using System;

namespace ZB.MOM.WW.LmxOpcUa.Host.Domain
{
    /// <summary>
    ///     Event args for connection state transitions. (MXA-002)
    /// </summary>
    public class ConnectionStateChangedEventArgs : EventArgs
    {
        /// <summary>
        ///     Initializes a new instance of the <see cref="ConnectionStateChangedEventArgs" /> class.
        /// </summary>
        /// <param name="previous">The connection state being exited.</param>
        /// <param name="current">The connection state being entered.</param>
        /// <param name="message">Additional context about the transition, such as a connection fault or reconnect attempt.</param>
        public ConnectionStateChangedEventArgs(ConnectionState previous, ConnectionState current, string message = "")
        {
            PreviousState = previous;
            CurrentState = current;
            Message = message ?? "";
        }

        /// <summary>
        ///     Gets the previous MXAccess connection state before the transition was raised.
        /// </summary>
        public ConnectionState PreviousState { get; }

        /// <summary>
        ///     Gets the new MXAccess connection state that the bridge moved into.
        /// </summary>
        public ConnectionState CurrentState { get; }

        /// <summary>
        ///     Gets an operator-facing message that explains why the connection state changed.
        /// </summary>
        public string Message { get; }
    }
}