || '50', 10), 200)))
    }

    if (sub === 'tasks' && parts[2] && method === 'DELETE') {
      const r = await nbiRequest(`/tasks/${parts[2]}`, 'DELETE')
      return json(res, r.status, r.data)
    }

    if (!sub && method === 'DELETE') {
      const r = await nbiRequest(`/devices/${encodeURIComponent(deviceId)}`, 'DELETE')
      return json(res, r.status, r.data)
    }

    return json(res, 400, { error: 'Unknown device endpoint' })
  } catch (e) {
    log('GenieACS error:', e.message)
    return json(res, 502, { error: 'GenieACS NBI error: ' + e.message })
  }
}

async function handleACSConfig (req, res, method, path) {
  if (!cfg.GENIEACS_NBI_URL) return json(res, 503, { error: 'GenieACS NBI not configured' })
  try {
    const resource = path.replace('/acs/', '').split('/').filter(Boolean)[0]
    const endpoints = { provisions: '/provisions/', presets: '/presets/', 'virtual-parameters': '/virtual-parameters/', files: '/files/', faults: '/faults/' }

    if (resource === 'export' && method === 'GET') {
      const [provisions, presets, virtualParams, files, faults] = await Promise.all(
        ['/provisions/', '/presets/', '/virtual-parameters/', '/files/', '/faults/'].map(p => nbiRequest(p).then(r => r.data).catch(() => []))
      )
      const arr = v => Array.isArray(v) ? v : []
      return json(res, 200, {
        exportedAt: new Date().toISOString(), source: cfg.GENIEACS_NBI_URL,
        provisions: arr(provisions), presets: arr(presets), virtualParameters: arr(virtualParams),
        files: arr(files).map(f => ({ _id: f._id, metadata: f.metadata || {}, filename: f.filename, length: f.length, uploadDate: f.uploadDate })),
        faultCount: arr(faults).length,
        summary: { provisionCount: arr(provisions).length, presetCount: arr(presets).length, virtualParamCount: arr(virtualParams).length, fileCount: arr(files).length },
      })
    }

    if (endpoints[resource] && method === 'GET') {
      const parts = path.replace('/acs/', '').split('/').filter(Boolean)
      const nbiPath = parts[1] ? endpoints[resource] + encodeURIComponent(decodeURIComponent(parts[1])) : endpoints[resource]
      const r = await nbiRequest(nbiPath)
      return json(res, r.status, r.data)
    }

    return json(res, 404, { error: 'Unknown ACS config endpoint' })
  } catch (e) {
    log('ACS config error:', e.message)
    return json(res, 502, { error: 'GenieACS config error: ' + e.message })
  }
}

module.exports = { handle, handleACSConfig, summarizeDevice, cacheDevice, getCached, getCacheStats, fetchDeviceDetails, startPoller, stopPoller, logDeviceEvent, getDeviceEvents }