#include "pch.h"
#include "app.hpp"

App App::I; // singleton

void App::create()
{
    width = 800;
    height = 600;
}

void App::init()
{
    static const char* shader_v =
        "#version 150\n"
        "uniform mat4 mvp;"
        "in vec4 pos;"
        "in vec2 uvs;"
        "out vec2 uv;"
        "void main(){"
        "   gl_Position = mvp * pos;"
        "   uv = uvs;"
        "}";
    static const char* shader_f =
        "#version 150\n"
        "uniform sampler2D tex;"
        "in vec2 uv;"
        "out vec4 frag;"
        "void main(){"
        "   frag = texture(tex, uv, 0.0);"
        "}";
    static const char* shader_uv_f =
        "#version 150\n"
        "uniform sampler2D tex;"
        "in vec2 uv;"
        "out vec4 frag;"
        "void main(){"
        "   frag = vec4(uv,0,1);"
        "}";
    static const char* shader_color_v =
        "#version 150\n"
        "uniform mat4 mvp;"
        "in vec4 pos;"
        "void main(){"
        "   gl_Position = mvp * pos;"
        "}";
    static const char* shader_color_f =
        "#version 150\n"
        "uniform vec4 col;"
        "out vec4 frag;"
        "void main(){"
        "   frag = col;"
        "}";
    shader.create(shader_v, shader_f);
    shader_color.create(shader_color_v, shader_color_f);
    shader_uv.create(shader_v, shader_uv_f);
    plane.create<5>(50, 50);
    longPlane.create<1>(50, 25);
    circle.create<6>(25, 12);
    circle1.create<4>(25, 12);
    circle2.create<15>(25, 12);
    if (!tex.load("data/image.png"))
        printf("error loading image\n");
    
    glViewport(0, 0, width, height);
    glEnable(GL_TEXTURE);
    glDisable(GL_DEPTH_TEST);
    glPointSize(5);
    glLineWidth(15);
    
    int n;
    glGetIntegerv(GL_NUM_EXTENSIONS, &n);
    for (int i = 0; i < n; i++)
    {
        const unsigned char* s = glGetStringi(GL_EXTENSIONS, i);
        printf("GL ext %03d: %s\n", i, s);
    }
    printf("GL version: %s\n", glGetString(GL_VERSION));
    printf("GL vendor: %s\n", glGetString(GL_VENDOR));
    printf("GL renderer: %s\n", glGetString(GL_RENDERER));
    
    GLfloat width_range[2];
    glGetFloatv(GL_LINE_WIDTH_RANGE, width_range);
    printf("GL line range: %f - %f\n", width_range[0], width_range[1]);
}

void App::update(float dt)
{
    static float theta = 0;
    theta += M_PI * 0.5f * dt;
    float red = fabsf(sinf(theta));
    
//    glm::mat4 proj = glm::perspective(glm::radians(85.f), 1.f, .1f, 100.f);
//    glm::mat4 model = glm::translate(glm::vec3(0, 0, 0));
//    glm::mat4 view = glm::lookAt(glm::vec3(sinf(theta), 0, 1), glm::vec3(0, 0, 0), glm::vec3(0, 1, 0));

    float ar = width / height;
    glm::mat4 proj = glm::ortho<float>(0, width, height, 0, -1, 1);
    
    Shape* shapes[] = { &circle, &circle1, &circle2, &plane, &longPlane };

    //glClearColor(red, 0, 0, 1);
    glClear(GL_COLOR_BUFFER_BIT);
    
    auto s = glm::scale(glm::vec3(2));
    for (int i = 0; i < 5; i++)
    {
        shader.use();
        
        glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
        glActiveTexture(GL_TEXTURE0);
        tex.bind();
        shader.u_int("tex", 0);
        shader.u_mat4("mvp", proj * glm::translate(glm::vec3{75 + 120 * 1, 75 + 120 * i, 0.f}) * s);
        shapes[i]->draw_fill();
        tex.unbind();
        
        shader_color.use();
        shader.u_mat4("mvp", proj * glm::translate(glm::vec3{75 + 120 * 2, 75 + 120 * i, 0.f}) * s);
        shader_color.u_vec4("col", {1, 1, 1, 1});
        shapes[i]->draw_stroke();

        shader.u_mat4("mvp", proj * glm::translate(glm::vec3{75 + 120 * 0, 75 + 120 * i, 0.f}) * s);
        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
        shapes[i]->draw_fill();

        shader_uv.use();
        shader_uv.u_mat4("mvp", proj * glm::translate(glm::vec3{75 + 120 * 3, 75 + 120 * i, 0.f}) * s);
        shader_uv.u_int("tex", 0);
        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
        shapes[i]->draw_fill();
        glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
        shader_uv.u_mat4("mvp", proj * glm::translate(glm::vec3{75 + 120 * 4, 75 + 120 * i, 0.f}) * s);
        shapes[i]->draw_fill();
        tex.unbind();
    }
//    shader.use();
//    shader.u_mat4("mvp", proj * glm::translate(glm::vec3{width/2, height/2, 0.f}) * glm::scale(glm::vec3(10)));
//    shader.u_int("tex", 0);
//    glActiveTexture(GL_TEXTURE0);
//    tex.bind();
//    circle.draw_fill();
//    tex.unbind();
}