using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
#endif
using System.Collections;

[ExecuteInEditMode]
public class TextureAnimator : MonoBehaviour
{
	int numberToAnimate;
	int lastNum;
	public bool incrementListLength = false;
	public bool decrementListLength = false;
	
	public Material[] textureList;
	public bool[] enable_animation;
	public float[] fps;
	public int[] frames;
	public int[] columns;
	public int[] rows;
	
	//private static int largestNum; Maybe use this to record the largest state of the arrays in history,
	//so resizing back to a bigger size would remember entries. For now, no.
	
	// Use this for initialization
	void Start ()
	{
		//Reset numberToAnimate for the correct value when it changes to 0 upon script
		//restart or recompilation
		if(textureList != null)
		{
			if(numberToAnimate < textureList.Length)
			{
				numberToAnimate = textureList.Length;
				lastNum = numberToAnimate;
			}
		}
	}
	
	// Update is called once per frame
	void Update() 
	{
		//Using checkboxes as buttons to increase/decrease the list length
		//This is to avoid accidental clearing of the animation list
		if(incrementListLength)
		{
			numberToAnimate++;
			incrementListLength = false;
		}
		else if(decrementListLength)
		{
			numberToAnimate--;
			decrementListLength = false;
		}
		
		//If the list length changed, update all arrays to reflect that
		if(lastNum != numberToAnimate)
		{
			//Material[] m = textureList;
			System.Array.Resize<Material>(ref textureList,numberToAnimate);
			//bool[] e = enable_animation;
			System.Array.Resize<bool>(ref enable_animation,numberToAnimate);
			System.Array.Resize<float>(ref fps,numberToAnimate);
			System.Array.Resize<int>(ref frames,numberToAnimate);
			System.Array.Resize<int>(ref columns,numberToAnimate);
			System.Array.Resize<int>(ref rows,numberToAnimate);
			
			//If the list length grew, set default values to the new array elements
			//This avoids errors in the script execution
			if(numberToAnimate > lastNum)
			{
				if(gameObject.GetComponent(typeof(Renderer)) != null)
					textureList[lastNum] = GetComponent<Renderer>().sharedMaterial;
#if UNITY_EDITOR
				else
					textureList[lastNum] = (Material)AssetDatabase.LoadAssetAtPath("Assets/_Materials/tile_Lab_big.mat", typeof(Material));
#endif				
				enable_animation[lastNum] = true;
				fps[lastNum] = 10;
				frames[lastNum] = 1;
				columns[lastNum] = 1;
				rows[lastNum] = 1;
			}
			
			//Update lastNum to continue comparing it to numberToAnimate
			lastNum = numberToAnimate;
		}

		//Iterate through all existing textures to be animated, and change their current
		//frame as necessary
		for(int i = 0; i < numberToAnimate; i++)
		{
			if(enable_animation[i])
			{
				int index = (int)Mathf.Floor(Time.time * fps[i]);
				index %= frames[i];
				//Debug.Log("Index update -- index is now: " + index + ".");
				
				Vector2 size = new Vector2(1.0f / (float)columns[i], 1.0f / (float)rows[i]);
				
				int uIndex = index % columns[i]; //No need to round -- modulus always returns an integer
				int vIndex = (int)Mathf.Floor((float)index / (float)columns[i]); //Position was messing up because this was rounding instead of flooring
															 //E.g., index 2 should return vIndex of 0.
															 //Round: 2 (index)/4 (columns) or 0.5 and you get 1,
															 //Floor: 2/4 or 0.5 and you get 0.
				
				Vector2 offset = new Vector2((float)uIndex * size.x, Mathf.Repeat(1f - size.y - (float)vIndex * size.y,1f));
				
				textureList[i].SetTextureOffset("_MainTex", offset);
				textureList[i].SetTextureScale ("_MainTex", size);
			}
		}
	}
}