import { Vector2 } from "../Maths/math.vector";
import { Nullable } from "../types";
import { PostProcess, PostProcessOptions } from "./postProcess";
import { Effect } from "../Materials/effect";
import { Camera } from "../Cameras/camera";
import { Engine } from "../Engines/engine";
import { Constants } from "../Engines/constants";

import "../Shaders/chromaticAberration.fragment";
import { _TypeStore } from '../Misc/typeStore';
import { serialize, SerializationHelper } from '../Misc/decorators';

declare type Scene = import("../scene").Scene;

/**
 * The ChromaticAberrationPostProcess separates the rgb channels in an image to produce chromatic distortion around the edges of the screen
 */
export class ChromaticAberrationPostProcess extends PostProcess {
    /**
     * The amount of seperation of rgb channels (default: 30)
     */
    @serialize()
    aberrationAmount = 30;

    /**
     * The amount the effect will increase for pixels closer to the edge of the screen. (default: 0)
     */
    @serialize()
    radialIntensity = 0;

    /**
     * The normilized direction in which the rgb channels should be seperated. If set to 0,0 radial direction will be used. (default: Vector2(0.707,0.707))
     */
    @serialize()
    direction = new Vector2(0.707, 0.707);

    /**
     * The center position where the radialIntensity should be around. [0.5,0.5 is center of screen, 1,1 is top right corder] (default: Vector2(0.5 ,0.5))
     */
    @serialize()
    centerPosition = new Vector2(0.5, 0.5);

    /** The width of the screen to apply the effect on */
    @serialize()
    screenWidth: number;

    /** The height of the screen to apply the effect on */
    @serialize()
    screenHeight: number;

    /**
     * Gets a string identifying the name of the class
     * @returns "ChromaticAberrationPostProcess" string
     */
    public getClassName(): string {
        return "ChromaticAberrationPostProcess";
    }

    /**
     * Creates a new instance ChromaticAberrationPostProcess
     * @param name The name of the effect.
     * @param screenWidth The width of the screen to apply the effect on.
     * @param screenHeight The height of the screen to apply the effect on.
     * @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 Type of textures used when performing the post process. (default: 0)
     * @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, screenWidth: number, screenHeight: number, options: number | PostProcessOptions, camera: Nullable<Camera>, samplingMode?: number, engine?: Engine, reusable?: boolean, textureType: number = Constants.TEXTURETYPE_UNSIGNED_INT, blockCompilation = false) {
        super(name, "chromaticAberration", ["chromatic_aberration", "screen_width", "screen_height", "direction", "radialIntensity", "centerPosition"], [], options, camera, samplingMode, engine, reusable, null, textureType, undefined, null, blockCompilation);

        this.screenWidth = screenWidth;
        this.screenHeight = screenHeight;

        this.onApplyObservable.add((effect: Effect) => {
            effect.setFloat('chromatic_aberration', this.aberrationAmount);
            effect.setFloat('screen_width', screenWidth);
            effect.setFloat('screen_height', screenHeight);
            effect.setFloat('radialIntensity', this.radialIntensity);
            effect.setFloat2('direction', this.direction.x, this.direction.y);
            effect.setFloat2('centerPosition', this.centerPosition.x, this.centerPosition.y);
        });
    }

    /** @hidden */
    public static _Parse(parsedPostProcess: any, targetCamera: Camera, scene: Scene, rootUrl: string): Nullable<ChromaticAberrationPostProcess> {
        return SerializationHelper.Parse(() => {
            return new ChromaticAberrationPostProcess(
                parsedPostProcess.name,
                parsedPostProcess.screenWidth, parsedPostProcess.screenHeight,
                parsedPostProcess.options, targetCamera,
                parsedPostProcess.renderTargetSamplingMode,
                scene.getEngine(), parsedPostProcess.reusable,
                parsedPostProcess.textureType, false);
        }, parsedPostProcess, scene, rootUrl);
    }
}

_TypeStore.RegisteredTypes["BABYLON.ChromaticAberrationPostProcess"] = ChromaticAberrationPostProcess;