/* application.vala
 *
 * Copyright 2024 Erica Z
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * SPDX-License-Identifier: AGPL-3.0-or-later
 */

errordomain SubsonicError {
  ERROR
}

public delegate void Wavelet.SongCallback (Song song);

public class Wavelet.Artist : Object, Json.Serializable {
    public string index;
    public string id;
    public string name { get; private set; }
    public string? cover_art;
    public string? artist_image_url;
    public int64 album_count;
    public DateTime? starred;

    public Artist (string index, Json.Reader reader) {
        this.index = index;

        reader.read_member ("id");
        this.id = reader.get_string_value ();
        reader.end_member ();

        reader.read_member ("name");
        this.name = reader.get_string_value ();
        reader.end_member ();

        reader.read_member ("coverArt");
        this.cover_art = reader.get_string_value ();
        reader.end_member ();

        reader.read_member ("artistImageUrl");
        this.artist_image_url = reader.get_string_value ();
        reader.end_member ();

        reader.read_member ("albumCount");
        this.album_count = reader.get_int_value ();
        reader.end_member ();

        reader.read_member ("starred");
        if (reader.is_value ()) {
          this.starred = new DateTime.from_iso8601 (reader.get_string_value (), null);
        }
        reader.end_member ();
    }
}

public class Wavelet.Album : Object {
    public string id;
    public string name;

    public Album (Json.Reader reader) {
        reader.read_member ("id");
        this.id = reader.get_string_value ();
        reader.end_member ();

        reader.read_member ("name");
        this.name = reader.get_string_value ();
        reader.end_member ();
    }
}

public class Wavelet.Song : Object {
    public string id { get; private set; }
    public string title { get; private set; }
    public string album { get; private set; }
    public string artist { get; private set; }
    public int64 track { get; private set; }

    public Song (Json.Reader reader) {
        reader.read_member ("id");
        this.id = reader.get_string_value ();
        reader.end_member ();

        reader.read_member ("title");
        this.title = reader.get_string_value ();
        reader.end_member ();

        reader.read_member ("album");
        this.album = reader.get_string_value ();
        reader.end_member ();

        reader.read_member ("artist");
        this.artist = reader.get_string_value ();
        reader.end_member ();

        reader.read_member ("track");
        this.track = reader.get_int_value ();
        reader.end_member ();
    }
}

public struct Wavelet.API.PlayQueue {
    public string current;
    public int64 position;
    public DateTime changed;
    public string changed_by;
    public ListStore songs;

    internal PlayQueue.from_reader (Json.Reader reader) {
        reader.read_member ("current");
        this.current = reader.get_string_value ();
        reader.end_member ();

        reader.read_member ("position");
        this.position = reader.get_int_value ();
        reader.end_member ();

        reader.read_member ("changed");
        this.changed = new DateTime.from_iso8601 (reader.get_string_value (), null);
        reader.end_member ();

        reader.read_member ("changed_by");
        this.changed_by = reader.get_string_value ();
        reader.end_member ();

        //print("%s %lli %s %s\n",this.current, this.position, this.changed, this.changed_by);

        this.songs = new ListStore (typeof (Song));

        reader.read_member ("song");
        for (int i = 0; i < reader.count_elements (); i += 1) {
            reader.read_element (i);
            this.songs.append (new Song (reader));
            reader.end_element ();
        }
        reader.end_member ();
        assert (reader.get_error () == null);
    }
}

public class Wavelet.Subsonic : Object {
    public ListStore artist_list;
    public ListStore album_list;
    public ListStore song_list;

    private Soup.Session session;
    private string url;
    private string parameters;

    public Subsonic.with_password (string url, string username, string password) {
        this.url = url;
        this.parameters = @"u=$(Uri.escape_string(username))&p=$(Uri.escape_string(password))&v=1.16.1&c=eu.callcc.Wavelet&f=json";

        this.session = new Soup.Session ();

        this.artist_list = new ListStore (typeof (Artist));
        this.album_list = new ListStore (typeof (Album));
        this.song_list = new ListStore (typeof (Song));
    }

    public Subsonic.with_token (string url, string username, string token, string salt) {
        this.url = url;
        this.parameters = @"u=$(Uri.escape_string(username))&t=$(Uri.escape_string(token))&s=$(Uri.escape_string(salt))&v=1.16.1&c=eu.callcc.Wavelet&f=json";

        this.session = new Soup.Session ();

        this.artist_list = new ListStore (typeof (Artist));
        this.album_list = new ListStore (typeof (Album));
        this.song_list = new ListStore (typeof (Song));
    }

    private void unwrap_response (Json.Reader reader) throws Error {
        reader.read_member ("subsonic-response");

        reader.read_member ("status");
            if (reader.get_string_value () != "ok") {
                reader.end_member ();
                reader.read_member ("error");
                reader.read_member ("message");
                throw new SubsonicError.ERROR (reader.get_string_value () ?? "???");
            }
        reader.end_member();
    }

    public async void ping () throws Error {
        var msg = new Soup.Message ("GET", @"$(this.url)/rest/ping?$(this.parameters)");
        var bytes = yield this.session.send_and_read_async (msg, Priority.DEFAULT, null);
        assert (msg.get_status () == Soup.Status.OK);

        var parser = new Json.Parser ();
        parser.load_from_data ((string) bytes.get_data ());
        
        var reader = new Json.Reader (parser.get_root ());
        this.unwrap_response (reader);
    }

    public signal void done_reloading ();

    private int remaining_artists;
    private int remaining_albums;

    public async void reload () throws Error {
        this.artist_list.remove_all ();
        this.album_list.remove_all ();
        this.song_list.remove_all ();

        this.remaining_artists = 0;
        this.remaining_albums = 0;

        var msg = new Soup.Message ("GET", @"$(this.url)/rest/getArtists?$(this.parameters)");
        var bytes = yield this.session.send_and_read_async (msg, Priority.DEFAULT, null);

        var parser = new Json.Parser ();
        parser.load_from_data ((string) bytes.get_data ());

        var reader = new Json.Reader (parser.get_root ());
        this.unwrap_response (reader);

        reader.read_member ("artists");
        reader.read_member ("index");

        for (int i = 0; i < reader.count_elements (); i += 1) {
        //for (int i = 0; i < 1; i += 1) {
            reader.read_element (i);
            
            reader.read_member ("name");
            var index = reader.get_string_value ();
            reader.end_member ();

            reader.read_member ("artist");
            for (int j = 0; j < reader.count_elements (); j += 1) {
                reader.read_element (j);

                var artist = new Artist (index, reader);
                artist_list.append (artist);

                this.remaining_artists += 1;
                reload_artist.begin (artist.id);

                reader.end_element ();
            }
            reader.end_member ();

            reader.end_element ();

            assert (reader.get_error () == null);
        }
    }

    private async void reload_artist (string artist_id) throws Error {
        try {
            var msg = new Soup.Message ("GET", @"$(this.url)/rest/getArtist?id=$(artist_id)&$(this.parameters)");
            var bytes = yield this.session.send_and_read_async (msg, Priority.DEFAULT, null);
            assert (msg.get_status () == Soup.Status.OK);

            var parser = new Json.Parser ();
            parser.load_from_data ((string) bytes.get_data());

            var reader = new Json.Reader (parser.get_root ());
            this.unwrap_response (reader);

            reader.read_member ("artist");
            reader.read_member ("album");

            for (int i = 0; i < reader.count_elements (); i += 1) {
                reader.read_element (i);

                var album = new Album (reader);
                album_list.append (album);

                this.remaining_albums += 1;
                reload_album.begin (album.id);

                reader.end_element ();
            }

            assert (reader.get_error () == null);
        } catch (Error e) {
            warning ("could not reload artist %s: %s\n", artist_id, e.message);
        } finally {
            this.remaining_artists -= 1;
        }
    }

    private async void reload_album (string album_id) throws Error {
        try {
            var msg = new Soup.Message ("GET", @"$(this.url)/rest/getAlbum?id=$(album_id)&$(this.parameters)");
            var bytes = yield this.session.send_and_read_async (msg, Priority.DEFAULT, null);
            assert (msg.get_status () == Soup.Status.OK);

            var parser = new Json.Parser ();
            parser.load_from_data ((string) bytes.get_data());

            var reader = new Json.Reader(parser.get_root ());
            this.unwrap_response (reader);

            reader.read_member ("album");
            reader.read_member ("song");

            for (int i = 0; i < reader.count_elements (); i += 1) {
                reader.read_element (i);

                var song = new Song (reader);
                song_list.append (song);

                reader.end_element ();
            }

            assert (reader.get_error () == null);
        } catch (Error e) {
            warning ("could not reload album %s: %s\n", album_id, e.message);
        } finally {
            this.remaining_albums -= 1;
            if (this.remaining_artists == 0 && this.remaining_albums == 0) {
                this.done_reloading ();
            }
        }
    }

    public async void get_random_songs (string? parameters, SongCallback callback) throws Error {
        string str_parameters;
        if (parameters == null) {
            str_parameters = "";
        } else {
            str_parameters = @"$parameters&";
        }

        var msg = new Soup.Message("GET", @"$(this.url)/rest/getRandomSongs?$(str_parameters)size=500&$(this.parameters)");
        var bytes = yield this.session.send_and_read_async (msg, Priority.DEFAULT, null);
        assert (msg.get_status () == Soup.Status.OK);

        var parser = new Json.Parser ();
        parser.load_from_data ((string) bytes.get_data ());

        var reader = new Json.Reader (parser.get_root ());
        this.unwrap_response (reader);

        reader.read_member ("randomSongs");
        reader.read_member ("song");

        for (int i = 0; i < reader.count_elements (); i += 1) {
            reader.read_element (i);
            callback (new Song (reader));
            reader.end_element ();
        }

        assert (reader.get_error () == null);
    }

    public string stream_uri (string id) {
        return @"$(this.url)/rest/stream?id=$(id)&$(this.parameters)";
    }
}