package net.tylermurphy.Minecraft.Render.Data;

import java.nio.ByteBuffer;
import java.nio.IntBuffer;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import static org.lwjgl.opengl.GL30.*;

import org.lwjgl.opengl.EXTTextureFilterAnisotropic;
import org.lwjgl.opengl.GL;
import org.lwjgl.stb.STBImage;
import org.lwjgl.system.MemoryStack;

import net.tylermurphy.Minecraft.Util.Constants;

public class Texture {
	
    public ByteBuffer getImage() {
        return image;
    }

    public int getWidth() {
        return width;
    }

    public int getHeight() {
        return height;
    }

    private ByteBuffer image;
    private int width, height;

    private static List<Integer> ids = new ArrayList<Integer>();
    
    Texture(int width, int heigh, ByteBuffer image) {
        this.image = image;
        this.height = heigh;
        this.width = width;
    }
    
    public static Texture loadRawTextureData(String fileName) {
        ByteBuffer image;
        int width, height;
        try (MemoryStack stack = MemoryStack.stackPush()) {
            IntBuffer comp = stack.mallocInt(1);
            IntBuffer w = stack.mallocInt(1);
            IntBuffer h = stack.mallocInt(1);
            image = STBImage.stbi_load(Constants.PNG_LOCATION + fileName + ".png", w, h, comp, 4);
            if (image == null) {
                System.err.println("Couldn't load " + Constants.PNG_LOCATION + fileName + ".png");
            }
            width = w.get();
            height = h.get();
            return new Texture(width, height, image);
        }
    }
    
    private static int loadImage(String fileName) {
    	int id = glGenTextures();
    	Texture image = loadRawTextureData(fileName);
    	glActiveTexture(GL_TEXTURE0);
    	glBindTexture(GL_TEXTURE_2D, id);
    	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, image.getWidth(), image.getHeight(), 0, GL_RGBA, GL_UNSIGNED_BYTE, image.getImage());
        glGenerateMipmap(GL_TEXTURE_2D);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_LOD_BIAS, -1);
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
		glBindTexture(GL_TEXTURE_2D, 0);
		ids.add(id);
		return id;
    }
    
    public static int loadTexture(String fileName) {
    	return loadImage(fileName);
    }
    
    public static int loadFontAtlas(String fileName) {
    	return loadImage(fileName);
    }
    
    public static int loadTexture2DArray(HashMap<Integer, Texture> textures){
        int id = glGenTextures();
        glActiveTexture(GL_TEXTURE0);
        glBindTexture(GL_TEXTURE_2D, id);
        glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_LINEAR);
        glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_S, GL_REPEAT);
        glTexParameteri(GL_TEXTURE_2D_ARRAY, GL_TEXTURE_WRAP_T, GL_REPEAT);
        if (GL.getCapabilities().GL_EXT_texture_filter_anisotropic) {
            float maxAnisotropy = glGetFloat(EXTTextureFilterAnisotropic.GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT);
            glTexParameterf(GL_TEXTURE_2D_ARRAY, EXTTextureFilterAnisotropic.GL_TEXTURE_MAX_ANISOTROPY_EXT, maxAnisotropy);
        }
        glTexImage3D(GL_TEXTURE_2D_ARRAY, 0, GL_RGBA, textures.get(0).width, textures.get(0).height, textures.values().size(), 0, GL_RGBA, GL_UNSIGNED_BYTE, (ByteBuffer) null);
        for(Map.Entry<Integer, Texture> entry : textures.entrySet()){
            glTexSubImage3D(GL_TEXTURE_2D_ARRAY, 0, 0, 0, entry.getKey(), entry.getValue().width, entry.getValue().height, 1, GL_RGBA, GL_UNSIGNED_BYTE, entry.getValue().getImage());
        }
        glGenerateMipmap(GL_TEXTURE_2D_ARRAY);
        glBindTexture(GL_TEXTURE_2D_ARRAY, 0);
        ids.add(id);
        return id;
    }
    
    public static void cleanUp(){
		for(int id:ids){
			glDeleteTextures(id);
            glActiveTexture(GL_TEXTURE0);
            glBindTexture(GL_TEXTURE_2D_ARRAY, id);
		}
	}
}