#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <GL/glew.h>
#include <GLFW/glfw3.h>

#include "shader.h"

const char *vcode = "#version 330 core\n"
                    "layout (location = 0) in vec3 aPos;\n"
                    "void main()\n"
                    "{\n"
                    "   gl_Position = vec4(aPos, 1.0);\n"
                    "}";
const char *fcode = "#version 330 core\n"
                    "out vec4 FragColor;\n"
                    "void main()\n"
                    "{\n"
                    "FragColor = vec4(1.0, 1.0, 1.0, 1.0);\n"
                    "}\n";

int main()
{
    GLFWwindow *win;
    GLuint vsh, fsh, program;
    GLuint vao, vbo;
    int i;
    float saw[3000] = {};

    if (glfwInit() != 1) {
        fprintf(stderr, "failed to init glfw\n");
        return -1;
    }

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

    win = glfwCreateWindow(800, 600, "a title for a window!", NULL, NULL);
    if (win == NULL) {
        fprintf(stderr, "failed to open window\n");
        return -1;
    }

    glfwMakeContextCurrent(win);
    if (glewInit() != GLEW_OK) {
        fprintf(stderr, "Failed to init glew!");
        return -1;
    }

    /* generate  :-D */
    float total = 1;
    int k = 0;
    for (i = 0; i < 3000; i += 3) {
    /*
        if (i == 0) {
            continue;
        }
        */
        saw[i + 0] = (total += -0.002);
        saw[i + 1] = sinf(10 * (2 * 3.14) * k);
    /*  printf("%f\n", saw[i + 1]); */
        k++;
        printf("%f\n", saw[i]);
    }

    printf("%d\n", sizeof(sin));
    /* GL */
    vsh = vertex_compile(vcode);
    fsh = fragment_compile(fcode);
    program = shaders_link(vsh, fsh);

    glGenVertexArrays(1, &vao);
    glGenBuffers(1, &vbo);

    glBindVertexArray(vao);
    glBindBuffer(GL_ARRAY_BUFFER, vbo);
    glBufferData(GL_ARRAY_BUFFER, sizeof(saw), saw, GL_STATIC_DRAW);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);

    while (glfwWindowShouldClose(win) != 1) {
        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        glUseProgram(program);
        glBindVertexArray(vao);
        glDrawArrays(GL_LINE_STRIP, 0, 1000);

        glfwSwapBuffers(win);
        glfwPollEvents();
    }
    return 0;
}