/* ----------------------------------------------------------------------------

 Question Server
 GitLab: <https://gitlab.com/MrFry/mrfrys-node-server>

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program. If not, see <https://www.gnu.org/licenses/>.

 ------------------------------------------------------------------------- */

const express = require('express')
const bodyParser = require('body-parser')
const busboy = require('connect-busboy')
const cookieParser = require('cookie-parser')
const uuidv4 = require('uuid/v4') // TODO: deprecated, but imports are not supported
const fs = require('fs')
const app = express()

// const http = require('http')
// const https = require('https')

const logger = require('../../utils/logger.js')
const utils = require('../../utils/utils.js')
const actions = require('../../utils/actions.js')
const dbtools = require('../../utils/dbtools.js')
const auth = require('../../middlewares/auth.middleware.js')

const recivedFiles = 'public/recivedfiles'
const uloadFiles = 'public/f'
const dataFile = 'public/data.json'
const msgFile = 'stats/msgs'
const motdFile = 'public/motd'
const versionFile = 'public/version'
const passwordFile = 'data/dataEditorPasswords.json'
const dataEditsLog = 'stats/dataEdits'
const dailyDataCountFile = 'stats/dailyDataCount'
const usersDBPath = 'data/dbs/users.db'

if (!utils.FileExists(usersDBPath)) {
  throw new Error('No user DB exists yet! please run utils/dbSetup.js first!')
}
const authDB = dbtools.GetDB(usersDBPath)

const cookieSecret = uuidv4()
app.use(cookieParser(cookieSecret))
app.use(bodyParser.urlencoded({
  limit: '10mb',
  extended: true
}))
app.use(bodyParser.json({
  limit: '10mb'
}))
app.set('view engine', 'ejs')
app.set('views', [
  './modules/api/views',
  './sharedViews'
])
app.use(auth({
  authDB: authDB,
  jsonResponse: true
}))
app.use(express.static('public'))
app.use(busboy({
  limits: {
    fileSize: 50000 * 1024 * 1024
  }
}))

var data = actions.LoadJSON(dataFile)
var version = ''
var motd = ''

function LoadVersion () {
  version = utils.ReadFile(versionFile)
}

function LoadMOTD () {
  motd = utils.ReadFile(motdFile)
}

function Load () {
  utils.WatchFile(motdFile, (newData) => {
    logger.Log(`Motd changed: ${newData.replace(/\/n/g, '')}`)
    LoadMOTD()
  })
  utils.WatchFile(versionFile, (newData) => {
    logger.Log(`Version changed: ${newData.replace(/\/n/g, '')}`)
    LoadVersion()
  })

  LoadVersion()
  LoadMOTD()
}

Load()

// -------------------------------------------------------------

app.post('/login', (req, res) => {
  logger.LogReq(req)
  const pw = req.body.pw
  const ip = req.headers['cf-connecting-ip'] || req.connection.remoteAddress
  const user = dbtools.Select(authDB, 'users', {
    pw: pw
  })[0]

  if (user) {
    const sessionID = uuidv4()

    // FIXME: Users now can only log in in one session, this might be too strict.
    const existingSessions = dbtools.Select(authDB, 'sessions', {
      userID: user.id
    })

    if (existingSessions.length > 0) {
      logger.Log(`Multiple sessions ( ${existingSessions.length} ) for #${user.id}, deleting olds`, logger.GetColor('cyan'))
      existingSessions.forEach((sess) => {
        dbtools.Delete(authDB, 'sessions', {
          id: sess.id
        })
      })
    }

    dbtools.Update(authDB, 'users', {
      loginCount: user.loginCount + 1,
      lastIP: ip,
      lastLogin: new Date().toString()
    }, {
      id: user.id
    })

    dbtools.Insert(authDB, 'sessions', {
      id: sessionID,
      ip: ip,
      userID: user.id,
      createDate: new Date().toString()
    })

    // TODO: cookie age
    res.cookie('sessionID', sessionID)

    res.json({
      result: 'success',
      sessionID: sessionID
    })

    logger.Log(`Successfull login with user ID: #${user.id}`, logger.GetColor('cyan'))
  } else {
    logger.Log(`Login attempt with invalid pw: ${pw}`, logger.GetColor('cyan'))
    res.json({
      msg: 'invalid pw'
    })
  }
})

app.post('/logout', (req, res) => {
  logger.LogReq(req)
  const sessionID = req.cookies.sessionID

  // removing session from db
  dbtools.Delete(authDB, 'sessions', {
    id: sessionID
  })
  // TODO: remove old sessions every once in a while
  res.clearCookie('sessionID').json({
    result: 'success'
  })
})

// --------------------------------------------------------------

app.get('/', function (req, res) {
  logger.LogReq(req)
  res.redirect('https://www.youtube.com/watch?v=ieqGJgqiXFk')
})

app.post('/postfeedbackfile', function (req, res) {
  UploadFile(req, res, uloadFiles, (fn) => {
    res.json({ success: true })
  })

  logger.LogReq(req)
  logger.Log('New feedback file', logger.GetColor('bluebg'), true)
})

app.post('/postfeedback', function (req, res) {
  logger.LogReq(req)
  logger.Log('New feedback message', logger.GetColor('bluebg'), true)
  utils.AppendToFile(logger.GetDateString() + ':\n' + JSON.stringify(req.body), msgFile)
  res.json({ success: true })
})

function UploadFile (req, res, path, next) {
  try {
    var fstream
    req.pipe(req.busboy)
    req.busboy.on('file', function (fieldname, file, filename) {
      logger.Log('Uploading: ' + filename, logger.GetColor('blue'))

      utils.CreatePath(path, true)
      let d = new Date()
      let fn = d.getHours() + '' + d.getMinutes() + '' + d.getSeconds() + '_' + filename

      fstream = fs.createWriteStream(path + '/' + fn)
      file.pipe(fstream)
      fstream.on('close', function () {
        logger.Log('Upload Finished of ' + path + '/' + fn, logger.GetColor('blue'))
        next(fn)
      })
      fstream.on('error', function (err) {
        console.log(err)
        res.end('something bad happened :s')
      })
    })
  } catch (e) {
    logger.Log(`Unable to upload file!`, logger.GetColor('redbg'))
    console.log(e)
  }
}

app.route('/fosuploader').post(function (req, res, next) {
  UploadFile(req, res, uloadFiles, (fn) => {
    res.redirect('/f/' + fn)
  })
})

app.route('/badtestsender').post(function (req, res, next) {
  UploadFile(req, res, recivedFiles, (fn) => {
    res.redirect('back')
  })
  logger.LogReq(req)
})

app.get('/allqr.txt', function (req, res) {
  res.set('Content-Type', 'text/plain')
  res.send(data.toString())
  res.end()
  logger.LogReq(req)
})

// -------------------------------------------------------------------------------------------
// API

app.post('/uploaddata', (req, res) => {
  // body: JSON.stringify({
  //   newData: data,
  //   count: getCount(data),
  //   initialCount: initialCount,
  //   password: password,
  //   editedQuestions: editedQuestions
  // })

  const { count, initialCount, editedQuestions, password, newData } = req.body
  const respStatuses = {
    invalidPass: 'invalidPass',
    ok: 'ok',
    error: 'error'
  }

  logger.LogReq(req)

  try {
    // finding user
    const pwds = JSON.parse(utils.ReadFile(passwordFile))
    let user = Object.keys(pwds).find((key) => {
      const u = pwds[key]
      return u.password === password
    })
    user = pwds[user]

    // logging and stuff
    logger.Log(`Data upload`, logger.GetColor('bluebg'))
    logger.Log(`PWD: ${password}`, logger.GetColor('bluebg'))
    // returning if user password is not ok
    if (!user) {
      logger.Log(`Data upload: invalid password ${password}`, logger.GetColor('red'))
      utils.AppendToFile(logger.GetDateString() + '\n' + password + '(FAILED PASSWORD)\n' + JSON.stringify(editedQuestions) + '\n\n', dataEditsLog)
      res.json({ status: respStatuses.invalidPass })
      return
    }

    logger.Log(`Password accepted for ${user.name}`, logger.GetColor('bluebg'))
    logger.Log(`Old Subjects/Questions: ${initialCount.subjectCount} / ${initialCount.questionCount} | New: ${count.subjectCount} / ${count.questionCount} | Edited question count: ${Object.keys(editedQuestions).length}`, logger.GetColor('bluebg'))
    // saving detailed editedCount
    utils.AppendToFile(logger.GetDateString() + '\n' + JSON.stringify(user) + '\n' + JSON.stringify(editedQuestions) + '\n\n', dataEditsLog)

    // making backup
    utils.CopyFile('./' + dataFile, `./public/backs/data_before_${user.name}_${new Date().toString().replace(/ /g, '_')}`)
    logger.Log('Backup made')
    // writing data
    utils.WriteFile(JSON.stringify(newData), dataFile)
    logger.Log('New data file written')
    // reloading data file
    data = actions.LoadJSON(dataFile)
    // data = newData
    logger.Log('Data set to newData')

    res.json({
      status: respStatuses.ok,
      user: user.name
    })
    logger.Log('Data updating done!', logger.GetColor('bluebg'))
  } catch (e) {
    logger.Log(`Data upload error! `, logger.GetColor('redbg'))
    console.error(e)
    res.json({ status: respStatuses.error, msg: e.message })
  }
})

app.post('/isAdding', function (req, res) {
  logger.LogReq(req)

  // automatically saves to dataFile every n write
  // FIXME: req.body.datatoadd is for backwards compatibility, remove this sometime in the future
  let result = actions.ProcessIncomingRequest(
    req.body.datatoadd || req.body,
    data,
    { motd, version }
  )

  res.json({
    success: result !== -1,
    newQuestions: result
  })
})

app.get('/ask', function (req, res) {
  if (Object.keys(req.query).length === 0) {
    logger.DebugLog(`No query params`, 'ask', 1)
    res.json({
      message: `ask something! ?q=[question]&subj=[subject]&data=[question data]. 'subj' is optimal for faster result`,
      result: [],
      recievedData: JSON.stringify(req.query),
      success: false
    })
  } else {
    if (req.query.q && req.query.data) {
      let subj = req.query.subj || ''
      let question = req.query.q
      let recData = {}
      try {
        recData = JSON.parse(req.query.data)
      } catch (e) {
        logger.Log(`Unable to parse recieved question data! '${req.query.data}'`, logger.GetColor('redbg'))
      }
      let r = data.Search(question, subj, recData)

      res.json({
        result: r,
        success: true
      })
      logger.DebugLog(`Question result length: ${r.length}`, 'ask', 1)
      logger.DebugLog(r, 'ask', 2)
    } else {
      logger.DebugLog(`Invalid question`, 'ask', 1)
      res.json({
        message: `Invalid question :(`,
        result: [],
        recievedData: JSON.stringify(req.query),
        success: false
      })
    }
  }
})

function getSimplreRes () {
  return {
    subjects: data.length,
    questions: data.Subjects.reduce((acc, subj) => {
      return acc + subj.length
    }, 0)
  }
}
function getDetailedRes () {
  return data.Subjects.map((subj) => {
    return {
      name: subj.Name,
      count: subj.length
    }
  })
}

app.get('/datacount', function (req, res) {
  logger.LogReq(req)
  if (req.query.detailed === 'all') {
    res.json({
      detailed: getDetailedRes(),
      simple: getSimplreRes()
    })
  } else if (req.query.detailed) {
    res.json(getDetailedRes())
  } else {
    res.json(getSimplreRes())
  }
})

app.get('/infos', function (req, res) {
  let result = {
    result: 'success'
  }
  if (req.query.subjinfo) {
    result.subjinfo = getSimplreRes()
  }
  if (req.query.version) {
    result.version = version
  }
  if (req.query.motd) {
    result.motd = motd
  }
  res.json(result)
})

// -------------------------------------------------------------------------------------------

app.get('*', function (req, res) {
  res.status(404).render('404')
})

app.post('*', function (req, res) {
  res.status(404).render('404')
})

exports.app = app
exports.dailyAction = () => {
  utils.AppendToFile(JSON.stringify({
    date: new Date(),
    subjectCount: data.Subjects.length,
    questionCOunt: data.Subjects.reduce((acc, subj) => {
      return acc + subj.Questions.length
    }, 0)
  }), dailyDataCountFile)
}

logger.Log('API module started', logger.GetColor('yellow'))