let tracks = [],
  headers = [],
  subtitleStream
const { SubtitleStream } = MatroskaSubtitles

function parseSubs(stream) {
  if (video.src.endsWith(".mkv")) {
    if (subtitleStream) {
      subtitleStream = new SubtitleStream(subtitleStream)
    } else {
      subtitleStream = new SubtitleStream()
      // subtitleStream.once('tracks', pTracks => {
      //   pTracks.forEach(track => {
      //     tracks[track.number] = video.addTextTrack('captions', track.type, track.language);
      //     parseHeader(track.header, track.number);
      //     let spacerCue = new VTTCue(0.1, 9999, " ")
      //     spacerCue.line = -1
      //     tracks[track.number].addCue(spacerCue)
      //   })
      //   if (video.textTracks[0]) {
      //     video.textTracks[0].mode = "showing"
      //     displayHeader(headers[3])
      //   }
      // })
    }
    subtitleStream.on('subtitle', function (subtitle, trackNumber) {
      // subConvt(subtitle, trackNumber)
      console.log(subtitle)
    })
    stream.pipe(subtitleStream)
  }
}
const re_newline = /\\N/g, // replace \N with newline
  re_softbreak = /\\n/g,   // There's no equivalent function in WebVTT.
  re_hardspace = /\\h/g,    // Replace with  
  re_style = /\{([^}]+)\}/, // replace style
  re_header_format = /(?<=\[V4\+? Styles\][\s\S]*Format: [^\n]*)(.+)/i,
  re_header_style = /(?<=\[V4\+? Styles\][\s\S]*Style: [^\n]*)(.+)/ig;
function subConvt(result, trackNumber) {
  let cue = new VTTCue(result.time / 1000, (result.time + result.duration) / 1000, ""),
    text = result.text,
    positioned
    result.style = result.style.replace(/\ /g, "")
  if (tracks[trackNumber].label == "ass") {
    // Support for special characters in WebVTT.
    // For obvious reasons, the ampersand one *must* be first.
    text = text.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
    let style, tagsToClose = []; // Places to stash style info.
    // Subtitles may contain any number of override tags, so we'll loop through
    // to find them all.
    while ((style = text.match(re_style))) {
      let tagsToOpen = [], replaceString = '';
      if (style[1] && style[1].split) { // Stop throwing errors on empty tags.
        style = style[1].split("\\"); // Get an array of override commands.
        for (let j = 1; j < style.length; j++) {
          // Extract the current tag name.
          if (style[j]) {
            let tagCommand = style[j].match(/[a-zA-Z]+/)[0]
            // Give special reckognition to one-letter tags.
            let oneLetter = (tagCommand.length == 1) ? tagCommand : "";
            // "New" position commands. It is assumed that bottom center position is the default.
            if (tagCommand === "an") {
              let posNum = Number(style[j].substring(2, 3))
              positioned = 1
              if (Math.floor((posNum - 1) / 3) == 1) {
                cue.line = 8;
              } else if (Math.floor((posNum - 1) / 3) == 2) {
                cue.line = 1;
              } else {
                cue.line = -1;
              }
              if (posNum % 3 == 1) {
                cue.align = "start";
              } else if (posNum % 3 == 0) {
                cue.align = "end";
              }
              // Legacy position commands.
            } else if (oneLetter === "a" && !Number.isNaN(Number(style[j].substring(1, 2)))) {
              let posNum = Number(style[j].substring(1, 2));
              positioned = 1
              if (posNum > 8) {
                cue.line = 8;
              } else if (posNum > 4) {
                cue.line = 1;
              } else {
                cue.line = -1;
              }
              if ((posNum - 1) % 4 == 0) {
                cue.align = "start";
              } else if ((posNum - 1) % 4 == 2) {
                cue.align = "end";
              }
              // Map simple text decoration commands to equivalent WebVTT text tags.
              // NOTE: Strikethrough (the 's' tag) is not supported in WebVTT.
            } else if (['b', 'i', 'u', 's'].includes(oneLetter)) {
              if (Number(style[j].substring(1, 2)) === 0
                // The more elaborate 'b-tag', which we will treat as an on-off selector.
                || (style[j].match(/b\d{3}/)
                  && Number(style[j].match(/b(\d{3})/)[1]) < 500)
              ) {
                // Closing a tag.
                if (tagsToClose.includes(oneLetter)) {
                  // Nothing needs to be done if this tag isn't already open.
                  // HTML tags must be nested, so we must ensure that any tag nested inside
                  // the tag being closed are also closed, and then opened again once the
                  // current tag is closed.
                  while (tagsToClose.length > 0) {
                    let nowClosing = tagsToClose.pop();
                    replaceString += '</' + nowClosing + '>';
                    if (nowClosing !== oneLetter) {
                      tagsToOpen.push(nowClosing);
                    } else {
                      // There's no need to close the tags that the current tag
                      // is nested within.
                      break;
                    }
                  }
                }
              } else {
                // Opening a tag.
                if (!tagsToClose.includes(oneLetter)) {
                  // Nothing needs to be done if the tag is already open.
                  // If no, place the tag on the bottom of the stack of tags being opened.
                  tagsToOpen.splice(0, 0, oneLetter);
                }
              }
            } else if (oneLetter === 'r') {
              // Resetting override tags, by closing all open tags.
              // TODO: The 'r' tag can also be used to switch to a different named style,
              // however, named styles haven't been implemented.
              while (tagsToClose.length > 0) {
                replaceString += '</' + tagsToClose.pop() + '>';
              }
            }
            // Insert open-tags for tags in the to-open list.
            while (tagsToOpen.length > 0) {
              let nowOpening = tagsToOpen.pop();
              replaceString += '<' + nowOpening + '>';
              tagsToClose.push(nowOpening);
            }
          }
        }
      }
      text = text.replace(re_style, replaceString); // Replace override tag.
    }
    text = text.replace(re_newline, "\r\n").replace(re_softbreak, " ").replace(
      re_hardspace, "&nbsp;");
    let content = "<v." + result.style + ">" + text
    while (tagsToClose.length > 0) {
      content += '</' + tagsToClose.pop() + '>';
    }
    if (!positioned && headers[trackNumber].styles[result.style][headers[trackNumber].format.indexOf("Alignment")]) {
      let posNum = Number(headers[trackNumber].styles[result.style][headers[trackNumber].format.indexOf("Alignment")]);
      if (Math.floor((posNum - 1) / 3) == 1) {
        cue.line = 8;
      } else if (Math.floor((posNum - 1) / 3) == 2) {
        cue.line = 1;
      } else {
        cue.line = -1
      }
      if (posNum % 3 == 1) {
        cue.align = "start";
      } else if (posNum % 3 == 0) {
        cue.align = "end";
      }
    }
    cue.text = content;
  } else {
    cue.text = text;
    cue.line = -1
  }
  if (!Object.values(tracks[trackNumber].cues).some(c => c.text == cue.text && c.startTime == cue.startTime && c.endTime == cue.endTime)) {
    tracks[trackNumber].addCue(cue)
  }
}
function parseHeader(header, number) {
  headers[number] = {
    format: re_header_format.exec(header)[1].replace(/\ /g, "").split(","),
    styles: {
    }
  }
  header.match(re_header_style).forEach((item, index) => {
    item = item.replace(/\&h/gi, "").replace(/\ /g, "").split(",")
    headers[number].styles[item[headers[number].format.indexOf("Name")]] = item
  })
}
function displayHeader(header) {
  substyles.innerHTML = ""
  for (let style of Object.values(header.styles)) {
    let bordCol
    style[header.format.indexOf("OutlineColour")] ? bordCol = style[header.format.indexOf("OutlineColour")].match(/[\s\S]{1,2}/g).reverse().join("").slice(0, -2) : "#000"
    substyles.innerHTML += `
video::cue(.${style[header.format.indexOf("Name")]}) {
  color: #${style[header.format.indexOf("PrimaryColour")] ? style[header.format.indexOf("PrimaryColour")].match(/[\s\S]{1,2}/g).reverse().join("").slice(0, -2) : ""} !important;
  text-shadow: 2px 2px 0 #${bordCol},
    2px -2px 0 #${bordCol},
    -2px 2px 0 #${bordCol},
    -2px -2px 0 #${bordCol},
    2px 0px 0 #${bordCol},
    0px 2px 0 #${bordCol},
    -2px 0px 0 #${bordCol},
    0px -2px 0 #${bordCol},
    2px 2px 2px #${bordCol};
  font-weight: ${style[header.format.indexOf("Bold")] ? style[header.format.indexOf("Bold")] * -1 ? "400" : "300" : ""} !important;
  font-style: ${style[header.format.indexOf("Italic")] ? style[header.format.indexOf("Italic")] * -1 ? "italic" : "normal" : ""} !important;
  background: ${style[header.format.indexOf("BorderStyle")] ? style[header.format.indexOf("BorderStyle")] != 3 ? "none" : `#${bordCol}` : ""} !important;
}`
  }
}

// font-weight: ${style[header.format.indexOf("Bold")] ? style[header.format.indexOf("Bold")] * -1 ? "bold" : "normal" : ""} !important;