libravatarserv/src/libravatarserv.cpp

/*  This file is part of libravatarserv.
 *  Copyright © 2018, 2019 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" ||
                 avatar.fallback.substr(0, 5) == "retro")
        {
            try
            {
                uint8_t padwidth = avatar.size / 10;
                if (avatar.size < 60)
                {
                    padwidth = 0;
                }
                else if (padwidth < 10)
                {
                    padwidth = 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 });
                image.image = identicon.generate(avatar.digest, avatar.size);
                image.image.magick("PNG");
                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;
}