// TODO: add comments, I'm lazy :sleeping:

const
  bsync  = require('browser-sync'),
  GitLab = require('gitlab/dist/es5').default,
  df     = require('date-format'),
  fs     = require('fs'),
  klaw   = require('klaw-sync'),
  path   = require('path')

const
  gulp      = require('gulp'),
  pug       = require('gulp-pug'),
  sass      = require('gulp-sass'),
  stylelint = require('gulp-stylelint')

const { avgTime, freqUsers, labelsAlphabet } = require('./statistics')

const output = path.join(__dirname, 'public')

gulp.task('download', () => {
  const year =  new Date().getFullYear().toString()
  const month = months[new Date().getMonth()]
  const openedPath = path.join(__dirname, 'data', year, month, 'Opened')
  const closedPath = path.join(__dirname, 'data', year, month, 'Closed')

  checkPaths()

  const config = require('./config.json')
  const api = new GitLab({ token: config.token })

  api.Projects
    .show('tildes/tildes')
    .then((project) => {
      api.Issues
        .all({
          projectId: project.id
        })
        .then((issues) => {
          for (const issue of issues) {
            if (new Date(issue.created_at).getMonth() === new Date().getMonth()) {
              fs.writeFileSync(path.join(openedPath, issue.iid.toString()) + '.json', JSON.stringify(issue, null, 2))
            }
            if (new Date(issue.closed_at).getMonth() === new Date().getMonth()) {
              fs.writeFileSync(path.join(closedPath, issue.iid.toString()) + '.json', JSON.stringify(issue, null, 2))
            }
          }
        })
        .then(() => { console.log('Finished downloading, creating table and statistics.') })
        .then(createTable)
        .then(createStatistics)
    })
})

gulp.task('no-download', () => {
  createTable()
  createStatistics()
})

gulp.task('build', ['lint:sass'], () => {
  gulp
    .src('src/*.pug')
    .pipe(pug())
    .pipe(gulp.dest(output))

  gulp
    .src('src/posts/*.pug')
    .pipe(pug())
    .pipe(gulp.dest(output + '/posts'))

  gulp
    .src('src/sass/*.sass')
    .pipe(sass({ outputStyle: 'compressed' }))
    .pipe(gulp.dest(output + '/css'))

  gulp
    .src('src/favicons/**')
    .pipe(gulp.dest(output))
})

gulp.task('watch', () => {
  bsync.init({ server: output })
  gulp.watch('src/**', ['build']).on('change', bsync.reload)
})

gulp.task('lint:sass', () => {
  gulp
    .src('src/**/*.sass')
    .pipe(stylelint({ reporters: [{formatter: 'string', console: true}] }))
})

const months = [
  'January',
  'February',
  'March',
  'April',
  'May',
  'June',
  'July',
  'August',
  'September',
  'October',
  'November',
  'December'
]

function createTable() {
  const year =  new Date().getFullYear().toString()
  const month = months[new Date().getMonth()]
  const openedPath = path.join(__dirname, 'data', year, month, 'Opened')
  const closedPath = path.join(__dirname, 'data', year, month, 'Closed')

  checkPaths()

  let opened = klaw(openedPath)
  let closed = klaw(closedPath)

  opened.sort(function(a, b) {
    const aFile = require(a.path)
    const bFile = require(b.path)
    return (aFile.iid > bFile.iid) ? 1 : ((bFile.iid > aFile.iid) ? -1 : 0)
  })

  closed.sort(function(a, b) {
    const aFile = require(a.path)
    const bFile = require(b.path)
    return (aFile.iid > bFile.iid) ? 1 : ((bFile.iid > aFile.iid) ? -1 : 0)
  })

  let table = 'article(id="issue-table")\n'
  table += '  h2 Issue Table\n'

  table += '  h3(id="opened") Opened\n'
  table += '  table\n'
  table += '    thead\n'
  table += '      tr\n'
  table += '        td Issue\n'
  table += '        td Title\n'
  table += '        td Author\n'
  table += '        td Opened\n'
  table += '        td Closed\n'
  table += '    tbody\n'

  for (const file of opened) {
    const issue = require(file.path)
    table += '      tr\n'
    table += `        td: a(href="${issue.web_url}") ${issue.iid}\n`

    let title
    if (issue.title.length >= 50) {
      title = issue.title.substring(0, 47) + '...'
    } else {
      title = issue.title
    }

    table += `        td ${title}\n`
    table += `        td: a(href="${issue.author.web_url}") ${issue.author.username}\n`
    table += `        td ${df.asString('yyyy/MM/dd hh:mm:ss', new Date(issue.created_at))}\n`

    let closedAt
    if (issue.closed_at === null) {
      closedAt = ''
    } else {
      closedAt = df.asString('yyyy/MM/dd hh:mm:ss', new Date(issue.closed_at))
    }

    table += `        td ${closedAt}\n`
  }

  table += '\n  h3(id="closed") Closed\n'
  table += '  table\n'
  table += '    thead\n'
  table += '      tr\n'
  table += '        td Issue\n'
  table += '        td Title\n'
  table += '        td Author\n'
  table += '        td Opened\n'
  table += '        td Closed\n'
  table += '    tbody\n'

  for (const file of closed) {
    const issue = require(file.path)
    table += '      tr\n'
    table += `        td: a(href="${issue.web_url}") ${issue.iid}\n`

    let title
    if (issue.title.length >= 50) {
      title = issue.title.substring(0, 47) + '...'
    } else {
      title = issue.title
    }

    table += `        td ${title}\n`
    table += `        td: a(href="${issue.author.web_url}") ${issue.author.username}\n`
    table += `        td ${df.asString('yyyy/MM/dd hh:mm:ss', new Date(issue.created_at))}\n`

    let closedAt
    if (issue.closed_at === null) {
      closedAt = ''
    } else {
      closedAt = df.asString('yyyy/MM/dd hh:mm:ss', new Date(issue.closed_at))
    }

    table += `        td ${closedAt}\n`
  }

  table = table.replace('<', '')
  table = table.replace('>', '')
  fs.writeFileSync(path.join(__dirname, 'data', year, month, 'table.pug'), table, {encoding: 'UTF-8'})
}

function createStatistics() {
  const year =  new Date().getFullYear().toString()
  const month = months[new Date().getMonth()]
  const openedPath = path.join(__dirname, 'data', year, month, 'Opened')
  const closedPath = path.join(__dirname, 'data', year, month, 'Closed')

  checkPaths()

  let opened = klaw(openedPath)
  let closed = klaw(closedPath)

  let statistics = 'article(id="statistics")\n'
  statistics += '  h2 Statistics\n'

  statistics += `  p In the month of ${month} `
  statistics += `${opened.length} issues were opened and `
  statistics += `${closed.length} issues were closed.\n`

  statistics += `  p An average of ${(opened.length / 30).toFixed(2)} issues were opened `
  statistics += `and ${(closed.length / 30).toFixed(2)} issues were closed each day.\n`

  statistics += `  p The average time to close issues was ${avgTime(closed, 'days')} days `
  statistics += `or ${avgTime(closed, 'hours')} hours.\n`

  const topUsers = freqUsers(opened, 3)
  statistics += '  p Top 3 issue creators:\n'
  statistics += '  ol\n'
  for (const user in topUsers) {
    statistics += '    li\n'
    statistics += `      a(href="https://gitlab.com/${user}") ${user}\n`
    statistics += '      |\n'
    statistics += '      | with\n'
    statistics += '      |\n'
    statistics += `      a(href="https://gitlab.com/tildes/tildes/issues?state=all&author_username=${user}") ${topUsers[user]} issues created\n`
    statistics += '      | .\n'
  }

  let labels = labelsAlphabet(opened, true)
  statistics += '  p Amount of labels assigned to currently open issues:\n'
  statistics += '  ul\n'
  for (const label in labels) {
    statistics += '    li\n'
    statistics += `      a(href="https://gitlab.com/tildes/tildes/issues?state=opened&label_name%5B%5D=${label.replace(' ', '+')}") ${label}\n`
    statistics += '      | :\n'
    statistics += `      | ${labels[label]} `
    if (labels[label] === 1) statistics += 'time.\n'
    else statistics += 'times.\n'
  }

  labels = labelsAlphabet(closed, false)
  statistics += '  p Amount of labels assigned to closed issues:\n'
  statistics += '  ul\n'
  for (const label in labels) {
    statistics += '    li\n'
    statistics += `      a(href="https://gitlab.com/tildes/tildes/issues?state=closed&label_name%5B%5D=${label.replace(' ', '+')}") ${label}\n`
    statistics += '      | :\n'
    statistics += `      | ${labels[label]} `
    if (labels[label] === 1) statistics += 'time.\n'
    else statistics += 'times.\n'
  }

  fs.writeFileSync(path.join(__dirname, 'data', year, month, 'statistics.pug'), statistics, {encoding: 'UTF-8'})
}

// Checking if all the directories exist and creating them if not
// There's probably a better way to do this, like "mkdir -p <path>"
// TODO: rework checkPaths()
function checkPaths() {
  const year =  new Date().getFullYear().toString()
  const month = months[new Date().getMonth()]
  const openedPath = path.join(__dirname, 'data', year, month, 'Opened')
  const closedPath = path.join(__dirname, 'data', year, month, 'Closed')
  if (!fs.existsSync(path.join(__dirname, 'data'))) fs.mkdirSync(path.join(__dirname, 'data'))
  if (!fs.existsSync(path.join(__dirname, 'data', year))) fs.mkdirSync(path.join(__dirname, 'data', year))
  if (!fs.existsSync(path.join(__dirname, 'data', year, month))) fs.mkdirSync(path.join(__dirname, 'data', year, month))
  if (!fs.existsSync(openedPath)) fs.mkdirSync(openedPath)
  if (!fs.existsSync(closedPath)) fs.mkdirSync(closedPath)
}