/*  This file is part of libravatarserv.
 *  Copyright © 2022 tastytea <tastytea@tastytea.de>
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, version 3.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "image.hpp"

#include "types.hpp"

#include <identiconpp.hpp>
#include <Magick++/Blob.h>
#include <Magick++/Geometry.h>
#include <Magick++/Image.h>

#include <algorithm>
#include <cstdint>
#include <ios>
#include <iostream>
#include <string>
#include <string_view>

namespace libravatarserv::image {

Magick::Image get(const fs::path &filepath, const size_t size) {
    Magick::Image img;
    img.read(filepath);
    img.resize(Magick::Geometry(size, size));
    return img;
}

Magick::Image generate_identicon(const request_t &req) {

    const auto padwidth{[&req]() -> std::uint8_t {
        if (req.size < 60) {
            return 0;
        }
        return static_cast<std::uint8_t>(std::max(req.size / 10, 10));
    }()};

    Identiconpp identicon(5, 5, Identiconpp::algorithm::sigil, "fefefeff",
                          {
                              // The same colors ivatar uses.
                              "2d4fffff", // Blue
                              "feb42cff", // Yellow
                              "e279eaff", // Bright pink
                              "1eb3fdff", // Cyan
                              "E84D41ff", // Red
                              "31CB73ff", // Green
                              "8D45AAff"  // Dark pink
                          },
                          {padwidth, padwidth});
    Magick::Image img{
        identicon.generate(req.hash, static_cast<std::uint8_t>(req.size))};
    img.magick("PNG");

    return img;
}

void write(Magick::Image &img,
           const std::optional<std::string_view> magick_force) {
    std::string magick{magick_force.value_or(img.magick())};
    std::transform(magick.begin(), magick.end(), magick.begin(), ::tolower);

    const auto quality{[&img, &magick]() -> size_t {
        if (img.quality() != 0) {
            return img.quality(); // same as source
        }
        if (magick == "png") {
            return 100; // highest compression
        }
        if (magick == "webp") {
            if (img.magick() == "WEBP" || img.magick() == "PNG"
                || img.magick() == "GIF" || img.magick() == "SVG") {
                return 100; // lossless
            }
        }
        return 0; // default
    }()};

    img.magick(magick);
    img.quality(quality);

    Magick::Blob buffer;
    img.write(&buffer);

    std::cout << "Content-Type: image/" << magick << '\n';
    std::cout << "Content-Length: " << buffer.length() << "\n\n";
    std::cout.write(static_cast<const char *>(buffer.data()),
                    static_cast<std::streamsize>(buffer.length()));
}

} // namespace libravatarserv::image