using System;
using System.IO;
using System.Linq;
using XP.Common.Dump.Configs;
using XP.Common.Logging.Interfaces;

namespace XP.Common.Dump.Implementations
{
    /// <summary>
    /// Dump 文件自动清理组件，按保留天数策略删除过期文件
    /// Auto cleanup component for dump files, deletes expired files based on retention policy
    /// </summary>
    internal class DumpCleaner
    {
        private readonly DumpConfig _config;
        private readonly ILoggerService _logger;

        public DumpCleaner(DumpConfig config, ILoggerService logger)
        {
            _config = config ?? throw new ArgumentNullException(nameof(config));
            _logger = logger?.ForModule<DumpCleaner>() ?? throw new ArgumentNullException(nameof(logger));
        }

        /// <summary>
        /// 执行清理操作：删除超过保留天数的 .dmp 文件
        /// Execute cleanup: delete .dmp files older than retention days
        /// </summary>
        public void CleanExpiredFiles()
        {
            try
            {
                if (!Directory.Exists(_config.StoragePath))
                {
                    _logger.Debug("存储目录不存在，跳过清理：{Path} | Storage directory does not exist, skipping cleanup: {Path}", _config.StoragePath);
                    return;
                }

                var dmpFiles = Directory.GetFiles(_config.StoragePath, "*.dmp");
                var cutoffTime = DateTime.Now.AddDays(-_config.RetentionDays);
                var deletedCount = 0;

                foreach (var filePath in dmpFiles)
                {
                    try
                    {
                        var creationTime = File.GetCreationTime(filePath);
                        if (creationTime < cutoffTime)
                        {
                            var fileName = Path.GetFileName(filePath);
                            File.Delete(filePath);
                            deletedCount++;
                            _logger.Info("已删除过期 Dump 文件：{FileName} | Deleted expired dump file: {FileName}", fileName);
                        }
                    }
                    catch (Exception ex)
                    {
                        _logger.Error(ex, "删除 Dump 文件失败：{FilePath} | Failed to delete dump file: {FilePath}", filePath);
                    }
                }

                _logger.Info("Dump 清理完成，共删除 {Count} 个文件 | Dump cleanup completed, {Count} files deleted", deletedCount);
            }
            catch (Exception ex)
            {
                _logger.Error(ex, "Dump 清理过程发生异常：{Message} | Dump cleanup error: {Message}", ex.Message);
            }
        }
    }
}