/******************************************************************************
 * Spine Runtimes License Agreement
 * Last updated January 1, 2020. Replaces all prior versions.
 *
 * Copyright (c) 2013-2020, 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.
 *****************************************************************************/

module spine {

	/** Stores the current pose for a skeleton.
	 *
	 * See [Instance objects](http://esotericsoftware.com/spine-runtime-architecture#Instance-objects) in the Spine Runtimes Guide. */
	export class Skeleton {
		/** The skeleton's setup pose data. */
		data: SkeletonData;

		/** The skeleton's bones, sorted parent first. The root bone is always the first bone. */
		bones: Array<Bone>;

		/** The skeleton's slots. */
		slots: Array<Slot>;

		/** The skeleton's slots in the order they should be drawn. The returned array may be modified to change the draw order. */
		drawOrder: Array<Slot>;

		/** The skeleton's IK constraints. */
		ikConstraints: Array<IkConstraint>;

		/** The skeleton's transform constraints. */
		transformConstraints: Array<TransformConstraint>;

		/** The skeleton's path constraints. */
		pathConstraints: Array<PathConstraint>;

		/** The list of bones and constraints, sorted in the order they should be updated, as computed by {@link #updateCache()}. */
		_updateCache = new Array<Updatable>();
		updateCacheReset = new Array<Updatable>();

		/** The skeleton's current skin. May be null. */
		skin: Skin;

		/** The color to tint all the skeleton's attachments. */
		color: Color;

		/** Returns the skeleton's time. This can be used for tracking, such as with Slot {@link Slot#attachmentTime}.
		 * <p>
		 * See {@link #update()}. */
		time = 0;

		/** Scales the entire skeleton on the X axis. This affects all bones, even if the bone's transform mode disallows scale
	 	* inheritance. */
		scaleX = 1;

		/** Scales the entire skeleton on the Y axis. This affects all bones, even if the bone's transform mode disallows scale
	 	* inheritance. */
		scaleY = 1;

		/** Sets the skeleton X position, which is added to the root bone worldX position. */
		x = 0;

		/** Sets the skeleton Y position, which is added to the root bone worldY position. */
		y = 0;

		constructor (data: SkeletonData) {
			if (data == null) throw new Error("data cannot be null.");
			this.data = data;

			this.bones = new Array<Bone>();
			for (let i = 0; i < data.bones.length; i++) {
				let boneData = data.bones[i];
				let bone: Bone;
				if (boneData.parent == null)
					bone = new Bone(boneData, this, null);
				else {
					let parent = this.bones[boneData.parent.index];
					bone = new Bone(boneData, this, parent);
					parent.children.push(bone);
				}
				this.bones.push(bone);
			}

			this.slots = new Array<Slot>();
			this.drawOrder = new Array<Slot>();
			for (let i = 0; i < data.slots.length; i++) {
				let slotData = data.slots[i];
				let bone = this.bones[slotData.boneData.index];
				let slot = new Slot(slotData, bone);
				this.slots.push(slot);
				this.drawOrder.push(slot);
			}

			this.ikConstraints = new Array<IkConstraint>();
			for (let i = 0; i < data.ikConstraints.length; i++) {
				let ikConstraintData = data.ikConstraints[i];
				this.ikConstraints.push(new IkConstraint(ikConstraintData, this));
			}

			this.transformConstraints = new Array<TransformConstraint>();
			for (let i = 0; i < data.transformConstraints.length; i++) {
				let transformConstraintData = data.transformConstraints[i];
				this.transformConstraints.push(new TransformConstraint(transformConstraintData, this));
			}

			this.pathConstraints = new Array<PathConstraint>();
			for (let i = 0; i < data.pathConstraints.length; i++) {
				let pathConstraintData = data.pathConstraints[i];
				this.pathConstraints.push(new PathConstraint(pathConstraintData, this));
			}

			this.color = new Color(1, 1, 1, 1);
			this.updateCache();
		}

		/** Caches information about bones and constraints. Must be called if the {@link #getSkin()} is modified or if bones,
		 * constraints, or weighted path attachments are added or removed. */
		updateCache () {
			let updateCache = this._updateCache;
			updateCache.length = 0;
			this.updateCacheReset.length = 0;

			let bones = this.bones;
			for (let i = 0, n = bones.length; i < n; i++) {
				let bone = bones[i];
				bone.sorted = bone.data.skinRequired;
				bone.active = !bone.sorted;
			}

			if (this.skin != null) {
				let skinBones = this.skin.bones;
				for (let i = 0, n = this.skin.bones.length; i < n; i++) {
					let bone = this.bones[skinBones[i].index];
					do {
						bone.sorted = false;
						bone.active = true;
						bone = bone.parent;
					} while (bone != null);
				}
			}

			// IK first, lowest hierarchy depth first.
			let ikConstraints = this.ikConstraints;
			let transformConstraints = this.transformConstraints;
			let pathConstraints = this.pathConstraints;
			let ikCount = ikConstraints.length, transformCount = transformConstraints.length, pathCount = pathConstraints.length;
			let constraintCount = ikCount + transformCount + pathCount;

			outer:
			for (let i = 0; i < constraintCount; i++) {
				for (let ii = 0; ii < ikCount; ii++) {
					let constraint = ikConstraints[ii];
					if (constraint.data.order == i) {
						this.sortIkConstraint(constraint);
						continue outer;
					}
				}
				for (let ii = 0; ii < transformCount; ii++) {
					let constraint = transformConstraints[ii];
					if (constraint.data.order == i) {
						this.sortTransformConstraint(constraint);
						continue outer;
					}
				}
				for (let ii = 0; ii < pathCount; ii++) {
					let constraint = pathConstraints[ii];
					if (constraint.data.order == i) {
						this.sortPathConstraint(constraint);
						continue outer;
					}
				}
			}

			for (let i = 0, n = bones.length; i < n; i++)
				this.sortBone(bones[i]);
		}

		sortIkConstraint (constraint: IkConstraint) {
			constraint.active = constraint.target.isActive() && (!constraint.data.skinRequired || (this.skin != null && Utils.contains(this.skin.constraints, constraint.data, true)));
			if (!constraint.active) return;

			let target = constraint.target;
			this.sortBone(target);

			let constrained = constraint.bones;
			let parent = constrained[0];
			this.sortBone(parent);

			if (constrained.length > 1) {
				let child = constrained[constrained.length - 1];
				if (!(this._updateCache.indexOf(child) > -1)) this.updateCacheReset.push(child);
			}

			this._updateCache.push(constraint);

			this.sortReset(parent.children);
			constrained[constrained.length - 1].sorted = true;
		}

		sortPathConstraint (constraint: PathConstraint) {
			constraint.active = constraint.target.bone.isActive() && (!constraint.data.skinRequired || (this.skin != null && Utils.contains(this.skin.constraints, constraint.data, true)));
			if (!constraint.active) return;

			let slot = constraint.target;
			let slotIndex = slot.data.index;
			let slotBone = slot.bone;
			if (this.skin != null) this.sortPathConstraintAttachment(this.skin, slotIndex, slotBone);
			if (this.data.defaultSkin != null && this.data.defaultSkin != this.skin)
				this.sortPathConstraintAttachment(this.data.defaultSkin, slotIndex, slotBone);
			for (let i = 0, n = this.data.skins.length; i < n; i++)
				this.sortPathConstraintAttachment(this.data.skins[i], slotIndex, slotBone);

			let attachment = slot.getAttachment();
			if (attachment instanceof PathAttachment) this.sortPathConstraintAttachmentWith(attachment, slotBone);

			let constrained = constraint.bones;
			let boneCount = constrained.length;
			for (let i = 0; i < boneCount; i++)
				this.sortBone(constrained[i]);

			this._updateCache.push(constraint);

			for (let i = 0; i < boneCount; i++)
				this.sortReset(constrained[i].children);
			for (let i = 0; i < boneCount; i++)
				constrained[i].sorted = true;
		}

		sortTransformConstraint (constraint: TransformConstraint) {
			constraint.active = constraint.target.isActive() && (!constraint.data.skinRequired || (this.skin != null && Utils.contains(this.skin.constraints, constraint.data, true)));
			if (!constraint.active) return;

			this.sortBone(constraint.target);

			let constrained = constraint.bones;
			let boneCount = constrained.length;
			if (constraint.data.local) {
				for (let i = 0; i < boneCount; i++) {
					let child = constrained[i];
					this.sortBone(child.parent);
					if (!(this._updateCache.indexOf(child) > -1)) this.updateCacheReset.push(child);
				}
			} else {
				for (let i = 0; i < boneCount; i++) {
					this.sortBone(constrained[i]);
				}
			}

			this._updateCache.push(constraint);

			for (let ii = 0; ii < boneCount; ii++)
				this.sortReset(constrained[ii].children);
			for (let ii = 0; ii < boneCount; ii++)
				constrained[ii].sorted = true;
		}

		sortPathConstraintAttachment (skin: Skin, slotIndex: number, slotBone: Bone) {
			let attachments = skin.attachments[slotIndex];
			if (!attachments) return;
			for (let key in attachments) {
				this.sortPathConstraintAttachmentWith(attachments[key], slotBone);
			}
		}

		sortPathConstraintAttachmentWith (attachment: Attachment, slotBone: Bone) {
			if (!(attachment instanceof PathAttachment)) return;
			let pathBones = (<PathAttachment>attachment).bones;
			if (pathBones == null)
				this.sortBone(slotBone);
			else {
				let bones = this.bones;
				let i = 0;
				while (i < pathBones.length) {
					let boneCount = pathBones[i++];
					for (let n = i + boneCount; i < n; i++) {
						let boneIndex = pathBones[i];
						this.sortBone(bones[boneIndex]);
					}
				}
			}
		}

		sortBone (bone: Bone) {
			if (bone.sorted) return;
			let parent = bone.parent;
			if (parent != null) this.sortBone(parent);
			bone.sorted = true;
			this._updateCache.push(bone);
		}

		sortReset (bones: Array<Bone>) {
			for (let i = 0, n = bones.length; i < n; i++) {
				let bone = bones[i];
				if (!bone.active) continue;
				if (bone.sorted) this.sortReset(bone.children);
				bone.sorted = false;
			}
		}

		/** Updates the world transform for each bone and applies all constraints.
		 *
		 * See [World transforms](http://esotericsoftware.com/spine-runtime-skeletons#World-transforms) in the Spine
		 * Runtimes Guide. */
		updateWorldTransform () {
			let updateCacheReset = this.updateCacheReset;
			for (let i = 0, n = updateCacheReset.length; i < n; i++) {
				let bone = updateCacheReset[i] as Bone;
				bone.ax = bone.x;
				bone.ay = bone.y;
				bone.arotation = bone.rotation;
				bone.ascaleX = bone.scaleX;
				bone.ascaleY = bone.scaleY;
				bone.ashearX = bone.shearX;
				bone.ashearY = bone.shearY;
				bone.appliedValid = true;
			}
			let updateCache = this._updateCache;
			for (let i = 0, n = updateCache.length; i < n; i++)
				updateCache[i].update();
		}

		/** Sets the bones, constraints, and slots to their setup pose values. */
		setToSetupPose () {
			this.setBonesToSetupPose();
			this.setSlotsToSetupPose();
		}

		/** Sets the bones and constraints to their setup pose values. */
		setBonesToSetupPose () {
			let bones = this.bones;
			for (let i = 0, n = bones.length; i < n; i++)
				bones[i].setToSetupPose();

			let ikConstraints = this.ikConstraints;
			for (let i = 0, n = ikConstraints.length; i < n; i++) {
				let constraint = ikConstraints[i];
				constraint.mix = constraint.data.mix;
				constraint.softness = constraint.data.softness;
				constraint.bendDirection = constraint.data.bendDirection;
				constraint.compress = constraint.data.compress;
				constraint.stretch = constraint.data.stretch;
			}

			let transformConstraints = this.transformConstraints;
			for (let i = 0, n = transformConstraints.length; i < n; i++) {
				let constraint = transformConstraints[i];
				let data = constraint.data;
				constraint.rotateMix = data.rotateMix;
				constraint.translateMix = data.translateMix;
				constraint.scaleMix = data.scaleMix;
				constraint.shearMix = data.shearMix;
			}

			let pathConstraints = this.pathConstraints;
			for (let i = 0, n = pathConstraints.length; i < n; i++) {
				let constraint = pathConstraints[i];
				let data = constraint.data;
				constraint.position = data.position;
				constraint.spacing = data.spacing;
				constraint.rotateMix = data.rotateMix;
				constraint.translateMix = data.translateMix;
			}
		}

		/** Sets the slots and draw order to their setup pose values. */
		setSlotsToSetupPose () {
			let slots = this.slots;
			Utils.arrayCopy(slots, 0, this.drawOrder, 0, slots.length);
			for (let i = 0, n = slots.length; i < n; i++)
				slots[i].setToSetupPose();
		}

		/** @returns May return null. */
		getRootBone () {
			if (this.bones.length == 0) return null;
			return this.bones[0];
		}

		/** @returns May be null. */
		findBone (boneName: string) {
			if (boneName == null) throw new Error("boneName cannot be null.");
			let bones = this.bones;
			for (let i = 0, n = bones.length; i < n; i++) {
				let bone = bones[i];
				if (bone.data.name == boneName) return bone;
			}
			return null;
		}

		/** @returns -1 if the bone was not found. */
		findBoneIndex (boneName: string) {
			if (boneName == null) throw new Error("boneName cannot be null.");
			let bones = this.bones;
			for (let i = 0, n = bones.length; i < n; i++)
				if (bones[i].data.name == boneName) return i;
			return -1;
		}

		/** Finds a slot by comparing each slot's name. It is more efficient to cache the results of this method than to call it
		 * repeatedly.
		 * @returns May be null. */
		findSlot (slotName: string) {
			if (slotName == null) throw new Error("slotName cannot be null.");
			let slots = this.slots;
			for (let i = 0, n = slots.length; i < n; i++) {
				let slot = slots[i];
				if (slot.data.name == slotName) return slot;
			}
			return null;
		}

		/** @returns -1 if the bone was not found. */
		findSlotIndex (slotName: string) {
			if (slotName == null) throw new Error("slotName cannot be null.");
			let slots = this.slots;
			for (let i = 0, n = slots.length; i < n; i++)
				if (slots[i].data.name == slotName) return i;
			return -1;
		}

		/** Sets a skin by name.
		 *
		 * See {@link #setSkin()}. */
		setSkinByName (skinName: string) {
			let skin = this.data.findSkin(skinName);
			if (skin == null) throw new Error("Skin not found: " + skinName);
			this.setSkin(skin);
		}

		/** Sets the skin used to look up attachments before looking in the {@link SkeletonData#defaultSkin default skin}. If the
		 * skin is changed, {@link #updateCache()} is called.
		 *
		 * Attachments from the new skin are attached if the corresponding attachment from the old skin was attached. If there was no
		 * old skin, each slot's setup mode attachment is attached from the new skin.
		 *
		 * After changing the skin, the visible attachments can be reset to those attached in the setup pose by calling
		 * {@link #setSlotsToSetupPose()}. Also, often {@link AnimationState#apply()} is called before the next time the
		 * skeleton is rendered to allow any attachment keys in the current animation(s) to hide or show attachments from the new skin.
		 * @param newSkin May be null. */
		setSkin (newSkin: Skin) {
			if (newSkin == this.skin) return;
			if (newSkin != null) {
				if (this.skin != null)
					newSkin.attachAll(this, this.skin);
				else {
					let slots = this.slots;
					for (let i = 0, n = slots.length; i < n; i++) {
						let slot = slots[i];
						let name = slot.data.attachmentName;
						if (name != null) {
							let attachment: Attachment = newSkin.getAttachment(i, name);
							if (attachment != null) slot.setAttachment(attachment);
						}
					}
				}
			}
			this.skin = newSkin;
			this.updateCache();
		}


		/** Finds an attachment by looking in the {@link #skin} and {@link SkeletonData#defaultSkin} using the slot name and attachment
		 * name.
		 *
		 * See {@link #getAttachment()}.
		 * @returns May be null. */
		getAttachmentByName (slotName: string, attachmentName: string): Attachment {
			return this.getAttachment(this.data.findSlotIndex(slotName), attachmentName);
		}

		/** Finds an attachment by looking in the {@link #skin} and {@link SkeletonData#defaultSkin} using the slot index and
		 * attachment name. First the skin is checked and if the attachment was not found, the default skin is checked.
		 *
		 * See [Runtime skins](http://esotericsoftware.com/spine-runtime-skins) in the Spine Runtimes Guide.
		 * @returns May be null. */
		getAttachment (slotIndex: number, attachmentName: string): Attachment {
			if (attachmentName == null) throw new Error("attachmentName cannot be null.");
			if (this.skin != null) {
				let attachment: Attachment = this.skin.getAttachment(slotIndex, attachmentName);
				if (attachment != null) return attachment;
			}
			if (this.data.defaultSkin != null) return this.data.defaultSkin.getAttachment(slotIndex, attachmentName);
			return null;
		}

		/** A convenience method to set an attachment by finding the slot with {@link #findSlot()}, finding the attachment with
		 * {@link #getAttachment()}, then setting the slot's {@link Slot#attachment}.
		 * @param attachmentName May be null to clear the slot's attachment. */
		setAttachment (slotName: string, attachmentName: string) {
			if (slotName == null) throw new Error("slotName cannot be null.");
			let slots = this.slots;
			for (let i = 0, n = slots.length; i < n; i++) {
				let slot = slots[i];
				if (slot.data.name == slotName) {
					let attachment: Attachment = null;
					if (attachmentName != null) {
						attachment = this.getAttachment(i, attachmentName);
						if (attachment == null)
							throw new Error("Attachment not found: " + attachmentName + ", for slot: " + slotName);
					}
					slot.setAttachment(attachment);
					return;
				}
			}
			throw new Error("Slot not found: " + slotName);
		}


		/** Finds an IK constraint by comparing each IK constraint's name. It is more efficient to cache the results of this method
		 * than to call it repeatedly.
		 * @return May be null. */
		findIkConstraint (constraintName: string) {
			if (constraintName == null) throw new Error("constraintName cannot be null.");
			let ikConstraints = this.ikConstraints;
			for (let i = 0, n = ikConstraints.length; i < n; i++) {
				let ikConstraint = ikConstraints[i];
				if (ikConstraint.data.name == constraintName) return ikConstraint;
			}
			return null;
		}

		/** Finds a transform constraint by comparing each transform constraint's name. It is more efficient to cache the results of
		 * this method than to call it repeatedly.
		 * @return May be null. */
		findTransformConstraint (constraintName: string) {
			if (constraintName == null) throw new Error("constraintName cannot be null.");
			let transformConstraints = this.transformConstraints;
			for (let i = 0, n = transformConstraints.length; i < n; i++) {
				let constraint = transformConstraints[i];
				if (constraint.data.name == constraintName) return constraint;
			}
			return null;
		}

		/** Finds a path constraint by comparing each path constraint's name. It is more efficient to cache the results of this method
		 * than to call it repeatedly.
		 * @return May be null. */
		findPathConstraint (constraintName: string) {
			if (constraintName == null) throw new Error("constraintName cannot be null.");
			let pathConstraints = this.pathConstraints;
			for (let i = 0, n = pathConstraints.length; i < n; i++) {
				let constraint = pathConstraints[i];
				if (constraint.data.name == constraintName) return constraint;
			}
			return null;
		}

		/** Returns the axis aligned bounding box (AABB) of the region and mesh attachments for the current pose.
		 * @param offset An output value, the distance from the skeleton origin to the bottom left corner of the AABB.
		 * @param size An output value, the width and height of the AABB.
		 * @param temp Working memory to temporarily store attachments' computed world vertices. */
		getBounds (offset: Vector2, size: Vector2, temp: Array<number> = new Array<number>(2)) {
			if (offset == null) throw new Error("offset cannot be null.");
			if (size == null) throw new Error("size cannot be null.");
			let drawOrder = this.drawOrder;
			let minX = Number.POSITIVE_INFINITY, minY = Number.POSITIVE_INFINITY, maxX = Number.NEGATIVE_INFINITY, maxY = Number.NEGATIVE_INFINITY;
			for (let i = 0, n = drawOrder.length; i < n; i++) {
				let slot = drawOrder[i];
				if (!slot.bone.active) continue;
				let verticesLength = 0;
				let vertices: ArrayLike<number> = null;
				let attachment = slot.getAttachment();
				if (attachment instanceof RegionAttachment) {
					verticesLength = 8;
					vertices = Utils.setArraySize(temp, verticesLength, 0);
					(<RegionAttachment>attachment).computeWorldVertices(slot.bone, vertices, 0, 2);
				} else if (attachment instanceof MeshAttachment) {
					let mesh = (<MeshAttachment>attachment);
					verticesLength = mesh.worldVerticesLength;
					vertices = Utils.setArraySize(temp, verticesLength, 0);
					mesh.computeWorldVertices(slot, 0, verticesLength, vertices, 0, 2);
				}
				if (vertices != null) {
					for (let ii = 0, nn = vertices.length; ii < nn; ii += 2) {
						let x = vertices[ii], y = vertices[ii + 1];
						minX = Math.min(minX, x);
						minY = Math.min(minY, y);
						maxX = Math.max(maxX, x);
						maxY = Math.max(maxY, y);
					}
				}
			}
			offset.set(minX, minY);
			size.set(maxX - minX, maxY - minY);
		}

		/** Increments the skeleton's {@link #time}. */
		update (delta: number) {
			this.time += delta;
		}
	}
}
