#include <iostream>
#include <chrono>
#include <fstream>
#include <sstream>
#include <SFML/Graphics.hpp>

#ifdef linux
#include <CL/cl.h>
#include <CL/opencl.h>

#elif defined _WIN32
#include <CL/cl_gl.h>
#include <CL/cl.h>
#include <CL/opencl.h>
#include <windows.h>

#elif defined TARGET_OS_MAC
#include <OpenGL/gl.h>
# include <OpenGL/OpenGL.h>
# include <OpenCL/opencl.h>
#include <OpenCL/cl_gl_ext.h>
#include <OpenCL/cl_ext.h>

#endif
#include "TestPlatform.cpp"
#include "Map.h"
#include "Curses.h"
#include "util.hpp"
#include "RayCaster.h"
#include "CL_Wrapper.h"

const int WINDOW_X = 100;
const int WINDOW_Y = 100;





float elap_time(){
	static std::chrono::time_point<std::chrono::system_clock> start;
	static bool started = false;

	if (!started){
		start = std::chrono::system_clock::now();
		started = true;
	}

	std::chrono::time_point<std::chrono::system_clock> now = std::chrono::system_clock::now();
	std::chrono::duration<double> elapsed_time = now - start;
	return elapsed_time.count();
}

sf::Sprite window_sprite;
sf::Texture window_texture;

// Y: -1.57 is straight up
// Y: 1.57 is straight down


int main() {

    sf::RenderWindow window(sf::VideoMode(WINDOW_X, WINDOW_Y), "SFML");


    sf::Sprite s;
    sf::Texture t;

    CL_Wrapper c;
    c.acquire_platform_and_device();
    c.create_shared_context();
    c.create_command_queue();

    c.compile_kernel("../kernels/kernel.c", true, "hello");
    c.compile_kernel("../kernels/minimal_kernel.c", true, "min_kern");

    sf::Vector3i map_dim(100, 100, 100);
    Map* map = new Map(map_dim);

    map->setVoxel(sf::Vector3i(77, 50, 85), 5);

    cl_mem map_buff = clCreateBuffer(
            c.getContext(), CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR,
            sizeof(char) * map_dim.x * map_dim.y * map_dim.z, map->list, NULL
    );

    cl_mem dim_buff = clCreateBuffer(
            c.getContext(), CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR,
            sizeof(int) * 3, &map_dim, NULL
    );

    sf::Vector2i view_res(WINDOW_X, WINDOW_Y);

    cl_mem res_buff = clCreateBuffer(
            c.getContext(), CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR,
            sizeof(int) * 2, &view_res, NULL
    );


    double y_increment_radians = DegreesToRadians(50.0 / view_res.y);
    double x_increment_radians = DegreesToRadians(80.0 / view_res.x);

    // SFML 2.4 has Vector4 datatypes.......

    float view_matrix[view_res.x * view_res.y * 4];
    for (int y = -view_res.y / 2; y < view_res.y / 2; y++) {
        for (int x = -view_res.x / 2; x < view_res.x / 2; x++) {

            // The base ray direction to slew from
            sf::Vector3f ray(1, 0, 0);

            // Y axis, pitch
            ray = sf::Vector3f(
                    ray.z * sin(y_increment_radians * y) + ray.x * cos(y_increment_radians * y),
                    ray.y,
                    ray.z * cos(y_increment_radians * y) - ray.x * sin(y_increment_radians * y)
            );

            // Z axis, yaw
            ray = sf::Vector3f(
                    ray.x * cos(x_increment_radians * x) - ray.y * sin(x_increment_radians * x),
                    ray.x * sin(x_increment_radians * x) + ray.y * cos(x_increment_radians * x),
                    ray.z
            );

            int index = (x + view_res.x / 2) + view_res.x * (y + view_res.y / 2);
            ray = Normalize(ray);
            view_matrix[index * 4 + 0] = ray.x;
            view_matrix[index * 4 + 1] = ray.y;
            view_matrix[index * 4 + 2] = ray.z;
            view_matrix[index * 4 + 3] = 0;
        }
    }

    int ind = 367;
    printf("%i === %f, %f, %f\n", ind, view_matrix[ind * 4 + 0], view_matrix[ind * 4 + 1], view_matrix[ind * 4 + 2]);

    cl_mem view_matrix_buff = clCreateBuffer(
            c.getContext(), CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR,
            sizeof(float) * 3 * view_res.x * view_res.y, view_matrix, NULL
    );

    sf::Vector3f cam_dir(1.0f, 0.0f, 1.57f);

    cl_mem cam_dir_buff = clCreateBuffer(
            c.getContext(), CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR,
            sizeof(float) * 4, &cam_dir, NULL
    );


    sf::Vector3f cam_pos(55, 50, 50);
    cl_mem cam_pos_buff = clCreateBuffer(
            c.getContext(), CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR,
            sizeof(float) * 4, &cam_pos, NULL
    );


    unsigned char* pixel_array = new sf::Uint8[WINDOW_X * WINDOW_Y * 4];

    for (int i = 0; i < 100 * 100 * 4; i += 4) {

        pixel_array[i] = 255; // R?
        pixel_array[i + 1] = 255; // G?
        pixel_array[i + 2] = 255; // B?
        pixel_array[i + 3] = 100; // A?
    }

    t.create(100, 100);
    t.update(pixel_array);


    int error;

    cl_mem image_buff = clCreateFromGLTexture(
            c.getContext(), CL_MEM_WRITE_ONLY, GL_TEXTURE_2D,
            0, t.getNativeHandle(), &error);

    if (c.assert(error, "clCreateFromGLTexture"))
        return -1;

    error = clEnqueueAcquireGLObjects(c.getCommandQueue(), 1, &image_buff, 0, 0, 0);
    if (c.assert(error, "clEnqueueAcquireGLObjects"))
        return -1;



    c.store_buffer(map_buff, "map_buffer");
    c.store_buffer(dim_buff, "dim_buffer");
    c.store_buffer(res_buff, "res_buffer");
    c.store_buffer(view_matrix_buff, "view_matrix_buffer");
    c.store_buffer(cam_dir_buff, "cam_dir_buffer");
    c.store_buffer(cam_pos_buff, "cam_pos_buffer");
    c.store_buffer(image_buff, "image_buffer");

    c.set_kernel_arg("min_kern", 0, "map_buffer");
    c.set_kernel_arg("min_kern", 1, "dim_buffer");
    c.set_kernel_arg("min_kern", 2, "res_buffer");
    c.set_kernel_arg("min_kern", 3, "view_matrix_buffer");
    c.set_kernel_arg("min_kern", 4, "cam_dir_buffer");
    c.set_kernel_arg("min_kern", 5, "cam_pos_buffer");
    c.set_kernel_arg("min_kern", 6, "image_buffer");

    const int size = 100 * 100;
    c.run_kernel("min_kern", size);


    clFinish(c.getCommandQueue());

    error = clEnqueueReleaseGLObjects(c.getCommandQueue(), 1, &image_buff, 0, NULL, NULL);
    if (c.assert(error, "clEnqueueReleaseGLObjects"))
        return -1;

    s.setTexture(t);

    // The step size in milliseconds between calls to Update()
    // Lets set it to 16.6 milliseonds (60FPS)
    float step_size = 0.0166f;

    // Timekeeping values for the loop
    double  frame_time = 0.0,
            elapsed_time = 0.0,
            delta_time = 0.0,
            accumulator_time = 0.0,
            current_time = 0.0;

    fps_counter fps;

	// ============================= RAYCASTER SETUP ==================================

	// Setup the sprite and texture
	window_texture.create(WINDOW_X, WINDOW_Y);
	window_sprite.setPosition(0, 0);

	// State values

	sf::Vector3f cam_vec(0, 0, 0);

	RayCaster ray_caster(map, map_dim, view_res);


	// ===============================================================================

	// Mouse capture
	sf::Vector2i deltas;
	sf::Vector2i fixed(window.getSize());
	bool mouse_enabled = true;

	while (window.isOpen()) {

		// Poll for events from the user
		sf::Event event;
		while (window.pollEvent(event)) {

			// If the user tries to exit the application via the GUI
			if (event.type == sf::Event::Closed)
				window.close();
		}

		cam_vec.x = 0;
		cam_vec.y = 0;
		cam_vec.z = 0;

		if (sf::Keyboard::isKeyPressed(sf::Keyboard::Q)) {
			cam_vec.z = 1;
		}
		if (sf::Keyboard::isKeyPressed(sf::Keyboard::E)) {
			cam_vec.z = -1;
		}
		if (sf::Keyboard::isKeyPressed(sf::Keyboard::W)) {
			cam_vec.y = 1;
		}
		if (sf::Keyboard::isKeyPressed(sf::Keyboard::S)) {
			cam_vec.y = -1;
		}
		if (sf::Keyboard::isKeyPressed(sf::Keyboard::A)) {
			cam_vec.x = 1;
		}
		if (sf::Keyboard::isKeyPressed(sf::Keyboard::D)) {
			cam_vec.x = -1;
		}
        if (sf::Keyboard::isKeyPressed(sf::Keyboard::Left)) {
            cam_dir.z = -0.1f;
        }
        if (sf::Keyboard::isKeyPressed(sf::Keyboard::Right)) {
            cam_vec.z = +0.1f;
        }
        if (sf::Keyboard::isKeyPressed(sf::Keyboard::Down)) {
            cam_vec.y = +0.1f;
        }
        if (sf::Keyboard::isKeyPressed(sf::Keyboard::Up)) {
            cam_vec.y = -0.1f;
        }

		deltas = fixed - sf::Mouse::getPosition();
		if (deltas != sf::Vector2i(0, 0) && mouse_enabled == true) {

			// Mouse movement
			sf::Mouse::setPosition(fixed);
			cam_dir.y -= deltas.y / 300.0f;
			cam_dir.z -= deltas.x / 300.0f;
		}

		cam_pos.x += cam_vec.x / 1.0;
		cam_pos.y += cam_vec.y / 1.0;
		cam_pos.z += cam_vec.z / 1.0;

		std::cout << cam_vec.x << " : " << cam_vec.y << " : " << cam_vec.z << std::endl;


        // Time keeping
		elapsed_time = elap_time();
		delta_time = elapsed_time - current_time;
		current_time = elapsed_time;
		if (delta_time > 0.2f)
			delta_time = 0.2f;
		accumulator_time += delta_time;
		while ((accumulator_time - step_size) >= step_size) {
            accumulator_time -= step_size;

            // Update cycle
        }

        // Fps cycle
        // map->moveLight(sf::Vector2f(0.3, 0));

		window.clear(sf::Color::Black);

		// Cast the rays and get the image
		sf::Color* pixel_colors = ray_caster.CastRays(cam_dir, cam_pos);

        // Cast it to an array of Uint8's
		auto out = (sf::Uint8*)pixel_colors;

        window_texture.update(out);
		window_sprite.setTexture(window_texture);
		window.draw(window_sprite);

		// Give the frame counter the frame time and draw the average frame time
		fps.frame(delta_time);
		fps.draw(&window);


        window.draw(s);

		window.display();

	}
	return 0;
}