public errordomain Subsonic.Error {
    BAD_AUTHN,
    ERROR,
}

public delegate void Subsonic.SongCallback (Song song);

public class Subsonic.Artist : Object {
    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 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 ();
    }
}

public class Subsonic.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 struct Subsonic.Song {
    public string id;
    public string title;
    public string album;
    public string artist;
    public int64 track;
    public int64 year;
    public DateTime? starred; // TODO
    public int64 duration;
    public int64 play_count;
    public string? genre;
    public string cover_art;

    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 ();

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

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

        reader.read_member ("playCount");
        this.play_count = reader.get_int_value ();
        reader.end_member ();

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

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

public class Subsonic.Client : Object {
    private Soup.Session session;
    private string url;
    private string parameters;

    public Client.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.audrey";

        this.session = new Soup.Session ();
        this.session.user_agent = Audrey.Const.user_agent;
    }

    private void unwrap_response (Json.Reader reader) throws GLib.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 Subsonic.Error.ERROR (reader.get_string_value () ?? "???");
            }
        reader.end_member();
    }

    public async void ping () throws GLib.Error {
        var msg = new Soup.Message ("GET", @"$(this.url)/rest/ping?f=json&$(this.parameters)");
        if (msg == null) {
            throw new Subsonic.Error.BAD_AUTHN ("Bad message");
        }

        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 async void scrobble (string id) throws GLib.Error {
        var msg = new Soup.Message ("GET", @"$(this.url)/rest/scrobble?id=$(Uri.escape_string (id))&f=json&$(this.parameters)");
        assert (msg != null);

        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 async void get_random_songs (string? parameters, SongCallback callback) throws GLib.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&f=json&$(this.parameters)");
        assert (msg != null);

        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 (Song (reader));
            reader.end_element ();

            Idle.add (this.get_random_songs.callback);
            yield;
        }

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

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

    public string cover_art_uri (string id, int size = -1) {
        if (size >= 0) {
            return @"$(this.url)/rest/getCoverArt?id=$(Uri.escape_string(id))&$(this.parameters)";
        } else {
            return @"$(this.url)/rest/getCoverArt?size=$size&id=$(Uri.escape_string(id))&$(this.parameters)";
        }
    }

    public async Gdk.Pixbuf cover_art (
        string id,
        int size = -1,
        int priority = Priority.DEFAULT,
        Cancellable? cancellable = null
    )
            throws GLib.Error
    {
        var msg = new Soup.Message("GET", this.cover_art_uri (id, size));
        assert (msg != null);

        var stream = yield this.session.send_async (msg, priority, cancellable);
        if (msg.get_status () != Soup.Status.OK) {
            warning ("could not load cover art for %s: %s", id, Soup.Status.get_phrase (msg.get_status ()));
        }
        return yield new Gdk.Pixbuf.from_stream_async (stream, cancellable);
    }

    ~Client () {
        debug ("destroying subsonic client");
    }
}