using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Tango.Logging
{
    /// <summary>
    /// Represents an <see cref="ILogger"/> file logger.
    /// </summary>
    /// <seealso cref="Tango.Logging.ILogger" />
    public class FileLogger : ILogger
    {
        private DateTime _logFileDate;

        /// <summary>
        /// Gets the logs folder.
        /// </summary>
        public static String DefaultLogsFolder { get; private set; }

        /// <summary>
        /// Gets or sets the log file.
        /// </summary>
        public String LogFile { get; private set; }

        /// <summary>
        /// Gets the tag name which will be appended to the file.
        /// </summary>
        public String Tag { get; private set; }

        /// <summary>
        /// Gets or sets the log file folder.
        /// </summary>
        public String Folder { get; private set; }

        /// <summary>
        /// Initializes the <see cref="FileLogger"/> class.
        /// </summary>
        static FileLogger()
        {
            DefaultLogsFolder = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), "Twine", "Tango", "Logs", Path.GetFileNameWithoutExtension(AppDomain.CurrentDomain.FriendlyName));
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="FileLogger"/> class.
        /// </summary>
        public FileLogger()
        {
            _isEnabled = true;

            Tag = Path.GetFileNameWithoutExtension(AppDomain.CurrentDomain.FriendlyName);
            Folder = DefaultLogsFolder;
            Directory.CreateDirectory(Folder);
            LogFile = CreateLogFileName();
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="FileLogger"/> class.
        /// </summary>
        /// <param name="folder">Logs folder path.</param>
        /// <param name="tag">The tag name which will be appended to the file name.</param>
        public FileLogger(String folder, String tag)
            : this()
        {
            Folder = folder;
            Tag = tag;
            Directory.CreateDirectory(Folder);
            LogFile = CreateLogFileName();
        }

        /// <summary>
        /// Called when a new library trace is available.
        /// </summary>
        /// <param name="output">The output.</param>
        public void OnLog(LogItemBase output)
        {
            try
            {
                if (DateTime.Now.Date > _logFileDate.Date)
                {
                    File.AppendAllText(LogFile, Environment.NewLine + Environment.NewLine + "### This log file continues on the next log file ###" + Environment.NewLine);
                    LogFile = CreateLogFileName();
                    File.AppendAllText(LogFile, "### This log file is a continuation of a previous log file ###" + Environment.NewLine + Environment.NewLine);
                }

                File.AppendAllText(LogFile, output.ToString() + Environment.NewLine);
            }
            catch
            {
                Debug.WriteLine("Error Writing To Log File!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
            }
        }

        private bool _isEnabled;
        /// <summary>
        /// Gets or sets a value indicating whether this <see cref="ILogger" /> is enabled.
        /// </summary>
        public bool Enabled
        {
            get
            {
                return _isEnabled;
            }
            set
            {
                _isEnabled = value;
            }
        }

        /// <summary>
        /// Creates the name of the log file.
        /// </summary>
        /// <returns></returns>
        private String CreateLogFileName()
        {
            _logFileDate = DateTime.Now.Date;
            return Path.Combine(Folder, string.Format("{1}-{0:dd-MM-yyyy_HH-mm-ss}.log", DateTime.Now, Tag));
        }
    }
}