'use strict'
const cfg = require('./config')
const { log, json, parseBody } = require('./helpers')
const erp = require('./erp')

// Prefer bearer token (revocable, no password in env); fall back to Basic auth for legacy.
const authHeader = cfg.TRACCAR_TOKEN
  ? 'Bearer ' + cfg.TRACCAR_TOKEN
  : 'Basic ' + Buffer.from(cfg.TRACCAR_USER + ':' + cfg.TRACCAR_PASS).toString('base64')

async function traccarFetch (path) {
  const res = await fetch(cfg.TRACCAR_URL + path, {
    headers: { Authorization: authHeader, Accept: 'application/json' },
  })
  if (!res.ok) throw new Error(`Traccar ${res.status}: ${path}`)
  return res.json()
}

// Variante RAW (texte) — pour GPX/KML (Accept différent, pas de parse JSON).
async function traccarRaw (path, accept) {
  const res = await fetch(cfg.TRACCAR_URL + path, { headers: { Authorization: authHeader, Accept: accept } })
  if (!res.ok) throw new Error(`Traccar ${res.status}: ${path}`)
  return res.text()
}

// Résout l'appareil Traccar depuis ?device= OU ?tech= (technician_id puis docname Dispatch Technician).
async function deviceFor (url) {
  let device = url.searchParams.get('device'); const tech = url.searchParams.get('tech')
  if (!device && tech) {
    let rows = await erp.list('Dispatch Technician', { filters: [['technician_id', '=', tech]], fields: ['traccar_device_id'], limit: 1 })
    if (!rows.length) rows = await erp.list('Dispatch Technician', { filters: [['name', '=', tech]], fields: ['traccar_device_id'], limit: 1 })
    device = rows.length ? rows[0].traccar_device_id : null
  }
  return device
}

// Cache devices for 60s (they rarely change)
let _devCache = null, _devCacheTs = 0
async function getDevices () {
  if (_devCache && Date.now() - _devCacheTs < 60000) return _devCache
  _devCache = await traccarFetch('/api/devices?all=true')
  _devCacheTs = Date.now()
  return _devCache
}

async function getPositions (deviceIds) {
  if (!deviceIds?.length) return []
  const results = await Promise.allSettled(
    deviceIds.map(id => traccarFetch('/api/positions?deviceId=' + id))
  )
  return results.flatMap(r => r.status === 'fulfilled' ? r.value : [])
}

async function handle (req, res, method, path) {
  const sub = path.replace('/traccar', '').replace(/^\//, '')

  if (sub === 'devices' && method === 'GET') {
    try {
      return json(res, 200, await getDevices())
    } catch (e) {
      log('Traccar devices error:', e.message)
      return json(res, 502, { error: 'Traccar unavailable' })
    }
  }

  if (sub === 'positions' && method === 'GET') {
    try {
      const url = new URL(req.url, 'http://localhost')
      const ids = (url.searchParams.get('deviceIds') || '').split(',').map(Number).filter(Boolean)
      return json(res, 200, await getPositions(ids))
    } catch (e) {
      log('Traccar positions error:', e.message)
      return json(res, 502, { error: 'Traccar unavailable' })
    }
  }

  // Export GPX du parcours d'un tech sur une fenêtre (jour courant) — résout le device depuis Dispatch Technician.
  if (sub === 'gpx' && method === 'GET') {
    try {
      const url = new URL(req.url, 'http://localhost')
      const device = await deviceFor(url)
      if (!device) return json(res, 404, { error: 'Aucun appareil GPS associé à ce technicien' })
      const from = url.searchParams.get('from'); const to = url.searchParams.get('to')
      if (!from || !to) return json(res, 400, { error: 'from + to (ISO 8601) requis' })
      const gpx = await traccarRaw(`/api/positions?deviceId=${encodeURIComponent(device)}&from=${encodeURIComponent(from)}&to=${encodeURIComponent(to)}`, 'application/gpx+xml')
      res.writeHead(200, { 'Content-Type': 'application/gpx+xml; charset=utf-8', 'Content-Disposition': `attachment; filename="parcours-${device}-${String(from).slice(0, 10)}.gpx"` })
      return res.end(gpx)
    } catch (e) { log('Traccar gpx error:', e.message); return json(res, 502, { error: 'Traccar GPX indisponible' }) }
  }

  // Tracé GPS (breadcrumb) d'un tech sur UNE journée → coords [lon,lat] (JSON léger) pour superposer sur la carte.
  // IMPORTANT : exiger une plage EXACTE (1 jour) — sinon Traccar renvoie un volume énorme et lent.
  if (sub === 'track' && method === 'GET') {
    try {
      const url = new URL(req.url, 'http://localhost')
      const device = await deviceFor(url)
      if (!device) return json(res, 404, { error: 'Aucun appareil GPS associé à ce technicien' })
      const from = url.searchParams.get('from'); const to = url.searchParams.get('to')
      if (!from || !to) return json(res, 400, { error: 'from + to (ISO 8601) requis' })
      const pts = await traccarFetch(`/api/positions?deviceId=${encodeURIComponent(device)}&from=${encodeURIComponent(from)}&to=${encodeURIComponent(to)}`)
      const coords = (Array.isArray(pts) ? pts : []).filter(p => p.latitude != null && p.longitude != null).map(p => [p.longitude, p.latitude])
      return json(res, 200, { device, count: coords.length, coords })
    } catch (e) { log('Traccar track error:', e.message); return json(res, 502, { error: 'Traccar track indisponible' }) }
  }

  // Proxy any other Traccar API path (fallback)
  if (method === 'GET') {
    try {
      return json(res, 200, await traccarFetch('/api/' + sub))
    } catch (e) {
      return json(res, 502, { error: e.message })
    }
  }

  json(res, 404, { error: 'Traccar endpoint not found' })
}

module.exports = { handle, getDevices, getPositions }