//
//  App.h
//  GLGameTemplate
//
//  Created by Joshua Moerman on 5/4/12.
//  Copyright (c) 2012 Vadovas. All rights reserved.
//

#ifndef GLGameTemplate_App_h
#define GLGameTemplate_App_h

#import <GLKit/GLKit.h>

#include <memory>
#include <cmath>
#include "shader.h"

#define BUFFER_OFFSET(i) ((char *)NULL + (i))

struct App {
	std::unique_ptr<J::shader> program;
    
    GLKMatrix4 modelViewProjectionMatrix;
    GLKMatrix3 normalMatrix;
    float rotation;
	float aspect;
    
    GLuint vertexArray;
    GLuint vertexBuffer;
	
	App()
	: program(nullptr)
	, modelViewProjectionMatrix({{0}})
	, normalMatrix({{0}})
	, rotation(0)
	, aspect(0.75)
	, vertexArray(0)
	, vertexBuffer(0)
	{
		std::cout << "APP CONSTRUCTED" << std::endl;
		glEnable(GL_DEPTH_TEST);
		
		// shader
		NSString * vshader_file = [[NSBundle mainBundle] pathForResource:@"Shader" ofType:@"vsh"];
		NSString * fshader_file = [[NSBundle mainBundle] pathForResource:@"Shader" ofType:@"fsh"];
		std::vector<std::string> v;
		v.emplace_back("position");
		v.emplace_back("normal");
		program.reset(new J::shader([vshader_file UTF8String], [fshader_file UTF8String], std::move(v)));
		
		// vertex-buffer
		glGenVertexArraysOES(1, &vertexArray);
		glBindVertexArrayOES(vertexArray);
		
		glGenBuffers(1, &vertexBuffer);
		glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
		glBufferData(GL_ARRAY_BUFFER, sizeof(gCubeVertexData), gCubeVertexData, GL_STATIC_DRAW);
		
		glEnableVertexAttribArray(GLKVertexAttribPosition);
		glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, 24, BUFFER_OFFSET(0));
		glEnableVertexAttribArray(GLKVertexAttribNormal);
		glVertexAttribPointer(GLKVertexAttribNormal, 3, GL_FLOAT, GL_FALSE, 24, BUFFER_OFFSET(12));
		
		glBindVertexArrayOES(0);
	}
	
	~App(){
		glDeleteBuffers(1, &vertexBuffer);
		glDeleteVertexArraysOES(1, &vertexArray);
		std::cout << "APP DESTRUCTED" << std::endl;
	}
	
	void resize(float width, float height){
		aspect = std::abs(width/height);
	}
	
	void update(float dt){
		// projection matrix (perspective)
		GLKMatrix4 projectionMatrix = GLKMatrix4MakePerspective(GLKMathDegreesToRadians(65.0f), aspect, 0.1f, 100.0f);
		
		// model matrix (rotation)
		GLKMatrix4 baseModelViewMatrix = GLKMatrix4MakeTranslation(0.0f, 0.0f, -4.0f);
		baseModelViewMatrix = GLKMatrix4Rotate(baseModelViewMatrix, rotation, 0.0f, 1.0f, 0.0f);
		
		GLKMatrix4 modelViewMatrix = GLKMatrix4MakeTranslation(0.0f, 0.0f, 1.5f);
		modelViewMatrix = GLKMatrix4Rotate(modelViewMatrix, rotation, 1.0f, 1.0f, 1.0f);
		modelViewMatrix = GLKMatrix4Multiply(baseModelViewMatrix, modelViewMatrix);
		
		// setting stuff for later use in the shader
		normalMatrix = GLKMatrix3InvertAndTranspose(GLKMatrix4GetMatrix3(modelViewMatrix), NULL);
		modelViewProjectionMatrix = GLKMatrix4Multiply(projectionMatrix, modelViewMatrix);
		
		// time update
		rotation += dt * 0.5f;
	}
	
	void draw(){
		// clear
		float red = rand() / (float)RAND_MAX;
		glClearColor(red, 0.65f, 0.65f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		
		// bind and set up
		glBindVertexArrayOES(vertexArray);
		
		program->begin();
		program->set_uniform("modelViewProjectionMatrix", modelViewProjectionMatrix.m, 0);
		program->set_uniform("normalMatrix", normalMatrix.m, 0);
		
		// draw
		glDrawArrays(GL_TRIANGLES, 0, 36);
	}
	
	constexpr GLfloat gCubeVertexData[216] =  {
		// Data layout for each line below is:
		// positionX, positionY, positionZ,     normalX, normalY, normalZ,
		0.5f, -0.5f, -0.5f,        1.0f, 0.0f, 0.0f,
		0.5f, 0.5f, -0.5f,         1.0f, 0.0f, 0.0f,
		0.5f, -0.5f, 0.5f,         1.0f, 0.0f, 0.0f,
		0.5f, -0.5f, 0.5f,         1.0f, 0.0f, 0.0f,
		0.5f, 0.5f, -0.5f,          1.0f, 0.0f, 0.0f,
		0.5f, 0.5f, 0.5f,         1.0f, 0.0f, 0.0f,
		
		0.5f, 0.5f, -0.5f,         0.0f, 1.0f, 0.0f,
		-0.5f, 0.5f, -0.5f,        0.0f, 1.0f, 0.0f,
		0.5f, 0.5f, 0.5f,          0.0f, 1.0f, 0.0f,
		0.5f, 0.5f, 0.5f,          0.0f, 1.0f, 0.0f,
		-0.5f, 0.5f, -0.5f,        0.0f, 1.0f, 0.0f,
		-0.5f, 0.5f, 0.5f,         0.0f, 1.0f, 0.0f,
		
		-0.5f, 0.5f, -0.5f,        -1.0f, 0.0f, 0.0f,
		-0.5f, -0.5f, -0.5f,       -1.0f, 0.0f, 0.0f,
		-0.5f, 0.5f, 0.5f,         -1.0f, 0.0f, 0.0f,
		-0.5f, 0.5f, 0.5f,         -1.0f, 0.0f, 0.0f,
		-0.5f, -0.5f, -0.5f,       -1.0f, 0.0f, 0.0f,
		-0.5f, -0.5f, 0.5f,        -1.0f, 0.0f, 0.0f,
		
		-0.5f, -0.5f, -0.5f,       0.0f, -1.0f, 0.0f,
		0.5f, -0.5f, -0.5f,        0.0f, -1.0f, 0.0f,
		-0.5f, -0.5f, 0.5f,        0.0f, -1.0f, 0.0f,
		-0.5f, -0.5f, 0.5f,        0.0f, -1.0f, 0.0f,
		0.5f, -0.5f, -0.5f,        0.0f, -1.0f, 0.0f,
		0.5f, -0.5f, 0.5f,         0.0f, -1.0f, 0.0f,
		
		0.5f, 0.5f, 0.5f,          0.0f, 0.0f, 1.0f,
		-0.5f, 0.5f, 0.5f,         0.0f, 0.0f, 1.0f,
		0.5f, -0.5f, 0.5f,         0.0f, 0.0f, 1.0f,
		0.5f, -0.5f, 0.5f,         0.0f, 0.0f, 1.0f,
		-0.5f, 0.5f, 0.5f,         0.0f, 0.0f, 1.0f,
		-0.5f, -0.5f, 0.5f,        0.0f, 0.0f, 1.0f,
		
		0.5f, -0.5f, -0.5f,        0.0f, 0.0f, -1.0f,
		-0.5f, -0.5f, -0.5f,       0.0f, 0.0f, -1.0f,
		0.5f, 0.5f, -0.5f,         0.0f, 0.0f, -1.0f,
		0.5f, 0.5f, -0.5f,         0.0f, 0.0f, -1.0f,
		-0.5f, -0.5f, -0.5f,       0.0f, 0.0f, -1.0f,
		-0.5f, 0.5f, -0.5f,        0.0f, 0.0f, -1.0f
	};
};

#endif