BookmarkManager.java

package org.khanacademy.core.mylist;

import static com.google.common.base.Preconditions.checkNotNull;

import org.khanacademy.core.mylist.persistence.database.BookmarkDatabase;
import org.khanacademy.core.net.api.ApiBaseUrl;
import org.khanacademy.core.net.downloadmanager.FileDownloadManager;
import org.khanacademy.core.net.downloadmanager.KhanDownloadableResource;
import org.khanacademy.core.net.downloadmanager.KhanDownloadableResource.Key;
import org.khanacademy.core.net.downloadmanager.VideoDownloadManager;
import org.khanacademy.core.net.downloadmanager.persistence.database.DownloadManagerDatabase;
import org.khanacademy.core.topictree.identifiers.ContentItemIdentifier;
import org.khanacademy.core.topictree.identifiers.KhanIdentifier;

import com.google.common.base.Optional;

import java.util.List;

/**
 * TODO(mgp)
 */
public final class BookmarkManager {
    private final BookmarkDatabase mBookmarkDatabase;
    private final DownloadManagerDatabase mDownloadManagerDatabase;
    private final VideoDownloadManager mVideoDownloadManager;

    public BookmarkManager(final BookmarkDatabase bookmarkDatabase,
                           final DownloadManagerDatabase downloadManagerDatabase,
                           final ApiBaseUrl apiBaseUrl,
                           final FileDownloadManager<Key, KhanDownloadableResource> fileDownloadManager) {
        mBookmarkDatabase = checkNotNull(bookmarkDatabase);
        mDownloadManagerDatabase = checkNotNull(downloadManagerDatabase);

        // TODO(mgp): Pass in the database.
        mVideoDownloadManager = new VideoDownloadManager(apiBaseUrl, fileDownloadManager, null);
    }

    /**
     * Adds the given {@link Bookmark}.
     *
     * @throws
     */
    public void addBookmark(final Bookmark bookmark, final String userKaid) {
        mBookmarkDatabase.addBookmark(bookmark, userKaid);
    }

    private static boolean isVideoItemIdentifier(KhanIdentifier khanIdentifier) {
        switch (khanIdentifier.getIdentifierType()) {
            case CONTENT_ITEM:
                final ContentItemIdentifier contentItemIdentifier =
                        (ContentItemIdentifier) khanIdentifier;
                switch (contentItemIdentifier.itemKind) {
                    case VIDEO:
                        return true;
                    default:
                        break;
                }
            default:
                break;
        }
        return false;
    }

    /**
     * Deletes any {@link Bookmark} with the given {@link KhanIdentifier} from the database.
     *
     * @return {@code true} if the bookmark was found and removed, {@code false} if no such
     *         bookmark was found
     */
    public boolean removeBookmark(final KhanIdentifier identifier) {
        if (isVideoItemIdentifier(identifier)) {
            final ContentItemIdentifier videoItemIdentifier = (ContentItemIdentifier) identifier;
            getVideoDownloadManager().remove(videoItemIdentifier);
        }
        return mBookmarkDatabase.removeBookmark(identifier);
    }

    /**
     * @return an {@link Optional} containing the {@link Bookmark} for the given identifier, or
     *         {@link Optional#absent()} if no such bookmark exists
     */
    public Optional<Bookmark> fetchBookmark(final KhanIdentifier identifier) {
        return mBookmarkDatabase.fetchBookmark(identifier);
    }

    /**
     * @return a list of all {@link Bookmark} instances
     */
    public List<Bookmark> fetchAllBookmarks() {
        return mBookmarkDatabase.fetchAllBookmarks();
    }

    /**
     * @return the manager for video downloads
     */
    public VideoDownloadManager getVideoDownloadManager() {
        return mVideoDownloadManager;
    }
}