import {nextPowerOf2} from '../util';

import Renderer from './Renderer';
import MapData from '../model/MapData';


class MapView {
        private redrawPending: boolean = false;

	private vertexBuffer: WebGLBuffer;
	private textureBuffer: WebGLBuffer;


        private addTile(vertexData: number[], textureData: number[], x: number, y: number, tile: string, tileCount: number) {
                let tileID = this.tileMap.get(tile);
                if (tileID === undefined)
                        throw new Error('invalid tile specifier in map data');

                vertexData.push(x); vertexData.push(y);
                vertexData.push(x+1); vertexData.push(y);
                vertexData.push(x); vertexData.push(y+1);

                vertexData.push(x); vertexData.push(y+1);
                vertexData.push(x+1); vertexData.push(y);
                vertexData.push(x+1); vertexData.push(y+1);

                textureData.push((tileID) / tileCount); textureData.push(0);
                textureData.push((tileID+1) / tileCount); textureData.push(0);
                textureData.push((tileID) / tileCount); textureData.push(1);

                textureData.push((tileID) / tileCount); textureData.push(1);
                textureData.push((tileID+1) / tileCount); textureData.push(0);
                textureData.push((tileID+1) / tileCount); textureData.push(1);
        }

        constructor(private r: Renderer, private map: MapData, private tileTexture: WebGLTexture, private tileMap: Map<string, number>) {
                let vertexData: number[] = [];
                let textureData: number[] = [];

                let tileCount = nextPowerOf2(tileMap.size);

                for (let x = 0; x < map.width; x++) {
                        for (let y = 0; y < map.height; y++) {
                                this.addTile(vertexData, textureData, x, y, map.layers[0][y][x], tileCount);
                        }
                }

		this.vertexBuffer = r.createBuffer();
		r.gl.bindBuffer(r.gl.ARRAY_BUFFER, this.vertexBuffer);
		r.gl.bufferData(r.gl.ARRAY_BUFFER, new Float32Array(vertexData), r.gl.STATIC_DRAW);

		this.textureBuffer = r.createBuffer();
		r.gl.bindBuffer(r.gl.ARRAY_BUFFER, this.textureBuffer);
		r.gl.bufferData(r.gl.ARRAY_BUFFER, new Float32Array(textureData), r.gl.STATIC_DRAW);
        }

        draw(): void {
		this.r.gl.clear(this.r.gl.COLOR_BUFFER_BIT);

		this.r.gl.activeTexture(this.r.gl.TEXTURE0);
		this.r.gl.bindTexture(this.r.gl.TEXTURE_2D, this.tileTexture);
		this.r.gl.uniform1i(this.r.samplerLoc, 0);

		this.r.gl.bindBuffer(this.r.gl.ARRAY_BUFFER, this.vertexBuffer);
		this.r.gl.vertexAttribPointer(this.r.vertexPosLoc, 2, this.r.gl.FLOAT, false, 0, 0);

		this.r.gl.bindBuffer(this.r.gl.ARRAY_BUFFER, this.textureBuffer);
		this.r.gl.vertexAttribPointer(this.r.textureCoordLoc, 2, this.r.gl.FLOAT, false, 0, 0);

		this.r.gl.drawArrays(this.r.gl.TRIANGLES, 0, 6 * this.map.width * this.map.height);
        }
}

module MapView {
        export const tileSize = 32;
}


export default MapView;