using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using CoreAgent.ProtocolClient.Enums;
using CoreAgent.ProtocolClient.Models;
using Microsoft.Extensions.Logging;

namespace CoreAgent.ProtocolClient.Context.UeStateManager
{
    /// <summary>
    /// UE标识符管理类
    /// 负责管理UE信息、标识符映射、时间戳等状态
    /// 优化版本：增强异常处理、性能优化、代码拆分
    /// </summary>
    public partial class UeIdentifierManager
    {
        #region 公共属性 - 映射表

        /// <summary>
        /// TMSI到UE ID的映射表
        /// </summary>
        public Dictionary<uint, int> TmsiToUeId { get; set; } = new();

        /// <summary>
        /// 请求TMSI到UE ID的映射表
        /// </summary>
        public Dictionary<uint, int> RequestTmsiToUeId { get; set; } = new();

        /// <summary>
        /// IMSI到UE ID的映射表
        /// </summary>
        public Dictionary<string, List<int>> ImsiToUeId { get; set; } = new();

        /// <summary>
        /// PLMN到UE ID的映射表
        /// </summary>
        public Dictionary<string, List<int>> PlmnToUeId { get; set; } = new();

        /// <summary>
        /// Service Request TMSI到UE ID的映射表
        /// </summary>
        public Dictionary<uint, List<int>> SrTmsiToUeId { get; set; } = new();

        /// <summary>
        /// RNTI到UE ID的映射表
        /// </summary>
        public Dictionary<int, int> RntiToUeId { get; set; } = new();

        /// <summary>
        /// UE信息列表，以UE ID为键
        /// </summary>
        public Dictionary<int, UEInfo> UeList { get; set; } = new();

        #endregion

        #region 公共属性 - 时间戳和小区信息

        /// <summary>
        /// 最后处理的时间戳
        /// </summary>
        public long LastTimestamp { get; set; }

        /// <summary>
        /// 时间戳偏移量
        /// </summary>
        public long TimestampOffset { get; set; }

        /// <summary>
        /// 最后处理的小区ID
        /// </summary>
        public int? LastCell { get; set; }

        #endregion

        #region 私有字段 - 字符串缓存和性能优化

        /// <summary>
        /// 字符串到ID的映射缓存
        /// </summary>
        private readonly Dictionary<string, int> _stringIdCache = new();

        /// <summary>
        /// ID到字符串的列表缓存
        /// </summary>
        private readonly List<string> _stringList = new();

        /// <summary>
        /// 日志记录器
        /// </summary>
        private readonly ILogger<UeIdentifierManager> _logger;

        /// <summary>
        /// 缓存统计信息
        /// </summary>
        private readonly Dictionary<string, int> _cacheStats = new();

        /// <summary>
        /// 线程锁对象
        /// </summary>
        private readonly object _lockObject = new object();

        #endregion

        #region 构造函数

        /// <summary>
        /// 初始化UE标识符管理器
        /// </summary>
        /// <param name="logger">日志记录器</param>
        public UeIdentifierManager(ILogger<UeIdentifierManager> logger)
        {
            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
            InitializeProtocolTypeStrings();
            InitializeCacheStats();
        }

        #endregion

        #region 私有初始化方法

        /// <summary>
        /// 初始化协议类型字符串缓存
        /// </summary>
        private void InitializeProtocolTypeStrings()
        {
            try
            {
                string[] protocolTypeNames = Enum.GetNames(typeof(LogChannelId));
                foreach (var protocolTypeName in protocolTypeNames)
                {
                    StringToId(protocolTypeName);
                }
                _logger.LogDebug("协议类型字符串缓存初始化完成，共 {Count} 个类型", protocolTypeNames.Length);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "初始化协议类型字符串缓存失败");
                throw new CacheException("ProtocolTypeStrings", "初始化协议类型字符串缓存失败", ex);
            }
        }

        /// <summary>
        /// 初始化缓存统计信息
        /// </summary>
        private void InitializeCacheStats()
        {
            _cacheStats["StringToId"] = 0;
            _cacheStats["IdToString"] = 0;
            _cacheStats["CacheHits"] = 0;
            _cacheStats["CacheMisses"] = 0;
        }

        #endregion

        #region 公共方法 - 统计和监控

        /// <summary>
        /// 获取缓存统计信息
        /// </summary>
        /// <returns>缓存统计信息字典</returns>
        public Dictionary<string, int> GetCacheStats()
        {
            lock (_lockObject)
            {
                return new Dictionary<string, int>(_cacheStats);
            }
        }

        /// <summary>
        /// 获取映射表统计信息
        /// </summary>
        /// <returns>映射表统计信息</returns>
        public Dictionary<string, int> GetMappingStats()
        {
            return new Dictionary<string, int>
            {
                ["TmsiToUeId"] = TmsiToUeId.Count,
                ["RequestTmsiToUeId"] = RequestTmsiToUeId.Count,
                ["ImsiToUeId"] = ImsiToUeId.Count,
                ["PlmnToUeId"] = PlmnToUeId.Count,
                ["SrTmsiToUeId"] = SrTmsiToUeId.Count,
                ["RntiToUeId"] = RntiToUeId.Count,
                ["UeList"] = UeList.Count
            };
        }

        /// <summary>
        /// 清理缓存
        /// </summary>
        public void ClearCache()
        {
            lock (_lockObject)
            {
                _stringIdCache.Clear();
                _stringList.Clear();
                InitializeCacheStats();
                _logger.LogInformation("字符串缓存已清理");
            }
        }

        #endregion
    }
}