/*
 * Copyright (C) 2007 The Android Open Source Project
 * Copyright (C) 2012 Paul Watts (paulcwatts@gmail.com)
 *
 * 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 org.onebusaway.android.mock;

import android.annotation.TargetApi;
import android.net.Uri;
import android.os.Build;

import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.Set;

public class UriCompat {

    @TargetApi(value = 11)
    public static Set<String> getQueryParameterNames(Uri uri) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
            return uri.getQueryParameterNames();
        } else {
            return getQueryParameterNames_10(uri);
        }
    }

    //
    // Copied from newer Uri sources, useable with < 11 APIs.
    //
    private static Set<String> getQueryParameterNames_10(Uri uri) {
        String query = uri.getEncodedQuery();
        if (query == null) {
            return Collections.emptySet();
        }

        Set<String> names = new LinkedHashSet<String>();
        int start = 0;
        do {
            int next = query.indexOf('&', start);
            int end = (next == -1) ? query.length() : next;

            int separator = query.indexOf('=', start);
            if (separator > end || separator == -1) {
                separator = end;
            }

            String name = query.substring(start, separator);
            names.add(Uri.decode(name));

            // Move start to end of name.
            start = end + 1;
        } while (start < query.length());

        return Collections.unmodifiableSet(names);
    }
}