const path = require('path')
const config = require('../config.js')
const fs = require('fs')
const gm = require('gm')
const ffmpeg = require('fluent-ffmpeg')
const db = require('knex')(config.database)

const units = ['B', 'kB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB']

const utilsController = {}
utilsController.imageExtensions = ['.webp', '.jpg', '.jpeg', '.bmp', '.gif', '.png']
utilsController.videoExtensions = ['.webm', '.mp4', '.wmv', '.avi', '.mov', '.mkv']

utilsController.getPrettyDate = date => {
  return date.getFullYear() + '-' +
    (date.getMonth() + 1) + '-' +
    date.getDate() + ' ' +
    (date.getHours() < 10 ? '0' : '') +
    date.getHours() + ':' +
    (date.getMinutes() < 10 ? '0' : '') +
    date.getMinutes() + ':' +
    (date.getSeconds() < 10 ? '0' : '') +
    date.getSeconds()
}

utilsController.getPrettyBytes = num => {
  // MIT License
  // Copyright (c) Sindre Sorhus <sindresorhus@gmail.com> (sindresorhus.com)
  if (!Number.isFinite(num)) { return num }

  const neg = num < 0
  if (neg) { num = -num }
  if (num < 1) { return (neg ? '-' : '') + num + ' B' }

  const exponent = Math.min(Math.floor(Math.log10(num) / 3), units.length - 1)
  const numStr = Number((num / Math.pow(1000, exponent)).toPrecision(3))
  const unit = units[exponent]

  return (neg ? '-' : '') + numStr + ' ' + unit
}

utilsController.authorize = async (req, res) => {
  const token = req.headers.token
  if (token === undefined) {
    res.status(401).json({ success: false, description: 'No token provided.' })
    return
  }

  const user = await db.table('users').where('token', token).first()
  if (user) { return user }
  res.status(401).json({ success: false, description: 'Invalid token.' })
}

utilsController.generateThumbs = (file, basedomain) => {
  const ext = path.extname(file.name).toLowerCase()
  const isVideoExt = utilsController.videoExtensions.includes(ext)
  const isImageExt = utilsController.imageExtensions.includes(ext)

  if ((!isVideoExt && !isImageExt) ||
    (isVideoExt && config.uploads.generateThumbnails.video !== true) ||
    (isImageExt && config.uploads.generateThumbnails.image !== true)) {
    return
  }

  let thumbname = path.join(__dirname, '..', config.uploads.folder, 'thumbs', file.name.slice(0, -ext.length) + '.png')
  fs.access(thumbname, error => {
    if (error && error.code === 'ENOENT') {
      if (isVideoExt) {
        ffmpeg(path.join(__dirname, '..', config.uploads.folder, file.name))
          .thumbnail({
            timestamps: ['1%'],
            filename: '%b.png',
            folder: path.join(__dirname, '..', config.uploads.folder, 'thumbs'),
            size: '200x?'
          })
          .on('error', error => console.log('Error - ', error.message))
      } else if (isImageExt) {
        let size = {
          width: 200,
          height: 200
        }
        gm(path.join(__dirname, '..', config.uploads.folder, file.name))
          .resize(size.width, size.height + '>')
          .gravity('Center')
          .extent(size.width, size.height)
          .background('transparent')
          .write(thumbname, error => {
            if (error) { console.log('Error - ', error) }
          })
      }
    }
  })
}

utilsController.deleteFile = async file => {
  const ext = path.extname(file).toLowerCase()
  return new Promise((resolve, reject) => {
    fs.stat(path.join(__dirname, '..', config.uploads.folder, file), (error, stats) => {
      if (error) { return reject(error) }
      fs.unlink(path.join(__dirname, '..', config.uploads.folder, file), error => {
        if (error) { return reject(error) }
        if (!utilsController.imageExtensions.includes(ext) && !utilsController.videoExtensions.includes(ext)) {
          return resolve()
        }
        file = file.substr(0, file.lastIndexOf('.')) + '.png'
        fs.stat(path.join(__dirname, '..', config.uploads.folder, 'thumbs/', file), (error, stats) => {
          if (error) {
            if (error.code !== 'ENOENT') {
              console.log(error)
            }
            return resolve()
          }
          fs.unlink(path.join(__dirname, '..', config.uploads.folder, 'thumbs/', file), error => {
            if (error) { return reject(error) }
            return resolve()
          })
        })
      })
    })
  })
}

// This will return an array of IDs that could not be deleted
utilsController.bulkDeleteFilesByIds = async (ids, user) => {
  if (!user) { return }
  const files = await db.table('files')
    .whereIn('id', ids)
    .where(function () {
      if (user.username !== 'root') {
        this.where('userid', user.id)
      }
    })

  const failedIds = ids.filter(id => !files.find(file => file.id === id))

  // First, we delete all the physical files
  await Promise.all(files.map(file => {
    return utilsController.deleteFile(file.name).catch(error => {
      // ENOENT is missing file, for whatever reason, then just delete from db anyways
      if (error.code !== 'ENOENT') {
        console.log(error)
        failedIds.push(file.id)
      }
    })
  }))

  // Second, we filter out failed IDs
  const albumIds = []
  const updateDbIds = files.filter(file => !failedIds.includes(file.id))
  await Promise.all(updateDbIds.map(file => {
    return db.table('files')
      .where('id', file.id)
      .del()
      .then(() => {
        if (file.albumid && !albumIds.includes(file.albumid)) {
          albumIds.push(file.albumid)
        }
      })
      .catch(error => {
        console.error(error)
        failedIds.push(file.id)
      })
  }))

  // Third, we update albums, if necessary
  await Promise.all(albumIds.map(albumid => {
    return db.table('albums')
      .where('id', albumid)
      .update('editedAt', Math.floor(Date.now() / 1000))
  }))

  return failedIds
}

module.exports = utilsController