using UnityEngine;
using System.Collections;

namespace WorldComposer
{
    public class RTPMethods
    {
        public static Texture2D PrepareHeights(int num, int numLayers, Texture2D[] Heights)
        {
            // ReliefTerrain _targetRT=(ReliefTerrain)target;
            // ReliefTerrainGlobalSettingsHolder _target=_targetRT.globalSettingsHolder;

            // Texture2D[] Heights=_target.Heights;
            if (Heights == null) return null;

            for (int n = 0; n < Heights.Length; n++)
            {
                int min_size = 9999;
                for (int m = (n / 4) * 4; (m < ((n / 4) * 4 + 4)) && (m < Heights.Length); m++)
                {
                    if (Heights[m])
                    {
                        if (Heights[m].width < min_size) min_size = Heights[m].width;
                    }
                }
                /*
                AssetImporter _importer=AssetImporter.GetAtPath(AssetDatabase.GetAssetPath(Heights[n]));
                if (_importer) {
                    TextureImporter tex_importer=(TextureImporter)_importer;
                    bool reimport_flag=false;
                    if (!tex_importer.isReadable) {
                        Debug.LogWarning("Height texture "+n+" ("+Heights[n].name+") has been reimported as readable.");
                        tex_importer.isReadable=true;
                        reimport_flag=true;
                    }
                    if (!tex_importer.DoesSourceTextureHaveAlpha() && !tex_importer.grayscaleToAlpha) {
                        Debug.LogWarning("Height texture "+n+" ("+Heights[n].name+") has been reimported to have alpha channel.");
                        tex_importer.grayscaleToAlpha=true;
                        tex_importer.textureFormat=TextureImporterFormat.Alpha8;
                        reimport_flag=true;
                    }
                    if (Heights[n] && Heights[n].width>min_size) {
                        Debug.LogWarning("Height texture "+n+" ("+Heights[n].name+") has been reimported with "+min_size+" size.");
                        tex_importer.maxTextureSize=min_size;
                        reimport_flag=true;
                    }
                    if (reimport_flag) {
                        AssetDatabase.ImportAsset(AssetDatabase.GetAssetPath(Heights[n]),  ImportAssetOptions.ForceUpdate);
                    }
                }
                */
            }

            Texture2D[] heights = new Texture2D[4];
            int i;
            int _w = 256;
            // int _w_idx=0;
            int len = numLayers < 12 ? numLayers : 12;
            if (num >= len) return null;
            num = (num >> 2) * 4;
            for (i = num; i < num + 4; i++)
            {
                if (num < 4)
                {
                    heights[i] = i < Heights.Length ? Heights[i] : null;
                    if (heights[i])
                    {
                        _w = heights[i].width;
                        // _w_idx=i;
                    }
                }
                else if (num < 8)
                {
                    heights[i - 4] = i < Heights.Length ? Heights[i] : null;
                    if (heights[i - 4])
                    {
                        _w = heights[i - 4].width;
                        // _w_idx=i;
                    }
                }
                else
                {
                    heights[i - 8] = i < Heights.Length ? Heights[i] : null;
                    if (heights[i - 8])
                    {
                        _w = heights[i - 8].width;
                        // _w_idx=i;
                    }
                }
            }
            for (i = 0; i < 4; i++)
            {
                if (!heights[i])
                {
                    heights[i] = new Texture2D(_w, _w);
                    FillTex(heights[i], new Color32(255, 255, 255, 255));
                }
            }
            /*
			if (heights[i]) {
				try { 
					heights[i].GetPixels(0,0,4,4,0);
				} catch (Exception e) {
					Debug.LogError("Height texture "+i+" has to be marked as isReadable...");
					Debug.LogError(e.Message);
					// _target.activateObject=heights[i];
					return false;
				}
				if (heights[i].width!=_w) {
					Debug.LogError("Height textures should have the same size ! (check layer "+_w_idx+" and "+(num+i)+")");
					// _target.activateObject=heights[i];
					return false;
				}
			} 
		
			// else {
			if (heights[i] == null) {
				heights[i]=new Texture2D(_w, _w);
				FillTex(heights[i], new Color32(255,255,255,255));
			}
			//}
		}
		*/
            return CombineHeights(heights[0], heights[1], heights[2], heights[3]);
            /*	
            if (num<4) {
                _target.HeightMap=CombineHeights(heights[0], heights[1], heights[2], heights[3]);
            } else if (num<8) {
                _target.HeightMap2=CombineHeights(heights[0], heights[1], heights[2], heights[3]);
            } else if (num<12) {
                _target.HeightMap3=CombineHeights(heights[0], heights[1], heights[2], heights[3]);
            }
            return true;
            */
        }

        public static Texture2D CombineHeights(Texture2D source_tex0, Texture2D source_tex1, Texture2D source_tex2, Texture2D source_tex3)
        {
            Texture2D rendered_tex = new Texture2D(source_tex0.width, source_tex0.height, TextureFormat.ARGB32, true, true);
            byte[] colsR = get_alpha_channel(source_tex0);
            byte[] colsG = get_alpha_channel(source_tex1);
            byte[] colsB = get_alpha_channel(source_tex2);
            byte[] colsA = get_alpha_channel(source_tex3);
            Color32[] cols = rendered_tex.GetPixels32();
            for (int i = 0; i < cols.Length; i++)
            {
                cols[i].r = colsR[i];
                cols[i].g = colsG[i];
                cols[i].b = colsB[i];
                cols[i].a = colsA[i];
            }
            rendered_tex.SetPixels32(cols);
            rendered_tex.Apply(true, false);
            rendered_tex.Compress(true);
            //rendered_tex.Apply(true, true); // (non readable robione przy publishingu)
            rendered_tex.filterMode = FilterMode.Trilinear;
            return rendered_tex;
        }

        static byte[] get_alpha_channel(Texture2D source_tex)
        {
            Color32[] cols = source_tex.GetPixels32();
            byte[] ret = new byte[cols.Length];
            for (int i = 0; i < cols.Length; i++) ret[i] = cols[i].a;
            return ret;
        }

        static void FillTex(Texture2D tex, Color32 col)
        {
            Color32[] cols = tex.GetPixels32();
            for (int i = 0; i < cols.Length; i++)
            {
                cols[i].r = col.r;
                cols[i].g = col.g;
                cols[i].b = col.b;
                cols[i].a = col.a;
            }
            tex.SetPixels32(cols);
        }
    }
}