/******************************************************************************
 * Spine Runtimes Software License
 * Version 2.3
 * 
 * Copyright (c) 2013-2015, Esoteric Software
 * All rights reserved.
 * 
 * You are granted a perpetual, non-exclusive, non-sublicensable and
 * non-transferable license to use, install, execute and perform the Spine
 * Runtimes Software (the "Software") and derivative works solely for personal
 * or internal use. Without the written permission of Esoteric Software (see
 * Section 2 of the Spine Software License Agreement), you may not (a) modify,
 * translate, adapt or otherwise create derivative works, improvements of the
 * Software or develop new applications using the Software or (b) remove,
 * delete, alter or obscure any trademarks or any copyright, trademark, patent
 * or other intellectual property or proprietary rights notices on or in the
 * Software, including any copy thereof. Redistributions in binary or source
 * form must include this license and terms.
 * 
 * THIS SOFTWARE IS PROVIDED BY ESOTERIC SOFTWARE "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 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) 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 THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *****************************************************************************/

using System;
using System.Collections.Generic;

namespace Spine {
	public class Skeleton {
		internal SkeletonData data;
		internal ExposedList<Bone> bones;
		internal ExposedList<Slot> slots;
		internal ExposedList<Slot> drawOrder;
		internal ExposedList<IkConstraint> ikConstraints;
		private ExposedList<ExposedList<Bone>> boneCache = new ExposedList<ExposedList<Bone>>();
		internal Skin skin;
		internal float r = 1, g = 1, b = 1, a = 1;
		internal float time;
		internal bool flipX, flipY;
		internal float x, y;

		public SkeletonData Data { get { return data; } }
		public ExposedList<Bone> Bones { get { return bones; } }
		public ExposedList<Slot> Slots { get { return slots; } }
		public ExposedList<Slot> DrawOrder { get { return drawOrder; } }
		public ExposedList<IkConstraint> IkConstraints { get { return ikConstraints; } set { ikConstraints = value; } }
		public Skin Skin { get { return skin; } set { skin = value; } }
		public float R { get { return r; } set { r = value; } }
		public float G { get { return g; } set { g = value; } }
		public float B { get { return b; } set { b = value; } }
		public float A { get { return a; } set { a = value; } }
		public float Time { get { return time; } set { time = value; } }
		public float X { get { return x; } set { x = value; } }
		public float Y { get { return y; } set { y = value; } }
		public bool FlipX { get { return flipX; } set { flipX = value; } }
		public bool FlipY { get { return flipY; } set { flipY = value; } }

		public Bone RootBone {
			get {
				return bones.Count == 0 ? null : bones.Items[0];
			}
		}

		public Skeleton (SkeletonData data) {
			if (data == null) throw new ArgumentNullException("data cannot be null.");
			this.data = data;

			bones = new ExposedList<Bone>(data.bones.Count);
			foreach (BoneData boneData in data.bones) {
				Bone parent = boneData.parent == null ? null : bones.Items[data.bones.IndexOf(boneData.parent)];
				Bone bone = new Bone(boneData, this, parent);
				if (parent != null) parent.children.Add(bone);
				bones.Add(bone);
			}

			slots = new ExposedList<Slot>(data.slots.Count);
			drawOrder = new ExposedList<Slot>(data.slots.Count);
			foreach (SlotData slotData in data.slots) {
				Bone bone = bones.Items[data.bones.IndexOf(slotData.boneData)];
				Slot slot = new Slot(slotData, bone);
				slots.Add(slot);
				drawOrder.Add(slot);
			}

			ikConstraints = new ExposedList<IkConstraint>(data.ikConstraints.Count);
			foreach (IkConstraintData ikConstraintData in data.ikConstraints)
				ikConstraints.Add(new IkConstraint(ikConstraintData, this));

			UpdateCache();
			UpdateWorldTransform();
		}

		/// <summary>Caches information about bones and IK constraints. Must be called if bones or IK constraints are added or
		/// removed.</summary>
		public void UpdateCache () {
			ExposedList<ExposedList<Bone>> boneCache = this.boneCache;
			ExposedList<IkConstraint> ikConstraints = this.ikConstraints;
			int ikConstraintsCount = ikConstraints.Count;

			int arrayCount = ikConstraintsCount + 1;
			if (boneCache.Count > arrayCount) boneCache.RemoveRange(arrayCount, boneCache.Count - arrayCount);
			for (int i = 0, n = boneCache.Count; i < n; i++)
				boneCache.Items[i].Clear();
			while (boneCache.Count < arrayCount)
				boneCache.Add(new ExposedList<Bone>());

			ExposedList<Bone> nonIkBones = boneCache.Items[0];

			for (int i = 0, n = bones.Count; i < n; i++) {
				Bone bone = bones.Items[i];
				Bone current = bone;
				do {
					for (int ii = 0; ii < ikConstraintsCount; ii++) {
						IkConstraint ikConstraint = ikConstraints.Items[ii];
						Bone parent = ikConstraint.bones.Items[0];
						Bone child = ikConstraint.bones.Items[ikConstraint.bones.Count - 1];
						while (true) {
							if (current == child) {
								boneCache.Items[ii].Add(bone);
								boneCache.Items[ii + 1].Add(bone);
								goto outer;
							}
							if (child == parent) break;
							child = child.parent;
						}
					}
					current = current.parent;
				} while (current != null);
				nonIkBones.Add(bone);
			outer: { }
			}
		}

		/// <summary>Updates the world transform for each bone and applies IK constraints.</summary>
		public void UpdateWorldTransform () {
			ExposedList<Bone> bones = this.bones;
			for (int ii = 0, nn = bones.Count; ii < nn; ii++) {
				Bone bone = bones.Items[ii];
				bone.rotationIK = bone.rotation;
			}
			ExposedList<ExposedList<Bone>> boneCache = this.boneCache;
			ExposedList<IkConstraint> ikConstraints = this.ikConstraints;
			int i = 0, last = boneCache.Count - 1;
			while (true) {
				ExposedList<Bone> updateBones = boneCache.Items[i];
				for (int ii = 0, nn = updateBones.Count; ii < nn; ii++)
					updateBones.Items[ii].UpdateWorldTransform();
				if (i == last) break;
				ikConstraints.Items[i].apply();
				i++;
			}
		}

		/// <summary>Sets the bones and slots to their setup pose values.</summary>
		public void SetToSetupPose () {
			SetBonesToSetupPose();
			SetSlotsToSetupPose();
		}

		public void SetBonesToSetupPose () {
			ExposedList<Bone> bones = this.bones;
			for (int i = 0, n = bones.Count; i < n; i++)
				bones.Items[i].SetToSetupPose();

			ExposedList<IkConstraint> ikConstraints = this.ikConstraints;
			for (int i = 0, n = ikConstraints.Count; i < n; i++) {
				IkConstraint ikConstraint = ikConstraints.Items[i];
				ikConstraint.bendDirection = ikConstraint.data.bendDirection;
				ikConstraint.mix = ikConstraint.data.mix;
			}
		}

		public void SetSlotsToSetupPose () {
			ExposedList<Slot> slots = this.slots;
			drawOrder.Clear();
			for (int i = 0, n = slots.Count; i < n; i++)
				drawOrder.Add(slots.Items[i]);

			for (int i = 0, n = slots.Count; i < n; i++)
				slots.Items[i].SetToSetupPose(i);
		}

		/// <returns>May be null.</returns>
		public Bone FindBone (String boneName) {
			if (boneName == null) throw new ArgumentNullException("boneName cannot be null.");
			ExposedList<Bone> bones = this.bones;
			for (int i = 0, n = bones.Count; i < n; i++) {
				Bone bone = bones.Items[i];
				if (bone.data.name == boneName) return bone;
			}
			return null;
		}

		/// <returns>-1 if the bone was not found.</returns>
		public int FindBoneIndex (String boneName) {
			if (boneName == null) throw new ArgumentNullException("boneName cannot be null.");
			ExposedList<Bone> bones = this.bones;
			for (int i = 0, n = bones.Count; i < n; i++)
				if (bones.Items[i].data.name == boneName) return i;
			return -1;
		}

		/// <returns>May be null.</returns>
		public Slot FindSlot (String slotName) {
			if (slotName == null) throw new ArgumentNullException("slotName cannot be null.");
			ExposedList<Slot> slots = this.slots;
			for (int i = 0, n = slots.Count; i < n; i++) {
				Slot slot = slots.Items[i];
				if (slot.data.name == slotName) return slot;
			}
			return null;
		}

		/// <returns>-1 if the bone was not found.</returns>
		public int FindSlotIndex (String slotName) {
			if (slotName == null) throw new ArgumentNullException("slotName cannot be null.");
			ExposedList<Slot> slots = this.slots;
			for (int i = 0, n = slots.Count; i < n; i++)
				if (slots.Items[i].data.name.Equals(slotName)) return i;
			return -1;
		}

		/// <summary>Sets a skin by name (see SetSkin).</summary>
		public void SetSkin (String skinName) {
			Skin skin = data.FindSkin(skinName);
			if (skin == null) throw new ArgumentException("Skin not found: " + skinName);
			SetSkin(skin);
		}

		/// <summary>Sets the skin used to look up attachments before looking in the {@link SkeletonData#getDefaultSkin() default 
		/// skin}. Attachmentsfrom 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.</summary>
		/// <param name="newSkin">May be null.</param>
		public void SetSkin (Skin newSkin) {
			if (newSkin != null) {
				if (skin != null)
					newSkin.AttachAll(this, skin);
				else {
					ExposedList<Slot> slots = this.slots;
					for (int i = 0, n = slots.Count; i < n; i++) {
						Slot slot = slots.Items[i];
						String name = slot.data.attachmentName;
						if (name != null) {
							Attachment attachment = newSkin.GetAttachment(i, name);
							if (attachment != null) slot.Attachment = attachment;
						}
					}
				}
			}
			skin = newSkin;
		}

		/// <returns>May be null.</returns>
		public Attachment GetAttachment (String slotName, String attachmentName) {
			return GetAttachment(data.FindSlotIndex(slotName), attachmentName);
		}

		/// <returns>May be null.</returns>
		public Attachment GetAttachment (int slotIndex, String attachmentName) {
			if (attachmentName == null) throw new ArgumentNullException("attachmentName cannot be null.");
			if (skin != null) {
				Attachment attachment = skin.GetAttachment(slotIndex, attachmentName);
				if (attachment != null) return attachment;
			}
			if (data.defaultSkin != null) return data.defaultSkin.GetAttachment(slotIndex, attachmentName);
			return null;
		}

		/// <param name="attachmentName">May be null.</param>
		public void SetAttachment (String slotName, String attachmentName) {
			if (slotName == null) throw new ArgumentNullException("slotName cannot be null.");
			ExposedList<Slot> slots = this.slots;
			for (int i = 0, n = slots.Count; i < n; i++) {
				Slot slot = slots.Items[i];
				if (slot.data.name == slotName) {
					Attachment attachment = null;
					if (attachmentName != null) {
						attachment = GetAttachment(i, attachmentName);
						if (attachment == null) throw new Exception("Attachment not found: " + attachmentName + ", for slot: " + slotName);
					}
					slot.Attachment = attachment;
					return;
				}
			}
			throw new Exception("Slot not found: " + slotName);
		}

		/** @return May be null. */
		public IkConstraint FindIkConstraint (String ikConstraintName) {
			if (ikConstraintName == null) throw new ArgumentNullException("ikConstraintName cannot be null.");
			ExposedList<IkConstraint> ikConstraints = this.ikConstraints;
			for (int i = 0, n = ikConstraints.Count; i < n; i++) {
				IkConstraint ikConstraint = ikConstraints.Items[i];
				if (ikConstraint.data.name == ikConstraintName) return ikConstraint;
			}
			return null;
		}

		public void Update (float delta) {
			time += delta;
		}
	}
}
