using System;
using System.Xml.Linq;

namespace DataFileAnalyzer
{
    /// <summary>
    /// An error or a warning associated to a DataFile
    /// </summary>
    public class DataFileError
    {
        /// <summary>
        /// The error/warning codes
        /// </summary>
        public enum Codes
        {
            Generic = 0,
            BasicUpdate,
            NeedDependencies,
            ErrorComputingDependencies,
            WarningComputingDependencies,
            UnresolvedDependencies, 
            MissingFile,
            NotInPerforce, 
            Orphan, 
        }

        /// <summary>
        /// The error code
        /// </summary>
        public Codes Code { get; set; }

        /// <summary>
        /// The error message
        /// </summary>
        public string Message { get; set; }

        /// <summary>
        /// Constructor
        /// </summary>
        public DataFileError(string _message)
        {
            Code = Codes.Generic;
            Message = _message;
        }

        /// <summary>
        /// Constructor
        /// </summary>
        public DataFileError(Codes _code)
        {
            Code = _code;
            Message = null;
        }

        /// <summary>
        /// Constructor
        /// </summary>
        public DataFileError(Codes _code, string _message)
        {
            Code = _code;
            Message = _message;
        }

        /// <summary>
        /// String conversion
        /// </summary>
        public override string ToString()
        {
            if (string.IsNullOrEmpty(Message))
                return GetGenericMessage(Code);
            return Message;
        }

        /// <summary>
        /// Save the DataFileError to _element
        /// </summary>
        /// <returns>true if no error</returns>
        public bool Save(XElement _element)
        {
            _element.SetAttributeValue("Code", (int)Code);
            _element.SetAttributeValue("Message", Message);
            return true;
        }

        /// <summary>
        /// Load the DataFileError from _element
        /// </summary>
        /// <returns>true if no error</returns>
        public bool Load(XElement _element)
        {
            int codeInt;
            XAttribute attribute = _element.Attribute("Code");
            if (attribute != null && int.TryParse(attribute.Value, out codeInt))
                Code = (Codes)codeInt;
            else
                return false;

            attribute = _element.Attribute("Message");
            if (attribute != null)
                Message = attribute.Value;

            return true;
        }

        /// <summary>
        /// Convert code to a string
        /// </summary>
        public static string GetGenericMessage(Codes _code)
        {
            switch (_code)
            {
                case Codes.Generic:
                    return "Error.";
                case Codes.BasicUpdate:
                    return "An error occurred while checking the file.";
                case Codes.NeedDependencies:
                    return "Dependencies need to be recomputed.";
                case Codes.ErrorComputingDependencies:
                    return "An error occurred when computing dependencies.";
                case Codes.WarningComputingDependencies:
                    return "A warning was raised when computing dependencies.";
                case Codes.UnresolvedDependencies:
                    return "File has unresolved dependencies.";
                case Codes.MissingFile:
                    return "File is missing.";
                case Codes.NotInPerforce:
                    return "File is not on Perforce";
                case Codes.Orphan:
                    return "File is orphan";
            }
            return "Error.";
        }
    }
}