using LJLib.Tools.File;
using System;
using System.IO;

namespace LJLib.TextLog
{
    internal class RequestLogger : ILogger
    {
        private readonly string _logDir;
        private readonly object _syncRoot = new object();

        public RequestLogger(string logDir = null)
        {
            // 默认目录为执行目录下的 log 文件夹
            _logDir = logDir ?? Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "log");

            if (!Directory.Exists(_logDir))
                Directory.CreateDirectory(_logDir);
        }

        /// <summary>
        /// 获取今天的日志文件全路径
        /// </summary>
        private string GetTodayLogFile()
        {
            string fileName = $"REQUEST_{DateTime.Now:yyyyMMdd}.log";
            return Path.Combine(_logDir, fileName);
        }

        /// <summary>
        /// 写入日志
        /// </summary>
        public void WriteLog(string msg)
        {
            try
            {
                lock (_syncRoot)
                {
                    string filePath = GetTodayLogFile();

                    using (StreamWriter sw = new StreamWriter(filePath, true))
                    {
                        sw.WriteLine("====================================================================");
                        sw.WriteLine($"时间: {DateTime.Now:yyyy-MM-dd HH:mm:ss}");
                        sw.WriteLine("--------------------------------------------------------------------");
                        sw.WriteLine(msg);
                        sw.WriteLine("====================================================================");
                        sw.WriteLine();
                    }

                    // 清理过期日志（7天前的删除）
                    CleanupOldLogs();
                }
            }
            catch
            {
                // 这里可考虑写到系统事件日志或忽略
            }
        }

        /// <summary>
        /// 清理7天前的日志文件
        /// </summary>
        private void CleanupOldLogs()
        {
            try
            {
                var files = Directory.GetFiles(_logDir, "REQUEST_*.log");
                DateTime threshold = DateTime.Now.AddDays(-7);

                foreach (var file in files)
                {
                    string fileName = Path.GetFileNameWithoutExtension(file);
                    // 格式: REQUEST_yyyyMMdd
                    if (fileName.Length == "REQUEST_yyyyMMdd".Length &&
                        DateTime.TryParseExact(fileName.Replace("REQUEST_", ""),
                                               "yyyyMMdd",
                                               null,
                                               System.Globalization.DateTimeStyles.None,
                                               out DateTime logDate))
                    {
                        if (logDate < threshold.Date)
                        {
                            File.Delete(file);
                        }
                    }
                }
            }
            catch
            {
                // 忽略清理异常
            }
        }
    }
}