Moved projects to their own separate subdirectories

API/YABA.Service/BookmarkService.cs

@@ -0,0 +1,280 @@
+using AutoMapper;
+using HtmlAgilityPack;
+using Microsoft.AspNetCore.Http;
+using Microsoft.EntityFrameworkCore;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Net;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+using YABA.Common.DTOs.Bookmarks;
+using YABA.Common.DTOs.Tags;
+using YABA.Common.Extensions;
+using YABA.Common.Interfaces;
+using YABA.Data.Context;
+using YABA.Data.Extensions;
+using YABA.Models;
+using YABA.Service.Interfaces;
+
+namespace YABA.Service
+{
+    public class BookmarkService : IBookmarkService
+    {
+        private readonly YABAReadOnlyContext _roContext;
+        private readonly YABAReadWriteContext _context;
+        private readonly IHttpContextAccessor _httpContextAccessor;
+        private readonly IMapper _mapper;
+
+        public BookmarkService(
+            YABAReadOnlyContext roContext, 
+            YABAReadWriteContext context, 
+            IHttpContextAccessor httpContextAccessor,
+            IMapper mapper)
+        {
+            _roContext = roContext;
+            _context = context;
+            _httpContextAccessor = httpContextAccessor;
+            _mapper = mapper;
+        }
+
+        public IEnumerable<BookmarkDTO> GetAll(bool showHidden = false)
+        {
+            var currentUserId = GetCurrentUserId();
+            var userBookmarkDTOs = new List<BookmarkDTO>();
+
+
+            var showHiddenCondition = new Func<Bookmark, bool>(b => b.IsHidden || b.BookmarkTags.Where(x => x.Tag.UserId == currentUserId).Any(x => x.Tag.IsHidden));
+            var showNotHiddenCondition = new Func<Bookmark, bool>(b => !b.IsHidden && b.BookmarkTags.Where(x => x.Tag.UserId == currentUserId).All(bt => !bt.Tag.IsHidden));
+
+            var filteredBookmarks = _roContext.Bookmarks
+                .Include(b => b.BookmarkTags)
+                .ThenInclude(bt => bt.Tag)
+                .Where(b => b.UserId == currentUserId)
+                .Where(showHidden ? showHiddenCondition : showNotHiddenCondition)
+                .ToList();
+
+            foreach(var bookmark in filteredBookmarks)
+            {
+                var isBookmarkHidden = bookmark.IsHidden;
+                var bookmarkDTO = _mapper.Map<BookmarkDTO>(bookmark);
+                
+                var bookmarkTags = bookmark.BookmarkTags.Select(x => x.Tag);
+                bookmarkDTO.Tags = _mapper.Map<List<TagDTO>>(bookmarkTags);
+
+                userBookmarkDTOs.Add(bookmarkDTO);
+            }
+
+            return userBookmarkDTOs;
+        }
+
+        public async Task<BookmarkDTO?> CreateBookmark(CreateBookmarkRequestDTO request)
+        {
+            var currentUserId = GetCurrentUserId();
+
+            if (!_roContext.Users.UserExists(currentUserId)
+                || await _roContext.Bookmarks.AnyAsync(x => x.UserId == currentUserId && x.Url == request.Url)) return null;
+
+            var bookmark = _mapper.Map<Bookmark>(request);
+            UpdateBookmarkWithMetaData(bookmark);
+            bookmark.UserId = currentUserId;
+
+            var newEntity = await _context.Bookmarks.AddAsync(bookmark);
+
+            if (await _context.SaveChangesAsync() > 0)
+            {
+                var bookmarkDTO = _mapper.Map<BookmarkDTO>(newEntity.Entity);
+
+                if(request.Tags != null && request.Tags.Any())
+                    bookmarkDTO.Tags.AddRange(await UpdateBookmarkTags(bookmarkDTO.Id, request.Tags));
+                return bookmarkDTO;
+            }
+
+            return null;
+        }
+
+        public async Task<BookmarkDTO?> UpdateBookmark(int id, UpdateBookmarkRequestDTO request)
+        {
+            var currentUserId = GetCurrentUserId();
+
+            var bookmark = _context.Bookmarks.FirstOrDefault(x => x.UserId == currentUserId && x.Id == id);
+            var tags = new List<TagDTO>();
+
+            if (request.Tags != null && request.Tags.Any())
+                tags = (await UpdateBookmarkTags(id, request.Tags)).ToList();
+
+
+            if (bookmark == null) return null;
+
+            bookmark.Title = !string.IsNullOrEmpty(request.Title) ? request.Title : bookmark.Title;
+            bookmark.Description = !string.IsNullOrEmpty(request.Description) ? request.Description : bookmark.Description;
+            bookmark.Note = !string.IsNullOrEmpty(request.Note) ? request.Note : bookmark.Note;
+            bookmark.IsHidden = request.IsHidden;
+            bookmark.Url = !string.IsNullOrEmpty(request.Url) ? request.Url : bookmark.Url;
+            UpdateBookmarkWithMetaData(bookmark);
+
+            await _context.SaveChangesAsync();
+            var bookmarkDTO = _mapper.Map<BookmarkDTO>(bookmark);
+            bookmarkDTO.Tags = tags;
+            return bookmarkDTO;
+        }
+
+        public async Task<IEnumerable<TagDTO>?> UpdateBookmarkTags(int id, IEnumerable<string> tags)
+        {
+            var currentUserId = GetCurrentUserId();
+
+            if (!_roContext.Bookmarks.Any(x => x.Id == id && x.UserId == currentUserId)
+                 || tags == null || !tags.Any()) return null;
+
+            // Add tags that are not yet in the database
+            var savedUserTags = _context.Tags.Where(x => x.UserId == currentUserId).ToList();
+            var tagsToSave = tags.Except(savedUserTags.Select(x => x.Name).ToHashSet()).Select(x => new Tag { Name = x, UserId = currentUserId }).ToList();
+            await _context.Tags.AddRangeAsync(tagsToSave);
+            await _context.SaveChangesAsync();
+
+            // Add newly added tags to the lookup
+            savedUserTags.AddRange(tagsToSave);
+
+            var existingBookmarkTags = _roContext.BookmarkTags.Include(x => x.Tag).Where(x => x.BookmarkId == id).ToList();
+            var existingBookmarkTagsLookup = existingBookmarkTags.ToDictionary(k => k.TagId, v => v.Tag.Name);
+
+            var bookmarkTagsToRemove = existingBookmarkTagsLookup
+                .Where(x => !tags.Contains(x.Value))
+                .Select(x => new BookmarkTag { BookmarkId = id, TagId = x.Key });
+
+            var savedUserTagsByName = savedUserTags.ToDictionary(k => k.Name, v => v.Id);
+            var bookmarkTagsToAdd = tags.Except(existingBookmarkTagsLookup.Values)
+                .Select(x => new BookmarkTag { BookmarkId = id, TagId = savedUserTagsByName[x] });
+
+            _context.BookmarkTags.RemoveRange(bookmarkTagsToRemove);
+            await _context.BookmarkTags.AddRangeAsync(bookmarkTagsToAdd);
+
+            if (await _context.SaveChangesAsync() >= 0)
+            {
+                var updatedBookmarkTags = _roContext.BookmarkTags
+                    .Include(x => x.Tag)
+                    .Where(x => x.BookmarkId == id)
+                    .Select(x => x.Tag);
+
+                return _mapper.Map<IEnumerable<TagDTO>>(updatedBookmarkTags);
+            }
+
+            return null;
+        }
+
+        public async Task<BookmarkDTO?> Get(int id)
+        {
+            int.TryParse(_httpContextAccessor.HttpContext.User.Identity.GetUserId(), out int userId);
+            var bookmark = await _roContext.Bookmarks.FirstOrDefaultAsync(x => x.Id == id && x.UserId == userId);
+
+            if (bookmark == null) return null;
+
+            var bookmarkTags = _roContext.BookmarkTags
+                .Include(x => x.Tag)
+                .Where(x => x.BookmarkId == id)
+                .Select(x => x.Tag)
+                .ToList();
+
+            var bookmarkDTO = _mapper.Map<BookmarkDTO>(bookmark);
+            bookmarkDTO.Tags = _mapper.Map<List<TagDTO>>(bookmarkTags);
+
+            return bookmarkDTO;
+        }
+
+        public IEnumerable<TagDTO>? GetBookmarkTags(int id)
+        {
+            int.TryParse(_httpContextAccessor.HttpContext.User.Identity.GetUserId(), out int userId);
+            if (!_roContext.Bookmarks.Any(x => x.Id == id && x.UserId == userId)) return null;
+
+            var bookmarkTags = _roContext.BookmarkTags
+                .Include(x => x.Tag)
+                .Where(x => x.BookmarkId == id)
+                .Select(x => x.Tag)
+                .ToList();
+
+            return _mapper.Map<IEnumerable<TagDTO>>(bookmarkTags);
+        }
+
+        public async Task<int?> DeleteBookmark(int id)
+        {
+            var result = await DeleteBookmarks(new List<int> { id });
+            return result.FirstOrDefault();
+        }
+
+        public async Task<IEnumerable<int>?> DeleteBookmarks(IEnumerable<int> ids)
+        {
+            var currentUserId = GetCurrentUserId();
+
+            if (!await _roContext.Users.UserExistsAsync(currentUserId)) return null;
+
+            var entriesToDelete = _context.Bookmarks.Where(x => x.UserId == currentUserId && ids.Contains(x.Id)).ToList();
+            _context.Bookmarks.RemoveRange(entriesToDelete);
+
+            if (await _context.SaveChangesAsync() <= 0) return null;
+
+            return entriesToDelete.Select(x => x.Id);
+        }
+
+        public async Task<IEnumerable<int>?> HideBookmarks(IEnumerable<int> ids)
+        {
+            var currentUserId = GetCurrentUserId();
+
+            if (!await _roContext.Users.UserExistsAsync(currentUserId)) return null;
+
+            var entriesToHide = _context.Bookmarks.Where(x => x.UserId == currentUserId && ids.Contains(x.Id)).ToList();
+            entriesToHide.ForEach((x) => { x.IsHidden = !x.IsHidden; });
+
+            if(await _context.SaveChangesAsync() <= 0) return null;
+
+            return entriesToHide.Select(x => x.Id);
+        }
+
+        public IEnumerable<TagDTO> GetAllBookmarkTags(bool showHidden = false)
+        {
+            var currentUserId = GetCurrentUserId();
+
+            var activeUserTags = _roContext.BookmarkTags
+                .Include(x => x.Tag)
+                .Where(x => x.Tag.UserId == currentUserId && x.Tag.IsHidden == showHidden)
+                .ToList()
+                .GroupBy(x => x.Tag.Id)
+                .Select(g => g.First()?.Tag);
+
+            return _mapper.Map<IEnumerable<TagDTO>>(activeUserTags);
+        }
+
+        private int GetCurrentUserId()
+        {
+            int.TryParse(_httpContextAccessor.HttpContext.User.Identity.GetUserId(), out int userId);
+            return userId;
+        }
+
+        private void UpdateBookmarkWithMetaData(IBookmark bookmark)
+        {
+            var webClient = new WebClient();
+            webClient.Headers.Add("User-Agent", "APIClient");
+            var sourceData = webClient.DownloadString(bookmark.Url);
+            var title = Regex.Match(sourceData, @"\<title\b[^>]*\>\s*(?<Title>[\s\S]*?)\</title\>", RegexOptions.IgnoreCase).Groups["Title"].Value;
+            var description = string.Empty;
+
+            var getHtmlDoc = new HtmlWeb();
+            var document = getHtmlDoc.Load(bookmark.Url);
+            var metaTags = document.DocumentNode.SelectNodes("//meta");
+            if (metaTags != null)
+            {
+                foreach (var sitetag in metaTags)
+                {
+                    if (sitetag.Attributes["name"] != null && sitetag.Attributes["content"] != null && sitetag.Attributes["name"].Value == "description")
+
+                    {
+
+                        description = sitetag.Attributes["content"].Value;
+                    }
+                }
+            }
+
+            bookmark.Title = !string.IsNullOrEmpty(bookmark.Title) ? bookmark.Title : string.IsNullOrEmpty(title) ? bookmark.Url : title;
+            bookmark.Description = !string.IsNullOrEmpty(bookmark.Description) ? bookmark.Description : description;
+        }
+    }
+}

API/YABA.Service/Configuration/AutoMapperProfile.cs

@@ -0,0 +1,22 @@
+using AutoMapper;
+using YABA.Common.DTOs;
+using YABA.Common.DTOs.Bookmarks;
+using YABA.Common.DTOs.Tags;
+using YABA.Models;
+
+namespace YABA.Service.Configuration
+{
+    public class AutoMapperProfile : Profile
+    {
+        public AutoMapperProfile()
+        {
+            CreateMap<User, UserDTO>();
+            CreateMap<BookmarkDTO, Bookmark>();
+            CreateMap<Bookmark, BookmarkDTO>();
+            CreateMap<CreateBookmarkRequestDTO, Bookmark>();
+            CreateMap<Tag, TagDTO>();
+            CreateMap<CreateTagDTO, Tag>()
+                .ForMember(dest => dest.Name, opt => opt.MapFrom(src => src.Name.ToLowerInvariant()));
+        }
+    }
+}

API/YABA.Service/Configuration/DependencyInjectionConfiguration.cs

@@ -0,0 +1,17 @@
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using YABA.Service.Interfaces;
+
+namespace YABA.Service.Configuration
+{
+    public static class DependencyInjectionConfiguration
+    {
+        public static void AddServiceProjectDependencyInjectionConfiguration(this IServiceCollection services, IConfiguration configuration)
+        {
+            services.AddScoped<IUserService, UserService>();
+            services.AddScoped<IBookmarkService, BookmarkService>();
+            services.AddScoped<IMiscService, MiscService>();
+            services.AddScoped<ITagsService, TagsService>();
+        }
+    }
+}

API/YABA.Service/Interfaces/IBookmarkService.cs

@@ -0,0 +1,22 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using YABA.Common.DTOs.Bookmarks;
+using YABA.Common.DTOs.Tags;
+
+namespace YABA.Service.Interfaces
+{
+    public interface IBookmarkService
+    {
+        Task<BookmarkDTO?> CreateBookmark(CreateBookmarkRequestDTO request);
+        Task<BookmarkDTO?> UpdateBookmark(int id, UpdateBookmarkRequestDTO request);
+        Task<IEnumerable<TagDTO>?> UpdateBookmarkTags(int id, IEnumerable<string> tags);
+        IEnumerable<BookmarkDTO> GetAll(bool isHidden = false);
+        Task<BookmarkDTO?> Get(int id);
+        IEnumerable<TagDTO>? GetBookmarkTags(int id);
+        Task<int?> DeleteBookmark(int id);
+        Task<IEnumerable<int>?> DeleteBookmarks(IEnumerable<int> ids);
+        Task<IEnumerable<int>?> HideBookmarks(IEnumerable<int> ids);
+        IEnumerable<TagDTO> GetAllBookmarkTags(bool showHidden = false);
+        
+    }
+}

API/YABA.Service/Interfaces/IMiscService.cs

@@ -0,0 +1,9 @@
+using YABA.Common.DTOs;
+
+namespace YABA.Service.Interfaces
+{
+    public interface IMiscService
+    {
+        public WebsiteMetaDataDTO GetWebsiteMetaData(string url);
+    }
+}

API/YABA.Service/Interfaces/ITagsService.cs

@@ -0,0 +1,18 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using YABA.Common.DTOs.Tags;
+
+namespace YABA.Service.Interfaces
+{
+    public interface ITagsService
+    {
+        Task<IEnumerable<TagDTO>?> GetAll();
+        Task<TagDTO?> Get(int id);
+        Task<IEnumerable<TagDTO>?> UpsertTags(IEnumerable<TagDTO> tags);
+        Task<TagDTO?> UpsertTag(TagDTO tag);
+        Task<IEnumerable<int>?> DeleteTags(IEnumerable<int> ids);
+        Task<IEnumerable<int>?> HideTags(IEnumerable<int> ids);
+        Task<TagDTO?> CreateTag(CreateTagDTO request);
+        Task<TagDTO?> UpdateTag(int id, UpdateTagDTO request);
+    }
+}

API/YABA.Service/Interfaces/IUserService.cs

@@ -0,0 +1,12 @@
+using System.Threading.Tasks;
+using YABA.Common.DTOs;
+
+namespace YABA.Service.Interfaces
+{
+    public interface IUserService
+    {
+        bool IsUserRegistered(string authProviderId);
+        Task<UserDTO> RegisterUser(string authProviderId);
+        int GetUserId(string authProviderId);
+    }
+}

API/YABA.Service/MiscService.cs

@@ -0,0 +1,53 @@
+using HtmlAgilityPack;
+using System;
+using System.Net;
+using System.Text.RegularExpressions;
+using YABA.Common.DTOs;
+using YABA.Service.Interfaces;
+
+namespace YABA.Service
+{
+    public class MiscService : IMiscService
+    {
+        public MiscService() { }
+
+        public WebsiteMetaDataDTO GetWebsiteMetaData(string url)
+        {
+            try
+            {
+                var webClient = new WebClient();
+                webClient.Headers.Add("user-agent", "API-Application");
+                var sourceData = webClient.DownloadString(url);
+                var title = Regex.Match(sourceData, @"\<title\b[^>]*\>\s*(?<Title>[\s\S]*?)\</title\>", RegexOptions.IgnoreCase).Groups["Title"].Value;
+                var description = string.Empty;
+
+                var getHtmlDoc = new HtmlWeb();
+                var document = getHtmlDoc.Load(url);
+                var metaTags = document.DocumentNode.SelectNodes("//meta");
+                if (metaTags != null)
+                {
+                    foreach (var sitetag in metaTags)
+                    {
+                        if (sitetag.Attributes["name"] != null && sitetag.Attributes["content"] != null && sitetag.Attributes["name"].Value == "description")
+                        {
+                            description = sitetag.Attributes["content"].Value;
+                        }
+                    }
+                }
+
+                return new WebsiteMetaDataDTO
+                {
+                    Title = title,
+                    Description = description
+                };
+            } catch(Exception)
+            {
+                return new WebsiteMetaDataDTO
+                {
+                    Title = url,
+                    Description = string.Empty
+                };
+            }
+        }
+    }
+}

API/YABA.Service/TagsService.cs

@@ -0,0 +1,133 @@
+using AutoMapper;
+using Microsoft.AspNetCore.Http;
+using Microsoft.EntityFrameworkCore;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using YABA.Common.DTOs.Tags;
+using YABA.Common.Extensions;
+using YABA.Data.Context;
+using YABA.Data.Extensions;
+using YABA.Models;
+using YABA.Service.Interfaces;
+
+namespace YABA.Service
+{
+    public class TagsService : ITagsService
+    {
+        private readonly YABAReadOnlyContext _roContext;
+        private readonly YABAReadWriteContext _rwContext;
+        private readonly IHttpContextAccessor _httpContextAccessor;
+        private readonly IMapper _mapper;
+
+        public TagsService(
+            YABAReadOnlyContext roContext, 
+            YABAReadWriteContext rwContext,
+            IHttpContextAccessor httpContextAccessor, 
+            IMapper mapper)
+        {
+            _roContext = roContext;
+            _rwContext = rwContext;
+            _httpContextAccessor = httpContextAccessor;
+            _mapper = mapper;
+        }
+
+        public async Task<IEnumerable<TagDTO>?> GetAll()
+        {
+            var currentUserId = GetCurrentUserId();
+            if (!await _roContext.Users.UserExistsAsync(currentUserId)) return null;
+
+            var activeUserTags = _roContext.Tags
+                .Where(x => x.UserId == currentUserId)
+                .ToList();
+
+            return _mapper.Map<IEnumerable<TagDTO>>(activeUserTags);
+        }
+
+        public async Task<TagDTO?> Get(int id)
+        {
+            var currentUserId = GetCurrentUserId();
+            if (!await _roContext.Users.UserExistsAsync(currentUserId)) return null;
+
+            var bookmark = await _roContext.Tags.FirstOrDefaultAsync(x => x.Id == id && x.UserId == currentUserId);
+            return _mapper.Map<TagDTO>(bookmark);
+        }
+
+        public async Task<IEnumerable<TagDTO>?> UpsertTags(IEnumerable<TagDTO> tags)
+        {
+            var currentUserId = GetCurrentUserId();
+            if (!await _roContext.Users.UserExistsAsync(currentUserId)) return null;
+
+            var tagsToUpsert = tags.Select(x => new Tag { Id = x.Id, Name = x.Name.ToLower(), IsHidden = x.IsHidden, UserId = currentUserId});
+            _rwContext.Tags.UpsertRange(tagsToUpsert);
+            await _rwContext.SaveChangesAsync();
+
+            var newlyUpsertedTags = _roContext.Tags.Where(x => tagsToUpsert.Select(x => x.Name).Contains(x.Name)).ToList();
+            return _mapper.Map<IEnumerable<TagDTO>>(newlyUpsertedTags);
+        }
+
+        public async Task<IEnumerable<int>?> DeleteTags(IEnumerable<int> ids)
+        {
+            var currentUserId = GetCurrentUserId();
+            if (!await _roContext.Users.UserExistsAsync(currentUserId)) return null;
+
+            var entriesToDelete = _rwContext.Tags.Where(x => x.UserId == currentUserId && ids.Contains(x.Id)).ToList();
+            _rwContext.Tags.RemoveRange(entriesToDelete);
+
+            if (await _rwContext.SaveChangesAsync() <= 0) return null;
+
+            return entriesToDelete.Select(x => x.Id);
+        }
+
+        public async Task<IEnumerable<int>?> HideTags(IEnumerable<int> ids)
+        {
+            var currentUserId = GetCurrentUserId();
+            if (!await _roContext.Users.UserExistsAsync(currentUserId)) return null;
+
+            var entriesToHide = _rwContext.Tags.Where(x => x.UserId == currentUserId && ids.Contains(x.Id)).ToList();
+            entriesToHide.ForEach((x) => { x.IsHidden = !x.IsHidden; });
+
+            if (await _rwContext.SaveChangesAsync() <= 0) return null;
+
+            return entriesToHide.Select(x => x.Id);
+        }
+
+        public async Task<TagDTO?> UpsertTag(TagDTO tag) => (await UpsertTags(new List<TagDTO>() { tag }))?.FirstOrDefault();
+
+        public async Task<TagDTO?> CreateTag(CreateTagDTO request)
+        {
+            var currentUserId = GetCurrentUserId();
+
+            if(!(await _roContext.Users.UserExistsAsync(currentUserId))
+                || await _roContext.Tags.AnyAsync(x => x.UserId == currentUserId && x.Name.ToLower() == request.Name.ToLower()))
+                return null;
+
+            var tag = _mapper.Map<Tag>(request);
+            tag.UserId = currentUserId;
+
+            var newEntity = await _rwContext.Tags.AddAsync(tag);
+
+            return await _rwContext.SaveChangesAsync() > 0 ? _mapper.Map<TagDTO>(newEntity.Entity) : null;
+        }
+
+        public async Task<TagDTO?> UpdateTag(int id, UpdateTagDTO request)
+        {
+            var currentUserId = GetCurrentUserId();
+            var tag = await _rwContext.Tags.FirstOrDefaultAsync(x => x.UserId == currentUserId && x.Id == id);
+
+            if (tag == null) return null;
+
+            tag.Name = !string.IsNullOrEmpty(request.Name) ? request.Name.ToLower() : tag.Name;
+            tag.IsHidden = request.IsHidden.HasValue ? request.IsHidden.Value : tag.IsHidden;
+
+            return await _rwContext.SaveChangesAsync() > 0 ? _mapper.Map<TagDTO>(tag) : null;
+        }
+
+        private int GetCurrentUserId()
+        {
+            int.TryParse(_httpContextAccessor.HttpContext.User.Identity.GetUserId(), out int userId);
+            return userId;
+        }
+    }
+}

API/YABA.Service/UserService.cs

@@ -0,0 +1,79 @@
+using AutoMapper;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+using Npgsql;
+using System;
+using System.Linq;
+using System.Threading.Tasks;
+using YABA.Common.DTOs;
+using YABA.Data.Context;
+using YABA.Models;
+using YABA.Service.Interfaces;
+
+namespace YABA.Service
+{
+    public class UserService : IUserService
+    {
+        private readonly YABAReadOnlyContext _roContext;
+        private readonly YABAReadWriteContext _context;
+        private readonly IMapper _mapper;
+        private readonly ILogger<UserService> _logger;
+
+        public UserService (YABAReadOnlyContext roContext, YABAReadWriteContext context, IMapper mapper, ILogger<UserService> logger)
+        {
+            _roContext = roContext;
+            _context = context;
+            _mapper = mapper;
+            _logger = logger;
+        }
+
+        public bool IsUserRegistered(string authProviderId)
+        {
+            return _roContext.Users.Any(x => x.Auth0Id == authProviderId);
+        }
+
+        public async Task<UserDTO> RegisterUser(string authProviderId)
+        {
+            try
+            {
+                if (!IsUserRegistered(authProviderId))
+                {
+                    var userToRegister = new User
+                    {
+                        Auth0Id = authProviderId
+                    };
+
+                    var registedUser = _context.Users.Add(userToRegister);
+                    await _context.SaveChangesAsync();
+                }
+            } 
+            catch (Exception ex)
+            {
+                if(ex.InnerException is PostgresException &&
+                    ((PostgresException)ex.InnerException).Code == "23505")
+                {
+                    var postgresException = (PostgresException)ex.InnerException;
+                    _logger.LogWarning("Swallowing constraint violation: {@ConstraintName} for {@AuthProviderId}", postgresException.ConstraintName, authProviderId);
+                }
+                else
+                {
+                    throw ex;
+                }
+            }
+
+            return await Get(authProviderId);
+        }
+
+        public async Task<UserDTO> Get(string authProviderId)
+        {
+            var user = await _roContext.Users.FirstOrDefaultAsync(x => x.Auth0Id == authProviderId);
+            return _mapper.Map<UserDTO>(user);
+        }
+
+        public int GetUserId(string authProviderId)
+        {
+            var user = _roContext.Users.FirstOrDefault(x => x.Auth0Id == authProviderId);
+            return user != null ? user.Id : 0;
+        }
+    }
+}

API/YABA.Service/YABA.Service.csproj

@@ -0,0 +1,22 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="AutoMapper" Version="12.0.1" />
+    <PackageReference Include="HtmlAgilityPack" Version="1.11.46" />
+    <PackageReference Include="Microsoft.AspNetCore.Http.Abstractions" Version="2.2.0" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.Abstractions" Version="7.0.0" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="7.0.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\YABA.Common\YABA.Common.csproj" />
+    <ProjectReference Include="..\YABA.Data\YABA.Data.csproj" />
+    <ProjectReference Include="..\YABA.Models\YABA.Models.csproj" />
+  </ItemGroup>
+
+</Project>