/* spellchecker: disable */

import { mat4, vec3 } from 'gl-matrix';

import { auxiliaries } from 'webgl-operate';

import {
    Camera,
    Canvas,
    Context,
    DefaultFramebuffer,
    EventProvider,
    ForwardSceneRenderPass,
    Framebuffer,
    Geometry,
    GLTFLoader,
    GLTFPbrMaterial,
    Invalidate,
    Material,
    Navigation,
    Program,
    Renderer,
    Shader,
    Texture2D,
    Wizard,
} from 'webgl-operate';

import { Example } from './example';

/* spellchecker: enable */


// tslint:disable:max-classes-per-file

export class XToonRenderer extends Renderer {

    protected _loader: GLTFLoader;

    protected _navigation: Navigation;

    protected _forwardPass: ForwardSceneRenderPass;

    protected _camera: Camera;

    protected _texture: Texture2D;
    protected _framebuffer: Framebuffer;
    protected _program: Program;

    protected _uViewProjection: WebGLUniformLocation;
    protected _uModel: WebGLUniformLocation;
    protected _uNormal: WebGLUniformLocation;
    protected _uEye: WebGLUniformLocation;

    /**
     * Initializes and sets up rendering passes, navigation, loads a font face and links shaders with program.
     * @param context - valid context to create the object for.
     * @param identifier - meaningful name for identification of this instance.
     * @param mouseEventProvider - required for mouse interaction
     * @returns - whether initialization was successful
     */
    protected onInitialize(context: Context, callback: Invalidate,
        eventProvider: EventProvider): boolean {

        const gl = this._context.gl;

        this._loader = new GLTFLoader(this._context);

        this._framebuffer = new DefaultFramebuffer(this._context, 'DefaultFBO');
        this._framebuffer.initialize();

        const vert = new Shader(context, gl.VERTEX_SHADER, 'xtoon.vert');
        vert.initialize(require('./data/xtoon.vert'));
        const frag = new Shader(context, gl.FRAGMENT_SHADER, 'xtoon.frag');
        frag.initialize(require('./data/xtoon.frag'));

        this._program = new Program(context, 'PhongProgram');
        this._program.initialize([vert, frag], true);
        this._program.link();
        this._program.bind();

        this._uViewProjection = this._program.uniform('u_viewProjection');
        this._uModel = this._program.uniform('u_model');
        this._uEye = this._program.uniform('u_eye');

        this._uNormal = this._program.uniform('u_normal');

        gl.uniform1i(this._program.uniform('u_gradient'), 1);


        this._texture = new Texture2D(context, 'Texture');
        this._texture.initialize(1, 1, gl.RGB, gl.RGB, gl.UNSIGNED_BYTE);
        this._texture.wrap(gl.CLAMP_TO_EDGE, gl.CLAMP_TO_EDGE);
        this._texture.filter(gl.NEAREST, gl.NEAREST);
        // this._texture.filter(gl.LINEAR, gl.LINEAR_MIPMAP_LINEAR);
        // this._texture.maxAnisotropy(Texture2D.MAX_ANISOTROPY);

        this._texture.fetch('/examples/data/gradient.png', false).then(() => {
            this.invalidate(true);
        });


        /* Create and configure camera. */

        this._camera = new Camera();
        this._camera.center = vec3.fromValues(0.0, 0.0, 0.0);
        this._camera.up = vec3.fromValues(0.0, 1.0, 0.0);
        this._camera.eye = vec3.fromValues(0.0, 1.0, 2.0);
        this._camera.near = 0.5;
        this._camera.far = 4.0;

        /* Create and configure navigation */

        this._navigation = new Navigation(callback, eventProvider);
        this._navigation.camera = this._camera;

        /* Create and configure forward pass. */

        this._forwardPass = new ForwardSceneRenderPass(context);
        this._forwardPass.initialize();

        this._forwardPass.camera = this._camera;
        this._forwardPass.target = this._framebuffer;

        this._forwardPass.program = this._program;
        this._forwardPass.updateModelTransform = (matrix: mat4) => {
            gl.uniformMatrix4fv(this._uModel, false, matrix);
        };
        this._forwardPass.updateViewProjectionTransform = (matrix: mat4) => {
            gl.uniformMatrix4fv(this._uViewProjection, false, matrix);
        };

        this._forwardPass.bindUniforms = () => {
            gl.uniform3fv(this._uEye, this._camera.eye);
            gl.uniform1i(this._uNormal, 2);
        };

        this._forwardPass.bindGeometry = (geometry: Geometry) => {
        };

        this._forwardPass.bindMaterial = (material: Material) => {
            const pbrMaterial = material as GLTFPbrMaterial;
            auxiliaries.assert(pbrMaterial !== undefined, `Material ${material.name} is not a PBR material.`);

            pbrMaterial.normalTexture!.bind(gl.TEXTURE2);
            this._texture.bind(gl.TEXTURE1);
        };

        this.loadAsset();

        return true;
    }

    /**
     * Uninitializes Buffers, Textures, and Program.
     */
    protected onUninitialize(): void {
        super.uninitialize();

        // ToDo: make sure that all meshes and programs inside of the scene get cleaned

        // this._mesh.uninitialize();
        // this._meshProgram.uninitialize();
    }

    protected onDiscarded(): void {
        this._altered.alter('canvasSize');
        this._altered.alter('clearColor');
        this._altered.alter('frameSize');
        this._altered.alter('multiFrameNumber');
    }

    /**
     * This is invoked in order to check if rendering of a frame is required by means of implementation specific
     * evaluation (e.g., lazy non continuous rendering). Regardless of the return value a new frame (preparation,
     * frame, swap) might be invoked anyway, e.g., when update is forced or canvas or context properties have
     * changed or the renderer was invalidated @see{@link invalidate}.
     * Updates the navigaten and the AntiAliasingKernel.
     * @returns whether to redraw
     */
    protected onUpdate(): boolean {
        if (this._altered.frameSize) {
            this._camera.viewport = [this._frameSize[0], this._frameSize[1]];
        }
        if (this._altered.canvasSize) {
            this._camera.aspect = this._canvasSize[0] / this._canvasSize[1];
        }
        if (this._altered.clearColor) {
            this._forwardPass.clearColor = this._clearColor;
        }

        this._navigation.update();
        this._forwardPass.update();

        return this._altered.any || this._camera.altered;
    }

    /**
     * This is invoked in order to prepare rendering of one or more frames, regarding multi-frame rendering and
     * camera-updates.
     */
    protected onPrepare(): void {
        this._forwardPass.prepare();

        this._altered.reset();
        this._camera.altered = false;
    }

    protected onFrame(frameNumber: number): void {
        if (this.isLoading) {
            return;
        }

        this._forwardPass.frame();
    }

    protected onSwap(): void {
    }

    /**
     * Load asset from URI specified by the HTML select
     */
    protected loadAsset(): void {
        const uri = '/examples/data/matrix-chair.glb';
        this._forwardPass.scene = undefined;

        this._loader.uninitialize();
        this._loader.loadAsset(uri)
            .then(() => {
                this._forwardPass.scene = this._loader.defaultScene;
                this.finishLoading();
                this.invalidate(true);
            });
    }
}


export class XToonExample extends Example {

    private _canvas: Canvas;
    private _renderer: XToonRenderer;

    onInitialize(element: HTMLCanvasElement | string): boolean {

        this._canvas = new Canvas(element, { antialias: false });

        this._canvas.controller.multiFrameNumber = 1;
        this._canvas.framePrecision = Wizard.Precision.byte;
        this._canvas.frameScale = [1.0, 1.0];

        this._renderer = new XToonRenderer();
        this._canvas.renderer = this._renderer;

        return true;
    }

    onUninitialize(): void {
        this._canvas.dispose();
        (this._renderer as Renderer).uninitialize();
    }

    get canvas(): Canvas {
        return this._canvas;
    }

    get renderer(): XToonRenderer {
        return this._renderer;
    }

}