add(Friend)：添加好友相关逻辑

backend/IM_API/Services/FriendService.cs

@@ -1,7 +1,9 @@
 using AutoMapper;
 using IM_API.Dtos;
+using IM_API.Exceptions;
 using IM_API.Interface.Services;
 using IM_API.Models;
+using IM_API.Tools;
 using Microsoft.EntityFrameworkCore;
 
 namespace IM_API.Services
@@ -17,30 +19,51 @@ namespace IM_API.Services
             _logger = logger;
             _mapper = mapper;
         }
-
-        public Task<bool> BlockeFriendAsync(int friendId)
+        #region 拉黑好友
+        public async Task<bool> BlockeFriendAsync(int friendId)
         {
-            throw new NotImplementedException();
+            var friend = await _context.Friends.FirstOrDefaultAsync(x => x.Id == friendId);
+            if (friend == null) throw new BaseException(CodeDefine.FRIEND_RELATION_NOT_FOUND);
+            friend.StatusEnum = FriendStatus.Blocked;
+            await _context.SaveChangesAsync();
+            return true;
         }
-
-        public Task<bool> BlockFriendByUserIdAsync(int userId, int toUserId)
+        #endregion
+        #region 通过用户id拉黑好友
+        public async Task<bool> BlockFriendByUserIdAsync(int userId, int toUserId)
         {
-            throw new NotImplementedException();
+            var friend = await _context.Friends.FirstOrDefaultAsync(x => x.UserId == userId && x.FriendId == toUserId);
+            if (friend == null) throw new BaseException(CodeDefine.FRIEND_RELATION_NOT_FOUND);
+            friend.StatusEnum = FriendStatus.Blocked;
+            await _context.SaveChangesAsync();
+            return true;
         }
-
-        public Task<bool> DeleteFriendAsync(int friendId)
+        #endregion
+        #region 删除好友关系
+        public async Task<bool> DeleteFriendAsync(int friendId)
         {
-            throw new NotImplementedException();
+            var friend = await _context.Friends.FirstOrDefaultAsync(x => x.Id == friendId);
+            if (friend is null) throw new BaseException(CodeDefine.FRIEND_RELATION_NOT_FOUND);
+            _context.Friends.Remove(friend);
+            await _context.SaveChangesAsync();
+            return true;
         }
-
-        public Task<bool> DeleteFriendByUserIdAsync(int userId, int toUserId)
+        #endregion
+        #region 通过用户id删除好友关系
+        public async Task<bool> DeleteFriendByUserIdAsync(int userId, int toUserId)
         {
-            throw new NotImplementedException();
+            var friend = await _context.Friends.FirstOrDefaultAsync(x => x.UserId == userId && x.FriendId == toUserId);
+            if (friend is null) throw new BaseException(CodeDefine.FRIEND_RELATION_NOT_FOUND);
+            _context.Friends.Remove(friend);
+            await _context.SaveChangesAsync();
+            return true;
         }
+        #endregion
+        #region 获取好友列表
 
         public async Task<List<FriendInfoDto>> GetFriendListAsync(int userId, int page, int limit, bool desc)
         {
-            var query = _context.Friends.Where(x => x.UserId == userId);
+            var query = _context.Friends.Where(x => x.UserId == userId && x.StatusEnum == FriendStatus.Added);
             if (desc)
             {
                 query = query.OrderByDescending(x => x.UserId);
@@ -48,20 +71,104 @@ namespace IM_API.Services
             var friendList = await query.Skip((page - 1 * limit)).Take(limit).ToListAsync();
             return _mapper.Map<List<FriendInfoDto>>(friendList);
         }
-
-        public Task<FriendRequest> GetFriendRequestListAsync(int userId, bool isReceived, int page, int limit, bool desc)
+        #endregion
+        #region 获取好友请求列表
+        public async Task<List<FriendRequest>> GetFriendRequestListAsync(int userId, bool isReceived, int page, int limit, bool desc)
         {
-            throw new NotImplementedException();
+            var query = _context.FriendRequests.AsQueryable();
+            //是否为请求方
+            if (isReceived)
+            {
+                query = _context.FriendRequests.Where(x => x.ResponseUser == userId);
+            }
+            else
+            {
+                query = _context.FriendRequests.Where(x => x.RequestUser == userId);
+            }
+            if (desc)
+            {
+                query = query.OrderByDescending(x => x.Id);
+            }
+            var friendRequestList = await query.Skip((page - 1 * limit)).Take(limit).ToListAsync();
+            return friendRequestList;
         }
-
-        public Task<bool> HandleFriendRequestAsync(HandleFriendRequestDto requestDto)
+        #endregion
+        #region 处理好友请求
+        public async Task<bool> HandleFriendRequestAsync(HandleFriendRequestDto requestDto)
         {
-            throw new NotImplementedException();
-        }
+            //查询好友请求记录
+            var friendRequest = await _context.FriendRequests
+                .Include(e => e.ResponseUserNavigation)
+                .FirstOrDefaultAsync(x => x.Id == requestDto.RequestId);
+            
+            if (friendRequest is null) throw new BaseException(CodeDefine.FRIEND_REQUEST_NOT_FOUND);
+            
+            //查询好友关系
+            var friend = await _context.Friends.FirstOrDefaultAsync(
+                x => x.UserId == friendRequest.RequestUser && x.FriendId == friendRequest.ResponseUser
+                );
+            if (friend is null) throw new BaseException(CodeDefine.FRIEND_RELATION_NOT_FOUND);
 
-        public Task<bool> SendFriendRequestAsync(FriendRequestDto friendRequest)
-        {
-            throw new NotImplementedException();
+            if (friend.StatusEnum != FriendStatus.Pending) throw new BaseException(CodeDefine.FRIEND_REQUEST_EXISTS);
+            //处理好友请求操作
+            switch (requestDto.Action)
+            {
+                //拒绝后标记
+                case HandleFriendRequestAction.Reject:
+                    friend.StatusEnum = FriendStatus.Declined;
+                    friendRequest.StateEnum = FriendRequestState.Declined;
+                    break;
+
+                //同意后标记
+                case HandleFriendRequestAction.Accept:
+                    friend.StatusEnum = FriendStatus.Added;
+                    friendRequest.StateEnum = FriendRequestState.Passed;
+
+                    //根据当前好友请求为被申请方添加一条好友记录（注意：好友记录为双向）
+                    var ResponseFriend = _mapper.Map<Friend>(friendRequest);
+                    if (!string.IsNullOrEmpty(requestDto.RemarkName)) ResponseFriend.RemarkName = requestDto.RemarkName;
+                    _context.Friends.Add(ResponseFriend);
+                    break;
+
+                //无效操作
+                default:
+                    throw new BaseException(CodeDefine.INVALID_ACTION);
+            }
+
+            await _context.SaveChangesAsync();
+            return true;
         }
+        #endregion
+        #region 发起好友请求
+        public async Task<bool> SendFriendRequestAsync(FriendRequestDto dto)
+        {
+            //查询用户是否存在
+            bool isExist = await _context.Users.AnyAsync(x => x.Id == dto.ToUserId);
+            if (!isExist) throw new BaseException(CodeDefine.USER_NOT_FOUND);
+            bool isExistUser2 = await _context.Users.AnyAsync(x => x.Id == dto.FromUserId);
+            if(!isExistUser2) throw new BaseException(CodeDefine.USER_NOT_FOUND);
+            // 检查是否已有好友关系或待处理请求
+            bool alreadyExists = await _context.FriendRequests.AnyAsync(x =>
+                x.RequestUser == dto.FromUserId && x.ResponseUser == dto.ToUserId && x.StateEnum == FriendRequestState.Pending
+            );
+            if (alreadyExists)
+                throw new BaseException(CodeDefine.FRIEND_REQUEST_EXISTS);
+
+            //检查是否被对方拉黑
+            bool isBlocked = await _context.Friends.AnyAsync(x =>
+                x.UserId == dto.FromUserId && x.FriendId == dto.ToUserId && x.StatusEnum == FriendStatus.Blocked
+            );
+            if (isBlocked)
+                throw new BaseException(CodeDefine.FRIEND_REQUEST_REJECTED);
+
+            //生成实体
+            var friendRequst = _mapper.Map<FriendRequest>(dto);
+            var friend = _mapper.Map<Friend>(friendRequst);
+            _context.FriendRequests.Add(friendRequst);
+            _context.Friends.Add(friend);
+            await _context.SaveChangesAsync();
+            return true;
+        }
+        #endregion
     }
 }