/******************************************************************************
 * Spine Runtimes Software License v2.5
 *
 * Copyright (c) 2013-2016, 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 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 develop new applications using the Spine Runtimes or otherwise
 * create derivative works or improvements of the Spine Runtimes 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, 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 THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *****************************************************************************/

using System;
using UnityEngine;

namespace Spine.Unity {
	
	[ExecuteInEditMode]
	[AddComponentMenu("Spine/SkeletonAnimation")]
	[HelpURL("http://esotericsoftware.com/spine-unity-documentation#Controlling-Animation")]
	public class SkeletonAnimation : SkeletonRenderer, ISkeletonAnimation, IAnimationStateComponent {

		#region IAnimationStateComponent
		/// <summary>
		/// This is the Spine.AnimationState object of this SkeletonAnimation. You can control animations through it. 
		/// Note that this object, like .skeleton, is not guaranteed to exist in Awake. Do all accesses and caching to it in Start</summary>
		public Spine.AnimationState state;
		/// <summary>
		/// This is the Spine.AnimationState object of this SkeletonAnimation. You can control animations through it. 
		/// Note that this object, like .skeleton, is not guaranteed to exist in Awake. Do all accesses and caching to it in Start</summary>
		public Spine.AnimationState AnimationState { get { return this.state; } }
		#endregion

		#region Bone Callbacks ISkeletonAnimation
		protected event UpdateBonesDelegate _UpdateLocal;
		protected event UpdateBonesDelegate _UpdateWorld;
		protected event UpdateBonesDelegate _UpdateComplete;

		/// <summary>
		/// Occurs after the animations are applied and before world space values are resolved.
		/// Use this callback when you want to set bone local values.
		/// </summary>
		public event UpdateBonesDelegate UpdateLocal { add { _UpdateLocal += value; } remove { _UpdateLocal -= value; } }

		/// <summary>
		/// Occurs after the Skeleton's bone world space values are resolved (including all constraints).
		/// Using this callback will cause the world space values to be solved an extra time.
		/// Use this callback if want to use bone world space values, and also set bone local values.</summary>
		public event UpdateBonesDelegate UpdateWorld { add { _UpdateWorld += value; } remove { _UpdateWorld -= value; } }

		/// <summary>
		/// Occurs after the Skeleton's bone world space values are resolved (including all constraints).
		/// Use this callback if you want to use bone world space values, but don't intend to modify bone local values.
		/// This callback can also be used when setting world position and the bone matrix.</summary>
		public event UpdateBonesDelegate UpdateComplete { add { _UpdateComplete += value; } remove { _UpdateComplete -= value; } }
		#endregion

		#region Serialized state and Beginner API
		[SerializeField]
		[SpineAnimation]
		private string _animationName;
		public string AnimationName {
			get {
				if (!valid) {
					Debug.LogWarning("You tried access AnimationName but the SkeletonAnimation was not valid. Try checking your Skeleton Data for errors.");
					return null;
				}

				TrackEntry entry = state.GetCurrent(0);
				return entry == null ? null : entry.Animation.Name;
			}
			set {
				if (_animationName == value)
					return;
				_animationName = value;

				if (!valid) {
					Debug.LogWarning("You tried to change AnimationName but the SkeletonAnimation was not valid. Try checking your Skeleton Data for errors.");
					return;
				}

				if (string.IsNullOrEmpty(value))
					state.ClearTrack(0);
				else
					state.SetAnimation(0, value, loop);
			}
		}

		/// <summary>Whether or not <see cref="AnimationName"/> should loop. This only applies to the initial animation specified in the inspector, or any subsequent Animations played through .AnimationName. Animations set through state.SetAnimation are unaffected.</summary>
		public bool loop;

		/// <summary>
		/// The rate at which animations progress over time. 1 means 100%. 0.5 means 50%.</summary>
		/// <remarks>AnimationState and TrackEntry also have their own timeScale. These are combined multiplicatively.</remarks>
		public float timeScale = 1;
		#endregion

		#region Runtime Instantiation
		/// <summary>Adds and prepares a SkeletonAnimation component to a GameObject at runtime.</summary>
		/// <returns>The newly instantiated SkeletonAnimation</returns>
		public static SkeletonAnimation AddToGameObject (GameObject gameObject, SkeletonDataAsset skeletonDataAsset) {
			return SkeletonRenderer.AddSpineComponent<SkeletonAnimation>(gameObject, skeletonDataAsset);
		}

		/// <summary>Instantiates a new UnityEngine.GameObject and adds a prepared SkeletonAnimation component to it.</summary>
		/// <returns>The newly instantiated SkeletonAnimation component.</returns>
		public static SkeletonAnimation NewSkeletonAnimationGameObject (SkeletonDataAsset skeletonDataAsset) {
			return SkeletonRenderer.NewSpineGameObject<SkeletonAnimation>(skeletonDataAsset);
		}
		#endregion

		protected override void ClearState () {
			base.ClearState();
			if (state != null) state.ClearTracks();
		}

		public override void Initialize (bool overwrite) {
			if (valid && !overwrite)
				return;

			base.Initialize(overwrite);

			if (!valid)
				return;

			state = new Spine.AnimationState(skeletonDataAsset.GetAnimationStateData());

			#if UNITY_EDITOR
			if (!string.IsNullOrEmpty(_animationName)) {
				if (Application.isPlaying) {
					state.SetAnimation(0, _animationName, loop);
				} else {
					// Assume SkeletonAnimation is valid for skeletonData and skeleton. Checked above.
					var animationObject = skeletonDataAsset.GetSkeletonData(false).FindAnimation(_animationName);
					if (animationObject != null)
						animationObject.Apply(skeleton, 0f, 0f, false, null, 1f, true, false);
				}
				Update(0);
			}
			#else
			if (!string.IsNullOrEmpty(_animationName)) {
				state.SetAnimation(0, _animationName, loop);
				Update(0);
			}
			#endif
		}

		public void Update () {
			Update(Time.deltaTime);
		}

		public void Update (float deltaTime) {
			if (!valid)
				return;

			deltaTime *= timeScale;
			skeleton.Update(deltaTime);
			state.Update(deltaTime);
			state.Apply(skeleton);

			if (_UpdateLocal != null)
				_UpdateLocal(this);

			skeleton.UpdateWorldTransform();

			if (_UpdateWorld != null) {
				_UpdateWorld(this);
				skeleton.UpdateWorldTransform();
			}

			if (_UpdateComplete != null) {
				_UpdateComplete(this);
			}
		}

	}

}
