#include "font.h"
#include <iostream>

Font::Font(const std::string filepath){
    FT_Library ft;
    if (FT_Init_FreeType(&ft))
    {
        std::cout << "ERROR::FREETYPE: Could not init FreeType Library" << std::endl;
    }

    FT_Face face;
    if (FT_New_Face(ft, filepath.data(), 0, &face))
    {
        std::cout << "ERROR::FREETYPE: Failed to load font" << std::endl;  
    }

    FT_Set_Pixel_Sizes(face, 0, 48);

    glPixelStorei(GL_UNPACK_ALIGNMENT, 1); // disable byte-alignment restriction
  
    for (unsigned char c = 0; c < 128; c++)
    {
        createGlyphTexture(c, face);
    }

    glPixelStorei(GL_UNPACK_ALIGNMENT, 4); // Back to default value
    FT_Done_Face(face);
    FT_Done_FreeType(ft);
}

Font::~Font(){

}

void Font::createGlyphTexture(unsigned char c, FT_Face &face){
    if (FT_Load_Char(face, c, FT_LOAD_RENDER))
    {
        std::cout << "ERROR::FREETYTPE: Failed to load Glyph" << std::endl;
        return;
    }
    // generate texture
    unsigned int texture;
    glGenTextures(1, &texture);
    glBindTexture(GL_TEXTURE_2D, texture);
    glTexImage2D(
        GL_TEXTURE_2D,
        0,
        GL_RED,
        face->glyph->bitmap.width,
        face->glyph->bitmap.rows,
        0,
        GL_RED,
        GL_UNSIGNED_BYTE,
        face->glyph->bitmap.buffer
    );
    // set texture options
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    // now store character for later use
    unsigned int advance = static_cast<unsigned int>(face->glyph->advance.x);
    Character character = {
        texture, 
        glm::ivec2(face->glyph->bitmap.width, face->glyph->bitmap.rows),
        glm::ivec2(face->glyph->bitmap_left, face->glyph->bitmap_top),
        advance
    };
    m_characters.insert(std::pair<char, Character>(c, character));
}

Character& Font::getCharacter(char c){
    return m_characters[c];
}