import { Nullable } from "../types";
import { Constants } from "../Engines/constants";
import { Camera } from "../Cameras/camera";
import { PostProcess, PostProcessOptions } from "./postProcess";
import { Engine } from "../Engines/engine";

import "../Shaders/pass.fragment";
import "../Shaders/passCube.fragment";

    /**
     * PassPostProcess which produces an output the same as it's input
     */
    export class PassPostProcess extends PostProcess {
        /**
         * Creates the PassPostProcess
         * @param name The name of the effect.
         * @param options The required width/height ratio to downsize to before computing the render pass.
         * @param camera The camera to apply the render pass to.
         * @param samplingMode The sampling mode to be used when computing the pass. (default: 0)
         * @param engine The engine which the post process will be applied. (default: current engine)
         * @param reusable If the post process can be reused on the same frame. (default: false)
         * @param textureType The type of texture to be used when performing the post processing.
         * @param blockCompilation If compilation of the shader should not be done in the constructor. The updateEffect method can be used to compile the shader at a later time. (default: false)
         */
        constructor(name: string, options: number | PostProcessOptions, camera: Nullable<Camera> = null, samplingMode?: number, engine?: Engine, reusable?: boolean, textureType: number = Constants.TEXTURETYPE_UNSIGNED_INT, blockCompilation = false) {
            super(name, "pass", null, null, options, camera, samplingMode, engine, reusable, undefined, textureType, undefined, null, blockCompilation);
        }
    }

    /**
     * PassCubePostProcess which produces an output the same as it's input (which must be a cube texture)
     */
    export class PassCubePostProcess extends PostProcess {
        private _face = 0;

        /**
         * Gets or sets the cube face to display.
         *  * 0 is +X
         *  * 1 is -X
         *  * 2 is +Y
         *  * 3 is -Y
         *  * 4 is +Z
         *  * 5 is -Z
         */
        public get face(): number {
            return this._face;
        }

        public set face(value: number) {
            if (value < 0 || value > 5) {
                return;
            }

            this._face = value;
            switch (this._face) {
                case 0:
                    this.updateEffect("#define POSITIVEX");
                    break;
                case 1:
                    this.updateEffect("#define NEGATIVEX");
                    break;
                case 2:
                    this.updateEffect("#define POSITIVEY");
                    break;
                case 3:
                    this.updateEffect("#define NEGATIVEY");
                    break;
                case 4:
                    this.updateEffect("#define POSITIVEZ");
                    break;
                case 5:
                    this.updateEffect("#define NEGATIVEZ");
                    break;
            }
        }

        /**
         * Creates the PassCubePostProcess
         * @param name The name of the effect.
         * @param options The required width/height ratio to downsize to before computing the render pass.
         * @param camera The camera to apply the render pass to.
         * @param samplingMode The sampling mode to be used when computing the pass. (default: 0)
         * @param engine The engine which the post process will be applied. (default: current engine)
         * @param reusable If the post process can be reused on the same frame. (default: false)
         * @param textureType The type of texture to be used when performing the post processing.
         * @param blockCompilation If compilation of the shader should not be done in the constructor. The updateEffect method can be used to compile the shader at a later time. (default: false)
         */
        constructor(name: string, options: number | PostProcessOptions, camera: Nullable<Camera> = null, samplingMode?: number, engine?: Engine, reusable?: boolean, textureType: number = Constants.TEXTURETYPE_UNSIGNED_INT, blockCompilation = false) {
            super(name, "passCube", null, null, options, camera, samplingMode, engine, reusable, "#define POSITIVEX", textureType, undefined, null, blockCompilation);
        }
    }

    Engine._RescalePostProcessFactory = (engine: Engine) => {
        return new PassPostProcess("rescale", 1, null, Engine.TEXTURE_BILINEAR_SAMPLINGMODE, engine, false, Engine.TEXTURETYPE_UNSIGNED_INT);
    };