using System;
using System.Globalization;
using JD.Kernel.StaticHelpers;
using JD.Kernel.Structs;

namespace JD.LogService
{
    /// <summary>
    /// Represents an error or a warning.
    /// </summary>
    [Serializable]
    public class Error : LogEvent
    {
        #region Variables

        private string m_code = string.Empty;
        private object m_tag;

        #endregion

        #region Constructors

        public Error(LogCategory category)
            : base(category)
        {
            Throw.InvalidArgumentIf(category == LogCategory.Message, "Message is not considered to be a valid error category", "category");
        }

        public Error(LogCategory category, string message)
            : this(category)
        {
            Message = message;
        }

        public Error(LogCategory category, string message, params object[] args)
            : this(category, FormatString(message, args))
        {
        }
        
        [Obsolete("Log events are now mutable. Use the basic Error(LogCategory, string) constructor and set the rest of the properties. Subcategory is now obsolete.")] // 2011.01
        public Error(LogCategory category, FileLocation origin, string message, string subCategory, string code)
            : this(category, message)
        {
            Origin = origin;
            Code = code;
        }

        #endregion

        #region Static Creation

        /// <summary>
        /// Creates an error that wraps the given exception.
        /// </summary>
        /// <param name="ex">Exception that caused the error.</param>
        /// <param name="message">Message</param>
        /// <param name="args">Args</param>
        /// <returns></returns>
        public static Error FromException(Exception ex, string message, params object[] args)
        {
            return new Error(LogCategory.Error, message, args);
        }
        
        #endregion

        #region Properties

        /// <summary>
        /// Code of the error, if any.
        /// </summary>
        public string Code
        {
            get { return m_code; }
            set { m_code = value; }
        }

        /// <summary>
        /// Prefix used before the location part (ex.: 3> C:\file.txt)
        /// </summary>
        public string Prefix { get; set; }

        /// <summary>
        /// An opaque tag that can be used to store additional info about the error.
        /// </summary>
        public object Tag
        {
            get { return m_tag; }
            set { m_tag = value; }
        }

        #endregion

        #region Methods

        /// <summary>
        /// Returns the error in canonical format.
        /// </summary>
        /// <returns></returns>
        public override string ToCanonicalString()
        {
            return CanonicalError.Build(this);
        }

        public override int GetHashCode()
        {
            return Message.GetHashCode();
        }

        public override bool Equals(object obj)
        {
            Error toCompare = obj as Error;

            return toCompare != null && 
                Equals((LogEvent)obj) && 
                m_code == toCompare.m_code &&
                m_tag == toCompare.m_tag;
        }

        /// <summary>
        /// Overriden.
        /// </summary>
        /// <remarks>
        /// For a canonical error string, you might want to take a look at <see cref="ToCanonicalString"/>
        /// </remarks>
        /// <returns></returns>
        public override string ToString()
        {
            return string.Format(CultureInfo.CurrentCulture, "[{0}: Message={1}, Origin={2}, Code={3}]", Category, Message, Origin, Code);
        }

        #endregion
    }
}