//-----------------------------------------------------------------------
// <copyright file="ErrorLogGenerator.cs" company="Craig Sutherland">
//     Copyright (c) 2009 Craig Sutherland. All rights reserved.
// </copyright>
//-----------------------------------------------------------------------
/* 
 * Copyright (c) 2009 Craig Sutherland
 * 
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

namespace FastForward.WinCore
{
    using System;
    using System.IO;
    using System.Xml.Linq;

    /// <summary>
    /// Generates a log of an error.
    /// </summary>
    public static class ErrorLogGenerator
    {
        #region Public methods
        #region SaveLog()
        /// <summary>
        /// Saves a log of the error to the default location.
        /// </summary>
        /// <param name="error">The error to save.</param>
        /// <returns>The location the log was written to.</returns>
        public static string SaveLog(this Exception error)
        {
            return SaveLogTo(error, GetDefaultLogLocation());
        }
        #endregion

        #region SaveLogTo()
        /// <summary>
        /// Saves a log of the error to the specified location.
        /// </summary>
        /// <param name="error">The error to save.</param>
        /// <param name="logLocation">The folder to save the log in.</param>
        /// <returns>The location the log was written to.</returns>
        public static string SaveLogTo(this Exception error, string logLocation)
        {
            // Make sure there is an error to save
            if (error == null)
            {
                throw new ArgumentNullException("error");
            }

            // Make sure there is a log location and it exists
            if (string.IsNullOrEmpty(logLocation))
            {
                throw new ArgumentNullException("logLocation");
            }
            else if (!Directory.Exists(logLocation))
            {
                Directory.CreateDirectory(logLocation);
            }

            // Generate the log
            var log = new XElement("errorLog",
                    new XElement("environment",
                        new XAttribute("time", DateTime.Now.ToString("o")),
                        new XAttribute("os", Environment.OSVersion.VersionString),
                        new XAttribute("processors", Environment.ProcessorCount),
                        new XAttribute("clr", Environment.Version)));
            var thisError = error;
            var parent = log;
            while (thisError != null)
            {
                var errorEl = new XElement("error",
                    new XAttribute("type", error.GetType().FullName),
                    new XElement("message", error.Message),
                    new XElement("stack", error.StackTrace));
                parent.Add(errorEl);
                parent = errorEl;
                thisError = thisError.InnerException;
            }

            // Save the log
            var document = new XDocument(log);
            var logFile = Path.Combine(logLocation, string.Format("Error{0:yyyyMMddHHmmss}.xml", DateTime.Now));
            document.Save(logFile, SaveOptions.DisableFormatting);
            return logFile;
        }
        #endregion

        #region GetDefaultLogLocation()
        /// <summary>
        /// Gets the default log location.
        /// </summary>
        /// <returns>The default log location.</returns>
        public static string GetDefaultLogLocation()
        {
            var location = Path.Combine(
                Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
                Path.Combine("FastForward.NET", "ErrorLogs"));
            return location;
        }
        #endregion
        #endregion
    }
}