namespace WatsonTcp
{
    using System;

    /// <summary>
    /// Watson TCP server events.
    /// </summary>
    public class WatsonTcpServerEvents
    {
        #region Public-Members

        /// <summary>
        /// Event to fire when authentication is requested from a client.
        /// </summary>
        public event EventHandler<AuthenticationRequestedEventArgs> AuthenticationRequested;

        /// <summary>
        /// Event to fire when a client successfully authenticates.
        /// </summary>
        public event EventHandler<AuthenticationSucceededEventArgs> AuthenticationSucceeded;

        /// <summary>
        /// Event to fire when a client fails authentication.
        /// </summary>
        public event EventHandler<AuthenticationFailedEventArgs> AuthenticationFailed;

        /// <summary>
        /// Event to fire when a client connects to the server.
        /// The IP:port of the client is passed in the arguments.
        /// </summary>
        public event EventHandler<ConnectionEventArgs> ClientConnected;

        /// <summary>
        /// Event to fire when a client disconnects from the server.
        /// The IP:port is passed in the arguments along with the reason for the disconnection.
        /// </summary>
        public event EventHandler<DisconnectionEventArgs> ClientDisconnected;

        /// <summary>
        /// This event is fired when a message is received from a client and it is desired that WatsonTcp pass the byte array containing the message payload.
        /// If MessageReceived is set, StreamReceived will not be used.
        /// </summary>
        public event EventHandler<MessageReceivedEventArgs> MessageReceived; 

        /// <summary> 
        /// This event is fired when a stream is received from a client and it is desired that WatsonTcp pass the stream containing the message payload to your application. 
        /// If MessageReceived is set, StreamReceived will not be used.
        /// </summary>
        public event EventHandler<StreamReceivedEventArgs> StreamReceived;

        /// <summary>
        /// This event is fired when the server is started.
        /// </summary>
        public event EventHandler ServerStarted;

        /// <summary>
        /// This event is fired when the server is stopped.
        /// </summary>
        public event EventHandler ServerStopped;

        /// <summary>
        /// This event is fired when an exception is encountered.
        /// </summary>
        public event EventHandler<ExceptionEventArgs> ExceptionEncountered;

        #endregion

        #region Internal-Members

        internal bool IsUsingMessages
        {
            get
            {
                if (MessageReceived != null && MessageReceived.GetInvocationList().Length > 0) return true;
                return false;
            }
        }

        internal bool IsUsingStreams
        {
            get
            {
                if (StreamReceived != null && StreamReceived.GetInvocationList().Length > 0) return true;
                return false;
            }
        }

        #endregion

        #region Private-Members

        #endregion

        #region Constructors-and-Factories

        /// <summary>
        /// Instantiate.
        /// </summary>
        public WatsonTcpServerEvents()
        {

        }

        #endregion

        #region Public-Methods

        #endregion

        #region Internal-Methods

        internal void HandleAuthenticationRequested(object sender, AuthenticationRequestedEventArgs args)
        {
            WrappedEventHandler(() => AuthenticationRequested?.Invoke(sender, args), "AuthenticationRequested", sender);
        }

        internal void HandleAuthenticationSucceeded(object sender, AuthenticationSucceededEventArgs args)
        {
            WrappedEventHandler(() => AuthenticationSucceeded?.Invoke(sender, args), "AuthenticationSucceeded", sender);
        }

        internal void HandleAuthenticationFailed(object sender, AuthenticationFailedEventArgs args)
        {
            WrappedEventHandler(() => AuthenticationFailed?.Invoke(sender, args), "AuthenticationFailed", sender);
        }

        internal void HandleClientConnected(object sender, ConnectionEventArgs args)
        {
            WrappedEventHandler(() => ClientConnected?.Invoke(sender, args), "ClientConnected", sender);
        }

        internal void HandleClientDisconnected(object sender, DisconnectionEventArgs args)
        {
            WrappedEventHandler(() => ClientDisconnected?.Invoke(sender, args), "ClientDisconnected", sender);
        }

        internal void HandleMessageReceived(object sender, MessageReceivedEventArgs args)
        {
            WrappedEventHandler(() => MessageReceived?.Invoke(sender, args), "MessageReceived", sender);
        }

        internal void HandleStreamReceived(object sender, StreamReceivedEventArgs args)
        {
            WrappedEventHandler(() => StreamReceived?.Invoke(sender, args), "StreamReceived", sender);
        }

        internal void HandleServerStarted(object sender, EventArgs args)
        {
            WrappedEventHandler(() => ServerStarted?.Invoke(sender, args), "ServerStarted", sender);
        }

        internal void HandleServerStopped(object sender, EventArgs args)
        {
            WrappedEventHandler(() => ServerStopped?.Invoke(sender, args), "ServerStopped", sender);
        }

        internal void HandleExceptionEncountered(object sender, ExceptionEventArgs args)
        {
            WrappedEventHandler(() => ExceptionEncountered?.Invoke(sender, args), "ExceptionEncountered", sender);
        }

        #endregion

        #region Private-Methods

        internal void WrappedEventHandler(Action action, string handler, object sender)
        {
            if (action == null) return;

            Action<Severity, string> logger = ((WatsonTcpServer)sender).Settings.Logger;

            try
            {
                action.Invoke();
            }
            catch (Exception e)
            {
                logger?.Invoke(Severity.Error, "Event handler exception in " + handler + ": " + Environment.NewLine + e.ToString());
            }
        }

        #endregion
    }
}