storage.js

const Me = imports.misc.extensionUtils.getCurrentExtension();
const {Soup, Gio, GLib, Shell} = imports.gi;
const Convenience = Me.imports.convenience;
const Keys = Me.imports.keys;
const settings = Convenience.getSettings();

const DATA_DIRECTORY = GLib.get_home_dir() + "/.gnome-lyrics-extension/";

var StorageManager = class Storage_Manager {

    constructor() {

    }

    _download_album_art(url, file) {
        const fstream = file.replace(null, false, Gio.FileCreateFlags.NONE, null);
        const request = Soup.Message.new('GET', url);

        // got_chunk event
        request.connect('got_chunk', (message, chunk) => {
            if (message.status_code == 200) {
                fstream.write(chunk.get_data(), null);
            }
        });

        const httpSession = new Soup.SessionAsync();
        httpSession.queue_message(request, (httpSession, message) => {
            // request completed
            fstream.close(null);
            if (message.status_code != 200) {
                file.delete(null);
            }
        });
    }

    _save_lyrics(title, artist, lyrics) {
        const lyrics_name = this._make_lyrics_filename(title, artist);
        const file = Gio.file_new_for_path(lyrics_name);
        if (file) {
            this._create_dir(DATA_DIRECTORY);
            const raw = file.replace(null, false, Gio.FileCreateFlags.NONE, null);
            const out = Gio.BufferedOutputStream.new_sized(raw, 4096);
            Shell.write_string_to_stream(out, lyrics);
            out.close(null);
        }
    }

    _save_image(title, artist, pic_url) {
        const pic_name = this._make_image_filename(title, artist);
        const file = Gio.file_new_for_path(pic_name);
        if (file) {
            this._create_dir(DATA_DIRECTORY);
            if (settings.get_boolean(Keys.ENABLE_COVER)) {
                this._download_album_art(pic_url, file);
            }
        }
    }

    is_lyrics_available(title, artist) {
        const filename = this._make_lyrics_filename(title, artist);
        return Gio.file_new_for_path(filename).query_exists(null);
    }

    save(title, artist, lyrics, pic_url) {
        this._save_lyrics(title, artist, lyrics);
        this._save_image(title, artist, pic_url);
    }

    get_image_gicon(title, artist) {
        return Gio.icon_new_for_string(this.get_image(title, artist));
    }

    get_image(title, artist) {
        let filename = '';
        if (this.is_lyrics_available(title, artist)) {
            filename = this._make_image_url(title, artist);
        }
        return filename;
    }

    get_lyrics(title, artist) {
        const filename = this._make_lyrics_filename(title, artist);
        let content = '';
        try {
            content = Shell.get_file_contents_utf8_sync(filename);
        } catch (e) {
            return content;
        }
        return content;
    }

    _create_dir(dir_path) {
        const dir = Gio.file_new_for_path(dir_path);
        if (!dir.query_exists(null)) {
            try {
                dir.make_directory(null);
            } catch (e) {
            }
        }
    }

    _make_image_filename(title, artist) {
        return DATA_DIRECTORY + `${title}_${artist}`.replace(/[\s\/]/g, '_');
    }

    _make_image_url(title, artist) {
        return 'file://' + this._make_image_filename(title, artist);
    }

    _make_lyrics_filename(title, artist) {
        return this._make_image_filename(title, artist) + '.lyrics';
    }
}