/******************************************************************************
 * 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 type { BlendMode, Bone, Event, NumberArrayLike, Slot, TextureAtlas, TrackEntry } from "@esotericsoftware/spine-core";
import {
	AnimationState,
	AnimationStateData,
	AtlasAttachmentLoader,
	ClippingAttachment,
	Color,
	MeshAttachment,
	Physics,
	RegionAttachment,
	Skeleton,
	SkeletonBinary,
	SkeletonClipping,
	SkeletonData,
	SkeletonJson,
	Skin,
	Utils,
	Vector2,
} from "@esotericsoftware/spine-core";
import { Assets } from "@pixi/assets";
import { type IPointData, Point, Ticker } from "@pixi/core";
import type { DisplayObject, IDestroyOptions } from "@pixi/display";
import { Bounds, Container } from "@pixi/display";
import { Graphics } from "@pixi/graphics";
import { DarkSlotMesh } from "./DarkSlotMesh.js";
import { SlotMesh } from "./SlotMesh.js";
import type { ISpineDebugRenderer, SpineDebugRenderer } from "./SpineDebugRenderer.js";
import type { SpineTexture } from "./SpineTexture.js";
import "@pixi/events";

/**
 * Options to create a {@link Spine} using {@link Spine.from}.
 */
export interface SpineFromOptions {
	/** the asset name for the skeleton `.skel` or `.json` file previously loaded into the Assets */
	skeleton: string;

	/** the asset name for the atlas file previously loaded into the Assets */
	atlas: string;

	/**  The value passed to the skeleton reader. If omitted, 1 is passed. See {@link SkeletonBinary.scale} for details. */
	scale?: number;

	/**  Set the {@link Spine.autoUpdate} value. If omitted, it is set to `true`. */
	autoUpdate?: boolean;

	/**
	 * If `true`, use the dark tint renderer to render the skeleton
	 * If `false`, use the default pixi renderer to render the skeleton
	 * If `undefined`, use the dark tint renderer if at least one slot has tint black
	 */
	darkTint?: boolean;

	/** The bounds provider to use. If undefined the bounds will be dynamic, calculated when requested and based on the current frame. */
	boundsProvider?: SpineBoundsProvider,

	/** Set {@link AtlasAttachmentLoader.allowMissingRegions} property on the AtlasAttachmentLoader. */
	allowMissingRegions?: boolean;

	/** The ticker to use when {@link autoUpdate} is `true`. Defaults to {@link Ticker.shared}. */
	ticker?: Ticker,
};

export interface SpineOptions {
	/** the {@link SkeletonData} used to instantiate the skeleton */
	skeletonData: SkeletonData;

	/**  See {@link SpineFromOptions.autoUpdate}. */
	autoUpdate?: boolean;

	/**  See {@link SpineFromOptions.darkTint}. */
	darkTint?: boolean;

	/**  See {@link SpineFromOptions.boundsProvider}. */
	boundsProvider?: SpineBoundsProvider,

	/** See {@link SpineFromOptions.ticker}. */
	ticker?: Ticker,
}

/**
 * AnimationStateListener {@link https://en.esotericsoftware.com/spine-api-reference#AnimationStateListener events} exposed for Pixi.
 */
export interface SpineEvents {
	complete: [trackEntry: TrackEntry];
	dispose: [trackEntry: TrackEntry];
	end: [trackEntry: TrackEntry];
	event: [trackEntry: TrackEntry, event: Event];
	interrupt: [trackEntry: TrackEntry];
	start: [trackEntry: TrackEntry];
}

/** A bounds provider calculates the bounding box for a skeleton, which is then assigned as the size of the SpineGameObject. */
export interface SpineBoundsProvider {
	/** Returns the bounding box for the skeleton, in skeleton space. */
	calculateBounds (gameObject: Spine): {
		x: number;
		y: number;
		width: number;
		height: number;
	};
}

/** A bounds provider that provides a fixed size given by the user. */
export class AABBRectangleBoundsProvider implements SpineBoundsProvider {
	constructor (
		private x: number,
		private y: number,
		private width: number,
		private height: number,
	) { }
	calculateBounds () {
		return { x: this.x, y: this.y, width: this.width, height: this.height };
	}
}

/** A bounds provider that calculates the bounding box from the setup pose. */
export class SetupPoseBoundsProvider implements SpineBoundsProvider {
	/**
	 * @param clipping If true, clipping attachments are used to compute the bounds. False, by default.
	 */
	constructor (
		private clipping = false,
	) { }

	calculateBounds (gameObject: Spine) {
		if (!gameObject.skeleton) return { x: 0, y: 0, width: 0, height: 0 };
		// Make a copy of animation state and skeleton as this might be called while
		// the skeleton in the GameObject has already been heavily modified. We can not
		// reconstruct that state.
		const skeleton = new Skeleton(gameObject.skeleton.data);
		skeleton.setupPose();
		skeleton.updateWorldTransform(Physics.update);
		const bounds = skeleton.getBoundsRect(this.clipping ? new SkeletonClipping() : undefined);
		return bounds.width === Number.NEGATIVE_INFINITY
			? { x: 0, y: 0, width: 0, height: 0 }
			: bounds;
	}
}

/** A bounds provider that calculates the bounding box by taking the maximumg bounding box for a combination of skins and specific animation. */
export class SkinsAndAnimationBoundsProvider
	implements SpineBoundsProvider {
	/**
	 * @param animation The animation to use for calculating the bounds. If null, the setup pose is used.
	 * @param skins The skins to use for calculating the bounds. If empty, the default skin is used.
	 * @param timeStep The time step to use for calculating the bounds. A smaller time step means more precision, but slower calculation.
	 * @param clipping If true, clipping attachments are used to compute the bounds. False, by default.
	 */
	constructor (
		private animation: string | null,
		private skins: string[] = [],
		private timeStep: number = 0.05,
		private clipping = false,
	) { }

	calculateBounds (gameObject: Spine): {
		x: number;
		y: number;
		width: number;
		height: number;
	} {
		if (!gameObject.skeleton || !gameObject.state)
			return { x: 0, y: 0, width: 0, height: 0 };
		// Make a copy of animation state and skeleton as this might be called while
		// the skeleton in the GameObject has already been heavily modified. We can not
		// reconstruct that state.
		const animationState = new AnimationState(gameObject.state.data);
		const skeleton = new Skeleton(gameObject.skeleton.data);
		const clipper = this.clipping ? new SkeletonClipping() : undefined;
		const data = skeleton.data;
		if (this.skins.length > 0) {
			const customSkin = new Skin("custom-skin");
			for (const skinName of this.skins) {
				const skin = data.findSkin(skinName);
				if (skin == null) continue;
				customSkin.addSkin(skin);
			}
			skeleton.setSkin(customSkin);
		}
		skeleton.setupPose();

		const animation = this.animation != null ? data.findAnimation(this.animation) : null;

		if (animation == null) {
			skeleton.updateWorldTransform(Physics.update);
			const bounds = skeleton.getBoundsRect(clipper);
			return bounds.width === Number.NEGATIVE_INFINITY
				? { x: 0, y: 0, width: 0, height: 0 }
				: bounds;
		} else {
			let minX = Number.POSITIVE_INFINITY,
				minY = Number.POSITIVE_INFINITY,
				maxX = Number.NEGATIVE_INFINITY,
				maxY = Number.NEGATIVE_INFINITY;
			animationState.clearTracks();
			animationState.setAnimation(0, animation, false);
			const steps = Math.max(animation.duration / this.timeStep, 1.0);
			for (let i = 0; i < steps; i++) {
				const delta = i > 0 ? this.timeStep : 0;
				animationState.update(delta);
				animationState.apply(skeleton);
				skeleton.update(delta);
				skeleton.updateWorldTransform(Physics.update);

				const bounds = skeleton.getBoundsRect(clipper);
				minX = Math.min(minX, bounds.x);
				minY = Math.min(minY, bounds.y);
				maxX = Math.max(maxX, bounds.x + bounds.width);
				maxY = Math.max(maxY, bounds.y + bounds.height);
			}
			const bounds = {
				x: minX,
				y: minY,
				width: maxX - minX,
				height: maxY - minY,
			};
			return bounds.width === Number.NEGATIVE_INFINITY
				? { x: 0, y: 0, width: 0, height: 0 }
				: bounds;
		}
	}
}

/**
 * The class to instantiate a {@link Spine} game object in Pixi.
 * Create and customize the default configuration using the static method {@link Spine.createOptions},
 * then pass it to the constructor.
 */
export class Spine extends Container {
	/** The skeleton for this Spine game object. */
	public skeleton: Skeleton;
	/** The animation state for this Spine game object. */
	public state: AnimationState;

	private darkTint = false;
	private hasNeverUpdated = true;

	private _debug?: ISpineDebugRenderer | undefined = undefined;
	public get debug (): ISpineDebugRenderer | undefined {
		return this._debug;
	}
	/** Pass a {@link SpineDebugRenderer} or create your own {@link ISpineDebugRenderer} to render bones, meshes, ...
	 * @example spineGO.debug = new SpineDebugRenderer();
	 */
	public set debug (value: ISpineDebugRenderer | undefined) {
		if (this._debug) {
			this._debug.unregisterSpine(this);
		}
		if (value) {
			value.registerSpine(this);
		}
		this._debug = value;
	}

	protected slotMeshFactory: () => ISlotMesh = () => new SlotMesh();

	beforeUpdateWorldTransforms: (object: Spine) => void = () => { };
	afterUpdateWorldTransforms: (object: Spine) => void = () => { };

	private _autoUpdate: boolean = false;
	private _ticker: Ticker = Ticker.shared;

	public get autoUpdate (): boolean {
		return this._autoUpdate;
	}
	/** When `true`, the Spine AnimationState and the Skeleton will be automatically updated using the {@link ticker}. */
	public set autoUpdate (value: boolean) {
		if (value && !this._autoUpdate) {
			this._ticker.add(this.internalUpdate, this);
		} else if (!value && this._autoUpdate) {
			this._ticker.remove(this.internalUpdate, this);
		}
		this._autoUpdate = value;
	}

	/** The ticker to use when {@link autoUpdate} is `true`. Defaults to {@link Ticker.shared}. */
	public get ticker (): Ticker {
		return this._ticker;
	}
	/** Sets the ticker to use when {@link autoUpdate} is `true`. If `autoUpdate` is already `true`, the update callback will be moved from the old ticker to the new one. */
	public set ticker (value: Ticker) {
		if (this._ticker === value) return;

		if (this._autoUpdate) {
			this._ticker.remove(this.internalUpdate, this);
			value.add(this.internalUpdate, this);
		}

		this._ticker = value;
	}

	private meshesCache = new Map<Slot, ISlotMesh>();

	private static vectorAux: Vector2 = new Vector2();
	private static clipper: SkeletonClipping = new SkeletonClipping();

	private static QUAD_TRIANGLES = [0, 1, 2, 2, 3, 0];
	private static VERTEX_SIZE = 2 + 2 + 4;
	private static DARK_VERTEX_SIZE = 2 + 2 + 4 + 4;

	private lightColor = new Color();
	private darkColor = new Color();
	private clippingVertAux = new Float32Array(6);

	private _boundsProvider?: SpineBoundsProvider;
	/** The bounds provider to use. If undefined the bounds will be dynamic, calculated when requested and based on the current frame. */
	public get boundsProvider (): SpineBoundsProvider | undefined {
		return this._boundsProvider;
	}
	public set boundsProvider (value: SpineBoundsProvider | undefined) {
		this._boundsProvider = value;
		if (value) {
			this._boundsSpineID = -1;
			this._boundsSpineDirty = true;
			this.interactiveChildren = false;
		} else {
			this.interactiveChildren = true;
			this.hitArea = null;
		}
		if (!this.hasNeverUpdated) {
			this.calculateBounds();
		}
	}
	private _boundsPoint = new Point();
	private _boundsSpineID = -1;
	private _boundsSpineDirty = true;

	constructor (options: SkeletonData | SpineOptions | SpineFromOptions) {
		super();

		if (options instanceof SkeletonData)
			options = { skeletonData: options };
		else if ("skeleton" in options)
			options = new.target.createOptions(options);

		const { autoUpdate = true, boundsProvider, darkTint, skeletonData, ticker } = options;
		this.skeleton = new Skeleton(skeletonData);
		this.state = new AnimationState(new AnimationStateData(skeletonData));
		if (ticker) this._ticker = ticker;
		this.autoUpdate = autoUpdate;
		this.boundsProvider = boundsProvider;

		// dark tint can be enabled by options, otherwise is enable if at least one slot has tint black
		this.darkTint = darkTint === undefined
			? this.skeleton.slots.some(slot => !!slot.data.setup.darkColor)
			: darkTint;
		if (this.darkTint) this.slotMeshFactory = () => new DarkSlotMesh();
	}

	/** If {@link Spine.autoUpdate} is `false`, this method allows to update the AnimationState and the Skeleton with the given delta. */
	public update (deltaSeconds: number): void {
		this.internalUpdate(0, deltaSeconds);
	}

	protected internalUpdate (_deltaFrame: number, deltaSeconds?: number): void {
		this.hasNeverUpdated = false;

		const delta = deltaSeconds ?? this._ticker.deltaMS / 1000;
		this.state.update(delta);
		this.state.apply(this.skeleton);
		this.beforeUpdateWorldTransforms(this);
		this.skeleton.update(delta);
		this.skeleton.updateWorldTransform(Physics.update);
		this.afterUpdateWorldTransforms(this);
	}

	/** Render the meshes based on the current skeleton state, render debug information, then call {@link Container.updateTransform}. */
	public override updateTransform (): void {
		this.renderMeshes();
		this.sortChildren();
		this.debug?.renderDebug(this);
		super.updateTransform();
	}

	/** Destroy Spine game object elements, then call the {@link Container.destroy} with the given options */
	public override destroy (options?: boolean | IDestroyOptions | undefined): void {
		if (this.autoUpdate) this.autoUpdate = false;
		for (const [, mesh] of this.meshesCache) {
			mesh?.destroy();
		}
		this.state.clearListeners();
		this.debug = undefined;
		this.meshesCache.clear();
		this.slotsObject.clear();

		for (const maskKey in this.clippingSlotToPixiMasks) {
			const mask = this.clippingSlotToPixiMasks[maskKey];
			mask.destroy();
			delete this.clippingSlotToPixiMasks[maskKey];
		}

		super.destroy(options);
	}

	private resetMeshes (): void {
		for (const [, mesh] of this.meshesCache) {
			mesh.zIndex = -1;
			mesh.visible = false;
		}
	}

	protected _calculateBounds (): void {
		if (this.hasNeverUpdated) {
			this.internalUpdate(0, 0);
			this.renderMeshes();
		}
	}

	/**
	 * Check the existence of a mesh for the given slot.
	 * If you want to manually handle which meshes go on which slot and how you cache, overwrite this method.
	 */
	protected hasMeshForSlot (slot: Slot) {
		return this.meshesCache.has(slot);
	}

	/**
	 * Search the mesh corresponding to the given slot or create it, if it does not exists.
	 * If you want to manually handle which meshes go on which slot and how you cache, overwrite this method.
	 */
	protected getMeshForSlot (slot: Slot): ISlotMesh {
		let mesh = this.hasMeshForSlot(slot) ? this.meshesCache.get(slot) : null;

		if (!mesh) {
			mesh = this.slotMeshFactory();
			this.addChild(mesh);
			this.meshesCache.set(slot, mesh);
		} else {
			mesh.visible = true;
		}

		return mesh;
	}

	public slotsObject = new Map<Slot, { container: Container, followAttachmentTimeline: boolean }>();
	private getSlotFromRef (slotRef: number | string | Slot): Slot {
		let slot: Slot | null;
		if (typeof slotRef === 'number') slot = this.skeleton.slots[slotRef];
		else if (typeof slotRef === 'string') slot = this.skeleton.findSlot(slotRef);
		else slot = slotRef;

		if (!slot) throw new Error(`No slot found with the given slot reference: ${slotRef}`);

		return slot;
	}
	/**
	 * Add a pixi Container as a child of the Spine object.
	 * The Container will be rendered coherently with the draw order of the slot.
	 * If an attachment is active on the slot, the pixi Container will be rendered on top of it.
	 * If the Container is already attached to the given slot, nothing will happen.
	 * If the Container is already attached to another slot, it will be removed from that slot
	 * before adding it to the given one.
	 * If another Container is already attached to this slot, the old one will be removed from this
	 * slot before adding it to the current one.
	 * @param slotRef - The slot index, or the slot name, or the Slot where the pixi object will be added to.
	 * @param pixiObject - The pixi Container to add.
	 * @param options - Optional settings for the attachment.
	 * @param options.followAttachmentTimeline - If true, the attachment will follow the slot's attachment timeline.
	 */
	addSlotObject (slotRef: number | string | Slot, pixiObject: Container, options?: { followAttachmentTimeline?: boolean }): void {
		const slot = this.getSlotFromRef(slotRef);
		const oldPixiObject = this.slotsObject.get(slot)?.container;
		if (oldPixiObject && oldPixiObject === pixiObject) return;

		// search if the pixiObject was already in another slotObject
		for (const [otherSlot, { container: oldPixiObjectAnotherSlot }] of this.slotsObject) {
			if (otherSlot !== slot && oldPixiObjectAnotherSlot === pixiObject) {
				this.removeSlotObject(otherSlot, pixiObject);
				break;
			}
		}

		if (oldPixiObject) this.removeChild(oldPixiObject);

		this.slotsObject.set(slot, {
			container: pixiObject,
			followAttachmentTimeline: options?.followAttachmentTimeline || false,
		});
		this.addChild(pixiObject);
	}
	/**
	 * Return the Container connected to the given slot, if any.
	 * Otherwise return undefined
	 * @param pixiObject - The slot index, or the slot name, or the Slot to get the Container from.
	 * @returns a Container if any, undefined otherwise.
	 */
	getSlotObject (slotRef: number | string | Slot): Container | undefined {
		const element = this.slotsObject.get(this.getSlotFromRef(slotRef));
		return element ? element.container : undefined;
	}

	/**
	 * Remove a slot object from the given slot.
	 * If `pixiObject` is passed and attached to the given slot, remove it from the slot.
	 * If `pixiObject` is not passed and the given slot has an attached Container, remove it from the slot.
	 * @param slotRef - The slot index, or the slot name, or the Slot where the pixi object will be remove from.
	 * @param pixiObject - Optional, The pixi Container to remove.
	 */
	removeSlotObject (slotRef: number | string | Slot, pixiObject?: Container): void {
		const slot = this.getSlotFromRef(slotRef);
		const slotObject = this.slotsObject.get(slot)?.container;
		if (!slotObject) return;

		// if pixiObject is passed, remove only if it is equal to the given one
		if (pixiObject && pixiObject !== slotObject) return;

		this.removeChild(slotObject);
		this.slotsObject.delete(slot);
	}

	/**
	 * Removes all PixiJS containers attached to any slot.
	 */
	public removeSlotObjects () {
		for (const [, slotObject] of this.slotsObject) {
			slotObject.container.removeFromParent();
		}
		this.slotsObject.clear();
	}

	private verticesCache: NumberArrayLike = Utils.newFloatArray(1024);
	private clippingSlotToPixiMasks: Record<string, Graphics> = {};
	private pixiMaskCleanup (slot: Slot) {
		const mask = this.clippingSlotToPixiMasks[slot.data.name];
		if (mask) {
			delete this.clippingSlotToPixiMasks[slot.data.name];
			mask.destroy();
		}
	}

	private updateSlotObject (element: { container: Container, followAttachmentTimeline: boolean }, slot: Slot, zIndex: number) {
		const { container: slotObject, followAttachmentTimeline } = element

		const pose = slot.applied;
		const followAttachmentValue = followAttachmentTimeline ? Boolean(pose.attachment) : true;
		slotObject.visible = this.skeleton.drawOrder.includes(slot) && followAttachmentValue;

		if (slotObject.visible) {
			let applied = slot.bone.applied;

			const matrix = slotObject.localTransform;
			matrix.a = applied.a;
			matrix.b = applied.c;
			matrix.c = -applied.b;
			matrix.d = -applied.d;
			matrix.tx = applied.worldX;
			matrix.ty = applied.worldY;
			slotObject.transform.setFromMatrix(matrix);

			slotObject.zIndex = zIndex + 1;
			slotObject.alpha = this.skeleton.color.a * pose.color.a;
		}
	}

	private updateAndSetPixiMask (pixiMaskSource: PixiMaskSource | null, pixiObject: Container) {
		if (Spine.clipper.isClipping() && pixiMaskSource) {
			let mask = this.clippingSlotToPixiMasks[pixiMaskSource.slot.data.name] as Graphics;
			if (!mask) {
				mask = new Graphics();
				this.clippingSlotToPixiMasks[pixiMaskSource.slot.data.name] = mask;
				this.addChild(mask);
			}
			if (!pixiMaskSource.computed) {
				pixiMaskSource.computed = true;
				const clippingAttachment = pixiMaskSource.slot.applied.attachment as ClippingAttachment;
				const worldVerticesLength = clippingAttachment.worldVerticesLength;
				if (this.clippingVertAux.length < worldVerticesLength) this.clippingVertAux = new Float32Array(worldVerticesLength);
				clippingAttachment.computeWorldVertices(this.skeleton, pixiMaskSource.slot, 0, worldVerticesLength, this.clippingVertAux, 0, 2);
				mask.clear().lineStyle(0).beginFill(0x000000);
				mask.moveTo(this.clippingVertAux[0], this.clippingVertAux[1]);
				for (let i = 2; i < worldVerticesLength; i += 2) {
					mask.lineTo(this.clippingVertAux[i], this.clippingVertAux[i + 1]);
				}
				mask.finishPoly();
			}
			pixiObject.mask = mask;
		} else if (pixiObject.mask) {
			pixiObject.mask = null;
		}
	}

	/*
	* Colors in pixi are premultiplied.
	* Pixi blending modes are modified to work with premultiplied colors. We cannot create custom blending modes.
	* Textures are loaded as premultiplied (see assers/atlasLoader.ts: alphaMode: `page.pma ? ALPHA_MODES.PMA : ALPHA_MODES.UNPACK`):
	* - textures non premultiplied are premultiplied on GPU on upload
	* - textures premultiplied are uploaded on GPU as is since they are already premultiplied
	*
	* We need to take this into consideration and calculates final colors for both light and dark color as if textures were always premultiplied.
	* This implies for example that alpha for dark tint is always 1. This is way in DarkTintRenderer we have only the alpha of the light color.
	* If we ever want to load texture as non premultiplied on GPU, we must add a new dark alpha parameter to the TintMaterial and set the alpha.
	*/
	private renderMeshes (): void {
		this.resetMeshes();

		let triangles: Array<number> | null = null;
		let uvs: NumberArrayLike | null = null;
		let pixiMaskSource: PixiMaskSource | null = null;
		const drawOrder = this.skeleton.drawOrder;

		for (let i = 0, n = drawOrder.length, slotObjectsCounter = 0; i < n; i++) {
			const slot = drawOrder[i];

			// render pixi object on the current slot on top of the slot attachment
			const pixiObject = this.slotsObject.get(slot);
			const zIndex = i + slotObjectsCounter;
			if (pixiObject) {
				this.updateSlotObject(pixiObject, slot, zIndex + 1);
				slotObjectsCounter++;
				this.updateAndSetPixiMask(pixiMaskSource, pixiObject.container);
			}

			const pose = slot.applied;
			const useDarkColor = !!pose.darkColor;
			const vertexSize = useDarkColor ? Spine.DARK_VERTEX_SIZE : Spine.VERTEX_SIZE;
			if (!slot.bone.active) {
				Spine.clipper.clipEnd(slot);
				this.pixiMaskCleanup(slot);
				continue;
			}
			const attachment = pose.attachment;
			let attachmentColor: Color | null;
			let texture: SpineTexture | null;
			let numFloats = 0;
			const skeleton = this.skeleton;
			if (attachment instanceof RegionAttachment) {
				const region = attachment;
				attachmentColor = region.color;
				numFloats = vertexSize * 4;
				region.computeWorldVertices(slot, this.verticesCache, 0, vertexSize);
				triangles = Spine.QUAD_TRIANGLES;
				uvs = region.uvs;
				texture = <SpineTexture>region.region?.texture;
			} else if (attachment instanceof MeshAttachment) {
				const mesh = attachment;
				attachmentColor = mesh.color;
				numFloats = (mesh.worldVerticesLength >> 1) * vertexSize;
				if (numFloats > this.verticesCache.length) {
					this.verticesCache = Utils.newFloatArray(numFloats);
				}
				mesh.computeWorldVertices(skeleton, slot, 0, mesh.worldVerticesLength, this.verticesCache, 0, vertexSize);
				triangles = mesh.triangles;
				uvs = mesh.uvs;
				texture = <SpineTexture>mesh.region?.texture;
			} else if (attachment instanceof ClippingAttachment) {
				Spine.clipper.clipStart(skeleton, slot, attachment);
				pixiMaskSource = { slot, computed: false };
				continue;
			} else {
				if (this.hasMeshForSlot(slot)) {
					this.getMeshForSlot(slot).visible = false;
				}
				Spine.clipper.clipEnd(slot);
				this.pixiMaskCleanup(slot);
				continue;
			}
			if (texture != null) {
				const skeletonColor = skeleton.color;
				const slotColor = pose.color;
				const alpha = skeletonColor.a * slotColor.a * attachmentColor.a;
				this.lightColor.set(
					skeletonColor.r * slotColor.r * attachmentColor.r,
					skeletonColor.g * slotColor.g * attachmentColor.g,
					skeletonColor.b * slotColor.b * attachmentColor.b,
					alpha
				);
				if (pose.darkColor != null) {
					this.darkColor.set(
						pose.darkColor.r,
						pose.darkColor.g,
						pose.darkColor.b,
						1,
					);
				} else {
					this.darkColor.set(0, 0, 0, 1);
				}

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

				if (Spine.clipper.isClipping() && Spine.clipper.clipTriangles(this.verticesCache, triangles, triangles.length, uvs, this.lightColor, this.darkColor, useDarkColor, vertexSize)) {
					finalVertices = Spine.clipper.clippedVertices;
					finalVerticesLength = finalVertices.length;

					finalIndices = Spine.clipper.clippedTriangles;
					finalIndicesLength = finalIndices.length;
				} else {
					const verts = this.verticesCache;
					for (let v = 2, u = 0, n = numFloats; v < n; v += vertexSize, u += 2) {
						let tempV = v;
						verts[tempV++] = this.lightColor.r;
						verts[tempV++] = this.lightColor.g;
						verts[tempV++] = this.lightColor.b;
						verts[tempV++] = this.lightColor.a;

						verts[tempV++] = uvs[u];
						verts[tempV++] = uvs[u + 1];

						if (useDarkColor) {
							verts[tempV++] = this.darkColor.r;
							verts[tempV++] = this.darkColor.g;
							verts[tempV++] = this.darkColor.b;
							verts[tempV++] = this.darkColor.a;
						}
					}
					finalVertices = this.verticesCache;
					finalVerticesLength = numFloats;
					finalIndices = triangles;
					finalIndicesLength = triangles.length;
				}

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

				const mesh = this.getMeshForSlot(slot);
				mesh.renderable = true;
				mesh.zIndex = zIndex;
				mesh.updateFromSpineData(texture, slot.data.blendMode, slot.data.name, finalVertices, finalVerticesLength, finalIndices, finalIndicesLength, useDarkColor);
			}

			Spine.clipper.clipEnd(slot);
			this.pixiMaskCleanup(slot);
		}
		Spine.clipper.clipEnd();
	}

	calculateBounds () {
		if (!this._boundsProvider) {
			super.calculateBounds();
			return;
		}

		const transform = this.transform;
		if (this._boundsSpineID === transform._worldID) return;

		this.updateBounds();

		const bounds = this._localBounds;
		const p = this._boundsPoint;

		p.set(bounds.minX, bounds.minY);
		transform.worldTransform.apply(p, p);
		this._bounds.minX = p.x
		this._bounds.minY = p.y;

		p.set(bounds.maxX, bounds.maxY)
		transform.worldTransform.apply(p, p);
		this._bounds.maxX = p.x
		this._bounds.maxY = p.y;
	}

	updateBounds () {
		if (!this._boundsProvider || !this._boundsSpineDirty) return;

		this._boundsSpineDirty = false;

		if (!this._localBounds) {
			this._localBounds = new Bounds();
		}

		const boundsSpine = this._boundsProvider.calculateBounds(this);

		const bounds = this._localBounds;
		bounds.clear();
		bounds.minX = boundsSpine.x;
		bounds.minY = boundsSpine.y;
		bounds.maxX = boundsSpine.x + boundsSpine.width;
		bounds.maxY = boundsSpine.y + boundsSpine.height;

		this.hitArea = this._localBounds.getRectangle();
	}

	/**
	 * Set the position of the bone given in input through a {@link IPointData}.
	 * @param bone: the bone name or the bone instance to set the position
	 * @param outPos: the new position of the bone.
	 * @throws {Error}: if the given bone is not found in the skeleton, an error is thrown
	 */
	public setBonePosition (bone: string | Bone, position: IPointData): void {
		const actualBone = typeof bone === "string" ? this.skeleton.findBone(bone) : bone;

		if (!actualBone) throw Error(`Cannot set bone position, bone ${String(bone)} not found`);
		Spine.vectorAux.set(position.x, position.y);

		const applied = actualBone.applied;
		if (actualBone.parent) {
			const aux = actualBone.parent.applied.worldToLocal(Spine.vectorAux);
			applied.x = aux.x;
			applied.y = aux.y;
		} else {
			applied.x = Spine.vectorAux.x;
			applied.y = Spine.vectorAux.y;
		}
	}

	/**
	 * Return the position of the bone given in input into an {@link IPointData}.
	 * @param bone: the bone name or the bone instance to get the position from
	 * @param outPos: an optional {@link IPointData} to use to return the bone position, rathern than instantiating a new object.
	 * @returns {IPointData | undefined}: the position of the bone, or undefined if no matching bone is found in the skeleton
	 */
	public getBonePosition (bone: string | Bone, outPos?: IPointData): IPointData | undefined {
		const actualBone = typeof bone === "string" ? this.skeleton.findBone(bone) : bone;

		if (!actualBone) {
			console.error(`Cannot get bone position! Bone ${String(bone)} not found`);
			return outPos;
		}

		if (!outPos) {
			outPos = { x: 0, y: 0 };
		}

		outPos.x = actualBone.applied.worldX;
		outPos.y = actualBone.applied.worldY;
		return outPos;
	}

	/** Converts a point from the skeleton coordinate system to the Pixi world coordinate system. */
	skeletonToPixiWorldCoordinates (point: { x: number; y: number }) {
		this.worldTransform.apply(point, point);
	}

	/** Converts a point from the Pixi world coordinate system to the skeleton coordinate system. */
	pixiWorldCoordinatesToSkeleton (point: { x: number; y: number }) {
		this.worldTransform.applyInverse(point, point);
	}

	/** Converts a point from the Pixi world coordinate system to the bone's local coordinate system. */
	pixiWorldCoordinatesToBone (point: { x: number; y: number }, bone: Bone) {
		this.pixiWorldCoordinatesToSkeleton(point);
		if (bone.parent) {
			bone.parent.applied.worldToLocal(point as Vector2);
		} else {
			bone.applied.worldToLocal(point as Vector2);
		}
	}

	/** A cache containing skeleton data and atlases already loaded by {@link Spine.from}. */
	public static readonly skeletonCache: Record<string, SkeletonData> = Object.create(null);

	/**
	 * Get a convenient initialization configuration for your Spine game object.
	 * Before instantiating a Spine game object, the skeleton (`.skel` or `.json`) and the atlas text files must be loaded into the Assets. For example:
	 * ```
	 * PIXI.Assets.add("sackData", "/assets/sack-pro.skel");
	 * PIXI.Assets.add("sackAtlas", "/assets/sack-pma.atlas");
	 * await PIXI.Assets.load(["sackData", "sackAtlas"]);
	 * ```
	 * Once a Spine game object is created, its skeleton data is cached into {@link Spine.skeletonCache} using the key:
	 * `${skeletonAssetName}-${atlasAssetName}-${options?.scale ?? 1}`
	 *
	 * @param options - Options to configure the Spine game object. See {@link SpineFromOptions}
	 * @returns {SpineOptions} The configuration ready to be passed to the Spine constructor
	 */
	public static createOptions ({ skeleton, atlas, scale = 1, darkTint, autoUpdate = true, boundsProvider, allowMissingRegions, ticker }: SpineFromOptions): SpineOptions {
		const cacheKey = `${skeleton}-${atlas}-${scale}`;

		let skeletonData = Spine.skeletonCache[cacheKey];
		if (!skeletonData) {
			// biome-ignore lint/suspicious/noExplicitAny: json skeleton is any
			const skeletonAsset = Assets.get<any | Uint8Array>(skeleton);
			const atlasAsset = Assets.get<TextureAtlas>(atlas);
			const attachmentLoader = new AtlasAttachmentLoader(atlasAsset, allowMissingRegions);
			const parser = skeletonAsset instanceof Uint8Array ? new SkeletonBinary(attachmentLoader) : new SkeletonJson(attachmentLoader);
			parser.scale = scale;
			skeletonData = parser.readSkeletonData(skeletonAsset);
			Spine.skeletonCache[cacheKey] = skeletonData;
		}
		return { skeletonData, darkTint, autoUpdate, boundsProvider, ticker };
	}

	/**
	 * @deprecated Use directly the Spine constructor or {@link createOptions} to make options and customize it to pass to the constructor
	 * Before instantiating a Spine game object, the skeleton (`.skel` or `.json`) and the atlas text files must be loaded into the Assets. For example:
	 * ```
	 * PIXI.Assets.add("sackData", "/assets/sack-pro.skel");
	 * PIXI.Assets.add("sackAtlas", "/assets/sack-pma.atlas");
	 * await PIXI.Assets.load(["sackData", "sackAtlas"]);
	 * ```
	 * Once a Spine game object is created, its skeleton data is cached into {@link Spine.skeletonCache} using the key:
	 * `${skeletonAssetName}-${atlasAssetName}-${options?.scale ?? 1}`
	 *
	 * @param options - Options to configure the Spine game object. See {@link SpineFromOptions}
	 * @returns {Spine} The Spine game object instantiated
	 */
	public static from (options: SpineFromOptions) {
		return new Spine(Spine.createOptions(options));
	}

	public get tint (): number {
		return this.skeleton.color.toRgb888();
	}
	public set tint (value: number) {
		Color.rgb888ToColor(this.skeleton.color, value);
	}
}

type PixiMaskSource = {
	slot: Slot,
	computed: boolean, // prevent to reculaculate vertices for a mask clipping multiple pixi objects
}

Skeleton.yDown = true;

/**
 * Represents the mesh type used in a Spine objects. Available implementations are {@link DarkSlotMesh} and {@link SlotMesh}.
 */
export interface ISlotMesh extends DisplayObject {
	name: string;
	updateFromSpineData (
		slotTexture: SpineTexture,
		slotBlendMode: BlendMode,
		slotName: string,
		finalVertices: NumberArrayLike,
		finalVerticesLength: number,
		finalIndices: NumberArrayLike,
		finalIndicesLength: number,
		darkTint: boolean
	): void;
}