Implemented Friends layer

1 files changed, 70 insertions, 0 deletions

diff --git a/src/DevHive.Services/Services/FriendsService.cs b/src/DevHive.Services/Services/FriendsService.cs
new file mode 100644
index 0000000..21a2aac
--- /dev/null
+++ b/src/DevHive.Services/Services/FriendsService.cs
@@ -0,0 +1,70 @@
+using System;
+using System.Threading.Tasks;
+using AutoMapper;
+using DevHive.Data.Models;
+using DevHive.Data.Repositories;
+using DevHive.Services.Models.Identity.User;
+using DevHive.Services.Options;
+
+namespace DevHive.Services.Services
+{
+	public class FriendsService : UserService
+	{
+		private readonly FriendsRepository _friendsRepository;
+		private readonly IMapper _friendsMapper;
+
+		public FriendsService(DevHiveContext context, IMapper mapper, JWTOptions jwtOptions) 
+			: base(context, mapper, jwtOptions)
+		{
+			this._friendsRepository = new FriendsRepository(context);
+			this._friendsMapper = mapper;
+		}
+
+		//Create
+		public async Task<bool> AddFriend(Guid userId, Guid friendId)
+		{
+			User user = await this._friendsRepository.GetByIdAsync(userId);
+			User friend = await this._friendsRepository.GetByIdAsync(friendId);
+
+			return user != default(User) && friend != default(User) ? 
+				await this._friendsRepository.AddFriendAsync(user, friend) : 
+				throw new ArgumentException("Invalid user!");
+		}
+		
+		//Read
+		public async Task<UserServiceModel> GetFriendById(Guid friendId)
+		{
+			if(!_friendsRepository.DoesUserExist(friendId))
+				throw new ArgumentException("User does not exist!");
+
+			User friend = await this._friendsRepository.GetByIdAsync(friendId);
+
+			return this._friendsMapper.Map<UserServiceModel>(friend);
+		}
+	
+		public async Task<bool> RemoveFriend(Guid userId, Guid friendId)
+		{
+			if(!this._friendsRepository.DoesUserExist(userId) && 
+				!this._friendsRepository.DoesUserExist(friendId))
+					throw new ArgumentException("Invalid user!");
+
+			User user = await this._friendsRepository.GetByIdAsync(userId);
+
+			if(!this.DoesUserHaveFriends(user))
+				throw new ArgumentException("User does not have any friends.");
+
+			return await this.RemoveFriend(user.Id, friendId);
+		}
+
+		//Validation
+		private bool DoesUserHaveThisFriend(User user, User friend)
+		{
+			return user.Friends.Contains(friend);
+		}
+
+		private bool DoesUserHaveFriends(User user)
+		{
+			return user.Friends.Count >= 1;
+		}
+	}
+}
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