//
// Copyright 2014 Perforce Software Inc.
//

using log4net.Appender;
using log4net.Core;
using log4net.Repository.Hierarchy;
using System.ComponentModel;
using System.Globalization;
using System.IO;

namespace Perforce {
    public class NotifyAppender : AppenderSkeleton, INotifyPropertyChanged {

        #region Members and events
        private static string _notification;
        private event PropertyChangedEventHandler _propertyChanged;

        public event PropertyChangedEventHandler PropertyChanged {
            add { _propertyChanged += value; }
            remove { _propertyChanged -= value; }
        }
        #endregion

        /// <summary>
        /// Get or set the notification message.
        /// </summary>
        public string Notification {
            get {
                return _notification; ;
            }
            set {
                if (_notification != value) {
                    _notification = value;
                    OnChange();
                }
            }
        }

        public LogLevel CurrentLogLevel {
            get {
                var h = (Hierarchy)log4net.LogManager.GetRepository();
                var level = h.Root.Level;
                var logLevel = LogLevel.Fatal;
                if (level == Level.All || level == Level.Debug) {
                    logLevel = LogLevel.Debug;
                } else if (level == Level.Error) {
                    logLevel = LogLevel.Error;
                } else if (level == Level.Warn) {
                    logLevel = LogLevel.Warning;
                } else if (level == Level.Info) {
                    logLevel = LogLevel.Info;
                }
                return logLevel;
            }
            set {
                var h = (Hierarchy)log4net.LogManager.GetRepository();
                switch (value) {
                    case LogLevel.Debug:
                        h.Root.Level = Level.Debug;
                        break;
                    case LogLevel.Error:
                        h.Root.Level = Level.Error;
                        break;
                    case LogLevel.Fatal:
                        h.Root.Level = Level.Fatal;
                        break;
                    case LogLevel.Info:
                        h.Root.Level = Level.Info;
                        break;
                    case LogLevel.Warning:
                        h.Root.Level = Level.Warn;
                        break;
                }
                OnChange();
            }
        }

        /// <summary>
        /// Raise the change notification.
        /// </summary>
        private void OnChange() {
            PropertyChangedEventHandler handler = _propertyChanged;
            if (handler != null) {
                handler(this, new PropertyChangedEventArgs(string.Empty));
            }
        }

        /// <summary>
        /// Get a reference to the log instance.
        /// </summary>
        public NotifyAppender Appender {
            get {
                return Log.Appender;
            }

        }

        /// <summary>
        /// Append the log information to the notification.
        /// </summary>
        /// <param name="loggingEvent">The log event.</param>
        protected override void Append(LoggingEvent loggingEvent) {
            StringWriter writer = new StringWriter(CultureInfo.InvariantCulture);
            Layout.Format(writer, loggingEvent);
            Notification += writer.ToString();
        }
    }
}