#include "tex_loader.h"
#include "hid_handler.h"

TexLoader tex_loader;

bool TexLoader::LoadPng(const std::string& path)
{
    // Already loaded?
    if (tex_loader.loadedTextures.contains(path))
    {
        return true;
    }

    hid_handler.log << "Loading image: " << path.c_str() << std::endl;

    // Read file into buffer
    std::ifstream file(path, std::ios::binary | std::ios::ate);
    if (!file)
    {
        hid_handler.log << "Failed to load image: not found." << std::endl;
        tex_loader.loadedTextures[path] = LoadedTexture{};
        return false;
    }

    std::streamsize size = file.tellg();
    file.seekg(0, std::ios::beg);

    std::vector<unsigned char> buffer(size);
    if (!file.read((char*)buffer.data(), size))
    {
        hid_handler.log << "Failed to load image: unable to read file." << std::endl;

        tex_loader.loadedTextures[path] = LoadedTexture{};
        return false;
    }

    // Decode PNG
    std::vector<unsigned char> decoded;
    unsigned long w, h;
    if (decodePNG(decoded, w, h, buffer.data(), buffer.size(), true) != 0)
    {
        hid_handler.log << "Failed to load image: unable to decode." << std::endl;
        tex_loader.loadedTextures[path] = LoadedTexture{};
        return false;
    }

    // Create OpenGL texture
    GLuint texID;
    glGenTextures(1, &texID);
    glBindTexture(GL_TEXTURE_2D, texID);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8,
        (GLsizei)w, (GLsizei)h,
        0, GL_RGBA, GL_UNSIGNED_BYTE, decoded.data());

    LoadedTexture tex;
    tex.texID = texID;
    tex.width = (int)w;
    tex.height = (int)h;

    tex_loader.loadedTextures[path] = tex;
    return true;
}

std::tuple<GLuint, int, int> TexLoader::GetPng(const std::string& path)
{
    auto it = tex_loader.loadedTextures.find(path);
    if (it != tex_loader.loadedTextures.end())
    {
        return { it->second.texID, it->second.width, it->second.height };
    }

    return { 0, 0, 0 };
}

void TexLoader::Cleanup()
{
    for (auto& [_, tex] : tex_loader.loadedTextures)
    {
        if (tex.texID)
            glDeleteTextures(1, &tex.texID);
    }
    tex_loader.loadedTextures.clear();
}