class Label implements Drawable {

	private _graphs: Array<Graph>;

	private _point: Point;
	private _text: string;
	private _align: string;
	private _centered: boolean;
	private _color: string;
	private _font: string;
	
	constructor(point: Point, text: string, align: string = "start", 
		centered: boolean = false, color: string = "black", font: string = "10px sans-serif") {

		this._point = point;
		this._text = text;
		this._align = align;
		this._centered = centered;
		this._color = color;
		this._font = font;

		this._graphs = [];

	}

	public draw(graph: Graph) {
		var pt: {x: number; y: number;} = this._point.toCanvas(graph);


		if(this._centered) {
			pt.x -= Math.floor(graph.context.measureText(this._text).width / 2);
			pt.y -= Math.floor(graph.context.measureText("o").width / 2);
		}

		graph.context.textAlign = this._align;
		graph.context.font = this._font;
		graph.context.fillStyle = this._color;

		graph.context.fillText(this._text, pt.x, pt.y);

	}

	private updateGraphs() {
		for (var i = 0; i < this._graphs.length; i++) {
			this._graphs[i].update();
		}
	}

	public add(graph: Graph) {
		this._graphs.push(graph);
	}

	public remove(graph: Graph) {
		for(var i = this._graphs.length - 1; i >= 0; i--) {
    		if(this._graphs[i] === graph) {
    		   this._graphs.splice(i, 1);
    		}
		}
	}

	equals(other: Label): boolean {
		return this._point.equals(other.point) && this._text.valueOf() === other.text.valueOf() 
		&& this._align.valueOf() === other.align.valueOf() && this._centered === other.centered 
		&& this._color.valueOf() === other.color.valueOf() && this._font.valueOf() === other.font.valueOf(); 
	}

	toString() {
		return this._text + " " + this._point.toString();
	}

	public get point() : Point {
		return this._point;
	}

	public set point(v : Point) {
		this._point = v;
		this.updateGraphs();
	}

	public get text() : string {
		return this._text;
	}

	public set text(v : string) {
		this._text = v;
		this.updateGraphs();
	}

	public get align() : string {
		return this._align;
	}

	public set align(v : string) {
		this._align = v;
	}

	public get centered() : boolean {
		return this._centered;
	}

	public set centered(v : boolean) {
		this._centered = v;
		this.updateGraphs();
	}

	public get color() : string {
		return this._color;
	}

	public set color(v : string) {
		this._color = v;
		this.updateGraphs();
	}

	public get font() : string {
		return this._font;
	}

	public set font(v : string) {
		this._font = v;
		this.updateGraphs();
	}
  
}