var notes = {
    'C0':16.35,
   'C#0': 17.32,
   '#C0': 17.32,
   'Db0': 17.32,
   'D0': 18.35,
   'D#0': 19.45,
   '#D0': 19.45,
   'Eb0': 19.45,
   'E0': 20.60,
   'F0': 21.83,
   'F#0': 23.12,
   '#F0': 23.12,
   'Gb0': 23.12,
   'G0': 24.50,
   'G#0': 25.96,
   '#G0': 25.96,
   'Ab0': 25.96,
   'A0': 27.50,
   'A#0': 29.14,
   '#A0': 29.14,
   'Bb0': 29.14,
   'B0': 30.87,
   'C1': 32.70,
   'C#1': 34.65,
   '#C1': 34.65,
   'Db1': 34.65,
   'D1': 36.71,
   'D#1': 38.89,
   '#D1': 38.89,
   'Eb1': 38.89,
   'E1': 41.20,
   'F1': 43.65,
   'F#1': 46.25,
   '#F1': 46.25,
   'Gb1': 46.25,
   'G1': 49.00,
   'G#1': 51.91,
   '#G1': 51.91,
   'Ab1': 51.91,
   'A1': 55.00,
   'A#1': 58.27,
   '#A1': 58.27,
   'Bb1': 58.27,
   'B1': 61.74,
   'C2': 65.41,
   'C#2': 69.30,
   '#C2': 69.30,
   'Db2': 69.30,
   'D2': 73.42,
   'D#2': 77.78,
   '#D2': 77.78,
   'Eb2': 77.78,
   'E2': 82.41,
   'F2': 87.31,
   'F#2': 92.50,
   '#F2': 92.50,
   'Gb2': 92.50,
   'G2': 98.00,
   'G#2': 103.83,
   '#G2': 103.83,
   'Ab2': 103.83,
   'A2': 110.00,
   'A#2': 116.54,
   '#A2': 116.54,
   'Bb2': 116.54,
   'B2': 123.47,
   'C3': 130.81,
   'C#3': 138.59,
   '#C3': 138.59,
   'Db3': 138.59,
   'D3': 146.83,
   'D#3': 155.56,
   '#D3': 155.56,
   'Eb3': 155.56,
   'E3': 164.81,
   'F3': 174.61,
   'F#3': 185.00,
   '#F3': 185.00,
   'Gb3': 185.00,
   'G3': 196.00,
   'G#3': 207.65,
   '#G3': 207.65,
   'Ab3': 207.65,
   'A3': 220.00,
   'A#3': 233.08,
   '#A3': 233.08,
   'Bb3': 233.08,
   'B3': 246.94,
   'C4': 261.63,
   'C#4': 277.18,
   '#C4': 277.18,
   'Db4': 277.18,
   'D4': 293.66,
   'D#4': 311.13,
   '#D4': 311.13,
   'Eb4': 311.13,
   'E4': 329.63,
   'F4': 349.23,
   'F#4': 369.99,
   '#F4': 369.99,
   'Gb4': 369.99,
   'G4': 392.00,
   'G#4': 415.30,
   '#G4': 415.30,
   'Ab4': 415.30,
   'A4': 440.00,
   'A#4': 466.16,
   '#A4': 466.16,
   'Bb4': 466.16,
   'B4': 493.88,
   'C5': 523.25,
   'C#5': 554.37,
   '#C5': 554.37,
   'Db5': 554.37,
   'D5': 587.33,
   'D#5': 622.25,
   '#D5': 622.25,
   'Eb5': 622.25,
   'E5': 659.26,
   'F5': 698.46,
   'F#5': 739.99,
   '#F5': 739.99,
   'Gb5': 739.99,
   'G5': 783.99,
   'G#5': 830.61,
   '#G5': 830.61,
   'Ab5': 830.61,
   'A5': 880.00,
   'A#5': 932.33,
   '#A5': 932.33,
   'Bb5': 932.33,
   'B5': 987.77,
   'C6': 1046.50,
   'C#6': 1108.73,
   '#C6': 1108.73,
   'Db6': 1108.73,
   'D6': 1174.66,
   'D#6': 1244.51,
   '#D6': 1244.51,
   'Eb6': 1244.51,
   'E6': 1318.51,
   'F6': 1396.91,
   'F#6': 1479.98,
   '#F6': 1479.98,
   'Gb6': 1479.98,
   'G6': 1567.98,
   'G#6': 1661.22,
   '#G6': 1661.22,
   'Ab6': 1661.22,
   'A6': 1760.00,
   'A#6': 1864.66,
   '#A6': 1864.66,
   'Bb6': 1864.66,
   'B6': 1975.53,
   'C7': 2093.00,
   'C#7': 2217.46,
   '#C7': 2217.46,
   'Db7': 2217.46,
   'D7': 2349.32,
   'D#7': 2489.02,
   '#D7': 2489.02,
   'Eb7': 2489.02,
   'E7': 2637.02,
   'F7': 2793.83,
   'F#7': 2959.96,
   '#F7': 2959.96,
   'Gb7': 2959.96,
   'G7': 3135.96,
   'G#7': 3322.44,
   '#G7': 3322.44,
   'Ab7': 3322.44,
   'A7': 3520.00,
   'A#7': 3729.31,
   '#A7': 3729.31,
   'Bb7': 3729.31,
   'B7': 3951.07,
   'C8': 4186.01
}
let songs = {
  zelda:`2#a1 2f1 4- 8#a1 8c2 8d2 8#d2 2f2 2- 4f2 4f2 8#f2 8#g2 2#a2 2- 4#a2 8#a2 8- 8#g2 8#f2 4#g2 8#f2 2f2 2- 2f2 4#d2 8#d2 8f2 2#f2 2- 4f2 4#d2 4#c2 8#c2 8#d2 2f2 2- 4#d2 4#c2 4c2 8c2 8d2 2e2 2- 2g2 1f2`,
  indiana: `4e2 8- 8f2 8g2 8- 1c3 8- 4d2 8- 8e2 1f2 4- 4g2 8- 8a2 8b2 8- 1f3 4- 4a2 8- 8b2 2c3 2d3 2e3 4e2 8- 8f2 8g2 8- 1c34- 4d3 8- 8e3 1f3`,
  adams: `4#f1 8#f1 8#f1 8#f1 4b1 16#d2 4b1 16#g1 4e1 4#c2 16a1 4#a1 16#c2 4#a1 16#f1 4#d1 4b1 16#f1 4b1 16#d2 4b1 16#g1 4e1 4#c2 16b1 4#a1 16#f1 4#g1 16#a1 2b1 16#f1 4b1 16#d2 4b1 16#g1 4e1 4#c2 16a1 4#a1 16#c2 4#a1 16#f1 4#d1 4b1 16#f1 4b1 16#d2 4b1 16#g1 4e1`,
  simpsons: `4c2 4e2 4#f2 8a2 4.g2 4e2 4c2 8a1 8#f1 8#f1 8#f1 2g1 4- 8#f1 8#f1 8#f1 8g1 4#a1 8c2 8c2 8c2 4c2`,
  rickRoll: `8g1 8a1 8c2 8a1 4e2 8- 4e2 8- 4.d1 4- 8- 8g1 8a1 8c2 8a1 4d2 8- 4d2 8- 4c2 8b1 4.a1 8g1 8a1 8c2 8a1 2c2 4d2 4b1 4a1 4.g1 8- 4g1 2d2 2.c1 4- 8g1 8a1 8c2 8a1 4e2 8- 4e2 8- 4.d1 4- 8- 8g1 8a1 8c2`,
  titanic:`2d2 2e2 4a1 2a2 4g2 8#f2 2e2 4#f2 4g2 2#f2 4e2 4d2 4#c2 2d2 4#c2 1b1 1a1 1d2 2e2 4a1 2a2 4g2 8#f2 2e2 4#f2 4g2 2#f2 4e2 4d2 4#c2 2d2 4#c2 4#c2 2d2 4e2 2#f2 2e2 1d2`,
  comefaithfull:`4g1 2g1 4d1 4g1 2a1 2d1 4b1 4a1 4b1 4c2 2b1 4a1 4g1 2g1 4#f1 4e1 4#f1 4g1 4a1 4b1 2#f1 4.e1 8d1 2.d1`
}

let playing = false;
let osc = null;
let nextNoteTimeout =null;
let melody = []
let index = 0;
let bpm = 100
let baseLength = 1000;
//http://nokia.nigelcoldwell.co.uk/tunes.html

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
var oscillator = audioCtx.createOscillator();
let gainNode = audioCtx.createGain();
gainNode.gain.value = 0.5;

function playNote(){
  
  if(index < melody.length) {
    let melodyPos = melody[index];
    let noteLength =/^[0-9]*/.exec(melodyPos)[0];
    let curNote = notes[melodyPos.substring(noteLength.length)] || 0;
    if(!noteLength) noteLength = 1;
    //console.log(`playing note: ${melody[index]} (${curNote}) for ${noteLength}`)
    osc.frequency.setValueAtTime(curNote, audioCtx.currentTime); 
    nextNoteTimeout = setTimeout(playNote,baseLength/noteLength);
    index++;
  }
  else{
    pause();
  }
}

let run = function() {
  if(playing) pause();
  else play();
}

let pause = function() {
  index =0;
  clearTimeout(nextNoteTimeout);
  document.getElementById("run").innerHTML = "play";
  playing = false;
  osc.stop();
}

let play = function() {
  playing= true;
   document.getElementById("run").innerHTML = "pause";
    melody = document.getElementById("melody").value.toUpperCase().split(" ");
    osc = audioCtx.createOscillator();
    osc.type = 'square';
    osc.frequency.setValueAtTime(0, audioCtx.currentTime); 
    osc.connect(gainNode);
    gainNode.connect(audioCtx.destination)
    osc.start();
    index =0;
    playNote();
}

let updateVolume =function() {
 gainNode.gain.value = document.getElementById("volumeRange").value;
  document.getElementById("volumeDisplay").innerHTML = `${Math.round(gainNode.gain.value*100)}%`
}

let updateBPM = function() {
  bpm = document.getElementById("bpmRange").value;
  //at 100bpm every 60 seconds we want 100 beats
  //(60/100) *1000
  baseLength = (60/bpm) * 1000;
  document.getElementById("bpmDisplay").innerHTML = `${bpm}bpm`
}

let populate = function(song) {
  document.getElementById("melody").value = songs[song]
}