import { LegacyTweetRaw, TimelineMediaExtendedRaw } from './timeline-v1';
import { Photo, Video } from './tweets';
import { isFieldDefined, NonNullableField } from './type-util';

const reHashtag = /\B(\#\S+\b)/g;
const reCashtag = /\B(\$\S+\b)/g;
const reTwitterUrl = /https:(\/\/t\.co\/([A-Za-z0-9]|[A-Za-z]){10})/g;
const reUsername = /\B(\@\S{1,15}\b)/g;

export function parseMediaGroups(media: TimelineMediaExtendedRaw[]): {
  sensitiveContent?: boolean;
  photos: Photo[];
  videos: Video[];
} {
  const photos: Photo[] = [];
  const videos: Video[] = [];
  let sensitiveContent: boolean | undefined = undefined;

  for (const m of media
    .filter(isFieldDefined('id_str'))
    .filter(isFieldDefined('media_url_https'))) {
    if (m.type === 'photo') {
      photos.push({
        id: m.id_str,
        url: m.media_url_https,
        alt_text: m.ext_alt_text,
      });
    } else if (m.type === 'video') {
      videos.push(parseVideo(m));
    }

    const sensitive = m.ext_sensitive_media_warning;
    if (sensitive != null) {
      sensitiveContent =
        sensitive.adult_content ||
        sensitive.graphic_violence ||
        sensitive.other;
    }
  }

  return { sensitiveContent, photos, videos };
}

function parseVideo(
  m: NonNullableField<TimelineMediaExtendedRaw, 'id_str' | 'media_url_https'>,
): Video {
  const video: Video = {
    id: m.id_str,
    preview: m.media_url_https,
  };

  let maxBitrate = 0;
  const variants = m.video_info?.variants ?? [];
  for (const variant of variants) {
    const bitrate = variant.bitrate;
    if (bitrate != null && bitrate > maxBitrate && variant.url != null) {
      let variantUrl = variant.url;
      const stringStart = 0;
      const tagSuffixIdx = variantUrl.indexOf('?tag=10');
      if (tagSuffixIdx !== -1) {
        variantUrl = variantUrl.substring(stringStart, tagSuffixIdx + 1);
      }

      video.url = variantUrl;
      maxBitrate = bitrate;
    }
  }

  return video;
}

export function reconstructTweetHtml(
  tweet: LegacyTweetRaw,
  photos: Photo[],
  videos: Video[],
): string {
  const media: string[] = [];

  // HTML parsing with regex :)
  let html = tweet.full_text ?? '';

  html = html.replace(reHashtag, linkHashtagHtml);
  html = html.replace(reCashtag, linkCashtagHtml);
  html = html.replace(reUsername, linkUsernameHtml);
  html = html.replace(reTwitterUrl, unwrapTcoUrlHtml(tweet, media));

  for (const { url } of photos) {
    if (media.indexOf(url) !== -1) {
      continue;
    }

    html += `<br><img src="${url}"/>`;
  }

  for (const { preview: url } of videos) {
    if (media.indexOf(url) !== -1) {
      continue;
    }

    html += `<br><img src="${url}"/>`;
  }

  html = html.replace(/\n/g, '<br>');

  return html;
}

function linkHashtagHtml(hashtag: string) {
  return `<a href="https://twitter.com/hashtag/${hashtag.replace(
    '#',
    '',
  )}">${hashtag}</a>`;
}

function linkCashtagHtml(cashtag: string) {
  return `<a href="https://twitter.com/search?q=%24${cashtag.replace(
    '$',
    '',
  )}">${cashtag}</a>`;
}

function linkUsernameHtml(username: string) {
  return `<a href="https://twitter.com/${username.replace(
    '@',
    '',
  )}">${username}</a>`;
}

function unwrapTcoUrlHtml(tweet: LegacyTweetRaw, foundedMedia: string[]) {
  return function (tco: string) {
    for (const entity of tweet.entities?.urls ?? []) {
      if (tco === entity.url && entity.expanded_url != null) {
        return `<a href="${entity.expanded_url}">${tco}</a>`;
      }
    }

    for (const entity of tweet.extended_entities?.media ?? []) {
      if (tco === entity.url && entity.media_url_https != null) {
        foundedMedia.push(entity.media_url_https);
        return `<br><a href="${tco}"><img src="${entity.media_url_https}"/></a>`;
      }
    }

    return tco;
  };
}