using System;
using System.Collections.Generic;
using HarmonyLib;
using RimWorld;
using UnityEngine;
using Verse;

namespace Rimworld_Animations_Patch
{
	public static class GraphicMaskingUtility
	{
		public static Texture2D GetReadableTexture2D(Texture2D source, int newWidth, int newHeight, Material mat = null) //rescales texture to newWidth and newHeight
		{
			source.filterMode = FilterMode.Trilinear;

			RenderTexture rt = RenderTexture.GetTemporary(newWidth, newHeight);
			rt.filterMode = FilterMode.Trilinear;

			RenderTexture.active = rt;
			if (mat != null)
			{ Graphics.Blit(source, rt, mat); }
			else
			{ Graphics.Blit(source, rt); }

			Texture2D nTex = new Texture2D(newWidth, newHeight, TextureFormat.RGBA32, mipChain: true);
			nTex.ReadPixels(new Rect(0, 0, newWidth, newHeight), 0, 0);
			nTex.name = source.name;
			nTex.filterMode = FilterMode.Trilinear;
			nTex.anisoLevel = 2;
			nTex.Apply(updateMipmaps: true);

			GL.Clear(true, true, Color.clear);
			RenderTexture.active = null;
			RenderTexture.ReleaseTemporary(rt);

			return nTex;
		}

		public static Texture2D GetReadableTexture2D(Texture2D source, Material mat = null)
		{
			return GetReadableTexture2D(source, source.width, source.height, mat);
		}

		public static Texture2D ApplyMaskToTexture2D(Texture2D mainTex, Texture2D maskTex, bool writeOverMainTex)
		{
			if (mainTex == null) { DebugMode.Message("ERROR: Cannot mask texture, mainTex is missing!"); return mainTex; }
			if (mainTex == null) { DebugMode.Message("ERROR: Cannot mask texture, maskTex is missing!"); return mainTex; }
		
			Color[] mainArray = GetReadableTexture2D(mainTex).GetPixels();
			Color[] maskArray = GetReadableTexture2D(maskTex, mainTex.width, mainTex.height).GetPixels();

			for (int j = 0; j < mainArray.Length; j++)
			{
				if (maskArray[j] == Color.white)
				{ /*null*/ }

				else if (maskArray[j].a == 0)
				{ mainArray[j].a = 0; }

				else if (mainArray[j].a > 0 && maskArray[j].a > 0 && writeOverMainTex)
				{ mainArray[j] = new Color(Mathf.Min(mainArray[j].r, maskArray[j].r), Mathf.Min(mainArray[j].g, maskArray[j].g), Mathf.Min(mainArray[j].b, maskArray[j].b), Mathf.Min(mainArray[j].a, maskArray[j].a)); }
			}

			Texture2D newTex = new Texture2D(mainTex.width, mainTex.height, TextureFormat.RGBA32, mipChain: true);
			newTex.SetPixels(mainArray);
			newTex.filterMode = FilterMode.Trilinear;
			newTex.anisoLevel = 2;
			newTex.Apply(updateMipmaps: true);

			return newTex;
		}

		public static Graphic ApplyGraphicMasks(Graphic graphic, Graphic graphicWithMask, bool writeOverMainTex)
		{
			for (int i = 0; i < 4; i++)
			{
				Texture2D mainTex = (Texture2D)graphic.MatAt(new Rot4(i)).mainTexture;
				Texture2D maskTex = graphicWithMask.MatAt(new Rot4(i)).GetMaskTexture();

				if (mainTex == null)
				{ DebugMode.Message("Main Texture2D not found for " + graphic.path + ". Rotation: " + i.ToString()); continue; }

				if (maskTex == null)
				{ DebugMode.Message("Mask Texture2D not found for " + graphic.path + ". Rotation: " + i.ToString()); continue; }

				graphic.MatAt(new Rot4(i)).mainTexture = ApplyMaskToTexture2D(mainTex, maskTex, writeOverMainTex);
			}

			return graphic;
		}
	}
}