namespace Renci.SshNet.Messages.Transport
{
    /// <summary>
    /// Represents SSH_MSG_KEX_DH_GEX_REQUEST message.
    /// </summary>
    [Message("SSH_MSG_KEX_DH_GEX_REQUEST", MessageNumber)]
    internal sealed class KeyExchangeDhGroupExchangeRequest : Message, IKeyExchangedAllowed
    {
        internal const byte MessageNumber = 34;

        /// <summary>
        /// Gets the minimum size, in bits, of an acceptable group.
        /// </summary>
        /// <value>
        /// The minimum.
        /// </value>
        public uint Minimum { get; private set; }

        /// <summary>
        /// Gets the preferred size, in bits, of the group the server will send.
        /// </summary>
        /// <value>
        /// The preferred.
        /// </value>
        public uint Preferred { get; private set; }

        /// <summary>
        /// Gets the maximum size, in bits, of an acceptable group.
        /// </summary>
        /// <value>
        /// The maximum.
        /// </value>
        public uint Maximum { 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; // Minimum
                capacity += 4; // Preferred
                capacity += 4; // Maximum
                return capacity;
            }
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="KeyExchangeDhGroupExchangeRequest"/> class.
        /// </summary>
        /// <param name="minimum">The minimum.</param>
        /// <param name="preferred">The preferred.</param>
        /// <param name="maximum">The maximum.</param>
        public KeyExchangeDhGroupExchangeRequest(uint minimum, uint preferred, uint maximum)
        {
            Minimum = minimum;
            Preferred = preferred;
            Maximum = maximum;
        }

        /// <summary>
        /// Called when type specific data need to be loaded.
        /// </summary>
        protected override void LoadData()
        {
            Minimum = ReadUInt32();
            Preferred = ReadUInt32();
            Maximum = ReadUInt32();
        }

        /// <summary>
        /// Called when type specific data need to be saved.
        /// </summary>
        protected override void SaveData()
        {
            Write(Minimum);
            Write(Preferred);
            Write(Maximum);
        }

        internal override void Process(Session session)
        {
            throw new System.NotImplementedException();
        }
    }
}
