import m from 'mithril'
import render from './lib/mithril-node-render'

import fetch from './fetch'
import { tidyOptions, youtubeKey } from './constants'

import isNode from 'detect-node'

let tidy
if (!isNode) {
  tidy = require('exports?tidy_html5!tidy-html5')
} else {
  tidy = require('tidy-html5').tidy_html5
}

export function cleanMarkup (html) {
  if (!html) {
    return Promise.resolve('')
  }

  return new Promise((resolve, reject) => {
    // fix center tags
    html = html.replace(/<center>/g, '<p style="text-align: center;">')
    html = html.replace(/<\/center>/g, '</p>')

    // replace HTML non-breaking spaces with normal spaces
    html = html.replace(/&nbsp;/g, ' ')

    html = fixParagraphIndent(html)

    html = fixDoubleSpacing(html)

    // Fix links pointing to pages on fimfiction
    // Example: <a href="/user/djazz" rel="nofollow">djazz</a>
    let matchLink = /(<a .?href=")(.+?)(".+?>)/g
    html = html.replace(matchLink, (match, head, url, tail) => {
      if (url.substring(0, 1) !== '#' && url.substring(0, 2) !== '//' && url.substring(0, 4) !== 'http') {
        if (url.substring(0, 1) === '/') {
          url = 'http://www.fimfiction.net' + url
        } else {
          // do something else
        }
      }

      return head + url + tail
    })

    let cache = new Map()
    let completeCount = 0

    function getYoutubeInfo (ids) {
      fetch('https://www.googleapis.com/youtube/v3/videos?id=' + ids + '&part=snippet&maxResults=50&key=' + youtubeKey).then((raw) => {
        let data
        try {
          data = JSON.parse(raw).items
        } catch (e) {

        }
        data.forEach((video) => {
          cache.set(video.id, video.snippet)
          completeCount++
        })
        if (completeCount === cache.size) {
          continueParsing()
        }
      })
    }

    let matchYoutube = /<div class="youtube_container">(.+?)<\/div>/g
    for (let ma; (ma = matchYoutube.exec(html));) {
      let youtubeId = ma[1].match(/src="https:\/\/www.youtube.com\/embed\/(.+?)"/)[1]
      cache.set(youtubeId, null)
    }

    if (cache.size === 0) {
      continueParsing()
    } else {
      getYoutubeInfo([...cache.keys()])
    }

    function continueParsing () {
      html = html.replace(matchYoutube, (match, contents) => {
        // console.log(match, contents)
        let youtubeId = contents.match(/src="https:\/\/www.youtube.com\/embed\/(.+?)"/)[1]
        let thumbnail = 'http://img.youtube.com/vi/' + youtubeId + '/hqdefault.jpg'
        let youtubeUrl = 'https://youtube.com/watch?v=' + youtubeId
        let title = 'Youtube Video'
        let caption = ''
        let data = cache.get(youtubeId)
        if (data) {
          thumbnail = (data.thumbnails.standard || data.thumbnails.high || data.thumbnails.medium || data.thumbnails.default).url
          title = data.title
          caption = data.title + ' on YouTube'
        }
        return render(m('figure.youtube', [
          m('a', {href: youtubeUrl},
            m('img', {src: thumbnail, alt: title})
          ),
          m('figcaption', m('a', {href: youtubeUrl}, caption))
        ]))
      })

      html = html.replace('<blockquote style="margin: 10px 0px; box-sizing:border-box; -moz-box-sizing:border-box;margin-right:25px; padding: 15px;background-color: #F7F7F7;border: 1px solid #AAA;width: 50%;float:left;box-shadow: 5px 5px 0px #EEE;">', '<blockquote class="left_insert">')
      html = html.replace('<blockquote style="margin: 10px 0px; box-sizing:border-box; -moz-box-sizing:border-box;margin-left:25px; padding: 15px;background-color: #F7F7F7;border: 1px solid #AAA;width: 50%;float:right;box-shadow: 5px 5px 0px #EEE;">', '<blockquote class="right_insert">')

      html = tidy(html, tidyOptions).trim()

      resolve(html)
    }
  })
}

export function fixDoubleSpacing (html) {
  // from FimFictionConverter by Nyerguds
  html = html.replace(/\s\s+/g, ' ')
  // push spaces to the closed side of tags
  html = html.replace(/\s+(<[a-z][^>]*>)\s+/g, ' $1')
  html = html.replace(/\s+(<\/[a-z][^>]*>)\s+/g, '$1 ')
  return html
}

export function fixParagraphIndent (html) {
  // from FimFictionConverter by Nyerguds
  let fixIndent = 2
  if (fixIndent > 0) {
    // only trigger indenting when finding as many whitespace characters in a row as indicated by the FixIndent setting.

    // Add indented class, with the search keeping into account that there could be opening tags behind the p tag.
    html = html.replace(new RegExp('<p>((<([^>]+)>)*)\\s{' + fixIndent + '}\\s*', 'g'), '<p class="indented">$1')
    html = html.replace(new RegExp('<p class="(((?!indented)[^>])*)">((<([^>]+)>)*)\\s{' + fixIndent + '}\\s*', 'g'), '<p class="indented $1">$3')

    // Cleanup of remaining start whitespace in already indented paragraphs:
    html = html.replace(/<p([^>]*)>((<[^>]+>)*)\\s+/g, '<p$1>$2')
  }
  return html
}