import Color = require("color");

/** Simple abstraction over a WebGL Texture */
export default class TextureData {
	public rowsPower2: number;
	public lengthPower2: number;
	private data: Float32Array;
	private texture: WebGLTexture;

	constructor(private rows: number, public length: number) {
		this.rowsPower2 = 2 ** Math.ceil(Math.log2(this.rows));
		this.lengthPower2 = 2 ** Math.ceil(Math.log2(length));
		this.data = new Float32Array(this.rowsPower2 * this.lengthPower2 * 4);
	}

	/** Set the data in the texture
     * @param value1 must be 0->1.0
     * @param value2 must be 0->1.0
     * @param value3 must be 0->1.0
     * @param value3 must be 0->1.0
     */
	public setValue(row: number, index: number, value1: number, value2: number, value3: number, value4: number): void {
		this.data[row * this.lengthPower2 * 4 + index * 4 + 0] = value1;
		this.data[row * this.lengthPower2 * 4 + index * 4 + 1] = value2;
		this.data[row * this.lengthPower2 * 4 + index * 4 + 2] = value3;
		this.data[row * this.lengthPower2 * 4 + index * 4 + 3] = value4;
	}

	/** Set the data in the texture
     * @param vec1 must be (0->1.0,0->1.0)
     * @param vec2 must be (0->1.0,0->1.0)
     */
	public setVec2(row: number, index: number, vec1: { x: number; y: number }, vec2: { x: number; y: number }): void {
		this.data[row * this.lengthPower2 * 4 + index * 4 + 0] = vec1.x;
		this.data[row * this.lengthPower2 * 4 + index * 4 + 1] = vec1.y;
		this.data[row * this.lengthPower2 * 4 + index * 4 + 2] = vec2.x;
		this.data[row * this.lengthPower2 * 4 + index * 4 + 3] = vec2.y;
	}

	public setColor(row: number, index: number, color: string): void {
		const colorObj = Color(color);
		const colorarray = colorObj.array();
		this.setValue(row, index, colorarray[0] / 256, colorarray[1] / 256, colorarray[2] / 256, colorObj.alpha());
	}

	public getData(): Float32Array {
		return this.data;
	}

	public bindTexture(gl: WebGLRenderingContext, register: number): WebGLTexture {
		var oldActive = gl.getParameter(gl.ACTIVE_TEXTURE);
		if (this.texture) gl.deleteTexture(this.texture);
		this.texture = gl.createTexture();
		gl.bindTexture(gl.TEXTURE_2D, this.texture);
		gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, this.lengthPower2, this.rowsPower2, 0, gl.RGBA, gl.FLOAT, this.data);

		gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
		gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
		gl.bindTexture(gl.TEXTURE_2D, null);

		gl.activeTexture(register); // working register 31, thanks.
		gl.bindTexture(gl.TEXTURE_2D, this.texture);
		gl.activeTexture(oldActive);
		return this.texture;
	}
}