#5 Extract the logic for teams into a service.

src/Wuzlstats/Services/TeamStatisticsService.cs

@@ -0,0 +1,115 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.EntityFrameworkCore;
+using Wuzlstats.Models;
+using Wuzlstats.ViewModels.Teams;
+
+namespace Wuzlstats.Services
+{
+    public class TeamStatisticsService
+    {
+        private readonly Db _db;
+
+        public TeamStatisticsService(Db db)
+        {
+            _db = db;
+        }
+
+        public async Task<IEnumerable<TeamViewModel>> FindTeamsOfLeagueAsync(int leagueId, int? daysForStatistics)
+        {
+            var gamesQuery = FetchGames(leagueId, daysForStatistics);
+
+            var teams = new List<TeamViewModel>();
+
+            var players2 = await _db.Players.Where(x => x.LeagueId == leagueId).ToListAsync();
+
+            var players = players2.Select(player => new PlayerViewModel
+            {
+                Id = player.Id,
+                Name = player.Name,
+                Image = player.Image == null || player.Image.Length <= 0 ? EmptyAvatar.Base64 : Convert.ToBase64String(player.Image)
+            }).ToList();
+
+            foreach (var game in await gamesQuery.ToListAsync())
+            {
+                var positions = await (from position in _db.PlayerPositions.AsNoTracking()
+                                       join player in _db.Players.AsNoTracking() on position.PlayerId equals player.Id
+                                       where position.GameId == game.Id
+                                       where position.Position != PlayerPositionTypes.Blue || position.Position != PlayerPositionTypes.Red
+                                       select new
+                                       {
+                                           position.Position,
+                                           Player = player
+                                       }).ToListAsync();
+
+                // team stats
+                if (positions.Count(x => x.Position == PlayerPositionTypes.BlueDefense) == 1
+                    && positions.Count(x => x.Position == PlayerPositionTypes.BlueOffense) == 1
+                    && positions.Count(x => x.Position == PlayerPositionTypes.RedDefense) == 1
+                    && positions.Count(x => x.Position == PlayerPositionTypes.RedOffense) == 1)
+                {
+                    var redOffense = players.Single(x => x.Id == positions.Single(y => y.Position == PlayerPositionTypes.RedOffense).Player.Id);
+                    var redDefense = players.Single(x => x.Id == positions.Single(y => y.Position == PlayerPositionTypes.RedDefense).Player.Id);
+                    var blueOffense = players.Single(x => x.Id == positions.Single(y => y.Position == PlayerPositionTypes.BlueOffense).Player.Id);
+                    var blueDefense = players.Single(x => x.Id == positions.Single(y => y.Position == PlayerPositionTypes.BlueDefense).Player.Id);
+
+                    var redTeam = teams.FirstOrDefault(x => x.Equals(redOffense, redDefense));
+                    if (redTeam == null)
+                    {
+                        redTeam = CreateTeam(redOffense, redDefense);
+                        teams.Add(redTeam);
+                    }
+                    var blueTeam = teams.FirstOrDefault(x => x.Equals(blueOffense, blueDefense));
+                    if (blueTeam == null)
+                    {
+                        blueTeam = CreateTeam(blueOffense, blueDefense);
+                        teams.Add(blueTeam);
+                    }
+
+                    if (game.BlueWins)
+                    {
+                        redTeam.Losses++;
+                        blueTeam.Wins++;
+                    }
+                    else if (game.RedWins)
+                    {
+                        redTeam.Wins++;
+                        blueTeam.Losses++;
+                    }
+                }
+            }
+
+            return teams;
+        }
+
+        public static TeamViewModel CreateTeam(PlayerViewModel p1, PlayerViewModel p2)
+        {
+            if (p1.Id <= p2.Id)
+            {
+                return new TeamViewModel
+                {
+                    Player1 = p1,
+                    Player2 = p2
+                };
+            }
+            return new TeamViewModel
+            {
+                Player1 = p2,
+                Player2 = p1
+            };
+        }
+
+        private IQueryable<Game> FetchGames(int leagueId, int? daysForStatistics)
+        {
+            var gamesQuery = _db.Games.AsNoTracking().Where(x => x.LeagueId == leagueId);
+            if (!daysForStatistics.HasValue)
+            {
+                return gamesQuery;
+            }
+            var date = DateTime.UtcNow.Date.AddDays(-daysForStatistics.Value);
+            return gamesQuery.Where(x => x.Date >= date);
+        }
+    }
+}