import { Router } from 'express'
import { config } from '../config.js'
import {
  parsePortalSession,
  requireAdminSession,
  setPortalSession,
} from '../middleware/session.js'
import {
  createDocument,
  getDocument,
  listDocuments,
  updateDocument,
  Query,
  ID,
} from '../services/appwriteAdmin.js'
import { getCustomerActivity } from '../services/customerActivity.js'
import { listInvoicesForClient } from '../services/invoiceNinja.js'
import { sanitizeMessage } from './chat.js'

const router = Router()

router.use(requireAdminSession)

function norm(value) {
  return String(value || '').toLowerCase()
}

function isDeployed(project) {
  return ['ready', 'deployed'].includes(norm(project.provisioningStatus || project.status))
}

function customerNameMap(customers) {
  const map = {}
  for (const c of customers) map[c.$id] = c.name || c.code || c.$id
  return map
}

// ---------------------------------------------------------------- Übersicht --
router.get('/overview', async (_req, res) => {
  try {
    const [projects, customers, access] = await Promise.all([
      listDocuments(config.collections.websiteProjects, [Query.limit(500)]),
      listDocuments(config.collections.customers, [Query.limit(500)]),
      listDocuments(config.collections.customerPortalAccess, [Query.limit(500)]),
    ])
    const nameById = customerNameMap(customers)

    const stageOf = (c) => {
      const s = norm(c.customerStatus)
      if (s === 'lead') return 'lead'
      if (s === 'lost') return 'lost'
      return 'customer'
    }

    const recentLogins = access
      .filter((a) => a.lastLoginAt)
      .sort((a, b) => String(b.lastLoginAt).localeCompare(String(a.lastLoginAt)))
      .slice(0, 5)
      .map((a) => ({
        customerName: nameById[a.customerId] || a.customerId,
        lastLoginAt: a.lastLoginAt,
      }))

    const recentProjects = [...projects]
      .sort((a, b) =>
        String(b.updatedAt || b.$updatedAt || '').localeCompare(String(a.updatedAt || a.$updatedAt || ''))
      )
      .slice(0, 5)
      .map((p) => ({
        projectName: p.projectName || p.subdomain || p.repoFullName || '',
        subdomain: p.subdomain || '',
        status: p.status || '',
        customerName: p.customerId ? nameById[p.customerId] || '' : '',
        updatedAt: p.updatedAt || p.$updatedAt || '',
      }))

    return res.json({
      projects: {
        total: projects.length,
        deployed: projects.filter(isDeployed).length,
        withoutWebsite: projects.filter((p) => !p.subdomain).length,
        assigned: projects.filter((p) => p.customerId).length,
      },
      customers: {
        total: customers.length,
        leads: customers.filter((c) => stageOf(c) === 'lead').length,
        fixed: customers.filter((c) => stageOf(c) === 'customer').length,
        portalEnabled: customers.filter((c) => c.portalAccessEnabled).length,
      },
      recentLogins,
      recentProjects,
    })
  } catch (err) {
    return res.status(500).json({ error: err.message || 'Übersicht konnte nicht geladen werden' })
  }
})

// ------------------------------------------------------------- Projektsuche --
router.get('/projects', async (req, res) => {
  const search = norm(req.query.search)
  try {
    const [projects, customers] = await Promise.all([
      listDocuments(config.collections.websiteProjects, [Query.limit(500)]),
      listDocuments(config.collections.customers, [Query.limit(500)]),
    ])
    const nameById = customerNameMap(customers)

    let items = projects.map((p) => ({
      id: p.$id,
      projectName: p.projectName || '',
      subdomain: p.subdomain || '',
      previewUrl: p.previewUrl || '',
      liveDomain: p.liveDomain || '',
      status: p.status || '',
      provisioningStatus: p.provisioningStatus || '',
      projectType: p.projectType || (p.subdomain ? 'website' : 'repo'),
      giteaRepoUrl: p.giteaRepoUrl || '',
      repoFullName: p.repoFullName || '',
      customerId: p.customerId || '',
      customerName: p.customerId ? nameById[p.customerId] || p.customerId : '',
      updatedAt: p.updatedAt || p.$updatedAt || '',
    }))

    if (search) {
      items = items.filter((p) =>
        [p.projectName, p.subdomain, p.repoFullName, p.customerName, p.status].some((v) =>
          norm(v).includes(search)
        )
      )
    }

    items.sort((a, b) => String(b.updatedAt).localeCompare(String(a.updatedAt)))
    return res.json({ projects: items })
  } catch (err) {
    return res.status(500).json({ error: err.message || 'Projekte konnten nicht geladen werden' })
  }
})

// -------------------------------------------------------------- Kundenliste --
router.get('/customers', async (req, res) => {
  const search = norm(req.query.search)
  try {
    const [customers, access, projects] = await Promise.all([
      listDocuments(config.collections.customers, [Query.orderAsc('name'), Query.limit(500)]),
      listDocuments(config.collections.customerPortalAccess, [Query.limit(500)]),
      listDocuments(config.collections.websiteProjects, [Query.limit(500)]),
    ])

    const lastLoginByCustomer = {}
    for (const a of access) {
      if (a.customerId && a.lastLoginAt) lastLoginByCustomer[a.customerId] = a.lastLoginAt
    }
    const projectCount = {}
    for (const p of projects) {
      if (p.customerId) projectCount[p.customerId] = (projectCount[p.customerId] || 0) + 1
    }

    let items = customers.map((c) => ({
      id: c.$id,
      code: c.code || '',
      name: c.name || '',
      email: c.email || '',
      phone: c.phone || '',
      location: c.location || '',
      customerStatus: c.customerStatus || '',
      portalAccessEnabled: Boolean(c.portalAccessEnabled),
      invoiceNinjaLinked: Boolean(c.invoiceNinjaClientId),
      lastLoginAt: lastLoginByCustomer[c.$id] || '',
      projectCount: projectCount[c.$id] || 0,
    }))

    if (search) {
      items = items.filter((c) =>
        [c.code, c.name, c.email, c.location].some((v) => norm(v).includes(search))
      )
    }

    return res.json({ customers: items })
  } catch (err) {
    return res.status(500).json({ error: err.message || 'Kunden konnten nicht geladen werden' })
  }
})

// ------------------------------------------- Kundennummer/Stammdaten pflegen --
router.patch('/customers/:customerId', async (req, res) => {
  const { code, location, phone } = req.body || {}
  const data = { updatedAt: new Date().toISOString() }
  if (code !== undefined) data.code = String(code).trim()
  if (location !== undefined) data.location = String(location).trim()
  if (phone !== undefined) data.phone = String(phone).trim()

  try {
    const updated = await updateDocument(config.collections.customers, req.params.customerId, data)
    return res.json({
      success: true,
      customer: { id: updated.$id, code: updated.code || '', name: updated.name || '' },
    })
  } catch (err) {
    const status = err.status || 500
    return res.status(status).json({ error: err.message || 'Kunde konnte nicht aktualisiert werden' })
  }
})

// -------------------------------------- Aktivität + Rechnungen eines Kunden --
router.get('/customers/:customerId/activity', async (req, res) => {
  try {
    const tickets = await getCustomerActivity(req.params.customerId, { ticketLimit: 50 })
    return res.json({ tickets })
  } catch (err) {
    return res.status(500).json({ error: err.message || 'Aktivität konnte nicht geladen werden' })
  }
})

router.get('/customers/:customerId/invoices', async (req, res) => {
  try {
    const customer = await getDocument(config.collections.customers, req.params.customerId)
    if (!customer.invoiceNinjaClientId) {
      return res.json({ linked: false, invoices: [] })
    }
    const invoices = await listInvoicesForClient(customer.invoiceNinjaClientId, { includeDrafts: true })
    return res.json({ linked: true, invoices })
  } catch (err) {
    const status = err.status || 500
    return res.status(status).json({ error: err.message || 'Rechnungen konnten nicht geladen werden' })
  }
})

// ------------------------------------------------------------------- Chat --
router.get('/chats', async (_req, res) => {
  try {
    const [messages, customers] = await Promise.all([
      listDocuments(config.collections.portalMessages, [
        Query.orderDesc('createdAt'),
        Query.limit(500),
      ]),
      listDocuments(config.collections.customers, [Query.limit(500)]),
    ])
    const nameById = customerNameMap(customers)

    const byCustomer = new Map()
    for (const msg of messages) {
      const entry = byCustomer.get(msg.customerId) || {
        customerId: msg.customerId,
        customerName: nameById[msg.customerId] || msg.customerId,
        lastText: msg.text || '',
        lastSender: msg.sender || '',
        lastAt: msg.createdAt || '',
        unreadFromCustomer: 0,
      }
      if (msg.sender === 'customer' && !msg.readByAdmin) entry.unreadFromCustomer += 1
      byCustomer.set(msg.customerId, entry)
    }

    const chats = [...byCustomer.values()].sort((a, b) =>
      String(b.lastAt).localeCompare(String(a.lastAt))
    )
    return res.json({ chats })
  } catch (err) {
    return res.status(500).json({ error: err.message || 'Chats konnten nicht geladen werden' })
  }
})

router.get('/chats/unread-count', async (_req, res) => {
  try {
    const docs = await listDocuments(config.collections.portalMessages, [
      Query.equal('readByAdmin', false),
      Query.equal('sender', 'customer'),
      Query.limit(100),
    ])
    return res.json({ unread: docs.length })
  } catch {
    return res.json({ unread: 0 })
  }
})

router.get('/chats/:customerId/messages', async (req, res) => {
  try {
    const queries = [
      Query.equal('customerId', req.params.customerId),
      Query.orderAsc('createdAt'),
      Query.limit(200),
    ]
    const since = String(req.query.since || '').trim()
    if (since) queries.push(Query.greaterThan('createdAt', since))

    const docs = await listDocuments(config.collections.portalMessages, queries)
    return res.json({ messages: docs.map(sanitizeMessage) })
  } catch (err) {
    return res.status(500).json({ error: err.message || 'Nachrichten konnten nicht geladen werden' })
  }
})

router.post('/chats/:customerId/messages', async (req, res) => {
  const text = String(req.body?.text || '').trim()
  if (!text || text.length > 2000) {
    return res.status(400).json({ error: 'Nachricht muss zwischen 1 und 2000 Zeichen lang sein.' })
  }

  try {
    const customer = await getDocument(config.collections.customers, req.params.customerId).catch(() => null)
    if (!customer) {
      return res.status(404).json({ error: 'Kunde nicht gefunden' })
    }

    const session = req.session
    const doc = await createDocument(
      config.collections.portalMessages,
      {
        customerId: customer.$id,
        sender: 'admin',
        senderName: session.adminName || session.name || 'Webklar-Team',
        text,
        readByAdmin: true,
        readByCustomer: false,
        createdAt: new Date().toISOString(),
      },
      ID.unique()
    )
    return res.status(201).json({ message: sanitizeMessage(doc) })
  } catch (err) {
    return res.status(500).json({ error: err.message || 'Nachricht konnte nicht gesendet werden' })
  }
})

router.post('/chats/:customerId/read', async (req, res) => {
  try {
    const docs = await listDocuments(config.collections.portalMessages, [
      Query.equal('customerId', req.params.customerId),
      Query.equal('readByAdmin', false),
      Query.equal('sender', 'customer'),
      Query.limit(100),
    ])
    for (const doc of docs) {
      await updateDocument(config.collections.portalMessages, doc.$id, { readByAdmin: true })
    }
    return res.json({ updated: docs.length })
  } catch (err) {
    return res.status(500).json({ error: err.message || 'Fehler beim Markieren' })
  }
})

// ------------------------------------------------------- Als Kunde ansehen --
router.post('/view-as/:customerId', async (req, res) => {
  try {
    const customer = await getDocument(config.collections.customers, req.params.customerId).catch(() => null)
    if (!customer) {
      return res.status(404).json({ error: 'Kunde nicht gefunden' })
    }

    const session = req.session
    setPortalSession(res, {
      role: 'admin',
      viewAs: true,
      appwriteUserId: session.appwriteUserId,
      adminName: session.adminName || session.name || 'Admin',
      adminEmail: session.adminEmail || session.email || '',
      customerId: customer.$id,
      name: customer.name || '',
      email: customer.email || '',
    })
    return res.json({ success: true, customer: { id: customer.$id, name: customer.name || '' } })
  } catch (err) {
    return res.status(500).json({ error: err.message || 'Ansicht konnte nicht gewechselt werden' })
  }
})

router.post('/exit-view-as', (req, res) => {
  const session = parsePortalSession(req) || req.session
  setPortalSession(res, {
    role: 'admin',
    appwriteUserId: session.appwriteUserId,
    name: session.adminName || session.name || 'Admin',
    email: session.adminEmail || session.email || '',
  })
  return res.json({ success: true })
})

export default router