let song;
let notes = [];
let columns = [870, 980, 1090, 1200]; // x positions for each column
let speed = 9; // speed of falling notes
let score = 0; // score from hitting notes/missing notes
let combo = 0;
let currentSong = null;
let nextNoteIndex = 0;
let currentState = 0;
let highlightedSongIndex = 0; // which song is currently selected
let timingOffset = 0; // milliseconds

const gameState = {
  MENU: 0,
  GAME: 1,
  END: 2,
};

let songs = [
  {
    name: "It's Going Down Now",
    file: "song1.mp3",
    timings: [527.9791666666666, 1327.9791666666667, 2010.6458333333333, 2559.9791666666665, 3199.9791666666665, 3797.3125, 4431.979166666666, 4949.3125, 5471.979166666666, 5951.979166666667, 6570.645833333334, 7178.645833333333, 7717.3125, 8341.3125, 8927.979166666666, 9471.979166666668, 10047.979166666666, 10650.645833333334, 11237.3125, 11839.979166666666, 12469.3125, 13077.3125, 13631.979166666668, 14101.3125, 14629.3125, 15178.645833333332, 15738.645833333332, 16261.312499999998, 16810.645833333332, 17397.3125, 17919.979166666668, 18559.979166666668], // milliseconds of when notes spawn
    columns: [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], // initially all 1, change them to 0, 1, 2, 3 for four columns
    durations: [180.10000000149012, 115.10000000149012, 209.80000000447035, 205.29999999701977, 290, 264.59999999403954, 274.79999999701977, 240, 235, 199.89999999850988, 264.5, 235.10000000149012, 209.70000000298023, 195, 204.69999999552965, 195, 205.19999999552965, 224.69999999552965, 169.79999999701977, 164.60000000149012, 180.20000000298023, 190.20000000298023, 175.20000000298023, 118.30000000447035, 140.20000000298023, 180.40000000596046, 125.10000000149012, 144.89999999850988, 120.10000000149012, 124.70000000298023, 89.5, 125.20000000298023] // note durations. 0 = tap note, > 0 = hold note
  },
  {
    name: "No More What Ifs",
    file: "song2.mp3",
    timings: [],
    columns: [],
    durations: [] // note durations. 0 = tap note, >0 = hold note
  }
];

function preload() {
  songs.forEach(song => {
    song.sound = loadSound(song.file); // Load sound files
  });
}

function setup() {
  createCanvas(1280, 720);
}

function draw() {
  background(0); // Always clear screen

  if (currentState === gameState.MENU) {
    drawMenu();
  } else if (currentState === gameState.GAME) {
    drawGame();

    // Draw score and combo if in game
    fill(255);
    textSize(32);
    textAlign(LEFT);
    text("Score: " + score, 20, 40);
    text("Combo: " + combo, 20, 80);
  }
}

function drawMenu() {
  textSize(48);
  fill(255);
  textAlign(CENTER, CENTER);
  text("Song Select", width / 2, 100);

  textSize(32);
  songs.forEach((song, i) => {
    let y = 250 + i * 60; // spacing songs vertically

    if (i === highlightedSongIndex) {
      fill(255, 200, 0); // highlighted
      text("> " + song.name, width / 2, y);
    } else {
      fill(255); // normal
      text(song.name, width / 2, y);
    }
  });
}

function drawGame() {
  // Draw hit zones
  columns.forEach((col, i) => {
    fill(50);
    rect(col - 25, height - 100, 50, 10);
  });

  // Manage notes
  if (song.isPlaying()) {
    let currentTime = (song.currentTime() * 1000) + timingOffset; // Correcting timing offset

    // Adjust for note fall time
    let fallTimeMs = (height - 100) / speed * (1000 / 60);

    // Spawn new notes based on the current time
    while (nextNoteIndex < currentSong.timings.length && currentTime >= currentSong.timings[nextNoteIndex] - fallTimeMs) {
      spawnNote(
        currentSong.columns[nextNoteIndex],
        currentSong.timings[nextNoteIndex],
        currentSong.durations[nextNoteIndex]
      );
      nextNoteIndex++;
    }
  }

  // Update and show notes
  for (let i = notes.length - 1; i >= 0; i--) {
    notes[i].update();
    notes[i].show();
    if (notes[i].y > height + 100) { // give some grace before removing
      notes.splice(i, 1); // remove missed notes
      combo = 0; // break combo if missed
      score -= 25; // reduce score for missed note
    }
  }
}

function spawnNote(column, startTime, duration) {
  notes.push(new Note(columns[column], startTime, duration));
}

class Note {
  constructor(x, startTime, duration) {
    this.x = x;
    this.startTime = startTime; // when the note spawns
    this.duration = duration; // how long you must hold
    this.y = 0;
    this.size = 40;
    this.holding = false; // if player is holding it
    this.heldTime = 0; // how long the player held
  }

  update() {
    this.y += speed;
    if (this.holding) {
      this.heldTime += deltaTime;
    }
  }

  show() {
    fill(255);
    if (this.duration > 0) {
      rect(this.x - this.size / 2, this.y - this.size / 2, this.size, this.duration / 10); // Longer rectangle for hold notes
    } else {
      rect(this.x - this.size / 2, this.y - this.size / 2, this.size, this.size); // Normal tap note
    }
  }
}

function keyPressed() {
  if (currentState === gameState.MENU) {
    // Navigating through songs
    if (key === 'q' || key === 'Q') {
      highlightedSongIndex = (highlightedSongIndex - 1 + songs.length) % songs.length;
    }
    if (key === 'e' || key === 'E') {
      highlightedSongIndex = (highlightedSongIndex + 1) % songs.length;
    }

    // Check ENTER key to select song
    if (keyCode === ENTER) {
      selectSong(highlightedSongIndex);
    }
  } else if (currentState === gameState.GAME) {
    // Handle key presses during the game state
    for (let i = notes.length - 1; i >= 0; i--) {
      if (keyMatches(notes[i])) {
        checkHit(notes[i], i);
        return;
      }
    }
  }
}

function keyReleased() {
  for (let i = notes.length - 1; i >= 0; i--) {
    if (notes[i].holding) {
      if (notes[i].heldTime >= notes[i].duration - 100) { // allow small error
        score += 50; // Good hold
        combo++;
      } else {
        score -= 25; // Released too early
      }
      notes.splice(i, 1); // Remove the hold note
    }
  }
}

function checkHit(note, index) {
  if (isNearTarget(note)) {
    if (note.duration > 0) {
      note.holding = true; // Hold notes are marked holding
    } else {
      notes.splice(index, 1); // Tap notes are deleted immediately
    }
    score += 25;
    combo++;
  } else {
    combo = 0; // Reset combo if missed
    score -= 25; // Decrease score for missed note
  }
}

function selectSong(index) {
  currentSong = songs[index];
  notes = [];
  nextNoteIndex = 0;
  song = currentSong.sound;
  song.play();
  song.jump(0); // ensure it starts from 0
  currentState = gameState.GAME;
}

// helpers
function keyMatches(note) {
  if (note.x === columns[0] && ['d', 'D'].includes(key)) return true;
  if (note.x === columns[1] && ['f', 'F'].includes(key)) return true;
  if (note.x === columns[2] && ['j', 'J'].includes(key)) return true;
  if (note.x === columns[3] && ['k', 'K'].includes(key)) return true;
  return false;
}

function isNearTarget(note) {
  return abs(note.y - (height - 100)) < 75;
}