#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <math.h>
#include "glad/glad.h"
#include <GLFW/glfw3.h>
#include "lib.h"

int SCREEN_WIDTH = 1024;
int SCREEN_HEIGHT = 768;

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

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

int main(void) {
    glfwInit();

    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

    GLFWwindow* window =
        checkPtr(glfwCreateWindow(SCREEN_WIDTH, SCREEN_HEIGHT, "Learn OpenGL", NULL, NULL),
                 "Error creating GLFW window");
    if (window == NULL) glfwTerminate();

    glfwMakeContextCurrent(window);

    checkCode(gladLoadGLLoader((GLADloadproc)glfwGetProcAddress), "Error initializing GLAD");

    glViewport(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT);

    glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);

    GLuint shaderProgram =
        compileShaderProgram("shaders/main.vert", "shaders/main.frag", NULL);

    // float vertices[] = {
    //     0.5f,  0.5f, 0.0f,  // top right
    //     0.5f, -0.5f, 0.0f,  // bottom right
    //     -0.5f, -0.5f, 0.0f,  // bottom left
    //     -0.5f,  0.5f, 0.0f   // top left
    // };
    // unsigned int indices[] = {  // note that we start from 0!
    //     0, 1, 3,   // first triangle
    //     1, 2, 3    // second triangle
    // };

    // float vertices[] = {
    //     -0.5f, -0.5f, 0.0f,
    //     0.5f, -0.5f, 0.0f,
    //     0.0f,  0.5f, 0.0f
    // };

    float v1[] = {
        -1.0f, -0.5f, 0.0f, 1.0f, 0.0f, 0.0f,
        0.0f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f,
        -0.5f,  0.5f, 0.0f, 0.0f, 0.0f, 1.0f,
    };

    float v2[] = {
        0.0f, -0.5f, 0.0f,
        1.0f, -0.5f, 0.0f,
        0.5f,  0.5f, 0.0f
    };

    GLuint vaos[2];
    GLuint vbos[2];
    unsigned int VBO1, VBO2;
    // unsigned int EBO;
    glGenVertexArrays(2, vaos);
    // glGenBuffers(1, &EBO);
    glGenBuffers(2, vbos);

    glBindVertexArray(vaos[0]);
    glBindBuffer(GL_ARRAY_BUFFER, vbos[0]);
    glBufferData(GL_ARRAY_BUFFER, sizeof(v1), v1, GL_STATIC_DRAW);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(float), (void*)(3*sizeof(float)));
    glEnableVertexAttribArray(1);

    glBindVertexArray(vaos[1]);
    glBindBuffer(GL_ARRAY_BUFFER, vbos[1]);
    glBufferData(GL_ARRAY_BUFFER, sizeof(v2), v2, GL_STATIC_DRAW);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);
    // glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
    // glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);

    glBindBuffer(GL_ARRAY_BUFFER, 0);
    glBindVertexArray(0);

    while (!glfwWindowShouldClose(window)) {
        processInput(window);

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

        float timeValue = glfwGetTime();
        float green = (sin(timeValue) / 2.0f) + 0.5f;
        glUseProgram(shaderProgram);
        int ourColorLoc = glGetUniformLocation(shaderProgram, "ourColor");
        glUniform4f(ourColorLoc, 0.0f, green, 0.0f, 1.0f);
        int offsetLoc = glGetUniformLocation(shaderProgram, "offset");
        glUniform1f(offsetLoc, 0.5f);

        glBindVertexArray(vaos[0]);
        glDrawArrays(GL_TRIANGLES, 0, 3);

        glBindVertexArray(vaos[1]);
        glDrawArrays(GL_TRIANGLES, 0, 3);
        // glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
        // glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
        // glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);

        glfwSwapBuffers(window);
        glfwPollEvents();
    }

    glDeleteVertexArrays(2, vaos);
    glDeleteBuffers(1, &VBO1);
    glDeleteBuffers(1, &VBO2);
    glDeleteProgram(shaderProgram);
    glfwTerminate();
    return 0;
}