// Example is based on examples from: http://brm.io/matter-js/, https://github.com/shiffman/p5-matter
// add also Benedict Gross credit

let Engine = Matter.Engine;
let Render = Matter.Render;
let World = Matter.World;
let Bodies = Matter.Bodies;
let Body = Matter.Body;
let Constraint = Matter.Constraint;
let Mouse = Matter.Mouse;
let MouseConstraint = Matter.MouseConstraint;
let Composites = Matter.Composites;
let Composite = Matter.Composite;

let engine;
let propeller;
let boxes = [];
let birds = [];
let colors = [];
let ground;
let slingshotBirds = [];
let greenBirds = [];
let slingshotConstraint;
let angle=0;
let angleSpeed=0.01;
let canvas;

let pinkSprite = [];
let pinkFrame = [];
let greenSprite = [];
let greenFrame = [];
let redSprite = [];
let redFrame = [];

let timeLeft = 20;
let started = false;
let gameOver = false;
let gameWon = false;
let greenCount = 2;
////////////////////////////////////////////////////////////
function preload()
{
  // Bird art by bevouliin.com
  // https://opengameart.org/content/fat-bird-sprite-sheets-for-gamedev
  // https://opengameart.org/content/pink-flappy-bird-sprite-sheets
  https://opengameart.org/content/bevouliin-free-red-flappy-bee-bird-game-character-sprite-sheets-for-game-developers
  pinkSprite.push(loadImage('/pink/frame-1.png'));
  pinkSprite.push(loadImage('/pink/frame-2.png'));
  pinkSprite.push(loadImage('/pink/frame-3.png'));
  pinkSprite.push(loadImage('/pink/frame-4.png'));
  greenSprite.push(loadImage('/green/frame-1.png'));
  greenSprite.push(loadImage('/green/frame-2.png'));
  greenSprite.push(loadImage('/green/frame-3.png'));
  greenSprite.push(loadImage('/green/frame-4.png'));
  redSprite.push(loadImage('/red/frame-1.png'));
  redSprite.push(loadImage('/red/frame-2.png'));
  redSprite.push(loadImage('/red/frame-3.png'));
  redSprite.push(loadImage('/red/frame-4.png'));
}
////////////////////////////////////////////////////////////
function setup() {
  canvas = createCanvas(1000, 600);

  engine = Engine.create();  // create an engine

  setupGround();

  setupPropeller();

  setupTower();

  setupSlingshot();

  setupMouseInteraction();
}
////////////////////////////////////////////////////////////
function draw() {
  background(0);

  Engine.update(engine);

  drawGround();

  drawPropeller();

  drawTower();

  drawBirds();

  drawSlingshot();

  drawGreenBirds();

  drawGUI();

  checkWin();
}

function checkWin()
{
  if(boxes.bodies.length == 0 && !gameOver)
  {
    gameWon = true;
  }
}

function drawGUI()
{
  // Press key to start
  if(!started)
  {
    textAlign(CENTER);
    textSize(40);
    stroke(0)
    strokeWeight(1);
    fill('yellow');
    text("Click or Press any key to start", width/2, height/2);
  }

  // draw birds
  textAlign(CENTER);
  textSize(30);
  stroke(0)
  strokeWeight(1);
  fill('white');
  image(pinkSprite[0], 20, 20, 30, 30);
  image(redSprite[0], 20, 50, 30, 30);
  image(greenSprite[0], 20, 80, 30, 30);
  text("∞", 80, 50);
  text("∞", 80, 80);
  
  text(greenCount.toString(), 80, 110);
  // draw instructions
  textSize(20);
  textAlign(LEFT);
  stroke(0)
  strokeWeight(1);
  fill(255);
  text("B: pink bird", width - 150, 50);
  text("R: red bird", width - 150, 70);
  text("G: green bird", width - 150, 90);
  text("←: faster spin", width - 150, 110);
  text("→: slower spin", width - 150, 130);

  // draw time left
  stroke(0)
  strokeWeight(1);
  fill('white');
  let textSizeCounter = 20;
  textSize(textSizeCounter);
  textAlign(CENTER);
  text("TIME LEFT", width /2, 20);
  if(started && !gameOver && !gameWon && frameCount % 60 == 0)
  {
    timeLeft -= 1;
  }

  // draw game over
  text(timeLeft.toString(), width /2, textSizeCounter * 2);
  if(timeLeft == 0 && !gameWon)
  {
    gameOver = true;
    textAlign(CENTER);
    textSize(40);
    stroke(0)
    strokeWeight(1);
    fill('red');
    text("GAME OVER", width/2, height/2);
    textSize(textSizeCounter);
    text("Refresh to start again", width/2, height/2 + textSizeCounter * 2 );
  }

  // game won
  if(gameWon)
  {
    textAlign(CENTER);
    textSize(40);
    stroke(0)
    strokeWeight(1);
    fill('orange');
    text("You have WON", width/2, height/2);
    textSize(textSizeCounter);
    text("Refresh to start again", width/2, height/2 + textSizeCounter * 2 );
  }
}

////////////////////////////////////////////////////////////
//use arrow keys to control propeller
function keyPressed(){
  started = true;
  if (keyCode == LEFT_ARROW){
    angleSpeed += 0.01;
  }
  else if (keyCode == RIGHT_ARROW){
    angleSpeed -= 0.01;
  }
}
////////////////////////////////////////////////////////////
function keyTyped(){
  if(gameOver || gameWon)
    return;
  //if 'b' create a new bird to use with propeller
  if (key==='b'){
    setupBird();
  }

  //if 'r' reset the slingshot
  if (key==='r'){
    //removeFromWorld(slingshotBird);
    removeFromWorld(slingshotConstraint);
    setupSlingshot(key);
  }

  if(key=='g'){
    removeFromWorld(slingshotConstraint);
    setupGreenBird();
  }
}

//**********************************************************************
//  HELPER FUNCTIONS - DO NOT WRITE BELOW THIS line
//**********************************************************************

//if mouse is released destroy slingshot constraint so that
//slingshot bird can fly off
function mouseReleased(){
  started = true;
  setTimeout(() => {
    slingshotConstraint.bodyB = null;
    slingshotConstraint.pointA = { x: 0, y: 0 };
  }, 100);
}
////////////////////////////////////////////////////////////
//tells you if a body is off-screen
function isOffScreen(body){
  let pos = body.position;
  return (pos.y > height)
  // Modified so bodies don't disappear when they're not completely off the screen yet
}
////////////////////////////////////////////////////////////
//removes a body from the physics world
function removeFromWorld(body) {
  if(body != null)
    World.remove(engine.world, body);
}
////////////////////////////////////////////////////////////
function drawVertices(vertices) {
  beginShape();
  for (let i = 0; i < vertices.length; i++) {
    vertex(vertices[i].x, vertices[i].y);
  }
  endShape(CLOSE);
}
////////////////////////////////////////////////////////////
function drawConstraint(constraint) {
  push();
  let offsetA = constraint.pointA;
  let posA = {x:0, y:0};
  if (constraint.bodyA) {
    posA = constraint.bodyA.position;
  }
  let offsetB = constraint.pointB;
  let posB = {x:0, y:0};
  if (constraint.bodyB) {
    posB = constraint.bodyB.position;
  }
  strokeWeight(5);
  stroke(255);
  line(
    posA.x + offsetA.x,
    posA.y + offsetA.y,
    posB.x + offsetB.x,
    posB.y + offsetB.y
  );
  pop();
}