libravatarserv/src/libravatarserv.cpp

/*  This file is part of libravatarserv.
 *  Copyright © 2018 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 <iostream>
#include <Magick++/Geometry.h>
#include <identiconpp.hpp>
#include "version.hpp"
#include "libravatarserv.hpp"

using std::cout;
using std::cerr;
using std::endl;

// Global variables
std::map<const string, const string> hash::table;
fs::path settings::avatar_dir;
settings::Settings settings::settings;

int main()
{
    cout << "Server: libravatarserv/" << global::version << endl;

    const char *request = std::getenv("REQUEST_URI");
    if (request == nullptr)
    {
        cout << "Status: 400 Bad Request\n\n";
        cerr << "Error: ${REQUEST_URI} is empty.\n";
        return 1;
    }
    http::Request avatar = http::parse_request(request);
    if (!hash::is_valid(avatar.digest))
    {
        cout << "Status: 400 Bad Request\n\n";
        cerr << "Error: Hash is invalid\n";
        return 1;
    }

    if (!settings::find_avatar_dir())
    {
        cout << "Status: 503 Service Unavailable\n\n";
        cerr << "Error: No avatars found.\n";
        return 3;
    }
    hash::fill_table();
    settings::read_settings();

    image::Image image = image::get(avatar.digest, avatar.size);
    if (image.error == 0)
    {
        image::write(image);
    }
    else
    {
        cerr << "Warning " << std::to_string(image.error)
             << ": Could not open file.\n";
        if (settings::settings.redirect_nouser)
        {
            http::send_redirect(avatar);
            return 0;
        }
        if (avatar.fallback.empty())
        {
            avatar.fallback = settings::settings.default_fallback;
        }
        if (avatar.fallback.substr(0, 3) == "404")
        {
            cout << "Status: 404 Not Found\n\n";
        }
        else if (avatar.fallback.substr(0, 4) == "http")
        {
            cout << "Status: 307 Temporary Redirect\n";
            cout << "Location: " << avatar.fallback << endl << endl;
        }
        else if (avatar.fallback.substr(0, 2) == "mp" ||
                 avatar.fallback.substr(0, 2) == "mm")
        {
            // MD5 hash of 'mp'
            image = image::get("1f2dfa567dcf95833eddf7aec167fec7",
                               avatar.size);
            if (image.error == 0)
            {
                image::write(image);
            }
            else
            {
                cerr << "Error: Mystery person not found.\n";
                // Jump to last else
                goto not_implemented;
            }
        }
        else if (avatar.fallback.substr(0, 9) == "identicon")
        {
            try
            {
                Identiconpp identicon(4, 4, Identiconpp::algorithm::sigil,
                            "ffffffff",
                            {   // The 16 named colors specified in HTML 4.01
                                // minus white, silver and gray.
                                "000000ff", // Black
                                "ff0000ff", // Red
                                "800000ff", // Maroon
                                "ffff00ff", // Yellow
                                "808000ff", // Olive
                                "00ff00ff", // lime
                                "008000ff", // Green
                                "00ffffff", // Aqua
                                "008080ff", // Teal
                                "0000ffff", // Blue
                                "000080ff", // Navy
                                "ff00ffff", // Fuchsia
                                "800080ff", // Purple
                            });
                Magick::Image img;
                img = identicon.generate(avatar.digest, avatar.size);
                img.magick("PNG");
                image::Image image({ 0, img });
                image::write(image);
            }
            catch (const std::exception &e)
            {
                cout << "Status: 500 Internal Server Error\n\n";
                cerr << "Error: Couldn't generate identicon ("
                     << e.what() << ").\n";
            }
        }
        else
        {
            not_implemented:
            if (settings::settings.redirect_nofallback)
            {
                http::send_redirect(avatar);
            }
            else
            {
                cout << "Status: 501 Not Implemented\n\n";
            }
        }
    }

    return 0;
}