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

App App::I; // singleton

void App::create()
{
    width = 800;
    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;"
        "}";
    static const char* shader_font_v =
        "#version 150\n"
        "uniform mat4 mvp;"
        "in vec2 pos;"
        "in vec2 uvs;"
        "out vec2 uv;"
        "void main(){"
        "   uv = uvs;"
        "   gl_Position = mvp * vec4(pos, 0, 1);"
        "}";
    static const char* shader_font_f =
        "#version 150\n"
        "uniform sampler2D tex;"
        "in vec2 uv;"
        "out vec4 frag;"
        "void main(){"
        //"   frag = vec4(1,0,0,1);"
        "   frag = texture(tex, uv);"
        "}";

#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["main"].update(width, height);

    sampler.create(GL_NEAREST);
    ShaderManager::create(kShader::Texture, shader_v, shader_f);
    ShaderManager::create(kShader::Color, shader_color_v, shader_color_f);
    ShaderManager::create(kShader::UVs, shader_v, shader_uv_f);
    ShaderManager::create(kShader::Font, shader_font_v, shader_font_f);
    WidgetBorder::m_plane.create<1>(1, 1);

    if (!tex.load("data/uvs.jpg"))
        printf("error loading image\n");

#if _WIN32
    FILE* font_file = fopen("C:\\Windows\\Fonts\\arial.ttf", "rb");
#else
    FILE* font_file = fopen("/Library/Fonts/Arial.ttf", "rb");
#endif
    if (font_file)
    {
        fseek(font_file, 0, SEEK_END);
        long sz = ftell(font_file);
        auto data = std::make_unique<uint8_t[]>(sz);
        fseek(font_file, 0, SEEK_SET);
        auto bytes = fread(data.get(), 1, sz, font_file);
        assert(bytes==sz);
        auto bitmap = std::make_unique<uint8_t[]>(w*h);
        chars.resize(num_chars);
        int ret = stbtt_BakeFontBitmap(data.get(), 0, 50, bitmap.get(), w, h, start_char, num_chars, chars.data());
        font_tex.create(w, h, GL_RED, bitmap.get());
        
        glGenBuffers(2, font_buffers);
        glGenVertexArrays(1, &font_array);
        
        glBindVertexArray(font_array);
        glEnableVertexAttribArray(0);
        glEnableVertexAttribArray(1);
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, font_buffers[1]);
        glBindBuffer(GL_ARRAY_BUFFER, font_buffers[0]);
        glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(glm::vec4), (GLvoid*)0);
        glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(glm::vec4), (GLvoid*)(sizeof(float)*2));
        glBindVertexArray(0);
    }
    plane.create<1>(400, 400);
    
    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)
{
    constexpr auto main_id = const_hash("main");

    glClearColor(.1f, .1f, .1f, 1.f);
    glViewport(0, 0, (GLsizei)width, (GLsizei)height);
    glClear(GL_COLOR_BUFFER_BIT);

    if (layout.reload())
    {
        layout[main_id].update(width, height);
    }

    /*
    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
    glEnable(GL_SCISSOR_TEST);
    for (auto& n : layout[main_id])
    {
        if (n.m_widget)
        {
            auto box = n.m_widget->clip;
            glScissor((int)box.x, (int)(height - box.y - box.w), (int)box.z, (int)box.w);
            n.m_widget->draw();
        }
    }
    glDisable(GL_SCISSOR_TEST); 
*/
    glm::mat4 proj = glm::ortho(0.f, width, height, 0.f, -1.f, 1.f);
    glm::mat4 tran = glm::translate(glm::vec3(200, 200, 0));


    if (chars.size())
    {
        static char str[64];
        static int counter = 0;
        counter++;
        sprintf(str, "frame %04d", counter);
        const auto len = strlen(str);
        float x = 0;
        float y = 0;
        std::vector<glm::vec4> v;
        std::vector<GLushort> idx;
        for (int i = 0; i < len; i++)
        {
            int c = str[i] - start_char;
            stbtt_aligned_quad q;
            stbtt_GetBakedQuad(chars.data(), w, h, c, &x, &y, &q, true);
            auto n = v.size();
            v.emplace_back(q.x0, q.y1, q.s0, q.t1);
            v.emplace_back(q.x0, q.y0, q.s0, q.t0);
            v.emplace_back(q.x1, q.y0, q.s1, q.t0);
            v.emplace_back(q.x1, q.y1, q.s1, q.t1);
            idx.push_back(n+0);
            idx.push_back(n+1);
            idx.push_back(n+2);
            idx.push_back(n+0);
            idx.push_back(n+2);
            idx.push_back(n+3);
        }
        font_array_count = (int)idx.size();
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, font_buffers[1]);
        glBufferData(GL_ELEMENT_ARRAY_BUFFER, idx.size() * sizeof(GLushort), idx.data(), GL_STATIC_DRAW);
        glBindBuffer(GL_ARRAY_BUFFER, font_buffers[0]);
        glBufferData(GL_ARRAY_BUFFER, v.size() * sizeof(glm::vec4), v.data(), GL_STATIC_DRAW);
        glBindBuffer(GL_ARRAY_BUFFER, 0);
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
    }

    glActiveTexture(GL_TEXTURE0);
    font_tex.bind();
    sampler.bind(0);
    ShaderManager::use(kShader::Font);
    ShaderManager::u_int(kShaderUniform::Tex, 0);
    ShaderManager::u_mat4(kShaderUniform::MVP, proj*tran);
    
//    plane.draw_fill();
    glBindVertexArray(font_array);
    glDrawElements(GL_TRIANGLES, font_array_count, GL_UNSIGNED_SHORT, 0);
    glBindVertexArray(0);
    
    font_tex.unbind();
    sampler.unbind();


/*
    static int i = 0;
    i = (i + 1) % 32;
    auto c = chars["hgfrr56789opk0876ryuewighfcuisdbn"[i] - 32];
    glm::vec2 a(c.x0, c.y0);
    glm::vec2 b(c.x1, c.y1);
    glm::vec2 s(512, 512);
    glm::vec2 tof = a / s;
    glm::vec2 tsz = (b - a) / s;

    glActiveTexture(GL_TEXTURE0);
    font_tex.bind();
    sampler.bind(0);
    ShaderManager::use(kShader::Font);
    ShaderManager::u_int(kShaderUniform::Tex, 0);
    ShaderManager::u_mat4(kShaderUniform::MVP, proj * tran);
    ShaderManager::u_vec2(kShaderUniform::Tof, tof);
    ShaderManager::u_vec2(kShaderUniform::Tsz, tsz);
    //plane.draw_fill();
    font_tex.unbind();
    sampler.unbind();
 */
}

void App::resize(float w, float h)
{
    constexpr auto main_id = const_hash("main");
    width = w;
    height = h;
    layout[main_id].update(w, h);
}

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)
{
    
}