//----------------------------------------------
//            NGUI: Next-Gen UI kit
// Copyright © 2011-2015 Tasharen Entertainment
//----------------------------------------------

using UnityEngine;
using System.Collections.Generic;

/// <summary>
/// Very simple sprite animation. Attach to a sprite and specify a common prefix such as "idle" and it will cycle through them.
/// </summary>

[ExecuteInEditMode]
[RequireComponent(typeof(UISprite))]
[AddComponentMenu("NGUI/UI/Sprite Animation")]
public class UISpriteAnimation : MonoBehaviour
{
	[HideInInspector][SerializeField] protected int mFPS = 30;
	[HideInInspector][SerializeField] protected string mPrefix = "";
	[HideInInspector][SerializeField] protected bool mLoop = true;
	[HideInInspector][SerializeField] protected bool mSnap = true;
	[HideInInspector][SerializeField] protected bool mUseRealTime = false;

    protected UISprite mSprite;
	protected float mDelta = 0f;
	protected int mIndex = 0;
	protected bool mActive = true;
    protected List<string> mSpriteNames = null;

	/// <summary>
	/// Number of frames in the animation.
	/// </summary>

	public int frames { get { return mSpriteNames != null ? mSpriteNames.Count : 0; } }

	/// <summary>
	/// Animation framerate.
	/// </summary>

	public int framesPerSecond { get { return mFPS; } set { mFPS = value; } }

	/// <summary>
	/// Set the name prefix used to filter sprites from the atlas.
	/// </summary>

	public string namePrefix { get { return mPrefix; } set { if (mPrefix != value) { mPrefix = value; RebuildSpriteList(); } } }

	/// <summary>
	/// Set the animation to be looping or not
	/// </summary>

	public bool loop { get { return mLoop; } set { mLoop = value; } }

    public bool PrefixSnap { get { return mSnap; } set { mSnap = value; } }

	/// <summary>
	/// Returns is the animation is still playing or not
	/// </summary>

	public bool isPlaying { get { return mActive; } }

	/// <summary>
	/// Rebuild the sprite list first thing.
	/// </summary>

	protected virtual void Start () { RebuildSpriteList(); }

	/// <summary>
	/// Advance the sprite animation process.
	/// </summary>

	protected virtual void Update ()
	{
		if (mActive && mSpriteNames != null && mSpriteNames.Count > 1 && Application.isPlaying && mFPS > 0)
		{
            if(mUseRealTime)
            {
                mDelta += RealTime.deltaTime;
            }
            else
            {
                mDelta += Time.deltaTime;
            }
            float rate = 1f / mFPS;

			if (rate < mDelta)
			{
				mDelta = (rate > 0f) ? mDelta - rate : 0f;

				if (++mIndex >= mSpriteNames.Count)
				{
					mIndex = 0;
					mActive = mLoop;
				}

				if (mActive)
				{
					mSprite.spriteName = mSpriteNames[mIndex];
					if (mSnap) mSprite.MakePixelPerfect();
				}
			}
		}
	}

    /// <summary>
    /// Rebuild the sprite list after changing the sprite name.
    /// </summary>
    private static Dictionary<string, Dictionary<string, List<string>>> _spriteNameCache = new Dictionary<string, Dictionary<string, List<string>>>();
	public void RebuildSpriteList ()
	{
		if (mSprite == null) mSprite = GetComponent<UISprite>();

		if (mSprite != null && mSprite.atlas != null)
		{
            var atlasName = mSprite.atlas.name;
            Dictionary<string, List<string>> atlasDic = null;
            List<string> prefixList = null;
            if (_spriteNameCache.TryGetValue(atlasName, out atlasDic) && atlasDic.TryGetValue(mPrefix, out prefixList))
            {
                mSpriteNames = prefixList;
            }
            else
            {
                mSpriteNames = new List<string>();
                List<UISpriteData> sprites = mSprite.atlas.spriteList;

                for (int i = 0, imax = sprites.Count; i < imax; ++i)
                {
                    UISpriteData sprite = sprites[i];

                    if (string.IsNullOrEmpty(mPrefix) || sprite.name.StartsWith(mPrefix))
                    {
                        mSpriteNames.Add(sprite.name);
                    }
                }
                mSpriteNames.Sort();
                if(!_spriteNameCache.ContainsKey(atlasName))
                {
                    atlasDic = new Dictionary<string, List<string>>();
                    _spriteNameCache.Add(atlasName, atlasDic);
                }
                if(!atlasDic.ContainsKey(mPrefix))
                {
                    atlasDic.Add(mPrefix, mSpriteNames);
                }
            }
		}
	}
	
	/// <summary>
	/// Reset the animation to the beginning.
	/// </summary>

	public void Play () { mActive = true; }

	/// <summary>
	/// Pause the animation.
	/// </summary>

	public void Pause () { mActive = false; }

	/// <summary>
	/// Reset the animation to frame 0 and activate it.
	/// </summary>

	public void ResetToBeginning ()
	{
		mActive = true;
		mIndex = 0;

		if (mSprite != null && mSpriteNames != null && mSpriteNames.Count > 0)
		{
			mSprite.spriteName = mSpriteNames[mIndex];
			if (mSnap) mSprite.MakePixelPerfect();
		}
	}
}