namespace Renci.SshNet.Messages.Connection
{
    /// <summary>
    /// Represents SSH_MSG_CHANNEL_OPEN_CONFIRMATION message.
    /// </summary>
    public class ChannelOpenConfirmationMessage : ChannelMessage
    {
        /// <inheritdoc />
        public override string MessageName
        {
            get
            {
                return "SSH_MSG_CHANNEL_OPEN_CONFIRMATION";
            }
        }

        /// <inheritdoc />
        public override byte MessageNumber
        {
            get
            {
                return 91;
            }
        }

        /// <summary>
        /// Gets the remote channel number.
        /// </summary>
        public uint RemoteChannelNumber { get; private set; }

        /// <summary>
        /// Gets the initial size of the window.
        /// </summary>
        /// <value>
        /// The initial size of the window.
        /// </value>
        public uint InitialWindowSize { get; private set; }

        /// <summary>
        /// Gets the maximum size of the packet.
        /// </summary>
        /// <value>
        /// The maximum size of the packet.
        /// </value>
        public uint MaximumPacketSize { get; private set; }

        /// <summary>
        /// Gets the size of the message in bytes.
        /// </summary>
        /// <value>
        /// The size of the messages in bytes.
        /// </value>
        protected override int BufferCapacity
        {
            get
            {
                var capacity = base.BufferCapacity;
                capacity += 4; // RemoteChannelNumber
                capacity += 4; // InitialWindowSize
                capacity += 4; // MaximumPacketSize
                return capacity;
            }
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="ChannelOpenConfirmationMessage"/> class.
        /// </summary>
        public ChannelOpenConfirmationMessage()
        {
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="ChannelOpenConfirmationMessage"/> class.
        /// </summary>
        /// <param name="localChannelNumber">The local channel number.</param>
        /// <param name="initialWindowSize">Initial size of the window.</param>
        /// <param name="maximumPacketSize">Maximum size of the packet.</param>
        /// <param name="remoteChannelNumber">The remote channel number.</param>
        public ChannelOpenConfirmationMessage(uint localChannelNumber, uint initialWindowSize, uint maximumPacketSize, uint remoteChannelNumber)
            : base(localChannelNumber)
        {
            InitialWindowSize = initialWindowSize;
            MaximumPacketSize = maximumPacketSize;
            RemoteChannelNumber = remoteChannelNumber;
        }

        /// <summary>
        /// Called when type specific data need to be loaded.
        /// </summary>
        protected override void LoadData()
        {
            base.LoadData();
            RemoteChannelNumber = ReadUInt32();
            InitialWindowSize = ReadUInt32();
            MaximumPacketSize = ReadUInt32();
        }

        /// <summary>
        /// Called when type specific data need to be saved.
        /// </summary>
        protected override void SaveData()
        {
            base.SaveData();
            Write(RemoteChannelNumber);
            Write(InitialWindowSize);
            Write(MaximumPacketSize);
        }

        internal override void Process(Session session)
        {
            session.OnChannelOpenConfirmationReceived(this);
        }
    }
}
