using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.Logging;
using Tango.LogViewer.UI.LogViewerFileParser;

namespace Tango.LogViewer.UI
{
    public class LogViewerManager
    {
        private ILogViewerParser _parser;

        public LogFile LogFile { get; set; }

        public string FileName { get; set; }

        public bool IsEmbeddedLog { get; set; }

        public int CountOfSet { get; set; }

        public LogViewerManager()
        {
            LogFile = null; ;
        }

        /// <summary>
        /// Create LogFile by given path.
        /// </summary>
        /// <param name="file">The file.</param>
        public void InitLogFile(String file)
        {
            LogFile = GetLogFile(file);
        }

        /// <summary>
        /// Gets set of log files by path.
        /// </summary>
        public LogFile GetLogFile(string filePath)
        {
            if (!File.Exists(filePath))
            {
                throw new IOException("File not found.");
            }
            if (Path.GetExtension(filePath) != ".log")
            {
                throw new IOException("Invalid log file extension. extension must be *.log");
            }

            var directoryName = Path.GetDirectoryName(filePath);
            var logfileName = Path.GetFileNameWithoutExtension(filePath);
            String fileName = logfileName;
            int index = logfileName.IndexOf("-");
            if (index >= 0)
            {
                fileName = logfileName.Substring(0, index);
            }
            int indexPos = logfileName.IndexOf(FileLogger.FILE_SET_EXTENSION);
            if (indexPos > 0)
            {
                logfileName = logfileName.Substring(0, indexPos);
            }

            String dateString = System.IO.Path.GetFileNameWithoutExtension(filePath).Replace($"{fileName}-", "").Replace("_session", "");
            indexPos = dateString.IndexOf(FileLogger.FILE_SET_EXTENSION);
            int indexOfFile = 0;
            CountOfSet = 0;
            if (indexPos > 0)
            {
                string fileNameIndex = dateString.Substring(indexPos + FileLogger.FILE_SET_EXTENSION.Length);
                string[] fileEntries = Directory.GetFiles(directoryName, $"{logfileName}*{Path.GetExtension(filePath)}").Where(x => Path.GetFileName(x).StartsWith(logfileName)).OrderBy(x => x).ToArray();
                CountOfSet = fileEntries.Length;
                int.TryParse(fileNameIndex, out indexOfFile);
                dateString = dateString.Substring(0, indexPos);
            }
            DateTime date = DateTime.ParseExact(dateString, "dd-MM-yyyy_HH-mm-ss", CultureInfo.InvariantCulture);
            return (new LogFile() { DateTime = date, File = filePath, FileName = logfileName, PartOfSet = indexOfFile > 0, SetStartIndex = indexOfFile, SetCount = CountOfSet });
        }

        /// <summary>
        /// Parses the this LogFile.
        /// </summary>
        public List<LogItemBase> Parse()
        {
            IsEmbeddedLog = false;
            FileName = "";
            List<LogItemBase> logItems = new List<LogItemBase>();
            if (LogFile == null)
                return logItems;

            FileName = LogFile.FileName;

            IsEmbeddedLog = FileName.StartsWith("Embedded");
            if (IsEmbeddedLog)
            {
                _parser = new EmbeddedLogViewerParser();
            }
            else
            {
                _parser = new ApplicationLogViewerParser();
            }

            if (LogFile.PartOfSet)
            {
                string extension = Path.GetExtension(LogFile.File);
                var directoryName = Path.GetDirectoryName(LogFile.File);

                string[] fileEntries = Directory.GetFiles(directoryName, $"{FileName}*{extension}").Where(x => Path.GetFileName(x).StartsWith(FileName)).OrderBy(x => x).ToArray();

                foreach (var file in fileEntries)
                {
                    _parser.Parse(file, LogFile.DateTime, ref logItems);
                }
            }
            else
            {
                _parser.Parse(LogFile.File, LogFile.DateTime, ref logItems);
            }

            return logItems;
        }
    }
}