import {ShaderMaterial} from 'three';
import {Object3D} from 'three';
import {Mesh} from 'three';
import {Material} from 'three';
import {PolyScene} from '../../engine/scene/PolyScene';
import {IUniform} from 'three';
import {UniformsUtils} from 'three';
export interface IUniforms {
	[uniform: string]: IUniform;
}
export interface MaterialWithUniforms extends Material {
	uniforms: IUniforms;
}

export enum CustomMaterialName {
	DISTANCE = 'customDistanceMaterial', // for point lights
	DEPTH = 'customDepthMaterial', // for spot lights and directional
	DEPTH_DOF = 'customDepthDOFMaterial', // for post/bokeh only (see in scene.)
}

export interface ObjectWithCustomMaterials extends Mesh {
	// customDistanceMaterial?: Material;
	// customDepthMaterial?: Material;
	customDepthDOFMaterial?: Material;
}
export interface MaterialWithCustomMaterials extends Material {
	customMaterials: {
		[key in CustomMaterialName]?: Material;
	};
}
export interface ShaderMaterialWithCustomMaterials extends ShaderMaterial {
	customMaterials: {
		[key in CustomMaterialName]?: Material;
	};
}
export interface MaterialWithSkinning extends Material {
	skinning: boolean;
	morphTargets: boolean;
}

import {WebGLRenderer} from 'three';
import {Scene} from 'three';
import {Camera} from 'three';
import {BufferGeometry} from 'three';
import {Group} from 'three';
import {ShaderAssemblerMaterial} from '../../engine/nodes/gl/code/assemblers/materials/_BaseMaterial';
import {
	assignUniformViaUserData,
	copyOnBeforeCompileData,
} from '../../engine/nodes/gl/code/assemblers/materials/OnBeforeCompile';
import {IUniformTexture} from '../../engine/nodes/utils/code/gl/Uniforms';

export type RenderHook = (
	renderer: WebGLRenderer,
	scene: Scene,
	camera: Camera,
	geometry: BufferGeometry,
	material: Material,
	group: Group | null // it's only 'Group', and not 'Group|null' in threejs types, but got null sometimes
) => void;
export type RenderHookWithObject = (
	renderer: WebGLRenderer,
	scene: Scene,
	camera: Camera,
	geometry: BufferGeometry,
	material: Material,
	group: Group | null, // it's only 'Group', and not 'Group|null' in threejs types, but got null sometimes
	object: Object3D
) => void;
const RENDER_HOOK_USER_DATA_KEY = 'POLY_render_hook';

interface MaterialWithRenderHook extends Material {
	userData: {
		[RENDER_HOOK_USER_DATA_KEY]?: RenderHookWithObject;
	};
}

const EMPTY_RENDER_HOOK: RenderHook = (
	renderer: WebGLRenderer,
	scene: Scene,
	camera: Camera,
	geometry: BufferGeometry,
	material: Material,
	group: Group | null
) => {};

interface CloneOptions {
	shareCustomUniforms: boolean;
	addCustomMaterials: boolean;
}
export function cloneMaterial(scene: PolyScene, srcMaterial: Material | ShaderMaterial, options: CloneOptions) {
	const clonedMaterial = srcMaterial.clone();
	const srcUniforms = (srcMaterial as ShaderMaterial).uniforms;
	if (srcUniforms) {
		(clonedMaterial as ShaderMaterial).uniforms = UniformsUtils.clone(srcUniforms);
	}
	copyOnBeforeCompileData(scene, {
		src: srcMaterial,
		dest: clonedMaterial,
		shareCustomUniforms: options.shareCustomUniforms,
	});

	if ((srcMaterial as MaterialWithCustomMaterials).customMaterials && options.addCustomMaterials) {
		const customNames = Object.keys((srcMaterial as MaterialWithCustomMaterials).customMaterials);
		if (customNames.length > 0) {
			(clonedMaterial as MaterialWithCustomMaterials).customMaterials = {};
		}
		for (const customName of customNames) {
			const matName = customName as CustomMaterialName;
			const customMaterial = (srcMaterial as MaterialWithCustomMaterials).customMaterials[matName];
			if (customMaterial) {
				const clonedCustomMaterial = cloneMaterial(scene, customMaterial, {
					...options,
					addCustomMaterials: false,
				});
				(clonedMaterial as MaterialWithCustomMaterials).customMaterials[matName] = clonedCustomMaterial;
			}
		}
	}

	return clonedMaterial;
}

export function applyCustomMaterials(object: Object3D, material: Material) {
	const materialWithCustom = material as MaterialWithCustomMaterials;
	if (materialWithCustom.customMaterials) {
		for (const customName of Object.keys(materialWithCustom.customMaterials)) {
			const matName = customName as CustomMaterialName;
			// http://blog.edankwan.com/post/three-js-advanced-tips-shadow
			const customMaterial = materialWithCustom.customMaterials[matName];
			if (customMaterial) {
				(object as ObjectWithCustomMaterials)[matName] = customMaterial;
				customMaterial.needsUpdate = true;
			}
		}
		// object.material = material.customMaterials.customDepthDOFMaterial
		// object.material = material.customMaterials.customDepthMaterial
		// object.material = material.customMaterials.customDistanceMaterial
	}
}

/*
//
// TODO:
// this render hook system has a big limitation,
// which is that if we clone the object, it may not be propagated correctly,
// since this is assigned at render time.
// This means that if we clone an object before it has been rendered,
// it won't have the onBeforeRender function, and therefore won't pass it on to its clone.
//
*/
export function addUserDataRenderHook(material: Material, renderHook: RenderHookWithObject) {
	material.userData[RENDER_HOOK_USER_DATA_KEY] = renderHook;
}
export function applyRenderHook(object: Object3D, material: MaterialWithRenderHook) {
	if (material.userData) {
		const renderHook: RenderHookWithObject | undefined = material.userData[RENDER_HOOK_USER_DATA_KEY];
		if (renderHook) {
			object.onBeforeRender = (
				renderer: WebGLRenderer,
				scene: Scene,
				camera: Camera,
				geometry: BufferGeometry,
				material: Material,
				group: Group | null
			) => {
				renderHook(renderer, scene, camera, geometry, material, group, object);
			};
			return;
		}
	}
	// make sure to reset the render hook if apply to a material that does not have any
	object.onBeforeRender = EMPTY_RENDER_HOOK;
}
export function assignUniforms(
	mat: Material,
	uniformName: string,
	uniform: IUniformTexture,
	assembler?: ShaderAssemblerMaterial
) {
	assignUniformViaUserData(mat, uniformName, uniform);
	if (assembler) {
		assignUniformForOnBeforeCompile(mat, uniformName, uniform, assembler);
	}
}
export function assignUniformForOnBeforeCompile(
	mat: Material,
	uniformName: string,
	uniform: IUniformTexture,
	assembler: ShaderAssemblerMaterial
) {
	assembler.addAdditionalTextureUniforms(uniformName, uniform);
}
export class CoreMaterial {
	static node(scene: PolyScene, material: Material) {
		return scene.node(material.name);
	}
	static clone = cloneMaterial;
	static applyCustomMaterials = applyCustomMaterials;
	static assignUniforms = assignUniforms;
	static assignUniformForOnBeforeCompile = assignUniformForOnBeforeCompile;
}