/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.media.browse;

import android.os.Bundle;

import java.util.Collections;
import java.util.List;

/**
 * @hide
 */
public class MediaBrowserUtils {
    /**
     * Compares whether two bundles are the same.
     */
    public static boolean areSameOptions(Bundle options1, Bundle options2) {
        if (options1 == options2) {
            return true;
        } else if (options1 == null) {
            return options2.getInt(MediaBrowser.EXTRA_PAGE, -1) == -1
                    && options2.getInt(MediaBrowser.EXTRA_PAGE_SIZE, -1) == -1;
        } else if (options2 == null) {
            return options1.getInt(MediaBrowser.EXTRA_PAGE, -1) == -1
                    && options1.getInt(MediaBrowser.EXTRA_PAGE_SIZE, -1) == -1;
        } else {
            return options1.getInt(MediaBrowser.EXTRA_PAGE, -1)
                    == options2.getInt(MediaBrowser.EXTRA_PAGE, -1)
                    && options1.getInt(MediaBrowser.EXTRA_PAGE_SIZE, -1)
                    == options2.getInt(MediaBrowser.EXTRA_PAGE_SIZE, -1);
        }
    }

    /**
     * Returnes true if the page options has duplicated items.
     */
    public static boolean hasDuplicatedItems(Bundle options1, Bundle options2) {
        int page1 = options1 == null ? -1 : options1.getInt(MediaBrowser.EXTRA_PAGE, -1);
        int page2 = options2 == null ? -1 : options2.getInt(MediaBrowser.EXTRA_PAGE, -1);
        int pageSize1 = options1 == null ? -1 : options1.getInt(MediaBrowser.EXTRA_PAGE_SIZE, -1);
        int pageSize2 = options2 == null ? -1 : options2.getInt(MediaBrowser.EXTRA_PAGE_SIZE, -1);

        int startIndex1, startIndex2, endIndex1, endIndex2;
        if (page1 == -1 || pageSize1 == -1) {
            startIndex1 = 0;
            endIndex1 = Integer.MAX_VALUE;
        } else {
            startIndex1 = pageSize1 * page1;
            endIndex1 = startIndex1 + pageSize1 - 1;
        }

        if (page2 == -1 || pageSize2 == -1) {
            startIndex2 = 0;
            endIndex2 = Integer.MAX_VALUE;
        } else {
            startIndex2 = pageSize2 * page2;
            endIndex2 = startIndex2 + pageSize2 - 1;
        }

        if (startIndex1 <= startIndex2 && startIndex2 <= endIndex1) {
            return true;
        } else if (startIndex1 <= endIndex2 && endIndex2 <= endIndex1) {
            return true;
        }
        return false;
    }

    /**
     * Returns a paged version of the given {@code list}, using the paging parameters in {@code
     * options}.
     */
    public static List<MediaBrowser.MediaItem> applyPagingOptions(
            List<MediaBrowser.MediaItem> list, final Bundle options) {
        if (list == null) {
            return null;
        }
        int page = options.getInt(MediaBrowser.EXTRA_PAGE, -1);
        int pageSize = options.getInt(MediaBrowser.EXTRA_PAGE_SIZE, -1);
        if (page == -1 && pageSize == -1) {
            return list;
        }
        int fromIndex = pageSize * page;
        int toIndex = fromIndex + pageSize;
        if (page < 0 || pageSize < 1 || fromIndex >= list.size()) {
            return Collections.EMPTY_LIST;
        }
        if (toIndex > list.size()) {
            toIndex = list.size();
        }
        return list.subList(fromIndex, toIndex);
    }
}