import Axis2D from './Axis2D';
import Alignment from './Alignment';

export class Rectangle {
	constructor(private x: number, private y: number, private width: number, private height: number) {
		if (width < 0) {
			throw 'Invalid width.';
		}
		if (height < 0) {
			throw 'Invalid height.';
		}
	}

	getOffset(axis: Axis2D, alignment = Alignment.START): number {
		var offset = NaN;

		switch (axis) {
			case Axis2D.X:
				offset = this.x;
				break;
			case Axis2D.Y:
				offset = this.y;
				break;
		}

		switch (alignment) {
			case Alignment.CENTER:
				offset += this.getSize(axis) / 2;
				break;
			case Alignment.END:
				offset += this.getSize(axis);
				break;
		}

		return offset;
	}

	getSize(axis: Axis2D): number {
		var result = NaN;

		switch (axis) {
			case Axis2D.X:
				result = this.width;
				break;
			case Axis2D.Y:
				result = this.height;
				break;
		}

		return result;
	}

	equals(value: Rectangle): boolean {
		return !!value &&
			value.getOffset(Axis2D.X) == this.getOffset(Axis2D.X) &&
			value.getOffset(Axis2D.Y) == this.getOffset(Axis2D.Y) &&
			value.getSize(Axis2D.X) == this.getSize(Axis2D.X) &&
			value.getSize(Axis2D.Y) == this.getSize(Axis2D.Y);
	}

	toString(): string {
		return '[illa.Rectangle x=' + this.getOffset(Axis2D.X) + ' y=' + this.getOffset(Axis2D.Y) +
			' width=' + this.getSize(Axis2D.X) + ' height=' + this.getSize(Axis2D.Y) + ']';
	}

	expand(top: number, right: number, bottom: number, left: number): Rectangle {
		return new Rectangle(this.getOffset(Axis2D.X) - left,
			this.getOffset(Axis2D.Y) - top,
			this.getSize(Axis2D.X) + left + right,
			this.getSize(Axis2D.Y) + top + bottom);
	}

	containsRect(rect: Rectangle): boolean {
		var result = false;
		if (rect) {
			result = true;
			for (var axis = Axis2D.X; axis <= Axis2D.Y; axis++) {
				if (rect.getOffset(axis, Alignment.START) < this.getOffset(axis, Alignment.START) ||
					rect.getOffset(axis, Alignment.END) > this.getOffset(axis, Alignment.END)) {
					result = false;
					break;
				}
			}
		}
		return result;
	}

	contains(x: number, y: number): boolean {
		return x >= this.x &&
			x < this.x + this.width &&
			y >= this.y &&
			y < this.y + this.height;
	}
}

export default Rectangle;