using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.IO;
using System.Linq;
using System.Runtime.Serialization.Formatters.Binary;
using System.Text;
using System.Threading.Tasks;

namespace Tango.Logging
{
    /// <summary>
    /// Represents a base class for log items.
    /// </summary>
    [Serializable]
    public abstract class LogItemBase : INotifyPropertyChanged
    {
        private static String base_path;

        [NonSerialized]
        private Object _logObject;
        /// <summary>
        /// Gets or sets an optional log object.
        /// </summary>
        [JsonIgnore]
        public Object LogObject
        {

            get { return _logObject; }
            set { _logObject = value; }
        }

        /// <summary>
        /// Gets or sets the caller method adding the exception.
        /// </summary>
        public String CallerMethodName { get; set; }

        /// <summary>
        /// Gets or sets the caller file.
        /// </summary>
        public String CallerFile { get; set; }

        /// <summary>
        /// Gets the relative caller file.
        /// </summary>
        [JsonIgnore]
        public String RelativeCallerFile
        {
            get { return GetRelativeCallerFilePath(); }
        }

        /// <summary>
        /// Gets the name of the caller file class.
        /// </summary>
        public String ClassName
        {
            get { return RelativeCallerFile.Split('\\').LastOrDefault()?.Split('.').FirstOrDefault(); }
        }

        /// <summary>
        /// Gets or sets the caller line number.
        /// </summary>
        public int CallerLineNumber { get; set; }

        /// <summary>
        /// Gets or sets the DateTime for the log.
        /// </summary>
        public DateTime TimeStamp { get; set; }

        /// <summary>
        /// Gets or sets the log category.
        /// </summary>
        public LogCategory Category { get; set; }

        /// <summary>
        /// Gets the log message.
        /// </summary>
        public abstract String Message { get; set; }

        /// <summary>
        /// Returns a formatted string of the log item.
        /// </summary>
        public abstract override String ToString();

        /// <summary>
        /// Gets the relative caller file path.
        /// </summary>
        /// <returns></returns>
        protected virtual String GetRelativeCallerFilePath()
        {
            if (base_path == null)
            {
                int index = CallerFile.IndexOf("Visual_Studio") + "Visual_Studio".Length + 1;
                String relative = CallerFile.Substring(index, CallerFile.Length - index);
                base_path = CallerFile.Replace(relative, "");
            }

            if (Path.IsPathRooted(CallerFile))
            {
                return CallerFile.Remove(0, base_path.Length);
            }
            else
            {
                return CallerFile;
            }
        }

        /// <summary>
        /// Serializes this log item using <see cref="BinaryFormatter"/>.
        /// </summary>
        /// <returns></returns>
        public byte[] Serialize()
        {
            using (MemoryStream ms = new MemoryStream())
            {
                BinaryFormatter f = new BinaryFormatter();
                f.Serialize(ms, this);
                return ms.ToArray();
            }
        }

        /// <summary>
        /// Deserializes the specified data using <see cref="BinaryFormatter"/> to create a log item.
        /// </summary>
        /// <param name="data">The data.</param>
        /// <returns></returns>
        public static LogItemBase Deserialize(byte[] data)
        {
            using (MemoryStream ms = new MemoryStream(data))
            {
                ms.Position = 0;
                BinaryFormatter f = new BinaryFormatter();
                return f.Deserialize(ms) as LogItemBase;
            }
        }

        /// <summary>
        /// Raises the property changed event.
        /// </summary>
        /// <param name="propName">Name of the property.</param>
        protected virtual void RaisePropertyChanged(String propName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propName));
        }

        /// <summary>
        /// Occurs when a property value changes.
        /// </summary>
        public event PropertyChangedEventHandler PropertyChanged;
    }
}