import { Router } from 'express'
import { config } from '../config.js'
import {
  getCustomerByAppwriteUserId,
  getCustomerByEmail,
  getDocument,
  getPortalAccessByCustomerId,
  listDocuments,
  updateDocument,
  Query,
} from '../services/appwriteAdmin.js'
import { loginWithAppwrite, getLoginCooldownRemainingSec } from '../services/appwriteClient.js'
import {
  clearPortalSession,
  setPortalSession,
} from '../middleware/session.js'
import {
  PREVIEW_COOKIE_NAME,
  clearPreviewSession,
  createPreviewSessionToken,
  previewSessionCookieOptions,
  verifyPreviewSessionToken,
} from '../services/previewSession.js'
import { consumeStaffPreviewToken } from '../services/staffPreviewTokens.js'

const router = Router()

function sanitizeCustomer(customer) {
  return {
    id: customer.$id,
    code: customer.code || '',
    name: customer.name || '',
    companyName: customer.companyName || '',
    email: customer.email || '',
    phone: customer.phone || '',
    location: customer.location || '',
    customerStatus: customer.customerStatus || '',
    portalAccessEnabled: Boolean(customer.portalAccessEnabled),
  }
}

async function validatePortalAccess(appwriteUserId, email) {
  let customer = await getCustomerByAppwriteUserId(appwriteUserId)
  if (!customer && email) {
    customer = await getCustomerByEmail(email)
  }
  if (!customer) {
    const error = new Error(
      `Kein Kundenkonto für diesen Login gefunden. Im Ticketsystem customers.appwriteUserId auf "${appwriteUserId}" setzen (E-Mail: ${email}).`
    )
    error.status = 403
    throw error
  }

  if (!customer.portalAccessEnabled) {
    const error = new Error('Portalzugang ist nicht freigeschaltet.')
    error.status = 403
    throw error
  }

  const portalAccess = await getPortalAccessByCustomerId(customer.$id)
  if (!portalAccess || !portalAccess.enabled) {
    const error = new Error('Portalzugang ist deaktiviert.')
    error.status = 403
    throw error
  }

  const status = (customer.customerStatus || '').toLowerCase()
  if (!config.allowedCustomerStatuses.includes(status)) {
    const error = new Error('Kundenkonto ist nicht aktiv.')
    error.status = 403
    throw error
  }

  return { customer, portalAccess }
}

async function syncCustomerAppwriteUserId(customer, appwriteUserId) {
  if (!customer?.$id || !appwriteUserId) return customer
  if (customer.appwriteUserId === appwriteUserId) return customer

  const now = new Date().toISOString()
  return updateDocument(config.collections.customers, customer.$id, {
    appwriteUserId,
    portalAccessEnabled: true,
    updatedAt: now,
  })
}

async function resolveSessionCustomer(session) {
  if (!session?.customerId) return null

  let customer = await getDocument(config.collections.customers, session.customerId).catch(() => null)
  if (customer) return customer

  if (session.appwriteUserId) {
    customer = await getCustomerByAppwriteUserId(session.appwriteUserId)
    if (customer) return customer
  }

  if (session.email) {
    customer = await getCustomerByEmail(session.email)
  }

  return customer
}

function isPreviewProjectReady(project) {
  if (!project) return false
  if (project.hasPreview === false) return false
  const status = (project.provisioningStatus || project.status || '').toLowerCase()
  return ['ready', 'deployed'].includes(status)
}

function isAdminSession(session) {
  return session?.role === 'admin' || (session?.labels || []).includes('admin')
}

function safePreviewRedirectUrl(url) {
  try {
    const parsed = new URL(String(url || ''))
    if (
      parsed.hostname.endsWith('.project.webklar.com') ||
      parsed.hostname === 'project.webklar.com'
    ) {
      return parsed.toString()
    }
  } catch {
    /* ignore */
  }
  return null
}

router.get('/login-status', (_req, res) => {
  const retryAfterSeconds = getLoginCooldownRemainingSec()
  res.json({
    blocked: retryAfterSeconds > 0,
    retryAfterSeconds,
  })
})

router.post('/login', async (req, res) => {
  const { email, password } = req.body || {}
  if (!email || !password) {
    return res.status(400).json({ error: 'E-Mail und Passwort erforderlich' })
  }

  try {
    const user = await loginWithAppwrite(email.trim(), password)
    let { customer, portalAccess } = await validatePortalAccess(user.$id, email.trim())
    customer = await syncCustomerAppwriteUserId(customer, user.$id)

    setPortalSession(res, {
      customerId: customer.$id,
      appwriteUserId: user.$id,
      name: customer.name || user.name || '',
      email: customer.email || user.email || email,
    })

    const previewToken = await createPreviewSessionToken({
      userId: user.$id,
      customerId: customer.$id,
      email: customer.email || user.email || email,
      name: customer.name || user.name || '',
      role: 'customer',
      labels: [],
      authSource: 'kundenbereich',
    })
    res.cookie(PREVIEW_COOKIE_NAME, previewToken, previewSessionCookieOptions())

    try {
      await updateDocument(config.collections.customerPortalAccess, portalAccess.$id, {
        lastLoginAt: new Date().toISOString(),
      })
    } catch (err) {
      console.warn('[auth] lastLoginAt update failed:', err.message)
    }

    return res.json({ success: true, customer: sanitizeCustomer(customer) })
  } catch (err) {
    const status = err.status || 500
    if (status === 429) {
      return res.status(429).json({
        error:
          err.message ||
          'Zu viele Anmeldeversuche. Bitte warte einige Minuten, bevor du es erneut versuchst.',
        retryAfterSeconds: getLoginCooldownRemainingSec(),
      })
    }
    if (err?.message?.includes('not authorized')) {
      return res.status(500).json({
        error:
          'Server-Konfiguration: APPWRITE_API_KEY benötigt databases.read für woms-database (customers, customerPortalAccess).',
      })
    }
    return res.status(status).json({ error: err.message || 'Anmeldung fehlgeschlagen' })
  }
})

router.post('/logout', (_req, res) => {
  clearPortalSession(res)
  clearPreviewSession(res)
  res.json({ success: true })
})

router.get('/preview-access', async (req, res) => {
  const token = req.cookies?.[PREVIEW_COOKIE_NAME]
  if (!token) {
    return res.status(401).json({ allowed: false })
  }

  const session = await verifyPreviewSessionToken(token)
  const admin = isAdminSession(session)
  if (!session || (!session.customerId && !admin)) {
    return res.status(401).json({ allowed: false })
  }

  const subdomain = String(req.query.subdomain || '')
    .trim()
    .toLowerCase()
  if (!subdomain) {
    return res.status(400).json({ allowed: false, error: 'subdomain required' })
  }

  try {
    const queries = [Query.equal('subdomain', subdomain), Query.limit(1)]
    if (!admin) {
      queries.splice(1, 0, Query.equal('customerId', session.customerId))
    }

    const projects = await listDocuments(config.collections.websiteProjects, queries)
    const project = projects[0]
    if (!project) {
      return res.json({ allowed: false, reason: 'no_project' })
    }
    if (!isPreviewProjectReady(project)) {
      return res.json({ allowed: false, reason: 'not_ready', projectId: project.$id })
    }
    return res.json({ allowed: true, projectId: project.$id })
  } catch (err) {
    return res.status(500).json({ allowed: false, error: err.message || 'Fehler' })
  }
})

router.get('/staff-preview', async (req, res) => {
  const tokenValue = String(req.query.token || '').trim()
  if (!tokenValue) {
    return res.status(400).send('Token fehlt')
  }

  const tokenData = consumeStaffPreviewToken(tokenValue)
  if (!tokenData) {
    return res.status(410).send('Der Preview-Link ist abgelaufen. Bitte erneut aus dem Ticketsystem oeffnen.')
  }

  const previewUrl = safePreviewRedirectUrl(tokenData.previewUrl)
  if (!previewUrl) {
    return res.status(400).send('Ungueltige Preview-URL')
  }

  const previewToken = await createPreviewSessionToken({
    userId: tokenData.userId,
    customerId: tokenData.customerId || '',
    email: tokenData.email || '',
    name: tokenData.name || 'Admin',
    role: 'admin',
    labels: ['admin'],
    authSource: 'ticket-admin',
  })
  res.cookie(PREVIEW_COOKIE_NAME, previewToken, previewSessionCookieOptions())
  return res.redirect(previewUrl)
})

router.get('/me', async (req, res) => {
  const raw = req.signedCookies?.[config.cookieName]
  if (!raw) {
    return res.json({ authenticated: false })
  }

  try {
    const session = JSON.parse(raw)
    if (!session.customerId || !session.appwriteUserId) {
      return res.json({ authenticated: false })
    }

    let customer = await resolveSessionCustomer(session)
    if (!customer) {
      clearPortalSession(res)
      clearPreviewSession(res)
      return res.json({ authenticated: false })
    }

    try {
      await validatePortalAccess(session.appwriteUserId, session.email || customer.email)
    } catch {
      clearPortalSession(res)
      clearPreviewSession(res)
      return res.json({ authenticated: false })
    }

    if (customer.appwriteUserId !== session.appwriteUserId) {
      customer = await syncCustomerAppwriteUserId(customer, session.appwriteUserId)
    }

    return res.json({
      authenticated: true,
      customer: sanitizeCustomer(customer),
    })
  } catch (err) {
    return res.status(500).json({ error: err.message || 'Fehler beim Laden' })
  }
})

export default router