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

App App::I; // singleton

void App::create()
{
    width = 500;
    height = 500;
}

void App::init()
{
    static const char* shader_v =
        "#version 150\n"
        "uniform mat4 mvp;"
        "in vec4 pos;"
        "in vec2 uvs;"
        "out vec3 uv;"
        "void main(){"
        "   uv = vec3(uvs, pos.w);"
        "   gl_Position = mvp * vec4(pos.xyz, 1.f);"
        "}";
    static const char* shader_f =
        "#version 150\n"
        "uniform sampler2D tex;"
        "in vec3 uv;"
        "out vec4 frag;"
        "void main(){"
        //"   frag = texture(tex, uv.xy/uv.z);"
        "   frag = texture(tex, uv.xy);"
        "}";
    static const char* shader_uv_f =
        "#version 150\n"
        "uniform sampler2D tex;"
        "in vec3 uv;"
        "out vec4 frag;"
        "void main(){"
        "   frag = vec4(uv.xy,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;"
        "}";

#ifdef _WIN32
    static CONSOLE_SCREEN_BUFFER_INFO info;
    GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &info);
    // colors: http://stackoverflow.com/questions/4053837/colorizing-text-in-the-console-with-c
    glDebugMessageCallback([](GLenum source, GLenum type, GLuint id,
        GLenum severity, GLsizei length, const GLchar* message, const void* userParam) 
    {
        static std::map<GLenum, int> colors = {
            { GL_DEBUG_SEVERITY_NOTIFICATION, 8 },
            { GL_DEBUG_SEVERITY_LOW, 8 },
            { GL_DEBUG_SEVERITY_MEDIUM, FOREGROUND_GREEN | FOREGROUND_INTENSITY },
            { GL_DEBUG_SEVERITY_HIGH, FOREGROUND_RED | FOREGROUND_INTENSITY },
        };
        SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), colors[severity]);
        printf("%.*s\n", length, message);
        FlushConsoleInputBuffer(GetStdHandle(STD_OUTPUT_HANDLE));
        SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), info.wAttributes);
    }, nullptr);
    glEnable(GL_DEBUG_OUTPUT); 
#endif
    
    layout.load("data/layout.xml");
    layout.update(width, height);

    sampler.create();
    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>(1, 1);

    if (!tex.load("data/uvs.jpg"))
        printf("error loading image\n");
    
    glEnable(GL_TEXTURE_2D);
    glDisable(GL_DEPTH_TEST);
    glPointSize(5);
    glLineWidth(2);
    
    //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)
{
    glm::mat4 proj = glm::ortho(0.f, width, height, 0.f, -1.f, 1.f);
    
    glClearColor(.1f, .1f, .1f, 1.f);
    glViewport(0, 0, (GLsizei)width, (GLsizei)height);
    glClear(GL_COLOR_BUFFER_BIT);

    layout.reload();

    glActiveTexture(GL_TEXTURE0);
    tex.bind();
    sampler.bind(0);
    shader.use();
    shader.u_int("tex", 0);
    shader_color.use();
    shader_color.u_vec4("col", { .3f, .3f, .3f, 1 });

    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
    glEnable(GL_SCISSOR_TEST);
    for (auto& n : layout)
    {
        glm::mat4 pivot = glm::translate(glm::vec3(.5f, .5f, 0.f));
        glm::mat4 scale = glm::scale(glm::vec3(n.m_size, 1.f));
        glm::mat4 pos = glm::translate(glm::vec3(n.m_pos, 0));
        auto mvp = proj * pos * scale * pivot;

        auto box = n.m_clip;
        glScissor(box.x, height - box.y - box.w, box.z, box.w);

        shader_color.u_vec4("col", n.color);
        shader_color.use();
        shader_color.u_mat4("mvp", mvp);
        plane.draw_fill();

        shader_color.u_vec4("col", { 1, 1, 1, 1 });
        shader_color.use();
        shader_color.u_mat4("mvp", mvp);
        plane.draw_stroke();
    }
    glDisable(GL_SCISSOR_TEST); 
    tex.unbind();
    sampler.unbind();
}

void App::resize(float w, float h)
{
    width = w;
    height = h;
    layout.update(width, height);
}

void App::mouse_down(int button, float x, float y)
{
    printf("mouse click %f %f\n", x, y);
}
void App::mouse_move(float x, float y)
{
    
}
void App::mouse_up(int button, float x, float y)
{
    
}