import { Nullable } from "babylonjs/types";
import { serialize, expandToProperty, serializeAsColor3, SerializationHelper } from "babylonjs/Misc/decorators";
import { Color3, Matrix } from "babylonjs/Maths/math";
import { IAnimatable } from "babylonjs/Misc/tools";
import { BaseTexture } from "babylonjs/Materials/Textures/baseTexture";
import { MaterialDefines } from "babylonjs/Materials/materialDefines";
import { MaterialHelper } from "babylonjs/Materials/materialHelper";
import { EffectCreationOptions, EffectFallbacks } from "babylonjs/Materials/effect";
import { PushMaterial } from "babylonjs/Materials/pushMaterial";
import { VertexBuffer } from "babylonjs/Meshes/buffer";
import { AbstractMesh } from "babylonjs/Meshes/abstractMesh";
import { SubMesh } from "babylonjs/Meshes/subMesh";
import { Mesh } from "babylonjs/Meshes/mesh";
import { Scene } from "babylonjs/scene";

import "./gradient.fragment";
import "./gradient.vertex";

class GradientMaterialDefines extends MaterialDefines {
    public EMISSIVE = false;
    public CLIPPLANE = false;
    public CLIPPLANE2 = false;
    public CLIPPLANE3 = false;
    public CLIPPLANE4 = false;
    public ALPHATEST = false;
    public DEPTHPREPASS = false;
    public POINTSIZE = false;
    public FOG = false;
    public NORMAL = false;
    public UV1 = false;
    public UV2 = false;
    public VERTEXCOLOR = false;
    public VERTEXALPHA = false;
    public NUM_BONE_INFLUENCERS = 0;
    public BonesPerMesh = 0;
    public INSTANCES = false;

    constructor() {
        super();
        this.rebuild();
    }
}

export class GradientMaterial extends PushMaterial {

    @serialize("maxSimultaneousLights")
    private _maxSimultaneousLights = 4;
    @expandToProperty("_markAllSubMeshesAsLightsDirty")
    public maxSimultaneousLights: number;

    // The gradient top color, red by default
    @serializeAsColor3()
    public topColor = new Color3(1, 0, 0);

    @serialize()
    public topColorAlpha = 1.0;

    // The gradient top color, blue by default
    @serializeAsColor3()
    public bottomColor = new Color3(0, 0, 1);

    @serialize()
    public bottomColorAlpha = 1.0;

    // Gradient offset
    @serialize()
    public offset = 0;

    @serialize()
    public scale = 1.0;

    @serialize()
    public smoothness = 1.0;

    @serialize("disableLighting")
    private _disableLighting = false;
    @expandToProperty("_markAllSubMeshesAsLightsDirty")
    public disableLighting: boolean;

    private _renderId: number;

    constructor(name: string, scene: Scene) {
        super(name, scene);
    }

    public needAlphaBlending(): boolean {
        return (this.alpha < 1.0 || this.topColorAlpha < 1.0 || this.bottomColorAlpha < 1.0);
    }

    public needAlphaTesting(): boolean {
        return true;
    }

    public getAlphaTestTexture(): Nullable<BaseTexture> {
        return null;
    }

    // Methods
    public isReadyForSubMesh(mesh: AbstractMesh, subMesh: SubMesh, useInstances?: boolean): boolean {
        if (this.isFrozen) {
            if (this._wasPreviouslyReady && subMesh.effect) {
                return true;
            }
        }

        if (!subMesh._materialDefines) {
            subMesh._materialDefines = new GradientMaterialDefines();
        }

        var defines = <GradientMaterialDefines>subMesh._materialDefines;
        var scene = this.getScene();

        if (!this.checkReadyOnEveryCall && subMesh.effect) {
            if (this._renderId === scene.getRenderId()) {
                return true;
            }
        }

        var engine = scene.getEngine();

        MaterialHelper.PrepareDefinesForFrameBoundValues(scene, engine, defines, useInstances ? true : false);

        MaterialHelper.PrepareDefinesForMisc(mesh, scene, false, this.pointsCloud, this.fogEnabled, this._shouldTurnAlphaTestOn(mesh), defines);

        defines._needNormals = MaterialHelper.PrepareDefinesForLights(scene, mesh, defines, false, this._maxSimultaneousLights, this._disableLighting);

        defines.EMISSIVE = this._disableLighting;

        // Attribs
        MaterialHelper.PrepareDefinesForAttributes(mesh, defines, false, true);

        // Get correct effect
        if (defines.isDirty) {
            defines.markAsProcessed();

            scene.resetCachedMaterial();

            // Fallbacks
            var fallbacks = new EffectFallbacks();
            if (defines.FOG) {
                fallbacks.addFallback(1, "FOG");
            }

            MaterialHelper.HandleFallbacksForShadows(defines, fallbacks);

            if (defines.NUM_BONE_INFLUENCERS > 0) {
                fallbacks.addCPUSkinningFallback(0, mesh);
            }

            //Attributes
            var attribs = [VertexBuffer.PositionKind];

            if (defines.NORMAL) {
                attribs.push(VertexBuffer.NormalKind);
            }

            if (defines.UV1) {
                attribs.push(VertexBuffer.UVKind);
            }

            if (defines.UV2) {
                attribs.push(VertexBuffer.UV2Kind);
            }

            if (defines.VERTEXCOLOR) {
                attribs.push(VertexBuffer.ColorKind);
            }

            MaterialHelper.PrepareAttributesForBones(attribs, mesh, defines, fallbacks);
            MaterialHelper.PrepareAttributesForInstances(attribs, defines);

            // Legacy browser patch
            var shaderName = "gradient";
            var join = defines.toString();

            var uniforms = ["world", "view", "viewProjection", "vEyePosition", "vLightsType",
                "vFogInfos", "vFogColor", "pointSize",
                "mBones",
                "vClipPlane", "vClipPlane2", "vClipPlane3", "vClipPlane4",
                "topColor", "bottomColor", "offset", "smoothness", "scale"
            ];
            var samplers: string[] = [];
            var uniformBuffers = new Array<string>();

            MaterialHelper.PrepareUniformsAndSamplersList(<EffectCreationOptions>{
                uniformsNames: uniforms,
                uniformBuffersNames: uniformBuffers,
                samplers: samplers,
                defines: defines,
                maxSimultaneousLights: 4
            });

            subMesh.setEffect(scene.getEngine().createEffect(shaderName,
                <EffectCreationOptions>{
                    attributes: attribs,
                    uniformsNames: uniforms,
                    uniformBuffersNames: uniformBuffers,
                    samplers: samplers,
                    defines: join,
                    fallbacks: fallbacks,
                    onCompiled: this.onCompiled,
                    onError: this.onError,
                    indexParameters: { maxSimultaneousLights: 4 }
                }, engine), defines);
        }
        if (!subMesh.effect || !subMesh.effect.isReady()) {
            return false;
        }

        this._renderId = scene.getRenderId();
        this._wasPreviouslyReady = true;

        return true;
    }

    public bindForSubMesh(world: Matrix, mesh: Mesh, subMesh: SubMesh): void {
        var scene = this.getScene();

        var defines = <GradientMaterialDefines>subMesh._materialDefines;
        if (!defines) {
            return;
        }

        var effect = subMesh.effect;
        if (!effect) {
            return;
        }

        this._activeEffect = effect;

        // Matrices
        this.bindOnlyWorldMatrix(world);
        this._activeEffect.setMatrix("viewProjection", scene.getTransformMatrix());

        // Bones
        MaterialHelper.BindBonesParameters(mesh, effect);

        if (this._mustRebind(scene, effect)) {
            // Clip plane
            MaterialHelper.BindClipPlane(effect, scene);

            // Point size
            if (this.pointsCloud) {
                this._activeEffect.setFloat("pointSize", this.pointSize);
            }

            MaterialHelper.BindEyePosition(effect, scene);
        }

        if (scene.lightsEnabled && !this.disableLighting) {
            MaterialHelper.BindLights(scene, mesh, this._activeEffect, defines, this.maxSimultaneousLights);
        }

        // View
        if (scene.fogEnabled && mesh.applyFog && scene.fogMode !== Scene.FOGMODE_NONE) {
            this._activeEffect.setMatrix("view", scene.getViewMatrix());
        }

        // Fog
        MaterialHelper.BindFogParameters(scene, mesh, this._activeEffect);

        this._activeEffect.setColor4("topColor", this.topColor, this.topColorAlpha);
        this._activeEffect.setColor4("bottomColor", this.bottomColor, this.bottomColorAlpha);
        this._activeEffect.setFloat("offset", this.offset);
        this._activeEffect.setFloat("scale", this.scale);
        this._activeEffect.setFloat("smoothness", this.smoothness);

        this._afterBind(mesh, this._activeEffect);
    }

    public getAnimatables(): IAnimatable[] {
        return [];
    }

    public dispose(forceDisposeEffect?: boolean): void {

        super.dispose(forceDisposeEffect);
    }

    public clone(name: string): GradientMaterial {
        return SerializationHelper.Clone(() => new GradientMaterial(name, this.getScene()), this);
    }

    public serialize(): any {
        var serializationObject = SerializationHelper.Serialize(this);
        serializationObject.customType = "BABYLON.GradientMaterial";
        return serializationObject;
    }

    public getClassName(): string {
        return "GradientMaterial";
    }

    // Statics
    public static Parse(source: any, scene: Scene, rootUrl: string): GradientMaterial {
        return SerializationHelper.Parse(() => new GradientMaterial(source.name, scene), source, scene, rootUrl);
    }
}