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

namespace CoreAgent.ProtocolClient.Context.UeStateManager
{
    /// <summary>
    /// UeIdentifierManager UE信息管理部分
    /// </summary>
    public partial class UeIdentifierManager
    {
        #region UE信息管理方法

        /// <summary>
        /// 合并两个UE的信息
        /// 性能优化：减少不必要的对象创建
        /// </summary>
        /// <param name="ueId1">第一个UE ID</param>
        /// <param name="ueId2">第二个UE ID</param>
        public void MergeUeInfo(int ueId1, int ueId2)
        {
            if (ueId1 <= 0 || ueId2 <= 0)
            {
                throw new UeInfoException(Math.Min(ueId1, ueId2), "UE ID必须大于0");
            }

            try
            {
                lock (_lockObject)
                {
                    UeList.TryGetValue(ueId1, out var ue1);
                    UeList.TryGetValue(ueId2, out var ue2);

                    if (ReferenceEquals(ue1, ue2))
                    {
                        if (ue2 == null)
                        {
                            ue2 = CreateUeInfo(ueId2);
                            UeList[ueId1] = ue2;
                        }
                    }
                    else if (ue1 == null)
                    {
                        UeList[ueId1] = ue2;
                    }
                    else if (ue2 == null)
                    {
                        UeList[ueId2] = ue1;
                        SyncPlmnFromExistingUe(ueId1, ueId2);
                    }
                    else
                    {
                        UeList[ueId2] = ue1;
                        SyncPlmnFromExistingUe(ueId1, ueId2);
                    }

                    _logger?.LogDebug("合并UE信息: UE {UeId1} 和 UE {UeId2}", ueId1, ueId2);
                }
            }
            catch (Exception ex)
            {
                _logger?.LogError(ex, "合并UE信息失败: UE {UeId1} 和 UE {UeId2}", ueId1, ueId2);
                throw new UeInfoException(Math.Min(ueId1, ueId2), $"合并UE信息失败: {ex.Message}");
            }
        }

        /// <summary>
        /// 创建新的UE信息
        /// </summary>
        /// <param name="ueId">UE ID</param>
        /// <returns>创建的UE信息</returns>
        private UEInfo CreateUeInfo(int ueId)
        {
            var ueInfo = new UEInfo
            {
                UeId = ueId,
                Caps = new ProtocolCaps { UeId = ueId }
            };

            UeList[ueId] = ueInfo;
            _logger?.LogDebug("创建新的UE信息: UE {UeId}", ueId);
            return ueInfo;
        }

        /// <summary>
        /// 获取UE信息
        /// </summary>
        /// <param name="ueId">UE ID</param>
        /// <returns>UE信息，如果不存在则返回null</returns>
        public UEInfo? GetUeInfo(int ueId)
        {
            if (ueId <= 0)
            {
                _logger?.LogWarning("尝试获取无效UE ID的信息: {UeId}", ueId);
                return null;
            }

            lock (_lockObject)
            {
                return UeList.TryGetValue(ueId, out var ueInfo) ? ueInfo : null;
            }
        }

        /// <summary>
        /// 获取UE能力信息，如果不存在则创建
        /// 同时根据ImsiToUeId映射表更新IMSI信息
        /// </summary>
        /// <param name="ueId">UE ID</param>
        /// <returns>UE能力信息</returns>
        public ProtocolCaps GetUeCaps(int ueId)
        {
            if (ueId <= 0)
            {
                throw new UeInfoException(ueId, "UE ID必须大于0");
            }

            lock (_lockObject)
            {
                if (!UeList.TryGetValue(ueId, out var ueInfo) || ueInfo == null)
                {
                    ueInfo = CreateUeInfo(ueId);
                }

                if (ueInfo.Caps == null)
                {
                    ueInfo.Caps = new ProtocolCaps { UeId = ueId };
                }

                // 根据ImsiToUeId映射表更新IMSI信息
                UpdateImsiFromMapping(ueId, ueInfo);

                return ueInfo.Caps;
            }
        }

        /// <summary>
        /// 根据ImsiToUeId映射表更新UE的IMSI信息
        /// 性能优化：使用LINQ提高查找效率
        /// </summary>
        /// <param name="ueId">UE ID</param>
        /// <param name="ueInfo">UE信息对象</param>
        private void UpdateImsiFromMapping(int ueId, UEInfo ueInfo)
        {
            var imsiMapping = ImsiToUeId.FirstOrDefault(kvp => kvp.Value.Contains(ueId));
            if (!string.IsNullOrEmpty(imsiMapping.Key))
            {
                ueInfo.Imsi = imsiMapping.Key;
                _logger?.LogDebug("更新UE {UeId} 的IMSI信息: {Imsi}", ueId, imsiMapping.Key);
            }
        }

        /// <summary>
        /// 从现有UE ID同步IMSI信息到新的UE ID
        /// </summary>
        /// <param name="existingUeId">现有UE ID</param>
        /// <param name="newUeId">新的UE ID</param>
        private void SyncImsiFromExistingUe(int existingUeId, int newUeId)
        {
            var imsiMapping = ImsiToUeId.FirstOrDefault(kvp => kvp.Value.Contains(existingUeId));
            if (!string.IsNullOrEmpty(imsiMapping.Key))
            {
                SetImsi(newUeId, imsiMapping.Key);
                _logger?.LogDebug("同步IMSI信息: 从UE {ExistingUeId} 到 UE {NewUeId}: {Imsi}",
                    existingUeId, newUeId, imsiMapping.Key);
            }
        }

        /// <summary>
        /// 从现有UE ID同步PLMN信息到新的UE ID
        /// </summary>
        /// <param name="existingUeId">现有UE ID</param>
        /// <param name="newUeId">新的UE ID</param>
        private void SyncPlmnFromExistingUe(int existingUeId, int newUeId)
        {
            var plmnMapping = PlmnToUeId.FirstOrDefault(kvp => kvp.Value.Contains(existingUeId));
            if (!string.IsNullOrEmpty(plmnMapping.Key))
            {
                SetPlmn(newUeId, plmnMapping.Key);
                _logger?.LogDebug("同步PLMN信息: 从UE {ExistingUeId} 到 UE {NewUeId}: {Plmn}",
                    existingUeId, newUeId, plmnMapping.Key);
            }
        }

        /// <summary>
        /// 获取UeList中UEInfo.UeId与Caps.UeId组合的字典
        /// </summary>
        /// <returns>包含UE ID和Caps UeId组合的字典，键为UEInfo.UeId，值为Caps.UeId</returns>
        public Dictionary<int, int> GetUeIdToCapsUeIdMapping()
        {
            lock (_lockObject)
            {
                var mapping = new Dictionary<int, int>();

                foreach (var kvp in UeList)
                {
                    var ueId = kvp.Key;
                    var ueInfo = kvp.Value;

                    if (ueInfo?.Caps != null)
                    {
                        mapping[ueId] = ueInfo.Caps.UeId;
                    }
                }

                return mapping;
            }
        }

        /// <summary>
        /// 批量获取UE信息
        /// 性能优化：批量处理减少锁开销
        /// </summary>
        /// <param name="ueIds">UE ID列表</param>
        /// <returns>UE信息字典</returns>
        public Dictionary<int, UEInfo> GetUeInfoBatch(IEnumerable<int> ueIds)
        {
            if (ueIds == null)
            {
                throw new ArgumentNullException(nameof(ueIds));
            }

            var result = new Dictionary<int, UEInfo>();
            lock (_lockObject)
            {
                foreach (var ueId in ueIds)
                {
                    if (UeList.TryGetValue(ueId, out var ueInfo))
                    {
                        result[ueId] = ueInfo;
                    }
                }
            }

            _logger?.LogDebug("批量获取UE信息，共获取 {Count} 个UE的信息", result.Count);
            return result;
        }

        #endregion
    }
}