// Mini Logo engine
// Based on Liogo compiler from Lionel Laské
// http://liogo.sourceforge.net
enyo.kind({
	name: "Liogo",	
	published: { canvas: undefined, image: undefined },

	// Create component
	create: function() {	
		this.inherited(arguments);
		this.commands = [];
		this.initheading = 90;
		this.canvasChanged();
	},
	
	// Canvas property changed
	canvasChanged: function(old) {
		this.initx = this.canvas.attributes.width / 2;
		this.inity = this.canvas.attributes.height / 2;
		this.width = this.canvas.attributes.width;
		this.height = this.canvas.attributes.height;
	},
	
	// Draw canvas an its content
	draw: function() {
		// Clear all
		this.ctx = this.canvas.node.getContext('2d');
		this.ctx.clearRect(0, 0, this.width, this.height);
		this.ctx.canvas.width = this.ctx.canvas.width;
		this.ctx.strokeStyle = "blue";
		this.ctx.lineWidth = 2;
		
		// Set init pos
		this.x = this.initx;
		this.y = this.inity;
		this.heading = this.initheading;
		this.ctx.moveTo(this.x, this.y);
		
		// Draw each command
		var i = 0;
		var len = this.commands.length;
		for (i = 0 ; i < len ; i++) {
			var action = this.commands[i];
			switch(action.command)
			{
			case 'f':
				this._do_forward(action.arg);
				break;
			case 'r':
				this._do_right(action.arg);
				break;
			case 'l':
				this._do_left(action.arg);
				break;
			}
			this.ctx.moveTo(this.x, this.y);
		}
		
		// Draw turtle
		this.ctx.translate(this.x, this.y);
		this.ctx.rotate((90-this.heading) * (Math.PI / 180));
		this.ctx.translate(-11,-14);
		this.ctx.drawImage(this.image, 0, 0);
	},
	
	// Clear all content
	clear: function() {
		this.commands = [];
		this.x = this.initx;
		this.y = this.inity;
		this.heading = 90;	
	},
	
	// Forward turtle to the value
	forward: function(value) {
		this.commands.push({command: 'f', arg: value});
	},
	
	// Turn left turtle to the angle value
	left: function(value) {
		this.commands.push({command: 'l', arg: value});
	},
	
	// Turn right turtle to the angle value
	right: function(value) {
		this.commands.push({command: 'r', arg: value});
	},
	
	// Process forward command, forward turtle using value and current heading
	_do_forward: function(value) {
		var radians = this.heading * (Math.PI/180);
		this.x = this.x + value * Math.cos(radians);
		this.y = this.y - value * Math.sin(radians);
		this.ctx.lineTo(this.x, this.y);
		this.ctx.stroke();
	},
	
	// Process left command, just change heading
	_do_left: function(value) {
		this.heading += value;
		if (this.heading > 360)
			this.heading -= 360;
	},
	
	// Process right command, just change heading
	_do_right: function(value) {
		this.heading -= value;
		if (this.heading < 0)
			this.heading += 360;
	}
});