#495 RateCommentAsync

RMuseum/Services/Implementation/GanjoorService-Partials/GanjoorService-CommentRating.cs

@@ -0,0 +1,99 @@
+using Microsoft.EntityFrameworkCore;
+using RMuseum.Models.Ganjoor;
+using RMuseum.Utils;
+using RSecurityBackend.Models.Generic;
+using System;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace RMuseum.Services.Implementation
+{
+    /// <summary>
+    /// IGanjoorService implementation
+    /// </summary>
+    public partial class GanjoorService : IGanjoorService
+    {
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param name="userId"></param>
+        /// <param name="commentId"></param>
+        /// <param name="value">+1: like, -1: dislike, 0: remove previous rating</param>
+        /// <returns></returns>
+        public async Task<RServiceResult<bool>> RateCommentAsync(Guid userId, int commentId, short value)
+        {
+            if(value != 1 && value != -1 && value != 0)
+            {
+                return new RServiceResult<bool>(false, "value != 1 && value != -1 && value != 0");
+            }
+            try
+            {
+                var oldRating = await _context.GanjoorCommentReactions.Where(c => c.GanjoorCommentId == commentId && c.UserId == userId).SingleOrDefaultAsync();
+                if(value == 0 && oldRating == null)
+                {
+                    return new RServiceResult<bool>(true);
+                }
+                if (oldRating != null)
+                {
+                    if (oldRating.Value == value)
+                    {
+                        return new RServiceResult<bool>(true);
+                    }
+                    if(value == 0)
+                    {
+                        _context.Remove(oldRating);
+                    }
+                    else
+                    {
+                        oldRating.Value = value;
+                        oldRating.ReactionDate = DateTime.Now;
+                        _context.Update(oldRating);
+                    }
+                    await _context.SaveChangesAsync();
+
+                    return await ReCalculateCommentSortKeyAsync(commentId);
+                }
+                else 
+                {
+                    var rating = new GanjoorCommentReaction()
+                    {
+                        GanjoorCommentId = commentId,
+                        UserId = userId,
+                        Value = value,
+                        ReactionDate = DateTime.Now,
+                    };
+                    _context.Add(rating);
+                    await _context.SaveChangesAsync();
+                    return await ReCalculateCommentSortKeyAsync(commentId);
+                }
+
+            }
+            catch (Exception exp)
+            {
+                return new RServiceResult<bool>(false, exp.ToString());
+            }
+        }
+
+        private async Task<RServiceResult<bool>> ReCalculateCommentSortKeyAsync(int commentId)
+        {
+            try
+            {
+                var likes = await _context.GanjoorCommentReactions.AsNoTracking().Where(r => r.GanjoorCommentId == commentId && r.Value == 1).SumAsync(r => r.Value);
+                var dislikes = await _context.GanjoorCommentReactions.AsNoTracking().Where(r => r.GanjoorCommentId == commentId && r.Value == -1).SumAsync(r => r.Value);
+                var comment = await _context.GanjoorComments.Where(c => c.Id == commentId).SingleOrDefaultAsync();
+                if(comment == null)
+                {
+                    return new RServiceResult<bool>(false, "comment == null");
+                }
+                comment.SortKey = GanjoorCommentRankingScoreCalculator.ComputeRankingScore(likes, dislikes);
+                _context.Update(comment);
+                await _context.SaveChangesAsync();
+                return new RServiceResult<bool>(true);
+            }
+            catch (Exception exp)
+            {
+                return new RServiceResult<bool>(false, exp.ToString());
+            }
+        }
+    }
+}