using System.Diagnostics.CodeAnalysis;
using System.Text;
using InABox.Core;

namespace InABox.Logging;

public class LogFileLogger : LoggerBase
{
    private static readonly object logfileLock = new();

    private string _folder;
    public string Folder
    {
        get => _folder;
        [MemberNotNull(nameof(_folder))]
        private set
        {
            _folder = value;
        }
    }

    private bool _trackSessions;
    private DateTime _sessionDay;
    private string? _sessionLogFileName;
    private string? _sessionJournalFileName;

    public LogFileLogger(string folder, bool trackSessions)
    {
        Folder = folder;

        _trackSessions = trackSessions;
        if (trackSessions)
        {
            if (!Directory.Exists(Folder))
            {
                Directory.CreateDirectory(Folder);
            }
        }
    }

    private enum LogFileType
    {
        Log,
        Journal
    }

    private string SessionFileName(LogFileType logFile)
    {
        if (_trackSessions)
        {
            var date = DateTime.Today;
            if(_sessionLogFileName is not null && _sessionJournalFileName is not null
                && _sessionDay == date)
            {
                return logFile == LogFileType.Log ? _sessionLogFileName : _sessionJournalFileName;
            }

            _sessionLogFileName = Path.Combine(Folder, $"{date:yyyy-MM-dd}.log");
            _sessionJournalFileName = Path.Combine(Folder, $"{date:yyyy-MM-dd}.sql");
            if (File.Exists(_sessionLogFileName)
                || File.Exists(_sessionJournalFileName))
            {
                var i = 1;
                do
                {
                    _sessionLogFileName = Path.Combine(Folder, $"{date:yyyy-MM-dd}_{i:d3}.log");
                    _sessionJournalFileName = Path.Combine(Folder, $"{date:yyyy-MM-dd}_{i:d3}.sql");
                    ++i;
                } while (File.Exists(_sessionLogFileName) || File.Exists(_sessionJournalFileName));
            }
            _sessionDay = date;

            return logFile == LogFileType.Log ? _sessionLogFileName : _sessionJournalFileName;
        }
        else
        {
            return logFile == LogFileType.Log
                ? Path.Combine(Folder, $"{DateTime.Today:yyyy-MM-dd}.log")
                : Path.Combine(Folder, $"{DateTime.Today:yyyy-MM-dd}.sql");
        }
    }

    public override void Send(LogType logtype, string user, string message, Guid transaction)
    {
        if (logtype == LogType.Update)
            UpdateJournal(message);
        else
            base.Send(logtype, user, message, transaction);
    }

    protected override void DoSend(string message)
    {
        if (!string.IsNullOrEmpty(Folder))
        {
            UpdateLogFile(message);
        }
    }
    private void UpdateLogFile(string msg)
    {
        if (!Directory.Exists(Folder)) Directory.CreateDirectory(Folder);
        var filename = SessionFileName(LogFileType.Log);
        try
        {
            lock (logfileLock)
            {
                using (var sw = new StreamWriter(filename, true, Encoding.UTF8, 65536))
                {
                    sw.WriteLine(msg);
                    sw.Close();
                }
            }
        }
        catch (Exception e)
        {
            Console.WriteLine("*** Failed to Update Log: " + e.Message);
            Console.WriteLine("*** Message: " + msg);
        }
    }

    private void UpdateJournal(string sql)
    {
        var filename = SessionFileName(LogFileType.Journal);
        try
        {
            lock (logfileLock)
            {
                using (var sw = new StreamWriter(filename, true, Encoding.UTF8, 65536))
                {
                    sw.WriteLine(sql);
                    sw.Close();
                }
            }
        }
        catch (Exception e)
        {
            Console.WriteLine("*** Failed to Update SQL Journal: " + e.Message);
            Console.WriteLine("*** Message: " + sql);
        }
    }

}