/*
 * Copyright (c) 2013, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
 *   * Neither the name of The Linux Foundation nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.android.bluetooth;

import android.util.Log;

public final class LeScanRequestArbitrator {
    private final static String TAG = "LeScanRequestArbitrator";
    private final static boolean DBG = false;
    public final static int LE_NORMAL_SCAN_TYPE = 1;
    public final static int LE_EXTENDED_SCAN_TYPE = 2;
    private static Object mLock = new Object();

    public static LeScanRequestArbitrator instance() {
        if(sArbitrator == null) {
            synchronized(mLock) {
                if(sArbitrator == null) {
                    sArbitrator = new LeScanRequestArbitrator();
                }
            }
        }
        return sArbitrator;
    }

    private LeScanRequestArbitrator() {
        mNormalScanClient = 0;
        mExtendedScanClient = 0;
    }

    public boolean RequestLeScan (int type) {
        synchronized(mLock) {
            if (LE_NORMAL_SCAN_TYPE == type) {
                /* Test and Set */
                if(0 == mExtendedScanClient) {
                    mNormalScanClient++;
                    return true;
                } else {
                    return false;
                }
            } else if (LE_EXTENDED_SCAN_TYPE == type){
                /* Test and Set */
                if(0 == mNormalScanClient && 0 == mExtendedScanClient) {
                    mExtendedScanClient++;
                    return true;
                } else {
                    return false;
                }
            } else {
                return false;
            }
        }
    }

    public void StopLeScan(int type) {
        synchronized(mLock) {
            if(LE_NORMAL_SCAN_TYPE == type) {
                mNormalScanClient--;
            } else if (LE_EXTENDED_SCAN_TYPE == type){
                mExtendedScanClient--;
            }
        }
    }

    private int mNormalScanClient = 0;
    private int mExtendedScanClient = 0;
    private static volatile LeScanRequestArbitrator sArbitrator = null;
}