package com.starshock.gl;

import com.starshock.game.Game;
import com.starshock.gl.address.types.*;
import com.starshock.gl.helper.GLHelper;

import java.nio.FloatBuffer;

import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.opengl.GL15.GL_ARRAY_BUFFER;
import static org.lwjgl.opengl.GL15.GL_STREAM_DRAW;
import static org.lwjgl.opengl.GL15.glBindBuffer;
import static org.lwjgl.opengl.GL20.*;
import static org.lwjgl.opengl.GL30.*;

public class Renderer {
    public TextureAddress masterTexture;
    public FrameBufferAddress gameFramebuffer, processingFramebuffer;
    public ProgramAddress gameProgram;
    public Unsync buffer;

    public Renderer() {
    }

    private void init() {
        masterTexture = GLHelper.createTextureFromPath("/res/sheet.png");

        gameFramebuffer = GLHelper.createFrameBufferAddress(Game.PURE_WIDTH, Game.PURE_HEIGHT);
        processingFramebuffer = GLHelper.createFrameBufferAddress(Game.PURE_WIDTH, Game.PURE_HEIGHT);

        ShaderAddress gameVertexShader = GLHelper.createShaderFromPath("/res/shader/game.vert", GL_VERTEX_SHADER);
        ShaderAddress gameFragmentShader = GLHelper.createShaderFromPath("/res/shader/game.frag", GL_FRAGMENT_SHADER);

        gameProgram = GLHelper.createProgram(gameVertexShader, gameFragmentShader);

        masterTexture.bind();
        gameProgram.use();

        int vao = glGenVertexArrays();
        glBindVertexArray(vao);

        int posAttrib = glGetAttribLocation(gameProgram.getAddress(), "position");
        glEnableVertexAttribArray(posAttrib);
        glVertexAttribPointer(posAttrib, 3, GL_FLOAT, false, 32, 0L);

        int colAttrib = glGetAttribLocation(gameProgram.getAddress(), "color");
        glEnableVertexAttribArray(colAttrib);
        glVertexAttribPointer(colAttrib, 3, GL_FLOAT, false, 32, 12L);

        int texAttrib = glGetAttribLocation(gameProgram.getAddress(), "texCoord");
        glEnableVertexAttribArray(texAttrib);
        glVertexAttribPointer(texAttrib, 2, GL_FLOAT, false, 32, 24L);

        buffer = new Unsync(GL_ARRAY_BUFFER, GL_STREAM_DRAW);
    }

    public void drawBuffer(Unsync buffer) {
        glBindBuffer(GL_ARRAY_BUFFER, buffer.currentBufferHandle());
        glDrawArrays(GL_TRIANGLES, 0, 6);
    }

    public void render() {
        glBindFramebuffer(GL_FRAMEBUFFER, 0);

        buffer.nextFrame();

        buffer.bind();

        buffer.ensureSize(6 * 32);

        FloatBuffer mapped = buffer.map().asFloatBuffer();

        mapped.put(new float[] {-1, 1, 0, 1, 0, 1, 0, 0});
        mapped.put(new float[] {1, 1, 0, 0, 1, 1, 1, 0});
        mapped.put(new float[] {1, -1, 0, 1, 1, 0, 1, 1});
        mapped.put(new float[] {-1, 1, 0, 1, 0, 1, 0, 0});
        mapped.put(new float[] {1, -1, 0, 0, 1, 1, 1, 1});
        mapped.put(new float[] {-1, -1, 0, 1, 1, 0, 0, 1});

        buffer.unmap();

        drawBuffer(buffer);
    }

    public static Renderer issueDefault() {
        Renderer defaultHandler = new Renderer();

        defaultHandler.init();

        return defaultHandler;
    }
}