const crypto = require('crypto')
const express = require('express')
const QRCode = require('qrcode')
const db = require('../lib/db')
const passwords = require('../lib/passwords')
const { uploader } = require('../lib/upload')
const { adminAuth } = require('../lib/auth')
const { uid, token, ok, fail, wrap, str } = require('../lib/http')
const { activityPayload, setPinned } = require('../lib/serialize')

const router = express.Router()
const auth = adminAuth()

router.post('/login', (req, res) => {
  const username = str(req.body && req.body.username)
  const password = String((req.body && req.body.password) || '')
  const session = db.update((data) => {
    const admin = data.admins.find((item) => item.username === username)
    if (!admin || !passwords.verify(password, admin.password)) return null
    admin.token = token()
    return { token: admin.token, username: admin.username }
  })
  if (!session) return fail(res, 401, '账号或密码错误')
  ok(res, session)
})

router.post('/password', auth, (req, res) => {
  const oldPassword = String((req.body && req.body.oldPassword) || '')
  const nextPassword = String((req.body && req.body.newPassword) || '')
  if (nextPassword.length < 6) return fail(res, 400, '新密码至少 6 位')
  if (!passwords.verify(oldPassword, req.admin.password)) return fail(res, 400, '原密码不正确')
  db.update(() => {
    req.admin.password = passwords.hash(nextPassword)
    req.admin.token = ''
  })
  ok(res, { relogin: true })
})

router.get('/stats', auth, (req, res) => {
  const data = db.read()
  const byActivity = data.activities.map((activity) => {
    const rows = data.signups.filter((item) => item.activityId === activity.id)
    return {
      id: activity.id,
      title: activity.title,
      signups: rows.length,
      checkins: rows.filter((item) => item.checkedIn).length
    }
  })
  const sharerMap = {}
  data.signups.forEach((item) => {
    const key = item.sourceSharer || '直接访问'
    sharerMap[key] = (sharerMap[key] || 0) + 1
  })
  ok(res, {
    activityCount: data.activities.length,
    signupCount: data.signups.length,
    checkinCount: data.signups.filter((item) => item.checkedIn).length,
    byActivity,
    bySharer: Object.keys(sharerMap).map((sharer) => ({ sharer, count: sharerMap[sharer] }))
  })
})

router.get('/users', auth, (req, res) => {
  const data = db.read()
  ok(
    res,
    data.users.map((user) => ({
      openid: user.openid,
      nickName: user.nickName || '',
      name: user.name || '',
      phone: user.phone || '',
      allowed: data.adminAllowlist.includes(user.openid),
      createdAt: user.createdAt || ''
    }))
  )
})

router.get('/allowlist', auth, (req, res) => {
  ok(res, db.read().adminAllowlist)
})

router.post('/allowlist', auth, (req, res) => {
  const openid = str(req.body && req.body.openid)
  if (!openid) return fail(res, 400, '缺少 openid')
  ok(
    res,
    db.update((data) => {
      if (!data.adminAllowlist.includes(openid)) data.adminAllowlist.push(openid)
      return data.adminAllowlist
    })
  )
})

router.delete('/allowlist/:openid', auth, (req, res) => {
  const openid = req.params.openid
  ok(
    res,
    db.update((data) => {
      data.adminAllowlist = data.adminAllowlist.filter((item) => item !== openid)
      return data.adminAllowlist
    })
  )
})

function clearOtherCurrent(data, keepId) {
  data.activities.forEach((item) => {
    if (item.id !== keepId) item.isCurrent = false
  })
}

router.get('/activities', auth, (req, res) => {
  ok(res, db.read().activities)
})

router.post('/activities', auth, (req, res) => {
  const created = db.update((data) => {
    const payload = activityPayload(req.body || {}, null, data)
    if (!payload.title) return null
    if (payload.isCurrent) clearOtherCurrent(data, payload.id)
    data.activities.push(payload)
    return payload
  })
  if (!created) return fail(res, 400, '请填写活动名称')
  ok(res, created)
})

router.put('/activities/:id', auth, (req, res) => {
  const result = db.update((data) => {
    const index = data.activities.findIndex((item) => item.id === req.params.id)
    if (index < 0) return { status: 404, error: '活动不存在' }
    const payload = activityPayload(req.body || {}, data.activities[index], data)
    if (!payload.title) return { status: 400, error: '请填写活动名称' }
    if (payload.isCurrent) clearOtherCurrent(data, payload.id)
    data.activities[index] = payload
    return { activity: payload }
  })
  if (result.error) return fail(res, result.status, result.error)
  ok(res, result.activity)
})

router.post('/activities/:id/pin', auth, (req, res) => {
  const result = db.update((data) => {
    const activity = data.activities.find((item) => item.id === req.params.id)
    if (!activity) return { status: 404, error: '活动不存在' }
    if (activity.status !== 'past') return { status: 400, error: '只能置顶往期活动' }
    return { activity: setPinned(activity, !!(req.body && req.body.pinned)) }
  })
  if (result.error) return fail(res, result.status, result.error)
  ok(res, result.activity)
})

router.delete('/activities/:id', auth, (req, res) => {
  const removed = db.update((data) => {
    if (!data.activities.some((item) => item.id === req.params.id)) return false
    data.activities = data.activities.filter((item) => item.id !== req.params.id)
    data.posters = data.posters.filter((item) => item.activityId !== req.params.id)
    data.checkinCodes = data.checkinCodes.filter((item) => item.activityId !== req.params.id)
    return true
  })
  if (!removed) return fail(res, 404, '活动不存在')
  ok(res, { id: req.params.id })
})

router.get('/posters', auth, (req, res) => {
  ok(res, db.read().posters)
})

router.post('/posters', auth, (req, res) => {
  const body = req.body || {}
  if (!body.activityId) return fail(res, 400, '请选择活动')
  const poster = {
    id: uid('m'),
    activityId: str(body.activityId),
    image: str(body.image),
    title: str(body.title, 60),
    enabled: body.enabled !== false,
    sort: Number(body.sort) || 0,
    createdAt: new Date().toISOString()
  }
  db.update((data) => data.posters.push(poster))
  ok(res, poster)
})

router.put('/posters/:id', auth, (req, res) => {
  const body = req.body || {}
  const updated = db.update((data) => {
    const poster = data.posters.find((item) => item.id === req.params.id)
    if (!poster) return null
    if (body.activityId != null) poster.activityId = str(body.activityId)
    if (body.image != null) poster.image = str(body.image)
    if (body.title != null) poster.title = str(body.title, 60)
    if (body.enabled != null) poster.enabled = !!body.enabled
    if (body.sort != null) poster.sort = Number(body.sort) || 0
    return poster
  })
  if (!updated) return fail(res, 404, '海报不存在')
  ok(res, updated)
})

router.delete('/posters/:id', auth, (req, res) => {
  const removed = db.update((data) => {
    const before = data.posters.length
    data.posters = data.posters.filter((item) => item.id !== req.params.id)
    return data.posters.length !== before
  })
  if (!removed) return fail(res, 404, '海报不存在')
  ok(res, { id: req.params.id })
})

router.post('/upload-file', auth, uploader())

function signupRows(activityId) {
  const rows = db.read().signups
  return activityId ? rows.filter((item) => item.activityId === activityId) : rows
}

router.get('/signups', auth, (req, res) => {
  ok(res, signupRows(str(req.query.activityId)))
})

function csvCell(value) {
  const text = value == null ? '' : String(value)
  // Prefix formula-leading cells so spreadsheets don't execute them.
  const safe = /^[=+\-@]/.test(text) ? `'${text}` : text
  return /[",\n\r]/.test(safe) ? `"${safe.replace(/"/g, '""')}"` : safe
}

router.get('/signups/export', adminAuth({ allowQueryToken: true }), (req, res) => {
  const header = ['姓名', '手机号', '公司', '活动', '分享人', '报名时间', '是否签到', '签到时间']
  const lines = [header.join(',')]
  signupRows(str(req.query.activityId)).forEach((item) => {
    lines.push(
      [
        item.name,
        item.phone,
        item.company,
        item.activityTitle,
        item.sourceSharer,
        item.createdAt,
        item.checkedIn ? '是' : '否',
        item.checkedInAt
      ]
        .map(csvCell)
        .join(',')
    )
  })
  res.setHeader('Content-Type', 'text/csv; charset=utf-8')
  res.setHeader('Content-Disposition', 'attachment; filename="signups.csv"')
  res.send(`\uFEFF${lines.join('\n')}`)
})

router.delete('/signups/:id', auth, (req, res) => {
  const removed = db.update((data) => {
    const before = data.signups.length
    data.signups = data.signups.filter((item) => item.id !== req.params.id)
    return data.signups.length !== before
  })
  if (!removed) return fail(res, 404, '报名不存在')
  ok(res, { id: req.params.id })
})

function withQr(code, width) {
  return QRCode.toDataURL(code.token, { width, margin: 1 }).then((qrDataUrl) =>
    Object.assign({}, code, { qrDataUrl })
  )
}

router.get(
  '/checkin-codes',
  auth,
  wrap(async (req, res) => {
    ok(res, await Promise.all(db.read().checkinCodes.map((code) => withQr(code, 280))))
  })
)

router.post(
  '/checkin-codes',
  auth,
  wrap(async (req, res) => {
    const activityId = str(req.body && req.body.activityId)
    const hours = Math.min(Math.max(Number(req.body && req.body.ttlHours) || 12, 1), 24 * 30)
    if (!db.read().activities.some((item) => item.id === activityId)) return fail(res, 404, '活动不存在')
    const code = {
      id: uid('c'),
      activityId,
      token: crypto.randomBytes(16).toString('hex'),
      createdAt: new Date().toISOString(),
      expiresAt: new Date(Date.now() + hours * 3600 * 1000).toISOString()
    }
    db.update((data) => data.checkinCodes.push(code))
    ok(res, await withQr(code, 360))
  })
)

module.exports = router