Add rating to chapter page & volume (if one chapter)

API/Services/RatingService.cs

@@ -0,0 +1,63 @@
+using System;
+using System.Threading.Tasks;
+using API.Data;
+using API.Data.Repositories;
+using API.DTOs;
+using API.Entities;
+using Microsoft.Extensions.Logging;
+
+namespace API.Services;
+
+public interface IRatingService
+{
+    Task<bool> UpdateChapterRating(int userId, UpdateChapterRatingDto dto);
+}
+
+public class RatingService: IRatingService
+{
+
+    private readonly IUnitOfWork _unitOfWork;
+    private readonly ILogger<RatingService> _logger;
+
+    public RatingService(IUnitOfWork unitOfWork, ILogger<RatingService> logger)
+    {
+        _unitOfWork = unitOfWork;
+        _logger = logger;
+    }
+
+    public async Task<bool> UpdateChapterRating(int userId, UpdateChapterRatingDto dto)
+    {
+        var user = await _unitOfWork.UserRepository.GetUserByIdAsync(userId, AppUserIncludes.ChapterRatings);
+        if (user == null) throw new UnauthorizedAccessException();
+
+        var rating = await _unitOfWork.UserRepository.GetUserChapterRatingAsync(dto.ChapterId, userId) ?? new AppUserChapterRating();
+
+        rating.Rating = Math.Clamp(dto.Rating, 0, 5);
+        rating.HasBeenRated = true;
+        rating.ChapterId = dto.ChapterId;
+
+        if (rating.Id == 0)
+        {
+            user.ChapterRatings.Add(rating);
+        }
+
+        _unitOfWork.UserRepository.Update(user);
+
+        try
+        {
+            if (!_unitOfWork.HasChanges() || await _unitOfWork.CommitAsync())
+            {
+                // Scrobble Update?
+                return true;
+            }
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "There was an exception while updating chapter rating");
+        }
+
+        await _unitOfWork.RollbackAsync();
+        user.ChapterRatings.Remove(rating);
+        return false;
+    }
+}