// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.md in the project root for license information.

using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;

namespace Microsoft.AspNet.SignalR.Messaging
{
    /// <summary>
    /// 
    /// </summary>
    [SuppressMessage("Microsoft.Performance", "CA1815:OverrideEqualsAndOperatorEqualsOnValueTypes", Justification = "Messages are never compared")]
    public struct MessageResult
    {
        private static readonly List<ArraySegment<Message>> _emptyList = new List<ArraySegment<Message>>();
        public readonly static MessageResult TerminalMessage = new MessageResult(terminal: true);

        /// <summary>
        /// Gets an <see cref="T:IList{Message}"/> associated with the result.
        /// </summary>
        [SuppressMessage("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures", Justification = "This is an optimization to avoid allocations.")]
        public IList<ArraySegment<Message>> Messages { get; private set; }

        public int TotalCount { get; private set; }

        public bool Terminal { get; set; }

        public MessageResult(bool terminal)
            : this(_emptyList, 0)
        {
            Terminal = terminal;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="MessageResult"/> struct.
        /// </summary>
        /// <param name="messages">The array of messages associated with this <see cref="MessageResult"/>.</param>
        /// <param name="totalCount">The amount of messages populated in the messages array.</param>
        public MessageResult(IList<ArraySegment<Message>> messages, int totalCount)
            : this()
        {
            Messages = messages;
            TotalCount = totalCount;
        }
    }
}