window.onload = async (e) => {
  const res = await (await fetch("/ranking", {})).json();
  window.ranking = res.positions;

  const offset = +window.location.search.slice(1);
  window.offset = offset;

  const canvas = document.querySelector('#graph');
  canvas.width = 0.35 * window.innerWidth;
  canvas.height = 0.50 * window.innerHeight;

  const now = Date.now() - offset * 1000;
  const curr = window.ranking.find(it => it.broadcastUnixTime < now);
  var current = curr.position.current;
  update(curr)
  setInterval(() => {
    const now = Date.now() - offset * 1000;
    const curr = window.ranking.find(it => it.broadcastUnixTime < now);

    if (curr.position.current != current) {
      current = curr.position.current;
      update(curr);
    }
  }, 1000);
};

function update(curr) {
  console.log("Updating");

  document.querySelector("#song-image").src = curr.track.coverUrl;

  const diff = document.querySelector("#song-diff");
  diff.innerText = curr.position.label;
  diff.classList = curr.position.type;

  document.querySelector("#title").innerText = curr.track.title;
  document.querySelector("#artist").innerText = `${curr.track.artist} (#${curr.position.current})`;

  getGraph(curr.track.artist, curr.track.title);
  queue(curr.position.current);
  getTrivia(curr)
}

async function getGraph(artist, title) {
  const res = await (await fetch(`/graph/${artist.replace("?", "")}/${title}`, {})).json();


  const cv = document.querySelector("#graph");
  const ctx = cv.getContext('2d');

  const width = cv.width;
  const labelSpace = 100;
  const barWidth = (width - labelSpace) / res.length;
  const height = cv.height;
  const graphHeight = height - 60;

  ctx.clearRect(0, 0, width, height);

  // Dots
  let minPos = 2001;
  let maxPos = -1;
  let minYear = undefined;
  let maxYear = undefined;
  for (let i = 0; i < res.length; i++) {
    const position = res[i].position;
    if (position != undefined) {
      if (position < minPos) {
        minPos = position;
        minYear = i;
      }
      if (position > maxPos) {
        maxPos = position;
        maxYear = i;
      }
    }
    
    const fraction = (position / 2000) * graphHeight;

    ctx.beginPath();
    ctx.fillStyle = "white";
    ctx.arc(labelSpace + barWidth * i + 10, fraction, 2.5, 0, 2*Math.PI);
    ctx.fill();
  }

  // Min and Max lines
  for (let p of [minPos, maxPos]) {
    const fraction = (p / 2000) * graphHeight;

    ctx.beginPath();
    ctx.strokeStyle = "#808080";
    ctx.lineWidth = 1;
    ctx.moveTo(labelSpace, fraction);
    ctx.lineTo(width, fraction);
    ctx.stroke();

    ctx.font = "40px sans-serif";
    ctx.fillStyle = "#808080";
    ctx.fillText(p.toString(), 0, fraction);
  }

  // Y axis
  for (let i = 200; i <= 2000; i += 200) {
    const fraction = (i / 2000) * graphHeight;

    const lineDist = 70;
    if (Math.abs(i-minPos) <= lineDist || Math.abs(i-maxPos) <= lineDist) {
      continue;
    }
    
    ctx.beginPath();
    ctx.strokeStyle = "#808080";
    ctx.lineWidth = 1;
    ctx.moveTo(labelSpace, fraction);
    ctx.lineTo(width, fraction);
    ctx.stroke();

    ctx.font = "40px sans-serif";
    ctx.fillStyle = "#808080";
    ctx.fillText(i.toString(), 0, fraction);
  }

  // X axis
  const startYear = 1999;
  const endYear   = 2025;
  const years     = endYear-startYear+1;
  for (let i of [...new Set([res.findIndex(it => it.position != undefined), minYear, maxYear])]) {
    const fraction = 10 + labelSpace + (i * (width - labelSpace)) / (years);
    console.log(fraction)

    let year = (100 + i - 1) % 100;

    ctx.beginPath();
    ctx.strokeStyle = "#808080";
    ctx.lineWidth = 1;
    ctx.moveTo(fraction, 0);
    ctx.lineTo(fraction, graphHeight);
    ctx.stroke();

    ctx.font = "40px sans-serif";
    ctx.fillStyle = "#808080";
    ctx.fillText(year.toString(), fraction-3, height-10);
  }

  // Line plot
  for (let i = 0; i < res.length-1; i++) {
    const curr = res[i].position;
    const next = res[i+1].position;
    const currFraction = (curr / 2000) * graphHeight;
    const nextFraction = (next / 2000) * graphHeight;

    // ctx.fillRect(barWidth * i, 0, barWidth, position / 10)
    ctx.beginPath();
    ctx.strokeStyle = "white";
    ctx.lineWidth = 5;
    ctx.lineCap = "round";
    ctx.moveTo(labelSpace + barWidth * i + 10, currFraction);
    ctx.lineTo(labelSpace + barWidth * (i+1) + 10, nextFraction);
    ctx.stroke();
  }
}

function queue(currPos) {
  const upcoming = window.ranking.filter(it => currPos - it.position.current < 10 && currPos - it.position.current >= -1)

  const queueEl = document.querySelector('#queue')
  queueEl.innerHTML = "";

  for (const song of upcoming.reverse()) {
    const broadcastDT = new Date(song.broadcastUnixTime + offset * 1000);
    queueEl.innerHTML += `
      <div class="queue-item${song.position.current == currPos ? " playing" : ""}">
        <img class="queue-image" src="${song.track.coverUrl}">
        <div class="queue-right-wrapper">
          <p class="song-title">${song.track.title}</p>
          <p class="song-artist">${song.track.artist}</p>
          <span class="song-time">
            <span class="song-diff queue-${song.position.type}">${song.position.label}</span>
            <span class="song-time">${broadcastDT.getHours().toString().padStart(2, "0")}:${broadcastDT.getMinutes().toString().padStart(2, "0")}</span>
          </span>
        </div>
      </div>
    `
  }
}

async function getTrivia(curr) {
  const res = await (await fetch(`/trivia/${curr.track.artist.replace("?", "")}`, {})).json();

  document.querySelector("#trivia-songcount").innerText = `${curr.track.artist} staat ${res.length} keer in de lijst.`;

  const artistsSongs = res.map(function (it) {
    return {
      position: window.ranking.find(rank => rank.track.title == it.title)?.position?.current,
      title: it.title
    }
  }).filter(it => it.position != undefined).sort((a,b) => a.position - b.position)


  if (artistsSongs[0].position == curr.position.current) {
    document.querySelector("#trivia-first").innerText = `Dit is het hoogste nummer van ${curr.track.artist} in de lijst.`;
  } else {
    document.querySelector("#trivia-first").innerText = `Het hoogste nummer van ${curr.track.artist} is ${artistsSongs[0].title} (#${artistsSongs[0].position}).`;
  }

  if (artistsSongs.at(-1).position == curr.position.current) {
    document.querySelector("#trivia-last").innerText = `Dit is het laagste nummer van ${curr.track.artist} in de lijst.`;
  } else {
    document.querySelector("#trivia-last").innerText = `Het laagste nummer van ${curr.track.artist} is ${artistsSongs.at(-1).title} (#${artistsSongs.at(-1).position}).`;
  }
}