/* ========================================================================
 * Copyright (c) 2005-2020 The OPC Foundation, Inc. All rights reserved.
 *
 * OPC Foundation MIT License 1.00
 * 
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * The complete license agreement can be found here:
 * http://opcfoundation.org/License/MIT/1.00/
 * ======================================================================*/

#if CLIENT_ASYNC

using System;
using System.Collections.Generic;
using System.Threading.Tasks;

namespace Opc.Ua.Client
{
    /// <summary>
    /// Manages a session with a server.
    /// Contains the async versions of the public session api.
    /// </summary>
    public partial class Session : SessionClient, IDisposable
    {
        #region Subscription Methods
        /// <summary>
        /// Removes a subscription from the session.
        /// </summary>
        /// <param name="subscription">The subscription to remove.</param>
        public async Task<bool> RemoveSubscriptionAsync(Subscription subscription)
        {
            if (subscription == null) throw new ArgumentNullException(nameof(subscription));

            if (subscription.Created)
            {
                await subscription.DeleteAsync(false).ConfigureAwait(false);
            }

            lock (SyncRoot)
            {
                if (!m_subscriptions.Remove(subscription))
                {
                    return false;
                }

                subscription.Session = null;
            }

            if (m_SubscriptionsChanged != null)
            {
                m_SubscriptionsChanged(this, null);
            }

            return true;
        }

        /// <summary>
        /// Removes a list of subscriptions from the sessiont.
        /// </summary>
        /// <param name="subscriptions">The list of subscriptions to remove.</param>
        public async Task<bool> RemoveSubscriptionsAsync(IEnumerable<Subscription> subscriptions)
        {
            if (subscriptions == null) throw new ArgumentNullException(nameof(subscriptions));

            List<Subscription> subscriptionsToDelete = new List<Subscription>();

            bool removed = PrepareSubscriptionsToDelete(subscriptions, subscriptionsToDelete);

            foreach (Subscription subscription in subscriptionsToDelete)
            {
                await subscription.DeleteAsync(true).ConfigureAwait(false);
            }

            if (removed)
            {
                if (m_SubscriptionsChanged != null)
                {
                    m_SubscriptionsChanged(this, null);
                }
            }

            return removed;
        }
        #endregion
    }
}
#endif