1 files changed, 47 insertions, 0 deletions
diff --git a/Services/GameService.cs b/Services/GameService.cs
new file mode 100644
index 0000000..01c084a
--- /dev/null
+++ b/Services/GameService.cs
@@ -0,0 +1,47 @@
+using Microsoft.EntityFrameworkCore;
+using BackendPIA.Models;
+
+namespace BackendPIA.Services {
+    public class GameService : IGameService {
+        private readonly ApplicationDbContext _context;
+
+        public GameService(ApplicationDbContext context) {
+            _context = context;
+        }
+
+        public async Task<IEnumerable<RaffleWinner>> GetWinners(long raffle_id) {
+            var raffle = await _context.Raffles.Include(r => r.Tickets.Select(t => t.Owner)).FirstOrDefaultAsync(r => r.Id == raffle_id);
+            Queue<long> prizes = new Queue<long>(_context.Prizes.Where(p => p.RaffleId == raffle_id).Select(p => p.Id));
+            var tickets = await _context.Tickets.Where(t => t.RaffleId == raffle_id).Select(t => t.Number).ToListAsync();
+            List<int> winners = GetTicketNumbers(raffle.Winners, tickets);
+            List<RaffleWinner> raffle_winners = new List<RaffleWinner>();
+
+            foreach(int winner in winners) {
+                var raffle_winner = new RaffleWinner { UserAccountId = raffle.Tickets.Where(t => t.Number == winner).First().UserAccountId,
+                                                       PrizeId = prizes.Dequeue(), RaffleId = raffle_id };
+                raffle_winners.Add(raffle_winner);
+                await _context.AddAsync(raffle_winner);
+            }
+
+            await _context.SaveChangesAsync();
+
+            return raffle_winners;
+        }
+
+        private List<int> GetTicketNumbers(int limit, List<int> tickets) {
+            List<int> winners = new List<int>();
+            Random rng = new Random();
+
+            while(winners.Count < limit) {
+                int i = rng.Next(tickets.Count - 1);
+
+                if(winners.Contains(tickets[i])) // Check for duplicate numbers. 
+                    continue;
+
+                winners.Append(tickets[i]);
+            }
+
+            return winners;
+        }
+    }
+}
+\ No newline at end of file