Merge pull request #28 from Team-Kaleidoscope/devHEADv0.2mainheroku/main

Second stage: Complete

31 files changed, 1793 insertions, 0 deletions

diff --git a/src/Services/DevHive.Services/Configurations/Mapping/CommentMappings.cs b/src/Services/DevHive.Services/Configurations/Mapping/CommentMappings.cs
new file mode 100644
index 0000000..5ca2a9e
--- /dev/null
+++ b/src/Services/DevHive.Services/Configurations/Mapping/CommentMappings.cs
@@ -0,0 +1,27 @@
+using DevHive.Data.Models;
+using AutoMapper;
+using DevHive.Services.Models.Comment;
+using DevHive.Common.Models.Misc;
+
+namespace DevHive.Services.Configurations.Mapping
+{
+	public class CommentMappings : Profile
+	{
+		public CommentMappings()
+		{
+			CreateMap<CreateCommentServiceModel, Comment>();
+			CreateMap<UpdateCommentServiceModel, Comment>()
+				.ForMember(dest => dest.Id, src => src.MapFrom(p => p.CommentId))
+				.ForMember(dest => dest.Message, src => src.MapFrom(p => p.NewMessage));
+
+			CreateMap<Comment, ReadCommentServiceModel>()
+				.ForMember(dest => dest.CommentId, src => src.MapFrom(p => p.Id))
+				.ForMember(dest => dest.IssuerFirstName, src => src.MapFrom(p => p.Creator.FirstName))
+				.ForMember(dest => dest.IssuerLastName, src => src.MapFrom(p => p.Creator.LastName))
+				.ForMember(dest => dest.IssuerUsername, src => src.MapFrom(p => p.Creator.UserName));
+
+			CreateMap<Comment, IdModel>()
+				.ForMember(dest => dest.Id, src => src.MapFrom(p => p.Id));
+		}
+	}
+}
diff --git a/src/Services/DevHive.Services/Configurations/Mapping/FeedMappings.cs b/src/Services/DevHive.Services/Configurations/Mapping/FeedMappings.cs
new file mode 100644
index 0000000..952e480
--- /dev/null
+++ b/src/Services/DevHive.Services/Configurations/Mapping/FeedMappings.cs
@@ -0,0 +1,11 @@
+using AutoMapper;
+
+namespace DevHive.Services.Configurations.Mapping
+{
+	public class FeedMappings : Profile
+	{
+		public FeedMappings()
+		{
+		}
+	}
+}
diff --git a/src/Services/DevHive.Services/Configurations/Mapping/LanguageMappings.cs b/src/Services/DevHive.Services/Configurations/Mapping/LanguageMappings.cs
new file mode 100644
index 0000000..9c572df
--- /dev/null
+++ b/src/Services/DevHive.Services/Configurations/Mapping/LanguageMappings.cs
@@ -0,0 +1,22 @@
+using DevHive.Data.Models;
+using AutoMapper;
+using DevHive.Services.Models.Language;
+
+namespace DevHive.Services.Configurations.Mapping
+{
+	public class LanguageMappings : Profile
+	{
+		public LanguageMappings()
+		{
+			CreateMap<LanguageServiceModel, Language>();
+			CreateMap<ReadLanguageServiceModel, Language>();
+			CreateMap<CreateLanguageServiceModel, Language>();
+			CreateMap<UpdateLanguageServiceModel, Language>();
+
+			CreateMap<Language, LanguageServiceModel>();
+			CreateMap<Language, ReadLanguageServiceModel>();
+			CreateMap<Language, CreateLanguageServiceModel>();
+			CreateMap<Language, UpdateLanguageServiceModel>();
+		}
+	}
+}
diff --git a/src/Services/DevHive.Services/Configurations/Mapping/PostMappings.cs b/src/Services/DevHive.Services/Configurations/Mapping/PostMappings.cs
new file mode 100644
index 0000000..1d7d88b
--- /dev/null
+++ b/src/Services/DevHive.Services/Configurations/Mapping/PostMappings.cs
@@ -0,0 +1,32 @@
+using DevHive.Data.Models;
+using AutoMapper;
+using DevHive.Services.Models.Post;
+using DevHive.Common.Models.Misc;
+using System.Collections.Generic;
+using DevHive.Services.Models;
+
+namespace DevHive.Services.Configurations.Mapping
+{
+	public class PostMappings : Profile
+	{
+		public PostMappings()
+		{
+			CreateMap<CreatePostServiceModel, Post>();
+			CreateMap<UpdatePostServiceModel, Post>()
+				.ForMember(dest => dest.Id, src => src.MapFrom(p => p.PostId))
+				// .ForMember(dest => dest.Files, src => src.Ignore())
+				.ForMember(dest => dest.Message, src => src.MapFrom(p => p.NewMessage));
+
+			CreateMap<Post, ReadPostServiceModel>()
+				.ForMember(dest => dest.PostId, src => src.MapFrom(p => p.Id))
+				.ForMember(dest => dest.CreatorFirstName, src => src.MapFrom(p => p.Creator.FirstName))
+				.ForMember(dest => dest.CreatorLastName, src => src.MapFrom(p => p.Creator.LastName))
+				.ForMember(dest => dest.CreatorUsername, src => src.MapFrom(p => p.Creator.UserName));
+
+			CreateMap<Post, IdModel>()
+				.ForMember(dest => dest.Id, src => src.MapFrom(x => x.Id));
+
+			CreateMap<List<Post>, ReadPageServiceModel>();
+		}
+	}
+}
diff --git a/src/Services/DevHive.Services/Configurations/Mapping/RatingMappings.cs b/src/Services/DevHive.Services/Configurations/Mapping/RatingMappings.cs
new file mode 100644
index 0000000..9ad5f25
--- /dev/null
+++ b/src/Services/DevHive.Services/Configurations/Mapping/RatingMappings.cs
@@ -0,0 +1,21 @@
+using AutoMapper;
+using DevHive.Data.Models;
+using DevHive.Services.Models.Rating;
+
+namespace DevHive.Services.Configurations.Mapping
+{
+	public class RatingMappings : Profile
+	{
+		public RatingMappings()
+		{
+			CreateMap<CreateRatingServiceModel, Rating>()
+				.ForMember(dest => dest.User, src => src.Ignore())
+				.ForMember(dest => dest.Post, src => src.Ignore())
+				.ForMember(dest => dest.Id, src => src.Ignore());
+
+			CreateMap<Rating, ReadRatingServiceModel>();
+
+			CreateMap<UpdateRatingServiceModel, Rating>();
+		}
+	}
+}
diff --git a/src/Services/DevHive.Services/Configurations/Mapping/RoleMapings.cs b/src/Services/DevHive.Services/Configurations/Mapping/RoleMapings.cs
new file mode 100644
index 0000000..e870ab1
--- /dev/null
+++ b/src/Services/DevHive.Services/Configurations/Mapping/RoleMapings.cs
@@ -0,0 +1,21 @@
+using AutoMapper;
+using DevHive.Data.Models;
+using DevHive.Services.Models.Role;
+
+namespace DevHive.Services.Configurations.Mapping
+{
+	public class RoleMappings : Profile
+	{
+		public RoleMappings()
+		{
+			CreateMap<CreateRoleServiceModel, Role>();
+			CreateMap<RoleServiceModel, Role>();
+			CreateMap<UpdateRoleServiceModel, Role>();
+
+			CreateMap<Role, RoleServiceModel>();
+			CreateMap<Role, UpdateRoleServiceModel>();
+
+			CreateMap<RoleServiceModel, UpdateRoleServiceModel>();
+		}
+	}
+}
diff --git a/src/Services/DevHive.Services/Configurations/Mapping/TechnologyMappings.cs b/src/Services/DevHive.Services/Configurations/Mapping/TechnologyMappings.cs
new file mode 100644
index 0000000..85b57f1
--- /dev/null
+++ b/src/Services/DevHive.Services/Configurations/Mapping/TechnologyMappings.cs
@@ -0,0 +1,21 @@
+using DevHive.Data.Models;
+using AutoMapper;
+using DevHive.Services.Models.Technology;
+
+namespace DevHive.Services.Configurations.Mapping
+{
+	public class TechnologyMappings : Profile
+	{
+		public TechnologyMappings()
+		{
+			CreateMap<CreateTechnologyServiceModel, Technology>();
+			CreateMap<UpdateTechnologyServiceModel, Technology>();
+			CreateMap<TechnologyServiceModel, Technology>();
+
+			CreateMap<Technology, CreateTechnologyServiceModel>();
+			CreateMap<Technology, TechnologyServiceModel>();
+			CreateMap<Technology, ReadTechnologyServiceModel>();
+			CreateMap<Technology, UpdateTechnologyServiceModel>();
+		}
+	}
+}
diff --git a/src/Services/DevHive.Services/Configurations/Mapping/UserMappings.cs b/src/Services/DevHive.Services/Configurations/Mapping/UserMappings.cs
new file mode 100644
index 0000000..5a39f73
--- /dev/null
+++ b/src/Services/DevHive.Services/Configurations/Mapping/UserMappings.cs
@@ -0,0 +1,31 @@
+using DevHive.Data.Models;
+using AutoMapper;
+using DevHive.Services.Models.User;
+
+namespace DevHive.Services.Configurations.Mapping
+{
+	public class UserMappings : Profile
+	{
+		public UserMappings()
+		{
+			CreateMap<UserServiceModel, User>();
+			CreateMap<RegisterServiceModel, User>()
+				.ForMember(dest => dest.PasswordHash, src => src.MapFrom(p => p.Password));
+			CreateMap<FriendServiceModel, User>()
+				.ForMember(dest => dest.Friends, src => src.Ignore());
+			CreateMap<UpdateUserServiceModel, User>()
+				.ForMember(dest => dest.Friends, src => src.Ignore());
+			CreateMap<UpdateFriendServiceModel, User>();
+
+			CreateMap<User, UserServiceModel>()
+				.ForMember(dest => dest.ProfilePictureURL, src => src.MapFrom(p => p.ProfilePicture.PictureURL))
+				.ForMember(dest => dest.Friends, src => src.MapFrom(p => p.Friends));
+			CreateMap<User, UpdateUserServiceModel>()
+				.ForMember(dest => dest.ProfilePictureURL, src => src.MapFrom(p => p.ProfilePicture.PictureURL));
+			CreateMap<User, FriendServiceModel>();
+
+			CreateMap<UserServiceModel, UpdateUserServiceModel>();
+			CreateMap<UserServiceModel, UpdateFriendServiceModel>();
+		}
+	}
+}
diff --git a/src/Services/DevHive.Services/DevHive.Services.csproj b/src/Services/DevHive.Services/DevHive.Services.csproj
new file mode 100644
index 0000000..2468711
--- /dev/null
+++ b/src/Services/DevHive.Services/DevHive.Services.csproj
@@ -0,0 +1,27 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net5.0</TargetFramework>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.2.0"/>
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="5.0.4">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="System.IdentityModel.Tokens.Jwt" Version="6.10.0"/>
+    <PackageReference Include="AutoMapper" Version="10.1.1"/>
+    <PackageReference Include="AutoMapper.Extensions.Microsoft.DependencyInjection" Version="8.1.1"/>
+    <PackageReference Include="CloudinaryDotNet" Version="1.15.1"/>
+    <PackageReference Include="SonarAnalyzer.CSharp" Version="8.20.0.28934"/>
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\..\Data\DevHive.Data\DevHive.Data.csproj"/>
+    <ProjectReference Include="..\DevHive.Services.Models\DevHive.Services.Models.csproj"/>
+    <ProjectReference Include="..\..\Common\DevHive.Common\DevHive.Common.csproj"/>
+    <ProjectReference Include="..\..\Common\DevHive.Common.Models\DevHive.Common.Models.csproj"/>
+  </ItemGroup>
+  <PropertyGroup>
+    <EnableNETAnalyzers>true</EnableNETAnalyzers>
+    <AnalysisLevel>latest</AnalysisLevel>
+  </PropertyGroup>
+</Project>
\ No newline at end of file
diff --git a/src/Services/DevHive.Services/Interfaces/ICloudService.cs b/src/Services/DevHive.Services/Interfaces/ICloudService.cs
new file mode 100644
index 0000000..040729f
--- /dev/null
+++ b/src/Services/DevHive.Services/Interfaces/ICloudService.cs
@@ -0,0 +1,14 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+
+namespace DevHive.Services.Interfaces
+{
+	public interface ICloudService
+	{
+		Task<List<string>> UploadFilesToCloud(List<IFormFile> formFiles);
+
+		Task<bool> RemoveFilesFromCloud(List<string> fileUrls);
+	}
+}
diff --git a/src/Services/DevHive.Services/Interfaces/ICommentService.cs b/src/Services/DevHive.Services/Interfaces/ICommentService.cs
new file mode 100644
index 0000000..6d92a5d
--- /dev/null
+++ b/src/Services/DevHive.Services/Interfaces/ICommentService.cs
@@ -0,0 +1,20 @@
+using System;
+using System.Threading.Tasks;
+using DevHive.Services.Models.Comment;
+
+namespace DevHive.Services.Interfaces
+{
+	public interface ICommentService
+	{
+		Task<Guid> AddComment(CreateCommentServiceModel createCommentServiceModel);
+
+		Task<ReadCommentServiceModel> GetCommentById(Guid id);
+
+		Task<Guid> UpdateComment(UpdateCommentServiceModel updateCommentServiceModel);
+
+		Task<bool> DeleteComment(Guid id);
+
+		Task<bool> ValidateJwtForCreating(Guid userId, string rawTokenData);
+		Task<bool> ValidateJwtForComment(Guid commentId, string rawTokenData);
+	}
+}
diff --git a/src/Services/DevHive.Services/Interfaces/IFeedService.cs b/src/Services/DevHive.Services/Interfaces/IFeedService.cs
new file mode 100644
index 0000000..b507b3b
--- /dev/null
+++ b/src/Services/DevHive.Services/Interfaces/IFeedService.cs
@@ -0,0 +1,11 @@
+using System.Threading.Tasks;
+using DevHive.Services.Models;
+
+namespace DevHive.Services.Interfaces
+{
+	public interface IFeedService
+	{
+		Task<ReadPageServiceModel> GetPage(GetPageServiceModel getPageServiceModel);
+		Task<ReadPageServiceModel> GetUserPage(GetPageServiceModel model);
+	}
+}
diff --git a/src/Services/DevHive.Services/Interfaces/IFriendsService.cs b/src/Services/DevHive.Services/Interfaces/IFriendsService.cs
new file mode 100644
index 0000000..52f23f3
--- /dev/null
+++ b/src/Services/DevHive.Services/Interfaces/IFriendsService.cs
@@ -0,0 +1,11 @@
+using System;
+using System.Threading.Tasks;
+
+namespace DevHive.Services.Interfaces
+{
+	public interface IFriendsService
+	{
+		Task<bool> AddFriend(Guid userId, string friendUsername);
+		Task<bool> RemoveFriend(Guid userId, string friendUsername);
+	}
+}
diff --git a/src/Services/DevHive.Services/Interfaces/ILanguageService.cs b/src/Services/DevHive.Services/Interfaces/ILanguageService.cs
new file mode 100644
index 0000000..fabbec2
--- /dev/null
+++ b/src/Services/DevHive.Services/Interfaces/ILanguageService.cs
@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using DevHive.Services.Models.Language;
+
+namespace DevHive.Services.Interfaces
+{
+	public interface ILanguageService
+	{
+		Task<Guid> CreateLanguage(CreateLanguageServiceModel createLanguageServiceModel);
+
+		Task<ReadLanguageServiceModel> GetLanguageById(Guid id);
+		HashSet<ReadLanguageServiceModel> GetLanguages();
+
+		Task<bool> UpdateLanguage(UpdateLanguageServiceModel languageServiceModel);
+
+		Task<bool> DeleteLanguage(Guid id);
+	}
+}
diff --git a/src/Services/DevHive.Services/Interfaces/IPostService.cs b/src/Services/DevHive.Services/Interfaces/IPostService.cs
new file mode 100644
index 0000000..5ccecff
--- /dev/null
+++ b/src/Services/DevHive.Services/Interfaces/IPostService.cs
@@ -0,0 +1,20 @@
+using System;
+using System.Threading.Tasks;
+using DevHive.Services.Models.Post;
+
+namespace DevHive.Services.Interfaces
+{
+	public interface IPostService
+	{
+		Task<Guid> CreatePost(CreatePostServiceModel createPostServiceModel);
+
+		Task<ReadPostServiceModel> GetPostById(Guid id);
+
+		Task<Guid> UpdatePost(UpdatePostServiceModel updatePostServiceModel);
+
+		Task<bool> DeletePost(Guid id);
+
+		Task<bool> ValidateJwtForCreating(Guid userId, string rawTokenData);
+		Task<bool> ValidateJwtForPost(Guid postId, string rawTokenData);
+	}
+}
diff --git a/src/Services/DevHive.Services/Interfaces/IProfilePictureService.cs b/src/Services/DevHive.Services/Interfaces/IProfilePictureService.cs
new file mode 100644
index 0000000..edf2775
--- /dev/null
+++ b/src/Services/DevHive.Services/Interfaces/IProfilePictureService.cs
@@ -0,0 +1,30 @@
+using System;
+using System.Threading.Tasks;
+using DevHive.Services.Models.ProfilePicture;
+
+namespace DevHive.Services.Interfaces
+{
+	public interface IProfilePictureService
+	{
+		/// <summary>
+		/// Get a profile picture by it's Guid
+		/// </summary>
+		/// <param name="id">Profile picture's Guid</param>
+		/// <returns>The profile picture's URL in the cloud</returns>
+		Task<string> GetProfilePictureById(Guid id);
+
+		/// <summary>
+		/// Uploads the given picture and assigns it's link to the user in the database
+		/// </summary>
+		/// <param name="profilePictureServiceModel">Contains User's Guid and the new picture to be updated</param>
+		/// <returns>The new profile picture's URL in the cloud</returns>
+		Task<string> UpdateProfilePicture(ProfilePictureServiceModel profilePictureServiceModel);
+
+		/// <summary>
+		/// Delete a profile picture from the cloud and the database
+		/// </summary>
+		/// <param name="id">The profile picture's Guid</param>
+		/// <returns>True if the picture is deleted, false otherwise</returns>
+		Task<bool> DeleteProfilePicture(Guid id);
+	}
+}
diff --git a/src/Services/DevHive.Services/Interfaces/IRatingService.cs b/src/Services/DevHive.Services/Interfaces/IRatingService.cs
new file mode 100644
index 0000000..be33300
--- /dev/null
+++ b/src/Services/DevHive.Services/Interfaces/IRatingService.cs
@@ -0,0 +1,20 @@
+using System;
+using System.Threading.Tasks;
+using DevHive.Data.Models;
+using DevHive.Services.Models.Rating;
+
+namespace DevHive.Services.Interfaces
+{
+	public interface IRatingService
+	{
+		Task<Guid> RatePost(CreateRatingServiceModel createRatingServiceModel);
+
+		Task<ReadRatingServiceModel> GetRatingById(Guid ratingId);
+		Task<ReadRatingServiceModel> GetRatingByPostAndUser(Guid userId, Guid postId);
+
+
+		Task<ReadRatingServiceModel> UpdateRating(UpdateRatingServiceModel updateRatingServiceModel);
+
+		Task<bool> DeleteRating(Guid ratingId);
+	}
+}
diff --git a/src/Services/DevHive.Services/Interfaces/IRoleService.cs b/src/Services/DevHive.Services/Interfaces/IRoleService.cs
new file mode 100644
index 0000000..36e5a01
--- /dev/null
+++ b/src/Services/DevHive.Services/Interfaces/IRoleService.cs
@@ -0,0 +1,17 @@
+using System;
+using System.Threading.Tasks;
+using DevHive.Services.Models.Role;
+
+namespace DevHive.Services.Interfaces
+{
+	public interface IRoleService
+	{
+		Task<Guid> CreateRole(CreateRoleServiceModel createRoleServiceModel);
+
+		Task<RoleServiceModel> GetRoleById(Guid id);
+
+		Task<bool> UpdateRole(UpdateRoleServiceModel updateRoleServiceModel);
+
+		Task<bool> DeleteRole(Guid id);
+	}
+}
diff --git a/src/Services/DevHive.Services/Interfaces/ITechnologyService.cs b/src/Services/DevHive.Services/Interfaces/ITechnologyService.cs
new file mode 100644
index 0000000..8f9510c
--- /dev/null
+++ b/src/Services/DevHive.Services/Interfaces/ITechnologyService.cs
@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using DevHive.Services.Models.Technology;
+
+namespace DevHive.Services.Interfaces
+{
+	public interface ITechnologyService
+	{
+		Task<Guid> CreateTechnology(CreateTechnologyServiceModel technologyServiceModel);
+
+		Task<ReadTechnologyServiceModel> GetTechnologyById(Guid id);
+		HashSet<ReadTechnologyServiceModel> GetTechnologies();
+
+		Task<bool> UpdateTechnology(UpdateTechnologyServiceModel updateTechnologyServiceModel);
+
+		Task<bool> DeleteTechnology(Guid id);
+	}
+}
diff --git a/src/Services/DevHive.Services/Interfaces/IUserService.cs b/src/Services/DevHive.Services/Interfaces/IUserService.cs
new file mode 100644
index 0000000..da07507
--- /dev/null
+++ b/src/Services/DevHive.Services/Interfaces/IUserService.cs
@@ -0,0 +1,62 @@
+using System;
+using System.Threading.Tasks;
+using DevHive.Common.Models.Identity;
+using DevHive.Services.Models.User;
+
+namespace DevHive.Services.Interfaces
+{
+	public interface IUserService
+	{
+		/// <summary>
+		/// Log ins an existing user and gives him/her a JWT Token for further authorization
+		/// </summary>
+		/// <param name="loginModel">Login service model, conaining user's username and password</param>
+		/// <returns>A JWT Token for authorization</returns>
+		Task<TokenModel> LoginUser(LoginServiceModel loginModel);
+
+		/// <summary>
+		/// Registers a new user and gives him/her a JWT Token for further authorization
+		/// </summary>
+		/// <param name="registerModel">Register service model, containing the new user's data</param>
+		/// <returns>A JWT Token for authorization</returns>
+		Task<TokenModel> RegisterUser(RegisterServiceModel registerModel);
+
+		/// <summary>
+		/// Get a user by his username. Used for querying profiles without provided authentication
+		/// </summary>
+		/// <param name="username">User's username, who's to be queried</param>
+		/// <returns>The queried user or null, if non existant</returns>
+		Task<UserServiceModel> GetUserByUsername(string username);
+
+		/// <summary>
+		/// Get a user by his Guid. Used for querying full user's profile
+		/// Requires authenticated user
+		/// </summary>
+		/// <param name="id">User's username, who's to be queried</param>
+		/// <returns>The queried user or null, if non existant</returns>
+		Task<UserServiceModel> GetUserById(Guid id);
+
+		/// <summary>
+		/// Updates a user's data, provided a full model with new details
+		/// Requires authenticated user
+		/// </summary>
+		/// <param name="updateUserServiceModel">Full update user model for updating</param>
+		/// <returns>Read model of the new user</returns>
+		Task<UserServiceModel> UpdateUser(UpdateUserServiceModel updateUserServiceModel);
+
+		/// <summary>
+		/// Deletes a user from the database and removes his data entirely
+		/// Requires authenticated user
+		/// </summary>
+		/// <param name="id">The user's Guid, who's to be deleted</param>
+		/// <returns>True if successfull, false otherwise</returns>
+		Task<bool> DeleteUser(Guid id);
+
+		/// <summary>
+		/// We don't talk about that!
+		/// </summary>
+		/// <param name="userId"></param>
+		/// <returns></returns>
+		Task<TokenModel> SuperSecretPromotionToAdmin(Guid userId);
+	}
+}
diff --git a/src/Services/DevHive.Services/Services/CloudinaryService.cs b/src/Services/DevHive.Services/Services/CloudinaryService.cs
new file mode 100644
index 0000000..61d06fc
--- /dev/null
+++ b/src/Services/DevHive.Services/Services/CloudinaryService.cs
@@ -0,0 +1,59 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+using CloudinaryDotNet;
+using CloudinaryDotNet.Actions;
+using DevHive.Services.Interfaces;
+using Microsoft.AspNetCore.Http;
+
+namespace DevHive.Services.Services
+{
+	public class CloudinaryService : ICloudService
+	{
+		// Regex for getting the filename without (final) filename extension
+		// So, from image.png, it will match image, and from doc.my.txt will match doc.my
+		private static readonly Regex s_imageRegex = new(".*(?=\\.)");
+
+		private readonly Cloudinary _cloudinary;
+
+		public CloudinaryService(string cloudName, string apiKey, string apiSecret)
+		{
+			this._cloudinary = new Cloudinary(new Account(cloudName, apiKey, apiSecret));
+		}
+
+		public async Task<List<string>> UploadFilesToCloud(List<IFormFile> formFiles)
+		{
+			List<string> fileUrls = new();
+			foreach (var formFile in formFiles)
+			{
+				string fileName = s_imageRegex.Match(formFile.FileName).ToString();
+
+				using var ms = new MemoryStream();
+				formFile.CopyTo(ms);
+				byte[] formBytes = ms.ToArray();
+
+				RawUploadParams rawUploadParams = new()
+				{
+					File = new FileDescription(fileName, new MemoryStream(formBytes)),
+					PublicId = fileName,
+					UseFilename = true
+				};
+
+				RawUploadResult rawUploadResult = await this._cloudinary.UploadAsync(rawUploadParams);
+				fileUrls.Add(rawUploadResult.Url.AbsoluteUri);
+			}
+
+			return fileUrls;
+		}
+
+		public async Task<bool> RemoveFilesFromCloud(List<string> fileUrls)
+		{
+			// Workaround, this method isn't fully implemented yet
+			await Task.Run(() => {});
+
+			return true;
+		}
+	}
+}
diff --git a/src/Services/DevHive.Services/Services/CommentService.cs b/src/Services/DevHive.Services/Services/CommentService.cs
new file mode 100644
index 0000000..1c388f6
--- /dev/null
+++ b/src/Services/DevHive.Services/Services/CommentService.cs
@@ -0,0 +1,169 @@
+using System;
+using System.Collections.Generic;
+using System.IdentityModel.Tokens.Jwt;
+using System.Linq;
+using System.Security.Claims;
+using System.Threading.Tasks;
+using AutoMapper;
+using DevHive.Common.Constants;
+using DevHive.Data.Interfaces;
+using DevHive.Data.Models;
+using DevHive.Services.Interfaces;
+using DevHive.Services.Models.Comment;
+
+namespace DevHive.Services.Services
+{
+	public class CommentService : ICommentService
+	{
+		private readonly IUserRepository _userRepository;
+		private readonly IPostRepository _postRepository;
+		private readonly ICommentRepository _commentRepository;
+		private readonly IMapper _postMapper;
+
+		public CommentService(IUserRepository userRepository, IPostRepository postRepository, ICommentRepository commentRepository, IMapper postMapper)
+		{
+			this._userRepository = userRepository;
+			this._postRepository = postRepository;
+			this._commentRepository = commentRepository;
+			this._postMapper = postMapper;
+		}
+
+		#region Create
+		public async Task<Guid> AddComment(CreateCommentServiceModel createCommentServiceModel)
+		{
+			if (!await this._postRepository.DoesPostExist(createCommentServiceModel.PostId))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Post));
+
+			Comment comment = this._postMapper.Map<Comment>(createCommentServiceModel);
+			comment.TimeCreated = DateTime.Now;
+
+			comment.Creator = await this._userRepository.GetByIdAsync(createCommentServiceModel.CreatorId);
+			comment.Post = await this._postRepository.GetByIdAsync(createCommentServiceModel.PostId);
+
+			bool success = await this._commentRepository.AddAsync(comment);
+			if (success)
+			{
+				Comment newComment = await this._commentRepository
+					.GetCommentByIssuerAndTimeCreatedAsync(comment.Creator.Id, comment.TimeCreated);
+
+				return newComment.Id;
+			}
+			else
+				return Guid.Empty;
+		}
+		#endregion
+
+		#region Read
+		public async Task<ReadCommentServiceModel> GetCommentById(Guid id)
+		{
+			Comment comment = await this._commentRepository.GetByIdAsync(id) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Comment));
+
+			User user = await this._userRepository.GetByIdAsync(comment.Creator.Id) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.User));
+
+			ReadCommentServiceModel readCommentServiceModel = this._postMapper.Map<ReadCommentServiceModel>(comment);
+			readCommentServiceModel.IssuerFirstName = user.FirstName;
+			readCommentServiceModel.IssuerLastName = user.LastName;
+			readCommentServiceModel.IssuerUsername = user.UserName;
+
+			return readCommentServiceModel;
+		}
+		#endregion
+
+		#region Update
+		public async Task<Guid> UpdateComment(UpdateCommentServiceModel updateCommentServiceModel)
+		{
+			if (!await this._commentRepository.DoesCommentExist(updateCommentServiceModel.CommentId))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Comment));
+
+			Comment comment = this._postMapper.Map<Comment>(updateCommentServiceModel);
+			comment.TimeCreated = DateTime.Now;
+
+			comment.Creator = await this._userRepository.GetByIdAsync(updateCommentServiceModel.CreatorId);
+			comment.Post = await this._postRepository.GetByIdAsync(updateCommentServiceModel.PostId);
+
+			bool result = await this._commentRepository.EditAsync(updateCommentServiceModel.CommentId, comment);
+
+			if (result)
+				return (await this._commentRepository.GetByIdAsync(updateCommentServiceModel.CommentId)).Id;
+			else
+				return Guid.Empty;
+		}
+		#endregion
+
+		#region Delete
+		public async Task<bool> DeleteComment(Guid id)
+		{
+			if (!await this._commentRepository.DoesCommentExist(id))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Comment));
+
+			Comment comment = await this._commentRepository.GetByIdAsync(id);
+			return await this._commentRepository.DeleteAsync(comment);
+		}
+		#endregion
+
+		#region Validations
+		/// <summary>
+		/// Checks whether the user Id in the token and the given user Id match
+		/// </summary>
+		public async Task<bool> ValidateJwtForCreating(Guid userId, string rawTokenData)
+		{
+			User user = await this.GetUserForValidation(rawTokenData);
+
+			return user.Id == userId;
+		}
+
+		/// <summary>
+		/// Checks whether the comment, gotten with the commentId,
+		/// is made by the user in the token
+		/// or if the user in the token is an admin
+		/// </summary>
+		public async Task<bool> ValidateJwtForComment(Guid commentId, string rawTokenData)
+		{
+			Comment comment = await this._commentRepository.GetByIdAsync(commentId) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Comment));
+			User user = await this.GetUserForValidation(rawTokenData);
+
+			//If user made the comment
+			if (comment.Creator.Id == user.Id)
+				return true;
+			//If user is admin
+			else if (user.Roles.Any(x => x.Name == Role.AdminRole))
+				return true;
+			else
+				return false;
+		}
+
+		/// <summary>
+		/// Returns the user, via their Id in the token
+		/// </summary>
+		private async Task<User> GetUserForValidation(string rawTokenData)
+		{
+			JwtSecurityToken jwt = new JwtSecurityTokenHandler().ReadJwtToken(rawTokenData.Remove(0, 7));
+
+			Guid jwtUserId = Guid.Parse(GetClaimTypeValues("ID", jwt.Claims).First());
+
+			User user = await this._userRepository.GetByIdAsync(jwtUserId) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.User));
+
+			return user;
+		}
+
+		/// <summary>
+		/// Returns all values from a given claim type
+		/// </summary>
+		private static List<string> GetClaimTypeValues(string type, IEnumerable<Claim> claims)
+		{
+			List<string> toReturn = new();
+
+			foreach (var claim in claims)
+				if (claim.Type == type)
+					toReturn.Add(claim.Value);
+
+			return toReturn;
+		}
+		#endregion
+	}
+}
+
diff --git a/src/Services/DevHive.Services/Services/FeedService.cs b/src/Services/DevHive.Services/Services/FeedService.cs
new file mode 100644
index 0000000..9c622b3
--- /dev/null
+++ b/src/Services/DevHive.Services/Services/FeedService.cs
@@ -0,0 +1,85 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using AutoMapper;
+using DevHive.Common.Constants;
+using DevHive.Data.Interfaces;
+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" method for more information on how it works.
+		/// </summary>
+		public async Task<ReadPageServiceModel> GetPage(GetPageServiceModel getPageServiceModel)
+		{
+			//TODO: Rework the initialization of User
+			User user = null;
+
+			if (getPageServiceModel.UserId != Guid.Empty)
+				user = await this._userRepository.GetByIdAsync(getPageServiceModel.UserId);
+			else if (!string.IsNullOrEmpty(getPageServiceModel.Username))
+				user = await this._userRepository.GetByUsernameAsync(getPageServiceModel.Username);
+			else
+				throw new InvalidDataException(string.Format(ErrorMessages.InvalidData, ClassesConstants.Data.ToLower()));
+
+			if (user == null)
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.User));
+
+			List<Post> posts = await this._feedRepository
+				.GetFriendsPosts(user.Friends.ToList(), getPageServiceModel.FirstRequestIssued, getPageServiceModel.PageNumber, getPageServiceModel.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" method for more information on how it works.
+		/// </summary>
+		public async Task<ReadPageServiceModel> GetUserPage(GetPageServiceModel model)
+		{
+			//TODO: Rework the initialization of User
+			User user = null;
+
+			if (!string.IsNullOrEmpty(model.Username))
+				user = await this._userRepository.GetByUsernameAsync(model.Username);
+			else
+				throw new InvalidDataException(string.Format(ErrorMessages.InvalidData, ClassesConstants.Data.ToLower()));
+
+			if (user == null)
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.User));
+
+			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;
+		}
+	}
+}
diff --git a/src/Services/DevHive.Services/Services/FriendsService.cs b/src/Services/DevHive.Services/Services/FriendsService.cs
new file mode 100644
index 0000000..98f654b
--- /dev/null
+++ b/src/Services/DevHive.Services/Services/FriendsService.cs
@@ -0,0 +1,45 @@
+using System;
+using System.Threading.Tasks;
+using DevHive.Common.Constants;
+using DevHive.Data.Interfaces;
+using DevHive.Data.Models;
+using DevHive.Services.Interfaces;
+
+namespace DevHive.Services.Services
+{
+	public class FriendsService : IFriendsService
+	{
+		private readonly IUserRepository _friendRepository;
+
+		public FriendsService(IUserRepository friendRepository)
+		{
+			this._friendRepository = friendRepository;
+		}
+
+		public async Task<bool> AddFriend(Guid userId, string friendUsername)
+		{
+			User user = await this._friendRepository.GetByIdAsync(userId) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, nameof(user)));
+
+			User friend = await this._friendRepository.GetByUsernameAsync(friendUsername) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, nameof(friend)));
+
+			bool addedToUser = user.Friends.Add(friend) && await this._friendRepository.EditAsync(userId, user);
+			bool addedToFriend = friend.Friends.Add(user) && await this._friendRepository.EditAsync(friend.Id, friend);
+			return addedToUser && addedToFriend;
+		}
+
+		public async Task<bool> RemoveFriend(Guid userId, string friendUsername)
+		{
+			User user = await this._friendRepository.GetByIdAsync(userId) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, nameof(user)));
+
+			User friend = await this._friendRepository.GetByUsernameAsync(friendUsername) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, nameof(friend)));
+
+			bool addedToUser = user.Friends.Remove(friend) && await this._friendRepository.EditAsync(userId, user);
+			bool addedToFriend = friend.Friends.Remove(user) && await this._friendRepository.EditAsync(friend.Id, friend);
+			return addedToUser && addedToFriend;
+		}
+	}
+}
diff --git a/src/Services/DevHive.Services/Services/LanguageService.cs b/src/Services/DevHive.Services/Services/LanguageService.cs
new file mode 100644
index 0000000..7ee7d9f
--- /dev/null
+++ b/src/Services/DevHive.Services/Services/LanguageService.cs
@@ -0,0 +1,91 @@
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.Threading.Tasks;
+using AutoMapper;
+using DevHive.Common.Constants;
+using DevHive.Data.Interfaces;
+using DevHive.Data.Models;
+using DevHive.Services.Interfaces;
+using DevHive.Services.Models.Language;
+
+namespace DevHive.Services.Services
+{
+	public class LanguageService : ILanguageService
+	{
+		private readonly ILanguageRepository _languageRepository;
+		private readonly IMapper _languageMapper;
+
+		public LanguageService(ILanguageRepository languageRepository, IMapper mapper)
+		{
+			this._languageRepository = languageRepository;
+			this._languageMapper = mapper;
+		}
+
+		#region Create
+		public async Task<Guid> CreateLanguage(CreateLanguageServiceModel createLanguageServiceModel)
+		{
+			if (await this._languageRepository.DoesLanguageNameExistAsync(createLanguageServiceModel.Name))
+				throw new DuplicateNameException(string.Format(ErrorMessages.AlreadyExists, ClassesConstants.Language));
+
+			Language language = this._languageMapper.Map<Language>(createLanguageServiceModel);
+			bool success = await this._languageRepository.AddAsync(language);
+
+			if (success)
+			{
+				Language newLanguage = await this._languageRepository.GetByNameAsync(createLanguageServiceModel.Name);
+				return newLanguage.Id;
+			}
+			else
+				return Guid.Empty;
+		}
+		#endregion
+
+		#region Read
+		public async Task<ReadLanguageServiceModel> GetLanguageById(Guid id)
+		{
+			Language language = await this._languageRepository.GetByIdAsync(id);
+
+			if (language == null)
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Language));
+
+			return this._languageMapper.Map<ReadLanguageServiceModel>(language);
+		}
+
+		public HashSet<ReadLanguageServiceModel> GetLanguages()
+		{
+			HashSet<Language> languages = this._languageRepository.GetLanguages();
+
+			return this._languageMapper.Map<HashSet<ReadLanguageServiceModel>>(languages);
+		}
+		#endregion
+
+		#region Update
+		public async Task<bool> UpdateLanguage(UpdateLanguageServiceModel languageServiceModel)
+		{
+			bool langExists = await this._languageRepository.DoesLanguageExistAsync(languageServiceModel.Id);
+			bool newLangNameExists = await this._languageRepository.DoesLanguageNameExistAsync(languageServiceModel.Name);
+
+			if (!langExists)
+				throw new DuplicateNameException(string.Format(ErrorMessages.AlreadyExists, ClassesConstants.Language));
+
+			if (newLangNameExists)
+				throw new DuplicateNameException(string.Format(ErrorMessages.AlreadyExists, ClassesConstants.Language));
+
+			Language lang = this._languageMapper.Map<Language>(languageServiceModel);
+			return await this._languageRepository.EditAsync(languageServiceModel.Id, lang);
+		}
+		#endregion
+
+		#region Delete
+		public async Task<bool> DeleteLanguage(Guid id)
+		{
+			if (!await this._languageRepository.DoesLanguageExistAsync(id))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Language));
+
+			Language language = await this._languageRepository.GetByIdAsync(id);
+			return await this._languageRepository.DeleteAsync(language);
+		}
+		#endregion
+	}
+}
diff --git a/src/Services/DevHive.Services/Services/PostService.cs b/src/Services/DevHive.Services/Services/PostService.cs
new file mode 100644
index 0000000..8580e82
--- /dev/null
+++ b/src/Services/DevHive.Services/Services/PostService.cs
@@ -0,0 +1,249 @@
+using System;
+using System.Collections.Generic;
+using System.IdentityModel.Tokens.Jwt;
+using System.Linq;
+using System.Security.Claims;
+using System.Threading.Tasks;
+using AutoMapper;
+using DevHive.Common.Constants;
+using DevHive.Data.Interfaces;
+using DevHive.Data.Models;
+using DevHive.Data.Models.Relational;
+using DevHive.Services.Interfaces;
+using DevHive.Services.Models.Post;
+
+namespace DevHive.Services.Services
+{
+	public class PostService : IPostService
+	{
+		private readonly ICloudService _cloudService;
+		private readonly IUserRepository _userRepository;
+		private readonly IPostRepository _postRepository;
+		private readonly ICommentRepository _commentRepository;
+		private readonly IMapper _postMapper;
+
+		public PostService(ICloudService cloudService, IUserRepository userRepository, IPostRepository postRepository, ICommentRepository commentRepository, IMapper postMapper)
+		{
+			this._cloudService = cloudService;
+			this._userRepository = userRepository;
+			this._postRepository = postRepository;
+			this._commentRepository = commentRepository;
+			this._postMapper = postMapper;
+		}
+
+		#region Create
+		public async Task<Guid> CreatePost(CreatePostServiceModel createPostServiceModel)
+		{
+			if (!await this._userRepository.DoesUserExistAsync(createPostServiceModel.CreatorId))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.User));
+
+			Post post = this._postMapper.Map<Post>(createPostServiceModel);
+
+			if (createPostServiceModel.Files.Count != 0)
+			{
+				List<string> fileUrls = await _cloudService.UploadFilesToCloud(createPostServiceModel.Files);
+				post.Attachments = GetPostAttachmentsFromUrls(post, fileUrls);
+			}
+
+			post.Creator = await this._userRepository.GetByIdAsync(createPostServiceModel.CreatorId);
+			post.TimeCreated = DateTime.Now;
+
+			bool success = await this._postRepository.AddAsync(post);
+			if (success)
+			{
+				Post newPost = await this._postRepository
+					.GetPostByCreatorAndTimeCreatedAsync(post.Creator.Id, post.TimeCreated);
+
+				await this._postRepository.AddNewPostToCreator(createPostServiceModel.CreatorId, newPost);
+
+				return newPost.Id;
+			}
+			else
+				return Guid.Empty;
+		}
+		#endregion
+
+		#region Read
+		public async Task<ReadPostServiceModel> GetPostById(Guid id)
+		{
+			Post post = await this._postRepository.GetByIdAsync(id) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Post));
+
+			// This can't happen in repo, because of how time is usually compared
+			post.Comments = post.Comments
+				.OrderByDescending(x => x.TimeCreated.ToFileTimeUtc())
+				.ToList();
+
+			User user = await this._userRepository.GetByIdAsync(post.Creator.Id) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.User));
+
+			int currentRating = 0;
+			foreach (Rating rating in post.Ratings)
+			{
+				if (rating.IsLike)
+					currentRating++;
+				else
+					currentRating--;
+			}
+
+			ReadPostServiceModel readPostServiceModel = this._postMapper.Map<ReadPostServiceModel>(post);
+			readPostServiceModel.CreatorFirstName = user.FirstName;
+			readPostServiceModel.CreatorLastName = user.LastName;
+			readPostServiceModel.CreatorUsername = user.UserName;
+			readPostServiceModel.FileUrls = post.Attachments.Select(x => x.FileUrl).ToList();
+			readPostServiceModel.CurrentRating = currentRating;
+
+			return readPostServiceModel;
+		}
+		#endregion
+
+		#region Update
+		public async Task<Guid> UpdatePost(UpdatePostServiceModel updatePostServiceModel)
+		{
+			if (!await this._postRepository.DoesPostExist(updatePostServiceModel.PostId))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Post));
+
+			Post post = this._postMapper.Map<Post>(updatePostServiceModel);
+
+			if (updatePostServiceModel.Files.Count != 0)
+			{
+				if (await this._postRepository.DoesPostHaveFiles(updatePostServiceModel.PostId))
+				{
+					List<string> fileUrlsToRemove = await this._postRepository.GetFileUrls(updatePostServiceModel.PostId);
+					bool success = await _cloudService.RemoveFilesFromCloud(fileUrlsToRemove);
+					if (!success)
+						throw new InvalidOperationException(string.Format(ErrorMessages.CannotDelete, ClassesConstants.Files.ToLower()));
+				}
+
+				List<string> fileUrls = await _cloudService.UploadFilesToCloud(updatePostServiceModel.Files) ??
+					throw new InvalidOperationException(string.Format(ErrorMessages.CannotUpload, ClassesConstants.Files.ToLower()));
+				post.Attachments = GetPostAttachmentsFromUrls(post, fileUrls);
+			}
+
+			post.Creator = await this._userRepository.GetByIdAsync(updatePostServiceModel.CreatorId);
+			post.Comments = await this._commentRepository.GetPostComments(updatePostServiceModel.PostId);
+			post.TimeCreated = DateTime.Now;
+
+			bool result = await this._postRepository.EditAsync(updatePostServiceModel.PostId, post);
+
+			if (result)
+				return (await this._postRepository.GetByIdAsync(updatePostServiceModel.PostId)).Id;
+			else
+				return Guid.Empty;
+		}
+		#endregion
+
+		#region Delete
+		public async Task<bool> DeletePost(Guid id)
+		{
+			if (!await this._postRepository.DoesPostExist(id))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Post));
+
+			Post post = await this._postRepository.GetByIdAsync(id);
+
+			if (await this._postRepository.DoesPostHaveFiles(id))
+			{
+				List<string> fileUrls = await this._postRepository.GetFileUrls(id);
+				bool success = await _cloudService.RemoveFilesFromCloud(fileUrls);
+				if (!success)
+					throw new InvalidOperationException(string.Format(ErrorMessages.CannotDelete, ClassesConstants.Files.ToLower()));
+			}
+
+			return await this._postRepository.DeleteAsync(post);
+		}
+		#endregion
+
+		#region Validations
+		/// <summary>
+		/// Checks whether the user Id in the token and the given user Id match
+		/// </summary>
+		public async Task<bool> ValidateJwtForCreating(Guid userId, string rawTokenData)
+		{
+			User user = await GetUserForValidation(rawTokenData);
+
+			return user.Id == userId;
+		}
+
+		/// <summary>
+		/// Checks whether the post, gotten with the postId,
+		/// is made by the user in the token
+		/// or if the user in the token is an admin
+		/// </summary>
+		public async Task<bool> ValidateJwtForPost(Guid postId, string rawTokenData)
+		{
+			Post post = await this._postRepository.GetByIdAsync(postId) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Post));
+			User user = await GetUserForValidation(rawTokenData);
+
+			//If user made the post
+			if (post.Creator.Id == user.Id)
+				return true;
+			//If user is admin
+			else if (user.Roles.Any(x => x.Name == Role.AdminRole))
+				return true;
+			else
+				return false;
+		}
+
+		/// <summary>
+		/// Checks whether the comment, gotten with the commentId,
+		/// is made by the user in the token
+		/// or if the user in the token is an admin
+		/// </summary>
+		public async Task<bool> ValidateJwtForComment(Guid commentId, string rawTokenData)
+		{
+			Comment comment = await this._commentRepository.GetByIdAsync(commentId) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Comment));
+			User user = await GetUserForValidation(rawTokenData);
+
+			//If user made the comment
+			if (comment.Creator.Id == user.Id)
+				return true;
+			//If user is admin
+			else if (user.Roles.Any(x => x.Name == Role.AdminRole))
+				return true;
+			else
+				return false;
+		}
+
+		/// <summary>
+		/// Returns the user, via their Id in the token
+		/// </summary>
+		private async Task<User> GetUserForValidation(string rawTokenData)
+		{
+			JwtSecurityToken jwt = new JwtSecurityTokenHandler().ReadJwtToken(rawTokenData.Remove(0, 7));
+
+			Guid jwtUserId = Guid.Parse(GetClaimTypeValues("ID", jwt.Claims).First());
+
+			User user = await this._userRepository.GetByIdAsync(jwtUserId) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.User));
+
+			return user;
+		}
+
+		/// <summary>
+		/// Returns all values from a given claim type
+		/// </summary>
+		private static List<string> GetClaimTypeValues(string type, IEnumerable<Claim> claims)
+		{
+			List<string> toReturn = new();
+
+			foreach (var claim in claims)
+				if (claim.Type == type)
+					toReturn.Add(claim.Value);
+
+			return toReturn;
+		}
+		#endregion
+
+		#region Misc
+		private static List<PostAttachments> GetPostAttachmentsFromUrls(Post post, List<string> fileUrls)
+		{
+			List<PostAttachments> postAttachments = new();
+			foreach (string url in fileUrls)
+				postAttachments.Add(new PostAttachments { Post = post, FileUrl = url });
+			return postAttachments;
+		}
+		#endregion
+	}
+}
diff --git a/src/Services/DevHive.Services/Services/ProfilePictureService.cs b/src/Services/DevHive.Services/Services/ProfilePictureService.cs
new file mode 100644
index 0000000..cafa7cb
--- /dev/null
+++ b/src/Services/DevHive.Services/Services/ProfilePictureService.cs
@@ -0,0 +1,101 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using DevHive.Common.Constants;
+using DevHive.Data.Interfaces;
+using DevHive.Data.Models;
+using DevHive.Services.Interfaces;
+using DevHive.Services.Models.ProfilePicture;
+using Microsoft.AspNetCore.Http;
+
+namespace DevHive.Services.Services
+{
+	public class ProfilePictureService : IProfilePictureService
+	{
+		private readonly IUserRepository _userRepository;
+		private readonly IProfilePictureRepository _profilePictureRepository;
+		private readonly ICloudService _cloudinaryService;
+
+		public ProfilePictureService(IUserRepository userRepository, IProfilePictureRepository profilePictureRepository, ICloudService cloudinaryService)
+		{
+			this._userRepository = userRepository;
+			this._profilePictureRepository = profilePictureRepository;
+			this._cloudinaryService = cloudinaryService;
+		}
+
+		public async Task<string> GetProfilePictureById(Guid id)
+		{
+			return (await this._profilePictureRepository.GetByIdAsync(id)).PictureURL;
+		}
+
+		public async Task<string> UpdateProfilePicture(ProfilePictureServiceModel profilePictureServiceModel)
+		{
+			ValidateProfPic(profilePictureServiceModel.ProfilePictureFormFile);
+			await ValidateUserExistsAsync(profilePictureServiceModel.UserId);
+
+			User user = await this._userRepository.GetByIdAsync(profilePictureServiceModel.UserId);
+			if (user.ProfilePicture.Id != Guid.Empty)
+			{
+				List<string> file = new() { user.ProfilePicture.PictureURL };
+				bool removed = await this._cloudinaryService.RemoveFilesFromCloud(file);
+
+				if (!removed)
+					throw new InvalidOperationException(string.Format(ErrorMessages.CannotDelete, ClassesConstants.Picture.ToLower()));
+			}
+
+			return await SaveProfilePictureInDatabase(profilePictureServiceModel);
+		}
+
+		public async Task<bool> DeleteProfilePicture(Guid id)
+		{
+			ProfilePicture profilePic = await this._profilePictureRepository.GetByIdAsync(id) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Picture));
+
+			bool removedFromDb = await this._profilePictureRepository.DeleteAsync(profilePic);
+			if (!removedFromDb)
+				throw new InvalidOperationException(string.Format(ErrorMessages.CannotDelete, ClassesConstants.Picture.ToLower()));
+
+			List<string> file = new() { profilePic.PictureURL };
+			bool removedFromCloud = await this._cloudinaryService.RemoveFilesFromCloud(file);
+			if (!removedFromCloud)
+				throw new InvalidOperationException(string.Format(ErrorMessages.CannotDelete, ClassesConstants.Picture.ToLower()));
+
+			return true;
+		}
+
+		private async Task<string> SaveProfilePictureInDatabase(ProfilePictureServiceModel profilePictureServiceModel)
+		{
+			List<IFormFile> file = new() { profilePictureServiceModel.ProfilePictureFormFile };
+			string picUrl = (await this._cloudinaryService.UploadFilesToCloud(file))[0];
+			ProfilePicture profilePic = new() { PictureURL = picUrl };
+
+			User user = await this._userRepository.GetByIdAsync(profilePictureServiceModel.UserId);
+			profilePic.UserId = user.Id;
+			profilePic.User = user;
+
+			bool success = await this._profilePictureRepository.AddAsync(profilePic);
+			if (!success)
+				throw new InvalidOperationException(string.Format(ErrorMessages.CannotUpload, ClassesConstants.Files.ToLower()));
+
+			user.ProfilePicture = profilePic;
+			bool userProfilePicAlter = await this._userRepository.EditAsync(user.Id, user);
+
+			if (!userProfilePicAlter)
+				throw new InvalidOperationException(string.Format(ErrorMessages.CannotEdit, "user's profile picture"));
+
+			return picUrl;
+		}
+
+		private static void ValidateProfPic(IFormFile profilePictureFormFile)
+		{
+			if (profilePictureFormFile.Length == 0)
+				throw new ArgumentNullException(nameof(profilePictureFormFile), string.Format(ErrorMessages.InvalidData, ClassesConstants.Data.ToLower()));
+		}
+
+		private async Task ValidateUserExistsAsync(Guid userId)
+		{
+			if (!await this._userRepository.DoesUserExistAsync(userId))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.User));
+		}
+	}
+}
diff --git a/src/Services/DevHive.Services/Services/RatingService.cs b/src/Services/DevHive.Services/Services/RatingService.cs
new file mode 100644
index 0000000..d6b4299
--- /dev/null
+++ b/src/Services/DevHive.Services/Services/RatingService.cs
@@ -0,0 +1,120 @@
+using System;
+using System.Threading.Tasks;
+using AutoMapper;
+using DevHive.Common.Constants;
+using DevHive.Data.Interfaces;
+using DevHive.Data.Models;
+using DevHive.Services.Interfaces;
+using DevHive.Services.Models.Rating;
+
+namespace DevHive.Services.Services
+{
+	public class RatingService : IRatingService
+	{
+		private readonly IPostRepository _postRepository;
+		private readonly IUserRepository _userRepository;
+		private readonly IRatingRepository _ratingRepository;
+		private readonly IMapper _mapper;
+
+		private const string NotRated = "{0} has not rated" + ClassesConstants.Post;
+
+		public RatingService(IPostRepository postRepository, IRatingRepository ratingRepository, IUserRepository userRepository, IMapper mapper)
+		{
+			this._postRepository = postRepository;
+			this._ratingRepository = ratingRepository;
+			this._userRepository = userRepository;
+			this._mapper = mapper;
+		}
+
+		#region Create
+		public async Task<Guid> RatePost(CreateRatingServiceModel createRatingServiceModel)
+		{
+			if (!await this._postRepository.DoesPostExist(createRatingServiceModel.PostId))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Post));
+
+			if (await this._ratingRepository.UserRatedPost(createRatingServiceModel.UserId, createRatingServiceModel.PostId))
+				throw new ArgumentException("User already rated the post!");
+
+			Rating rating = this._mapper.Map<Rating>(createRatingServiceModel);
+
+			rating.User = await this._userRepository.GetByIdAsync(createRatingServiceModel.UserId);
+			rating.Post = await this._postRepository.GetByIdAsync(createRatingServiceModel.PostId);
+
+			bool success = await this._ratingRepository.AddAsync(rating);
+
+			if (success)
+			{
+				Rating newRating = await this._ratingRepository.GetRatingByUserAndPostId(rating.User.Id, rating.Post.Id);
+
+				return newRating.Id;
+			}
+			else
+				return Guid.Empty;
+		}
+		#endregion
+
+		#region Read
+		public async Task<ReadRatingServiceModel> GetRatingById(Guid ratingId)
+		{
+			Rating rating = await this._ratingRepository.GetByIdAsync(ratingId);
+			if (rating is null)
+				return null;
+
+			ReadRatingServiceModel readRatingServiceModel = this._mapper.Map<ReadRatingServiceModel>(rating);
+			readRatingServiceModel.UserId = rating.User.Id;
+
+			return readRatingServiceModel;
+		}
+
+		public async Task<ReadRatingServiceModel> GetRatingByPostAndUser(Guid userId, Guid postId)
+		{
+			Rating rating = await this._ratingRepository.GetRatingByUserAndPostId(userId, postId);
+			if (rating is null)
+				return null;
+
+			ReadRatingServiceModel readRatingServiceModel = this._mapper.Map<ReadRatingServiceModel>(rating);
+			readRatingServiceModel.UserId = rating.User.Id;
+
+			return readRatingServiceModel;
+		}
+		#endregion
+
+		#region Update
+		public async Task<ReadRatingServiceModel> UpdateRating(UpdateRatingServiceModel updateRatingServiceModel)
+		{
+			Rating rating = await this._ratingRepository.GetRatingByUserAndPostId(updateRatingServiceModel.UserId, updateRatingServiceModel.PostId) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Rating));
+
+			User user = await this._userRepository.GetByIdAsync(updateRatingServiceModel.UserId) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.User));
+
+			if (!await this._ratingRepository.UserRatedPost(updateRatingServiceModel.UserId, updateRatingServiceModel.PostId))
+				throw new ArgumentException(string.Format(NotRated, ClassesConstants.User));
+
+			rating.User = user;
+			rating.IsLike = updateRatingServiceModel.IsLike;
+
+			bool result = await this._ratingRepository.EditAsync(updateRatingServiceModel.Id, rating);
+
+			if (result)
+			{
+				ReadRatingServiceModel readRatingServiceModel = this._mapper.Map<ReadRatingServiceModel>(rating);
+				return readRatingServiceModel;
+			}
+			else
+				return null;
+		}
+		#endregion
+
+		#region Delete
+		public async Task<bool> DeleteRating(Guid ratingId)
+		{
+			if (!await this._ratingRepository.DoesRatingExist(ratingId))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Rating));
+
+			Rating rating = await this._ratingRepository.GetByIdAsync(ratingId);
+			return await this._ratingRepository.DeleteAsync(rating);
+		}
+		#endregion
+	}
+}
diff --git a/src/Services/DevHive.Services/Services/RoleService.cs b/src/Services/DevHive.Services/Services/RoleService.cs
new file mode 100644
index 0000000..f61181a
--- /dev/null
+++ b/src/Services/DevHive.Services/Services/RoleService.cs
@@ -0,0 +1,71 @@
+using System;
+using System.Data;
+using System.Threading.Tasks;
+using AutoMapper;
+using DevHive.Common.Constants;
+using DevHive.Data.Interfaces;
+using DevHive.Data.Models;
+using DevHive.Services.Interfaces;
+using DevHive.Services.Models.Role;
+
+namespace DevHive.Services.Services
+{
+	public class RoleService : IRoleService
+	{
+		private readonly IRoleRepository _roleRepository;
+		private readonly IMapper _roleMapper;
+
+		public RoleService(IRoleRepository roleRepository, IMapper mapper)
+		{
+			this._roleRepository = roleRepository;
+			this._roleMapper = mapper;
+		}
+
+		public async Task<Guid> CreateRole(CreateRoleServiceModel createRoleServiceModel)
+		{
+			if (await this._roleRepository.DoesNameExist(createRoleServiceModel.Name))
+				throw new DuplicateNameException(string.Format(ErrorMessages.AlreadyExists, ClassesConstants.Role));
+
+			Role role = this._roleMapper.Map<Role>(createRoleServiceModel);
+			bool success = await this._roleRepository.AddAsync(role);
+
+			if (success)
+			{
+				Role newRole = await this._roleRepository.GetByNameAsync(createRoleServiceModel.Name);
+				return newRole.Id;
+			}
+			else
+				return Guid.Empty;
+
+		}
+
+		public async Task<RoleServiceModel> GetRoleById(Guid id)
+		{
+			Role role = await this._roleRepository.GetByIdAsync(id) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Role));
+
+			return this._roleMapper.Map<RoleServiceModel>(role);
+		}
+
+		public async Task<bool> UpdateRole(UpdateRoleServiceModel updateRoleServiceModel)
+		{
+			if (!await this._roleRepository.DoesRoleExist(updateRoleServiceModel.Id))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Role));
+
+			if (await this._roleRepository.DoesNameExist(updateRoleServiceModel.Name))
+				throw new DuplicateNameException(string.Format(ErrorMessages.AlreadyExists, ClassesConstants.Role));
+
+			Role role = this._roleMapper.Map<Role>(updateRoleServiceModel);
+			return await this._roleRepository.EditAsync(updateRoleServiceModel.Id, role);
+		}
+
+		public async Task<bool> DeleteRole(Guid id)
+		{
+			if (!await this._roleRepository.DoesRoleExist(id))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Role));
+
+			Role role = await this._roleRepository.GetByIdAsync(id);
+			return await this._roleRepository.DeleteAsync(role);
+		}
+	}
+}
diff --git a/src/Services/DevHive.Services/Services/TechnologyService.cs b/src/Services/DevHive.Services/Services/TechnologyService.cs
new file mode 100644
index 0000000..4cf84c5
--- /dev/null
+++ b/src/Services/DevHive.Services/Services/TechnologyService.cs
@@ -0,0 +1,92 @@
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.Threading.Tasks;
+using AutoMapper;
+using DevHive.Common.Constants;
+using DevHive.Data.Interfaces;
+using DevHive.Data.Models;
+using DevHive.Services.Interfaces;
+using DevHive.Services.Models.Technology;
+
+namespace DevHive.Services.Services
+{
+	public class TechnologyService : ITechnologyService
+	{
+		private readonly ITechnologyRepository _technologyRepository;
+		private readonly IMapper _technologyMapper;
+
+		public TechnologyService(ITechnologyRepository technologyRepository, IMapper technologyMapper)
+		{
+			this._technologyRepository = technologyRepository;
+			this._technologyMapper = technologyMapper;
+		}
+
+		#region Create
+		public async Task<Guid> CreateTechnology(CreateTechnologyServiceModel technologyServiceModel)
+		{
+			if (await this._technologyRepository.DoesTechnologyNameExistAsync(technologyServiceModel.Name))
+				throw new DuplicateNameException(string.Format(ErrorMessages.AlreadyExists, ClassesConstants.Technology));
+
+			Technology technology = this._technologyMapper.Map<Technology>(technologyServiceModel);
+			bool success = await this._technologyRepository.AddAsync(technology);
+
+			if (success)
+			{
+				Technology newTechnology = await this._technologyRepository.GetByNameAsync(technologyServiceModel.Name);
+				return newTechnology.Id;
+			}
+			else
+				return Guid.Empty;
+		}
+		#endregion
+
+		#region Read
+		public async Task<ReadTechnologyServiceModel> GetTechnologyById(Guid id)
+		{
+			Technology technology = await this._technologyRepository.GetByIdAsync(id);
+
+			if (technology == null)
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Technology));
+
+			return this._technologyMapper.Map<ReadTechnologyServiceModel>(technology);
+		}
+
+		public HashSet<ReadTechnologyServiceModel> GetTechnologies()
+		{
+			HashSet<Technology> technologies = this._technologyRepository.GetTechnologies();
+
+			return this._technologyMapper.Map<HashSet<ReadTechnologyServiceModel>>(technologies);
+		}
+		#endregion
+
+		#region Update
+		public async Task<bool> UpdateTechnology(UpdateTechnologyServiceModel updateTechnologyServiceModel)
+		{
+			if (!await this._technologyRepository.DoesTechnologyExistAsync(updateTechnologyServiceModel.Id))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Technology));
+
+			if (await this._technologyRepository.DoesTechnologyNameExistAsync(updateTechnologyServiceModel.Name))
+				throw new DuplicateNameException(string.Format(ErrorMessages.AlreadyExists, ClassesConstants.Technology));
+
+			Technology technology = this._technologyMapper.Map<Technology>(updateTechnologyServiceModel);
+			bool result = await this._technologyRepository.EditAsync(updateTechnologyServiceModel.Id, technology);
+
+			return result;
+		}
+		#endregion
+
+		#region Delete
+		public async Task<bool> DeleteTechnology(Guid id)
+		{
+			if (!await this._technologyRepository.DoesTechnologyExistAsync(id))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Technology));
+
+			Technology technology = await this._technologyRepository.GetByIdAsync(id);
+			bool result = await this._technologyRepository.DeleteAsync(technology);
+
+			return result;
+		}
+		#endregion
+	}
+}
diff --git a/src/Services/DevHive.Services/Services/UserService.cs b/src/Services/DevHive.Services/Services/UserService.cs
new file mode 100644
index 0000000..62576d4
--- /dev/null
+++ b/src/Services/DevHive.Services/Services/UserService.cs
@@ -0,0 +1,255 @@
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using AutoMapper;
+using DevHive.Common.Constants;
+using DevHive.Common.Jwt.Interfaces;
+using DevHive.Common.Models.Identity;
+using DevHive.Data.Interfaces;
+using DevHive.Data.Models;
+using DevHive.Services.Interfaces;
+using DevHive.Services.Models.User;
+
+namespace DevHive.Services.Services
+{
+	public class UserService : IUserService
+	{
+		private readonly IUserRepository _userRepository;
+		private readonly IRoleRepository _roleRepository;
+		private readonly ILanguageRepository _languageRepository;
+		private readonly ITechnologyRepository _technologyRepository;
+		private readonly IMapper _userMapper;
+		private readonly IJwtService _jwtService;
+
+		private const string NoYourselfAsFriend = "You cant add yourself as a friend(sry, bro)!";
+		private const string Rant = "Can't promote shit in this country...";
+
+
+		public UserService(IUserRepository userRepository,
+			ILanguageRepository languageRepository,
+			IRoleRepository roleRepository,
+			ITechnologyRepository technologyRepository,
+			IMapper mapper,
+			IJwtService jwtService)
+		{
+			this._userRepository = userRepository;
+			this._roleRepository = roleRepository;
+			this._userMapper = mapper;
+			this._languageRepository = languageRepository;
+			this._technologyRepository = technologyRepository;
+			this._jwtService = jwtService;
+		}
+
+		#region Authentication
+		public async Task<TokenModel> LoginUser(LoginServiceModel loginModel)
+		{
+			if (!await this._userRepository.DoesUsernameExistAsync(loginModel.UserName))
+				throw new InvalidDataException(string.Format(ErrorMessages.InvalidData, ClassesConstants.Username));
+
+			User user = await this._userRepository.GetByUsernameAsync(loginModel.UserName);
+
+			if (!await this._userRepository.VerifyPassword(user, loginModel.Password))
+				throw new InvalidDataException(string.Format(ErrorMessages.IncorrectData, ClassesConstants.Password.ToLower()));
+
+			List<string> roleNames = user.Roles.Select(x => x.Name).ToList();
+			return new TokenModel(this._jwtService.GenerateJwtToken(user.Id, user.UserName, roleNames));
+		}
+
+		public async Task<TokenModel> RegisterUser(RegisterServiceModel registerModel)
+		{
+			if (await this._userRepository.DoesUsernameExistAsync(registerModel.UserName))
+				throw new DuplicateNameException(string.Format(ErrorMessages.AlreadyExists, ClassesConstants.Username));
+
+			if (await this._userRepository.DoesEmailExistAsync(registerModel.Email))
+				throw new DuplicateNameException(string.Format(ErrorMessages.AlreadyExists, ClassesConstants.Email));
+
+
+			User user = this._userMapper.Map<User>(registerModel);
+
+			bool userResult = await this._userRepository.AddAsync(user);
+			bool roleResult = await this._userRepository.AddRoleToUser(user, Role.DefaultRole);
+
+			if (!userResult)
+				throw new InvalidOperationException(string.Format(ErrorMessages.CannotCreate, ClassesConstants.User.ToLower()));
+			if (!roleResult)
+				throw new InvalidOperationException(string.Format(ErrorMessages.CannotAdd, ClassesConstants.Role.ToLower()));
+
+			User createdUser = await this._userRepository.GetByUsernameAsync(registerModel.UserName);
+
+			List<string> roleNames = createdUser.Roles.Select(x => x.Name).ToList();
+			return new TokenModel(this._jwtService.GenerateJwtToken(createdUser.Id, createdUser.UserName, roleNames));
+		}
+		#endregion
+
+		#region Read
+		public async Task<UserServiceModel> GetUserById(Guid id)
+		{
+			User user = await this._userRepository.GetByIdAsync(id) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.User));
+
+			return this._userMapper.Map<UserServiceModel>(user);
+		}
+
+		public async Task<UserServiceModel> GetUserByUsername(string username)
+		{
+			User user = await this._userRepository.GetByUsernameAsync(username) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.User));
+
+			return this._userMapper.Map<UserServiceModel>(user);
+		}
+		#endregion
+
+		#region Update
+		public async Task<UserServiceModel> UpdateUser(UpdateUserServiceModel updateUserServiceModel)
+		{
+			await ValidateUserOnUpdate(updateUserServiceModel);
+
+			User user = await this._userRepository.GetByIdAsync(updateUserServiceModel.Id);
+			await PopulateUserModel(user, updateUserServiceModel);
+
+			if (updateUserServiceModel.Friends.Count > 0)
+				await CreateRelationToFriends(user, updateUserServiceModel.Friends.ToList());
+			else
+				user.Friends.Clear();
+
+			bool result = await this._userRepository.EditAsync(user.Id, user);
+
+			if (!result)
+				throw new InvalidOperationException(string.Format(ErrorMessages.CannotEdit, ClassesConstants.User.ToLower()));
+
+			User newUser = await this._userRepository.GetByIdAsync(user.Id);
+			return this._userMapper.Map<UserServiceModel>(newUser);
+		}
+		#endregion
+
+		#region Delete
+		public async Task<bool> DeleteUser(Guid id)
+		{
+			if (!await this._userRepository.DoesUserExistAsync(id))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.User));
+
+			User user = await this._userRepository.GetByIdAsync(id);
+			return await this._userRepository.DeleteAsync(user);
+		}
+		#endregion
+
+		#region Validations
+		/// <summary>
+		/// Checks whether the user in the model exists and whether the username in the model is already taken.
+		/// If the check fails (is false), it throws an exception, otherwise nothing happens
+		/// </summary>
+		private async Task ValidateUserOnUpdate(UpdateUserServiceModel updateUserServiceModel)
+		{
+			if (!await this._userRepository.DoesUserExistAsync(updateUserServiceModel.Id))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.User));
+
+			if (updateUserServiceModel.Friends.Any(x => x.UserName == updateUserServiceModel.UserName))
+				throw new InvalidOperationException(NoYourselfAsFriend);
+
+			if (!await this._userRepository.DoesUserHaveThisUsernameAsync(updateUserServiceModel.Id, updateUserServiceModel.UserName)
+					&& await this._userRepository.DoesUsernameExistAsync(updateUserServiceModel.UserName))
+				throw new DuplicateNameException(string.Format(ErrorMessages.AlreadyExists, ClassesConstants.Username.ToLower()));
+
+			List<string> usernames = new();
+			foreach (var friend in updateUserServiceModel.Friends)
+				usernames.Add(friend.UserName);
+
+			if (!await this._userRepository.ValidateFriendsCollectionAsync(usernames))
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.OneOrMoreFriends));
+		}
+		#endregion
+
+		#region Misc
+		public async Task<TokenModel> SuperSecretPromotionToAdmin(Guid userId)
+		{
+			User user = await this._userRepository.GetByIdAsync(userId) ??
+				throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.User) + " " + Rant);
+
+			if (!await this._roleRepository.DoesNameExist(Role.AdminRole))
+			{
+				Role adminRole = new() { Name = Role.AdminRole };
+				adminRole.Users.Add(user);
+
+				await this._roleRepository.AddAsync(adminRole);
+			}
+
+			Role admin = await this._roleRepository.GetByNameAsync(Role.AdminRole);
+
+			user.Roles.Add(admin);
+			await this._userRepository.EditAsync(user.Id, user);
+
+			User createdUser = await this._userRepository.GetByIdAsync(userId);
+			List<string> roleNames = createdUser
+						.Roles
+						.Select(x => x.Name)
+						.ToList();
+
+			return new TokenModel(this._jwtService.GenerateJwtToken(createdUser.Id, createdUser.UserName, roleNames));
+		}
+
+		private async Task PopulateUserModel(User user, UpdateUserServiceModel updateUserServiceModel)
+		{
+			user.UserName = updateUserServiceModel.UserName;
+			user.FirstName = updateUserServiceModel.FirstName;
+			user.LastName = updateUserServiceModel.LastName;
+			user.Email = updateUserServiceModel.Email;
+
+			//Do NOT allow a user to change his roles, unless he is an Admin
+			bool isAdmin = await this._userRepository.IsInRoleAsync(user, Role.AdminRole);
+
+			if (isAdmin)
+			{
+				HashSet<Role> roles = new();
+				foreach (var role in updateUserServiceModel.Roles)
+				{
+					Role returnedRole = await this._roleRepository.GetByNameAsync(role.Name) ??
+						throw new ArgumentNullException(string.Format(ErrorMessages.DoesNotExist, ClassesConstants.Role));
+
+					roles.Add(returnedRole);
+				}
+				user.Roles = roles;
+			}
+
+			HashSet<Language> languages = new();
+			int languagesCount = updateUserServiceModel.Languages.Count;
+			for (int i = 0; i < languagesCount; i++)
+			{
+				Language language = await this._languageRepository.GetByNameAsync(updateUserServiceModel.Languages.ElementAt(i).Name) ??
+					throw new InvalidDataException(string.Format(ErrorMessages.InvalidData, nameof(Language)));
+
+				languages.Add(language);
+			}
+			user.Languages = languages;
+
+			/* Fetch Technologies and replace model's*/
+			HashSet<Technology> technologies = new();
+			int technologiesCount = updateUserServiceModel.Technologies.Count;
+			for (int i = 0; i < technologiesCount; i++)
+			{
+				Technology technology = await this._technologyRepository.GetByNameAsync(updateUserServiceModel.Technologies.ElementAt(i).Name) ??
+					throw new InvalidDataException(string.Format(ErrorMessages.InvalidData, nameof(Technology)));
+
+
+				technologies.Add(technology);
+			}
+			user.Technologies = technologies;
+		}
+
+		private async Task CreateRelationToFriends(User user, List<UpdateFriendServiceModel> friends)
+		{
+			foreach (var friend in friends)
+			{
+				User amigo = await this._userRepository.GetByUsernameAsync(friend.UserName);
+
+				user.Friends.Add(amigo);
+				amigo.Friends.Add(user);
+
+				await this._userRepository.EditAsync(amigo.Id, amigo);
+			}
+		}
+		#endregion
+	}
+}