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/*
instances on stage:
ship_mc		-- is the ship.
asteroids_mc	- an empty movieclip that will contain all of the asteroids
bullets_mc		- an empty movieclip that will contain all of the asteroids

Symbols set up for linking and attaching through ActionScript:
AsteroidLarge	- The first and largest asteroid to be shown.
AsteroidMedium	- The second asteroid...two of these will spawn from the large asteroid
bullet			- The projectiles fired from the ship.
*/


var score:Number = 0;
var lives:Number = 3;

// INITIALIZATION =================================================
function startLevel():Void {
	//trace("startLevel");
	for (var i:Number = 0; i < 4; i++) {
		createAsteroid("AsteroidLarge");
	}
}

startLevel();


// ASTEROIDS =======================================================

function createAsteroid(size:String, x:Number, y:Number):Void {
	//trace("createAsteroid");
	var depth:Number = asteroids_mc.getNextHighestDepth();
	var ast:MovieClip = asteroids_mc.attachMovie(size, "asteroid" + depth, depth);
	/*if (x == undefined) {
		ast._x = Math.random() * Stage.width;
	} else {
		ast._x = x;
	}*/
	ast._x = x || Math.random() * Stage.width;
	ast._y = y || Math.random() * Stage.height; 
	ast._rotation = Math.random() * 360;
	ast.rv = Math.random() * 6 - 3;
	ast.xv = Math.random() * 6 - 3;
	ast.yv = Math.random() * 6 - 3;
	ast.onEnterFrame = moveAsteroid;
	ast.size = size;
}

function moveAsteroid():Void {
	this._x += this.xv;
	this._y += this.yv;
	this._rotation += this.rv;
	var radius:Number = this._width / 2;
	
	if (this._x > Stage.width + radius) {
		this._x = -radius;
	} else if (this._x < -radius) {
		this._x = Stage.width + radius;
	}
	if (this._y > Stage.height + radius) {
		this._y = -radius;
	} else if (this._y < -radius) {
		this._y = Stage.height + radius;
	}
}


// PROJECTILE COLLISIONS ===============================================
function checkCollision(bullet:MovieClip):Void {
	if (asteroids_mc.hitTest(bullet._x, bullet._y, true)) {
		for (var clip:String in asteroids_mc) {
			var ast:MovieClip = asteroids_mc[clip];
			if (ast.hitTest(bullet._x, bullet._y, true)) {
				spawnAsteroid(ast);
				bullet.removeMovieClip();
				break;
			}
		}
		
		// Check win.
		var counter:Number = 0;
		for (var clip:String in asteroids_mc) {
			counter++;
		}
		if (counter == 0) {
			startLevel();;
		}
	}
}
function checkCollision2(ship:MovieClip):Void {
	if (asteroids_mc.hitTest(ship._x, ship._y, true)) {
		for (var clip:String in asteroids_mc) {
			var ast:MovieClip = asteroids_mc[clip];
			if (ast.hitTest(ship._x, ship._y, true)) {
				shipDeath();
				break;
			}
		}
	}
}

function spawnAsteroid(ast:MovieClip):Void {
	switch (ast.size) {
		case "AsteroidLarge":
			var nextSize:String = "AsteroidMedium";
			score += 5;
			//trace("You have a large asteroid!");
			break;
		case "AsteroidMedium":
			score += 10;
			// If it's medium...
			break;
		default:
			// otherwise...
			
	}
	
	score_txt.text = score;
	
	createAsteroid(nextSize, ast._x, ast._y);
	createAsteroid(nextSize, ast._x, ast._y);
	ast.removeMovieClip();
}

function shipDeath():Void {
	trace ("hit test");
	ship_mc.removeMovieClip();
	lives--;
	break;
}

// EVERY BELOW THIS LINE IS THE SAME CODE AS WE WENT OVER LAST WEEK, FROM KEYBOARD CONTROL ============================
ship_mc.xv = 0;
ship_mc.yv = 0;
ship_mc.accel = 0;


function degToRad(num:Number):Number {
	return num * Math.PI / 180;
}

function moveShip():Void {
	var rads:Number = degToRad(ship_mc._rotation);
	var xa:Number = Math.cos(rads) * ship_mc.accel;
	var ya:Number = Math.sin(rads) * ship_mc.accel;
	ship_mc.xv += xa;
	ship_mc.yv += ya;
	
	
	var speed:Number = Math.sqrt((ship_mc.xv * ship_mc.xv) + (ship_mc.yv * ship_mc.yv));
	//trace(speed);
	if (speed > 10) {
		ship_mc.xv = Math.cos(rads) * 10;
		ship_mc.yv = Math.sin(rads) * 10;	
	}
	
	ship_mc._x += ship_mc.xv;
	ship_mc._y += ship_mc.yv;
	
	// Check bounds
	if (ship_mc._x > Stage.width ) {
		ship_mc._x = 0;
	} else if (ship_mc._x < 0) {
		ship_mc._x = Stage.width;
	}
	if (ship_mc._y > Stage.height) {
		ship_mc._y = 0;
	} else if (ship_mc._y < 0) {
		ship_mc._y = Stage.height;
	}
}

function onEnterFrame():Void {
	if (Key.isDown(Key.UP)) {
		ship_mc.accel = 0.5;
	} else {
		ship_mc.accel = 0;
	}
	
	if (Key.isDown(Key.LEFT)) {
		ship_mc._rotation -= 10;
	}
	if (Key.isDown(Key.RIGHT)) {
		ship_mc._rotation += 10;
	}
	
	moveShip();
	checkCollision2(ship_mc);
}


Key.addListener(this);
function onKeyUp():Void {
	if (Key.getCode() == Key.SPACE) {
		var d:Number = bullets_mc.getNextHighestDepth();
		var b:MovieClip = bullets_mc.attachMovie("bullet", "bullet" + d, d);
		b._x = ship_mc._x;
		b._y = ship_mc._y;
		b._rotation = ship_mc._rotation
		var rads:Number = degToRad(ship_mc._rotation);
		b.xv = Math.cos(rads) * 20;
		b.yv = Math.sin(rads) * 20;
		b.life = 0;
		b.onEnterFrame = function():Void {
			this._x += this.xv
			this._y += this.yv
			this.life ++;
			if (this.life > 8) {
				this._alpha -=10;  //alpha shift
			}
			if (this.life > 15) {
				this.removeMovieClip();
			}
			checkCollision(this);
		}
	}
}