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

namespace EFCDesk.Classes
{
    public class ProcessLogger
    {
        private readonly string _logDirectory;
        private readonly long _maxFileSizeBytes;
        private readonly object _lock = new object();

        private DateTime _currentLogDate;
        private string _currentLogFilePath;

        public ProcessLogger(string logDirectory = "Logs", string? logFileName = null, long maxFileSizeBytes = 1 * 1024 * 1024) // 1 MB
        {
            _logDirectory = logDirectory;
            _maxFileSizeBytes = maxFileSizeBytes;
            _currentLogDate = DateTime.Now;

            if (!Directory.Exists(_logDirectory))
            {
                Directory.CreateDirectory(_logDirectory);
            }

            _currentLogFilePath = GetLogFilePath(_currentLogDate, logFileName);
        }

        public void LogInfo(string message) => Log("INFO", message);
        public void LogWarning(string message) => Log("WARNING", message);
        public void LogError(string message, Exception? ex = null)
        {
            string fullMessage = message;
            if (ex != null)
            {
                fullMessage += $"{Environment.NewLine}Exception: {ex.Message}{Environment.NewLine}StackTrace: {ex.StackTrace}";
            }
            Log("ERROR", fullMessage);
        }

        private void Log(string level, string message)
        {
            string logEntry = $"[{DateTime.Now:yyyy-MM-dd HH:mm:ss}] [{level}] {message}";

            lock (_lock)
            {
                RotateLogFileIfNeeded();
                File.AppendAllText(_currentLogFilePath, logEntry + Environment.NewLine);
            }
        }

        private void RotateLogFileIfNeeded()
        {
            DateTime now = DateTime.Now;

            // Cambio de día: nuevo archivo
            if (now.Date != _currentLogDate.Date)
            {
                _currentLogDate = now;
                _currentLogFilePath = GetLogFilePath(_currentLogDate);
                return;
            }

            // Excede tamaño máximo: crear nuevo archivo con sufijo incremental
            if (File.Exists(_currentLogFilePath) &&
                new FileInfo(_currentLogFilePath).Length >= _maxFileSizeBytes)
            {
                int index = 1;
                string newPath;
                do
                {
                    newPath = GetLogFilePath(_currentLogDate, null, index++);
                } while (File.Exists(newPath));

                _currentLogFilePath = newPath;
            }
        }

        private string GetLogFilePath(DateTime date, string? customName = null, int index = 0)
        {
            string datePart = date.ToString("yyyyMMdd");
            string baseName = string.IsNullOrWhiteSpace(customName)
                ? $"log_{datePart}"
                : Path.GetFileNameWithoutExtension(customName);

            string extension = ".txt";
            string fileName = index == 0
                ? $"{baseName}{extension}"
                : $"{baseName}_{index}{extension}";

            return Path.Combine(_logDirectory, fileName);
        }

    }
}