Make voting work

2 files changed, 133 insertions, 0 deletions

diff --git a/backend/Elements.Backend/Services/FinishVoteService.cs b/backend/Elements.Backend/Services/FinishVoteService.cs
new file mode 100644
index 0000000..8486036
--- /dev/null
+++ b/backend/Elements.Backend/Services/FinishVoteService.cs
@@ -0,0 +1,95 @@
+using Elements.Data;
+using Elements.Data.Models;
+using Microsoft.EntityFrameworkCore;
+
+namespace Elements.Backend.Services;
+
+public class FinishVoteService
+{
+    private readonly ApplicationDbContext _dbContext;
+    private readonly ILogger<FinishVoteService> _logger;
+
+    public FinishVoteService(ApplicationDbContext dbContext, ILogger<FinishVoteService> logger)
+    {
+        _dbContext = dbContext;
+        _logger = logger;
+    }
+
+    public async Task DoSomethingAsync()
+    {
+        _logger.LogDebug("Starting finalizing votes");
+        List<Suggestion> finishedSuggestions = _dbContext.Suggestions
+            .Include(s => s.Votes)
+            .Where(s => DateTime.UtcNow > s.VotingEnd)
+            .ToList();
+
+        if (finishedSuggestions.Count == 0)
+            return;
+
+        bool finished = false;
+        while (!finished)
+        {
+            Suggestion currentSuggestion = finishedSuggestions.First();
+            int firstElementId = currentSuggestion.FirstElementId;
+            int secondElementId = currentSuggestion.SecondElementId;
+            //Get all suggestions with same recipe as current suggestion
+            List<Suggestion> sameRecipeSuggestions = finishedSuggestions.Where(s =>
+                    (s.FirstElementId == firstElementId && s.SecondElementId == secondElementId) ||
+                    (s.FirstElementId == secondElementId && s.SecondElementId == firstElementId))
+                .ToList();
+            sameRecipeSuggestions.Sort((s1, s2) => s2.Votes.Count.CompareTo(s1.Votes.Count));
+            
+            Suggestion winner;
+            if (sameRecipeSuggestions.Count > 1 &&
+                sameRecipeSuggestions[0].Votes.Count == sameRecipeSuggestions[1].Votes.Count)
+            {
+                List<Suggestion> sameAmountOfVotes = sameRecipeSuggestions
+                        .Where(s => s.Votes.Count == sameRecipeSuggestions[0].Votes.Count)
+                        .OrderBy(s => s.CreationDate)
+                        .ToList();
+
+                winner = sameAmountOfVotes[0];
+            }
+            else
+            {
+                winner = sameRecipeSuggestions[0];
+            }
+
+            Element newElement = new()
+            {
+                CreationDate = winner.CreationDate,
+                UserId = winner.UserId,
+                Name = winner.Name,
+                State = ElementState.HasColor,
+                IconPng = winner.Icon
+            };
+            await _dbContext.Elements.AddAsync(newElement);
+            await _dbContext.SaveChangesAsync();
+            
+            await _dbContext.Recipes.AddAsync(new Recipe
+            {
+                FirstElementId = winner.FirstElementId,
+                SecondElementId = winner.SecondElementId,
+                ResultElementId = newElement.Id,
+            });
+
+            //Delete votes
+            foreach (Vote vote in sameRecipeSuggestions.SelectMany(suggestion => suggestion.Votes))
+                _dbContext.Entry(vote).State = EntityState.Deleted;
+
+            //Delete suggestions
+            foreach (Suggestion suggestion in sameRecipeSuggestions)
+                _dbContext.Entry(suggestion).State = EntityState.Deleted;
+            
+            await _dbContext.SaveChangesAsync();
+            
+            finishedSuggestions = finishedSuggestions
+                .Where(s => !(s.FirstElementId == firstElementId && s.SecondElementId == secondElementId) &&
+                            !(s.FirstElementId == secondElementId && s.SecondElementId == firstElementId))
+                .ToList();
+            
+            if (finishedSuggestions.Count == 0)
+                finished = true;
+        }
+    }
+}
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diff --git a/backend/Elements.Backend/Services/PeriodicService.cs b/backend/Elements.Backend/Services/PeriodicService.cs
new file mode 100644
index 0000000..48cdf2f
--- /dev/null
+++ b/backend/Elements.Backend/Services/PeriodicService.cs
@@ -0,0 +1,38 @@
+namespace Elements.Backend.Services;
+
+class PeriodicService : BackgroundService
+{
+    private readonly TimeSpan _period = TimeSpan.FromMinutes(1);
+    private readonly ILogger<PeriodicService> _logger;
+    private readonly IServiceScopeFactory _factory;
+    public bool IsEnabled { get; set; } = true;
+
+    public PeriodicService(
+        ILogger<PeriodicService> logger, 
+        IServiceScopeFactory factory)
+    {
+        _logger = logger;
+        _factory = factory;
+    }
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        using PeriodicTimer timer = new PeriodicTimer(_period);
+        while (
+            !stoppingToken.IsCancellationRequested &&
+            await timer.WaitForNextTickAsync(stoppingToken))
+        {
+            try
+            {
+                if (!IsEnabled) continue;
+                await using AsyncServiceScope asyncScope = _factory.CreateAsyncScope();
+                FinishVoteService finishVoteService = asyncScope.ServiceProvider.GetRequiredService<FinishVoteService>();
+                await finishVoteService.DoSomethingAsync();
+            }
+            catch (Exception ex)
+            {
+                _logger.LogInformation($"Failed to execute periodic service, Error: {ex.Message}.");
+            }
+        }
+    }
+}
\ No newline at end of file