/******************************************************************************
 * Spine Runtimes License Agreement
 * Last updated April 5, 2025. Replaces all prior versions.
 *
 * Copyright (c) 2013-2025, Esoteric Software LLC
 *
 * Integration of the Spine Runtimes into software or otherwise creating
 * derivative works of the Spine Runtimes is permitted under the terms and
 * conditions of Section 2 of the Spine Editor License Agreement:
 * http://esotericsoftware.com/spine-editor-license
 *
 * Otherwise, it is permitted to integrate the Spine Runtimes into software
 * or otherwise create derivative works of the Spine Runtimes (collectively,
 * "Products"), provided that each user of the Products must obtain their own
 * Spine Editor license and redistribution of the Products in any form must
 * include this license and copyright notice.
 *
 * THE SPINE RUNTIMES ARE PROVIDED BY ESOTERIC SOFTWARE LLC "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL ESOTERIC SOFTWARE LLC BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES,
 * BUSINESS INTERRUPTION, OR LOSS OF USE, DATA, OR PROFITS) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *****************************************************************************/

import {
	AnimationState,
	AnimationStateData,
	ClippingAttachment,
	Color,
	MeshAttachment,
	type NumberArrayLike,
	Physics,
	RegionAttachment,
	Skeleton,
	SkeletonBinary,
	SkeletonClipping,
	type SkeletonData,
	SkeletonJson,
	Utils,
	Vector2,
} from "@esotericsoftware/spine-core";
import * as THREE from "three";

import { type MaterialWithMap, MeshBatcher } from "./MeshBatcher.js";
import type { ThreeJsTexture } from "./ThreeJsTexture.js";

type SkeletonMeshMaterialParametersCustomizer = (materialParameters: THREE.MaterialParameters) => void;
type SkeletonMeshConfiguration = {

	/** The skeleton data object loaded by using {@link SkeletonJson} or {@link SkeletonBinary} */
	skeletonData: SkeletonData,

	/** Set it to true to enable tint black rendering */
	twoColorTint?: boolean,

	/**
	 * The function used to create the materials for the meshes composing this Object3D.
	 * The material used must have the `map` property.
	 * By default a MeshStandardMaterial is used, so no light and shadows are available.
	 * Use a MeshStandardMaterial
	 *
	 * @param parameters The default parameters with which this function is invoked.
	 * You should pass this parameters, once personalized, to the costructor of the material you want to use.
	 * Default values are defined in {@link SkeletonMesh.DEFAULT_MATERIAL_PARAMETERS}.
	 *
	 * @returns An instance of the material you want to be used for the meshes of this Object3D. The material must have the `map` property.
	 */
	materialFactory?: (parameters: THREE.MaterialParameters) => MaterialWithMap,
};

export class SkeletonMesh extends THREE.Object3D {
	// public static readonly DEFAULT_MATERIAL_PARAMETERS: THREE.MaterialParameters = {
	public static readonly DEFAULT_MATERIAL_PARAMETERS: THREE.MaterialParameters = {
		side: THREE.DoubleSide,
		depthWrite: true,
		depthTest: true,
		transparent: true,
		alphaTest: 0.001,
		vertexColors: true,
		premultipliedAlpha: true,
	}

	tempPos: Vector2 = new Vector2();
	tempUv: Vector2 = new Vector2();
	tempLight = new Color();
	tempDark = new Color();
	skeleton: Skeleton;
	state: AnimationState;
	zOffset: number = 0.1;

	private batches = [] as MeshBatcher[];
	private materialFactory: (parameters: THREE.MaterialParameters) => MaterialWithMap;
	private nextBatchIndex = 0;
	private clipper: SkeletonClipping = new SkeletonClipping();

	static QUAD_TRIANGLES = [0, 1, 2, 2, 3, 0];
	static VERTEX_SIZE = 2 + 2 + 4;
	private vertexSize = 2 + 2 + 4;
	private twoColorTint: boolean;

	private vertices = Utils.newFloatArray(1024);
	private tempColor = new Color();
	private tempDarkColor = new Color();

	private _castShadow = false;
	private _receiveShadow = false;

	/**
	 * Create an Object3D containing meshes representing your Spine animation.
	 * Personalize your material providing a {@link SkeletonMeshConfiguration}
	 * @param skeletonData
	 */
	constructor (configuration: SkeletonMeshConfiguration)
	/**
	 * @deprecated This signature is deprecated, please use the one with a single {@link SkeletonMeshConfiguration} parameter
	 */
	constructor (
		skeletonData: SkeletonData,
		materialCustomizer: SkeletonMeshMaterialParametersCustomizer,
	)
	constructor (
		skeletonDataOrConfiguration: SkeletonData | SkeletonMeshConfiguration,
		materialCustomizer: SkeletonMeshMaterialParametersCustomizer = () => { }
	) {
		super();

		if (!('skeletonData' in skeletonDataOrConfiguration)) {
			const materialFactory = () => {
				const parameters: THREE.MaterialParameters = { ...SkeletonMesh.DEFAULT_MATERIAL_PARAMETERS };
				materialCustomizer(parameters);
				return new THREE.MeshBasicMaterial(parameters);
			};
			skeletonDataOrConfiguration = {
				skeletonData: skeletonDataOrConfiguration,
				materialFactory,
			}
		}

		this.twoColorTint = skeletonDataOrConfiguration.twoColorTint ?? true;
		if (this.twoColorTint) {
			this.vertexSize += 4;
		}

		this.materialFactory = skeletonDataOrConfiguration.materialFactory ?? (() => new THREE.MeshBasicMaterial(SkeletonMesh.DEFAULT_MATERIAL_PARAMETERS));
		this.skeleton = new Skeleton(skeletonDataOrConfiguration.skeletonData);
		const animData = new AnimationStateData(skeletonDataOrConfiguration.skeletonData);
		this.state = new AnimationState(animData);

		Object.defineProperty(this, 'castShadow', {
			get: () => this._castShadow,
			set: (value: boolean) => {
				this._castShadow = value;
				this.traverse((child) => {
					if (child instanceof MeshBatcher) {
						child.castShadow = value;
					}
				});
			},
		});

		Object.defineProperty(this, 'receiveShadow', {
			get: () => this._receiveShadow,
			set: (value: boolean) => {
				this._receiveShadow = value;
				// Propagate to children
				this.traverse((child) => {
					if (child instanceof MeshBatcher) {
						child.receiveShadow = value;
					}
				});
			},
		});
	}

	update (deltaTime: number) {
		const state = this.state;
		const skeleton = this.skeleton;

		state.update(deltaTime);
		state.apply(skeleton);
		skeleton.update(deltaTime);
		skeleton.updateWorldTransform(Physics.update);

		this.updateGeometry();
	}

	dispose () {
		for (let i = 0; i < this.batches.length; i++) {
			this.batches[i].dispose();
		}
	}

	private clearBatches () {
		for (let i = 0; i < this.batches.length; i++) {
			this.batches[i].clear();
			this.batches[i].visible = false;
		}
		this.nextBatchIndex = 0;
	}

	private nextBatch () {
		if (this.batches.length === this.nextBatchIndex) {
			const batch = new MeshBatcher(MeshBatcher.MAX_VERTICES, this.materialFactory, this.twoColorTint);
			batch.castShadow = this._castShadow;
			batch.receiveShadow = this._receiveShadow;
			this.add(batch);
			this.batches.push(batch);
		}
		const batch = this.batches[this.nextBatchIndex++];
		batch.visible = true;
		return batch;
	}

	private updateGeometry () {
		this.clearBatches();

		const clipper = this.clipper;

		let vertices: NumberArrayLike = this.vertices;
		let triangles: Array<number> | null = null;
		let uvs: NumberArrayLike | null = null;
		const skeleton = this.skeleton;
		const drawOrder = skeleton.drawOrder;
		let batch = this.nextBatch();
		batch.begin();
		let z = 0;
		const zOffset = this.zOffset;
		const vertexSize = this.vertexSize;
		for (let i = 0, n = drawOrder.length; i < n; i++) {
			const slot = drawOrder[i];
			if (!slot.bone.active) {
				clipper.clipEnd(slot);
				continue;
			}
			const pose = slot.applied;
			const attachment = pose.attachment;
			let attachmentColor: Color | null;
			let texture: ThreeJsTexture | null;
			let numFloats = 0;
			if (attachment instanceof RegionAttachment) {
				attachmentColor = attachment.color;
				vertices = this.vertices;
				numFloats = vertexSize * 4;
				attachment.computeWorldVertices(slot, vertices, 0, vertexSize);
				triangles = SkeletonMesh.QUAD_TRIANGLES;
				uvs = attachment.uvs;
				texture = <ThreeJsTexture>attachment.region?.texture;
			} else if (attachment instanceof MeshAttachment) {
				attachmentColor = attachment.color;
				vertices = this.vertices;
				numFloats = (attachment.worldVerticesLength >> 1) * vertexSize;
				if (numFloats > vertices.length) {
					vertices = this.vertices = Utils.newFloatArray(numFloats);
				}
				attachment.computeWorldVertices(
					skeleton,
					slot,
					0,
					attachment.worldVerticesLength,
					vertices,
					0,
					vertexSize
				);
				triangles = attachment.triangles;
				uvs = attachment.uvs;
				texture = <ThreeJsTexture>attachment.region?.texture;
			} else if (attachment instanceof ClippingAttachment) {
				clipper.clipEnd(slot);
				clipper.clipStart(skeleton, slot, attachment);
				continue;
			} else {
				clipper.clipEnd(slot);
				continue;
			}

			if (texture != null) {
				const skeletonColor = skeleton.color;
				const slotColor = pose.color;
				const alpha = skeletonColor.a * slotColor.a * attachmentColor.a;
				const color = this.tempColor;
				color.set(
					skeletonColor.r * slotColor.r * attachmentColor.r * alpha,
					skeletonColor.g * slotColor.g * attachmentColor.g * alpha,
					skeletonColor.b * slotColor.b * attachmentColor.b * alpha,
					alpha
				);

				const darkColor = this.tempDarkColor;
				if (!pose.darkColor)
					darkColor.set(0, 0, 0, 1);
				else {
					darkColor.r = pose.darkColor.r * alpha;
					darkColor.g = pose.darkColor.g * alpha;
					darkColor.b = pose.darkColor.b * alpha;
					darkColor.a = 1;
				}

				let finalVertices: NumberArrayLike;
				let finalVerticesLength: number;
				let finalIndices: NumberArrayLike;
				let finalIndicesLength: number;

				if (clipper.isClipping() && clipper.clipTriangles(vertices, triangles, triangles.length, uvs, color, darkColor, this.twoColorTint, vertexSize)) {
					const clippedVertices = clipper.clippedVertices;
					const clippedTriangles = clipper.clippedTriangles;
					finalVertices = clippedVertices;
					finalVerticesLength = clippedVertices.length;
					finalIndices = clippedTriangles;
					finalIndicesLength = clippedTriangles.length;
				} else {
					const verts = vertices;
					if (!this.twoColorTint) {
						for (let v = 2, u = 0, n = numFloats; v < n; v += vertexSize, u += 2) {
							verts[v] = color.r;
							verts[v + 1] = color.g;
							verts[v + 2] = color.b;
							verts[v + 3] = color.a;
							verts[v + 4] = uvs[u];
							verts[v + 5] = uvs[u + 1];
						}
					} else {
						for (let v = 2, u = 0, n = numFloats; v < n; v += vertexSize, u += 2) {
							verts[v] = color.r;
							verts[v + 1] = color.g;
							verts[v + 2] = color.b;
							verts[v + 3] = color.a;
							verts[v + 4] = uvs[u];
							verts[v + 5] = uvs[u + 1];
							verts[v + 6] = darkColor.r;
							verts[v + 7] = darkColor.g;
							verts[v + 8] = darkColor.b;
							verts[v + 9] = darkColor.a;
						}
					}

					finalVertices = vertices;
					finalVerticesLength = numFloats;
					finalIndices = triangles;
					finalIndicesLength = triangles.length;
				}

				if (finalVerticesLength === 0 || finalIndicesLength === 0) {
					clipper.clipEnd(slot);
					continue;
				}

				// Start new batch if this one can't hold vertices/indices
				if (
					!batch.canBatch(
						finalVerticesLength / this.vertexSize,
						finalIndicesLength
					)
				) {
					batch.end();
					batch = this.nextBatch();
					batch.begin();
				}

				const slotBlendMode = slot.data.blendMode;
				const slotTexture = texture.texture;
				const materialGroup = batch.findMaterialGroup(
					slotTexture,
					slotBlendMode
				);

				batch.addMaterialGroup(finalIndicesLength, materialGroup);
				batch.batch(
					finalVertices,
					finalVerticesLength,
					finalIndices,
					finalIndicesLength,
					z
				);
				z += zOffset;
			}

			clipper.clipEnd(slot);
		}
		clipper.clipEnd();
		batch.end();
	}
}