#include <stdio.h>
#include <string.h>
#include <GLFW/glfw3.h>
#include "typedef.h"

#define MAX(x, y) (((x) > (y)) ? (x) : (y))

static void error_callback(int error, const char* description)
{
    err("display: %s\n", description);
}

static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
{
    if(key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
        glfwSetWindowShouldClose(window, GLFW_TRUE);
}

extern unsigned char cam_data[];
extern unsigned int WIDTH;
extern unsigned int HEIGHT;

GLubyte pixels[BUF_CAP] = {0};

void pixel(int x, int y)
{
    // for rotating the screen
    int p = (y*WIDTH + x)*3;
    int b = ((HEIGHT-1-y)*WIDTH+x)*3;
    pixels[p+0] = cam_data[b+0];
    pixels[p+1] = cam_data[b+1];
    pixels[p+2] = cam_data[b+2];
}

int display(void)
{
    GLFWwindow* window;
    glfwSetErrorCallback(error_callback);

    if (!glfwInit()) {
        return 1;
    }

    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);

    window = glfwCreateWindow(WIDTH, HEIGHT, "Client", NULL, NULL);
    if (!window) {
        glfwTerminate();
        return 1;
    }

    glfwSetKeyCallback(window, key_callback);
    glfwMakeContextCurrent(window);
    glfwSwapInterval(1);

    while (!glfwWindowShouldClose(window))
    {
        glfwSetWindowSize(window, WIDTH, HEIGHT);

        for(int i = 0; i < HEIGHT; i++)
            for(int j = 0; j < WIDTH; j++)
                pixel(j, i);

        glClear(GL_COLOR_BUFFER_BIT);
        glDrawPixels(WIDTH, HEIGHT, GL_RGB, GL_UNSIGNED_BYTE, pixels);

        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    glfwDestroyWindow(window);
    glfwTerminate();

    return 0;
}