import path from 'node:path'
import { fileURLToPath } from 'node:url'
import express from 'express'
import { leadSchema, type LeadResponse } from '../../shared/lead.ts'
import { AmoClient, AmoError } from './amocrm.ts'
import { readAmoConfig, serverConfig } from './config.ts'
import { LeadService } from './lead-service.ts'
import { createRateLimiter } from './rate-limit.ts'

const rootDir = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '../..')
const clientDir = path.join(rootDir, 'dist/client')

const amoConfig = readAmoConfig()
const leadService = amoConfig ? new LeadService(new AmoClient(amoConfig)) : null

if (!leadService) {
  console.warn(
    '[amo] AMO_SUBDOMAIN / AMO_LONG_LIVED_TOKEN are not set — the site runs, but /api/leads/* will return 503.',
  )
}

const app = express()
// 'loopback', not true: only the local nginx hop is trusted, so req.ip is the
// address nginx actually observed and the rate limiter below cannot be
// side-stepped with a forged X-Forwarded-For header.
app.set('trust proxy', 'loopback')
app.use(express.json({ limit: '64kb' }))

const limiter = createRateLimiter({ limit: 8, windowMs: 10 * 60 * 1000 })

app.get('/api/health', (_req, res) => {
  res.json({ ok: true, amo: Boolean(leadService), pipelineId: amoConfig?.pipelineId ?? null })
})

app.post('/api/leads/hotels', async (req, res) => {
  const send = (status: number, body: LeadResponse) => res.status(status).json(body)

  const parsed = leadSchema.safeParse(req.body)
  if (!parsed.success) {
    const fields: Record<string, string> = {}
    for (const issue of parsed.error.issues) {
      const key = issue.path.join('.')
      if (key && !fields[key]) fields[key] = issue.message
    }
    return send(400, { ok: false, error: 'Проверьте заполненные поля.', fields })
  }

  const payload = parsed.data

  // Honeypot: answer exactly like a success so bots learn nothing.
  if (payload.website) {
    console.info('[lead] honeypot triggered from %s', req.ip)
    return send(200, { ok: true, leadId: 0, contactId: 0 })
  }

  const { allowed, retryAfterSeconds } = limiter(req.ip ?? 'unknown')
  if (!allowed) {
    res.setHeader('Retry-After', String(retryAfterSeconds))
    return send(429, { ok: false, error: 'Слишком много заявок с этого адреса. Попробуйте позже.' })
  }

  if (!leadService) {
    // Never drop a real lead silently — it must be findable in the logs.
    console.error('[lead] amoCRM is not configured. Lead payload:', JSON.stringify(payload))
    return send(503, { ok: false, error: 'Форма временно недоступна. Позвоните нам: +7 939 717-80-80.' })
  }

  try {
    const result = await leadService.submit(payload)
    console.info(
      '[lead] amoCRM lead %d (contact %d, %s)',
      result.leadId,
      result.contactId,
      result.contactCreated ? 'new contact' : 'existing contact',
    )
    return send(200, { ok: true, leadId: result.leadId, contactId: result.contactId })
  } catch (error) {
    console.error('[lead] amoCRM submission failed:', error)
    console.error('[lead] payload was:', JSON.stringify(payload))
    const message =
      error instanceof AmoError && error.status === 401
        ? 'CRM отклонила запрос. Мы уже разбираемся — позвоните нам: +7 939 717-80-80.'
        : 'Не удалось отправить заявку. Позвоните нам: +7 939 717-80-80.'
    return send(502, { ok: false, error: message })
  }
})

if (serverConfig.isProduction) {
  app.use(
    express.static(clientDir, {
      index: false,
      setHeaders(res, filePath) {
        // Vite fingerprints everything under /assets, so it can be cached hard.
        if (filePath.includes(`${path.sep}assets${path.sep}`)) {
          res.setHeader('Cache-Control', 'public, max-age=31536000, immutable')
        }
      },
    }),
  )

  // SPA fallback. Written as middleware because Express 5 no longer accepts a
  // bare '*' route pattern.
  app.use((req, res, next) => {
    if (req.method !== 'GET' || req.path.startsWith('/api/')) return next()
    res.sendFile(path.join(clientDir, 'index.html'))
  })
}

app.listen(serverConfig.port, serverConfig.host, () => {
  console.info(
    '[server] listening on http://localhost:%d%s',
    serverConfig.port,
    serverConfig.isProduction ? ` (serving ${path.relative(rootDir, clientDir)})` : ' (API only — run vite for the UI)',
  )
})