class Timer {
  i1 = 0;
  i2 = 0;
  currentInterval = 1;
  timerId;
  progress = 0;
  progressId;

  constructor(i1, i2) {
    this.i1 = i1;
    this.i2 = i2;
  }

  startTimer() {
    console.log("startTimer()");
    this.notify();
    if (this.timerId !== undefined) clearTimeout(this.timerId);
    document.getElementById("interval").innerHTML =
      this.currentInterval === 1 ? "Sitzen" : "Stehen";
    this.startProgress();
    this.timerId = setTimeout(
      () => {
        this.currentInterval = this.currentInterval === 1 ? 2 : 1;
        this.startTimer();
      },
      this.currentInterval === 1 ? this.i1 : this.i2
    );
  }

  notify() {
    console.log("notify()");
    if (Notification.permission === "granted") {
      new Notification(
        this.currentInterval === 1 ? "Du kannst sitzen" : "Steh auf, du Sack!"
      );
    } else if (Notification.permission !== "denied") {
      Notification.requestPermission().then((permission) => {
        if (permission === "granted") {
          new Notification(
            this.currentInterval === 1
              ? "Du kannst sitzen"
              : "Steh auf, du Sack!"
          );
        }
      });
    }
  }

  startProgress() {
    console.log("startProgress()");
    if (this.progressId !== undefined) clearInterval(this.progressId);
    this.progress = 0;
    this.draw();
    this.progressId = setInterval(() => {
      this.progress += 1000;
      this.draw();
    }, 1e3);
  }

  draw() {
    console.log("draw()");
    let timeRemaining =
      this.currentInterval === 1
        ? this.i1 - this.progress
        : this.i2 - this.progress;
    if (timeRemaining < 0) timeRemaining = 0;
    document.getElementById("timer").innerHTML =
      this.convertMillisecondsToTime(timeRemaining);
  }

  stop() {
    console.log("stop()");
    clearTimeout(this.timerId);
    this.timerId = undefined;
    clearInterval(this.progressId);
    this.progressId = undefined;
    this.progress = 0;
    document.getElementById("timer").innerHTML = "00:00:00";
  }

  convertMillisecondsToTime(milliseconds) {
    const s = Math.floor(milliseconds / 1000);
    const hours = Math.floor(s / 3600);
    const minutes = Math.floor((s % 3600) / 60);
    const seconds = s % 60;

    return `${hours.toString().padStart(2, "0")}:${minutes
      .toString()
      .padStart(2, "0")}:${seconds.toString().padStart(2, "0")}`;
  }
}

let timer;

function startTimer(e) {
  e.preventDefault();
  let interval1 = document.getElementById("interval1").value;
  let interval2 = document.getElementById("interval2").value;
  let i1 = parseInt(interval1);
  let i2 = parseInt(interval2);
  if (isNaN(i1) || isNaN(i2)) return;
  if (timer) timer.stop();
  timer = new Timer(i1 * 60 * 1e3, i2 * 60 * 1e3);
  timer.startTimer();
}

function stopTimer(e) {
  e.preventDefault();
  if (timer) timer.stop();
  timer = undefined;
}