#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <cstdio>
#include "FullScreenQuad.hpp"


const char *vertexShaderSource =
#include "fsq.vs"
;

const char *fragmentShaderSource =
#include "sdf.fs"
;

/*void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
    glViewport(0, 0, wdth, height);
}*/

void processInput(GLFWwindow *window)
{
    if(glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
        glfwSetWindowShouldClose(window, true);
}


unsigned int compVertexShader() {
    unsigned int vertexShader;
    vertexShader = glCreateShader(GL_VERTEX_SHADER);
    glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
    glCompileShader(vertexShader);
    return vertexShader;
}

unsigned int compFragmentShader() {
    unsigned int fragmentShader;
    fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
    glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
    glCompileShader(fragmentShader);

    GLint isCompiled = 0;
    glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &isCompiled);
    if(isCompiled == GL_FALSE)
    {
        GLint maxLength = 0;
        glGetShaderiv(fragmentShader, GL_INFO_LOG_LENGTH, &maxLength);

        // The maxLength includes the NULL character
        //std::vector<GLchar> errorLog(maxLength);
        char * errorLog = new char[maxLength]();
        glGetShaderInfoLog(fragmentShader, maxLength, &maxLength, errorLog);

        printf("\nFrag Log: %s\n",errorLog);

    }

    return fragmentShader;
}

unsigned int compShader() {
    unsigned int shaderProgram;
    shaderProgram = glCreateProgram();
    unsigned int vert = compVertexShader();
    unsigned int frag = compFragmentShader();
    glAttachShader(shaderProgram, vert);
    glAttachShader(shaderProgram, frag);
    glLinkProgram(shaderProgram);
    
    glDeleteShader(vert);
    glDeleteShader(frag);  

    return shaderProgram;
}


void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
    glViewport(0, 0, width, height);
}  

int main(int argc, char** argv) {

    GLFWwindow* window;

    if (!glfwInit())
        return -1;

    window = glfwCreateWindow(800, 600, "Hello World", NULL, NULL);

    if (!window)
    {
        glfwTerminate();
        return -1;
    }

    glfwMakeContextCurrent(window);

    GLenum err = glewInit();
    if (GLEW_OK != err) {
        fprintf(stderr, "GLEW error: %s\n", glewGetErrorString(err));
        return 1;
    }


    glViewport(0, 0, 800, 600);


    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);  

    unsigned int shaderProgramm = compShader();

    FullScreenQuad fsq{};

    while (!glfwWindowShouldClose(window))
    {
        processInput(window);
        /* Render here */


        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

	
        glUseProgram(shaderProgramm);

        glDrawArrays(GL_TRIANGLES, 0, 3);
        glBindVertexArray(fsq.getVAO());	
        glDrawArrays(GL_TRIANGLES, 0, 6);

        /* Poll for and process events */
        glfwPollEvents();

        glfwSwapBuffers(window);
    }

    glfwTerminate();
}