1 files changed, 84 insertions, 0 deletions
diff --git a/src/DevHive.Services/Services/FeedService.cs b/src/DevHive.Services/Services/FeedService.cs
new file mode 100644
index 0000000..f2f4a3a
--- /dev/null
+++ b/src/DevHive.Services/Services/FeedService.cs
@@ -0,0 +1,84 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using AutoMapper;
+using DevHive.Data.Interfaces.Repositories;
+using DevHive.Data.Models;
+using DevHive.Services.Interfaces;
+using DevHive.Services.Models;
+using DevHive.Services.Models.Post;
+
+namespace DevHive.Services.Services
+{
+	public class FeedService : IFeedService
+	{
+		private readonly IMapper _mapper;
+		private readonly IFeedRepository _feedRepository;
+		private readonly IUserRepository _userRepository;
+
+		public FeedService(IFeedRepository feedRepository, IUserRepository userRepository, IMapper mapper)
+		{
+			this._feedRepository = feedRepository;
+			this._userRepository = userRepository;
+			this._mapper = mapper;
+		}
+
+		/// <summary>
+		/// This method is used in the feed page.
+		/// See the FeedRepository "GetFriendsPosts" menthod for more information on how it works.
+        /// </summary>
+		public async Task<ReadPageServiceModel> GetPage(GetPageServiceModel model)
+		{
+			User user = null;
+
+			if (model.UserId != Guid.Empty)
+				user = await this._userRepository.GetByIdAsync(model.UserId);
+			else if (!string.IsNullOrEmpty(model.Username))
+				user = await this._userRepository.GetByUsernameAsync(model.Username);
+			else
+				throw new ArgumentException("Invalid given data!");
+
+			if (user == null)
+				throw new ArgumentException("User doesn't exist!");
+
+			if (user.Friends.Count == 0)
+				throw new ArgumentException("User has no friends to get feed from!");
+
+			List<Post> posts = await this._feedRepository
+				.GetFriendsPosts(user.Friends.ToList(), model.FirstRequestIssued, model.PageNumber, model.PageSize);
+
+			ReadPageServiceModel readPageServiceModel = new();
+			foreach (Post post in posts)
+				readPageServiceModel.Posts.Add(this._mapper.Map<ReadPostServiceModel>(post));
+
+			return readPageServiceModel;
+		}
+
+		/// <summary>
+		/// This method is used in the profile pages.
+		/// See the FeedRepository "GetUsersPosts" menthod for more information on how it works.
+        /// </summary>
+		public async Task<ReadPageServiceModel> GetUserPage(GetPageServiceModel model)
+		{
+			User user = null;
+
+			if (!string.IsNullOrEmpty(model.Username))
+				user = await this._userRepository.GetByUsernameAsync(model.Username);
+			else
+				throw new ArgumentException("Invalid given data!");
+
+			if (user == null)
+				throw new ArgumentException("User doesn't exist!");
+
+			List<Post> posts = await this._feedRepository
+				.GetUsersPosts(user, model.FirstRequestIssued, model.PageNumber, model.PageSize);
+
+			ReadPageServiceModel readPageServiceModel = new();
+			foreach (Post post in posts)
+				readPageServiceModel.Posts.Add(this._mapper.Map<ReadPostServiceModel>(post));
+
+			return readPageServiceModel;
+		}
+	}
+}