#1 Add service for retrieving players

src/Wuzlstats/Services/PlayersService.cs

@@ -0,0 +1,119 @@
+using Microsoft.Data.Entity;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Wuzlstats.Models;
+
+namespace Wuzlstats.Services
+{
+    public class PlayersService
+    {
+        private readonly Db _db;
+
+        public PlayersService(Db db)
+        {
+            _db = db;
+        }
+
+        public async Task<IEnumerable<PlayerDto>> FindPlayersOfLeague(int leagueId, int? daysForStatistics)
+        {
+            var gamesQuery = _db.Games.AsNoTracking().Where(x => x.LeagueId == leagueId);
+            if (daysForStatistics.HasValue)
+            {
+                var date = DateTime.UtcNow.Date.AddDays(-daysForStatistics.Value);
+                gamesQuery = gamesQuery.Where(x => x.Date >= date);
+            }
+
+            // EF7 beta4 does not support navigation properties in queries yet
+            // this complicates the code a lot, because we need joins :(
+
+            var players = new List<PlayerDto>();
+
+            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
+                                       select new
+                                       {
+                                           position.Position,
+                                           Player = player
+                                       }).ToListAsync();
+                // player stats
+                foreach (var position in positions)
+                {
+                    var player = players.FirstOrDefault(x => x.Equals(position.Player));
+                    if (player == null)
+                    {
+                        player = PlayerDto.Create(position.Player);
+                        players.Add(player);
+                    }
+                    // calculate count of single or team games
+                    if (position.Position == PlayerPositionTypes.Blue || position.Position == PlayerPositionTypes.Red)
+                    {
+                        player.SingleGames++;
+                    }
+                    else
+                    {
+                        player.TeamGames++;
+                    }
+
+                    // don't count ties
+                    if (game.BlueWins && (position.Position == PlayerPositionTypes.Blue || position.Position == PlayerPositionTypes.BlueDefense || position.Position == PlayerPositionTypes.BlueOffense))
+                    {
+                        player.Wins++;
+                    }
+                    else if (game.RedWins && (position.Position == PlayerPositionTypes.Red || position.Position == PlayerPositionTypes.RedDefense || position.Position == PlayerPositionTypes.RedOffense))
+                    {
+                        player.Wins++;
+                    }
+                    else if (game.RedWins &&
+                             (position.Position == PlayerPositionTypes.Blue || position.Position == PlayerPositionTypes.BlueDefense || position.Position == PlayerPositionTypes.BlueOffense))
+                    {
+                        player.Losses++;
+                    }
+                    else if (game.BlueWins &&
+                             (position.Position == PlayerPositionTypes.Red || position.Position == PlayerPositionTypes.RedDefense || position.Position == PlayerPositionTypes.RedOffense))
+                    {
+                        player.Losses++;
+                    }
+                    if (game.Date > player.LatestGame)
+                    {
+                        player.LatestGame = game.Date;
+                    }
+                }
+            }
+            return players.OrderByDescending(x => x.LatestGame);
+        }
+    }
+
+    public class PlayerDto
+    {
+        public int Id { get; set; }
+        public string Name { get; set; }
+        public byte[] Image { get; set; }
+        public int Wins { get; set; }
+        public int Losses { get; set; }
+        public int SingleGames { get; set; }
+        public int TeamGames { get; set; }
+        public DateTime LatestGame { get; set; }
+
+        public double Rank => Losses == 0 ? Wins : (Wins == 0 ? 0.1d / Losses : (double)Wins / Losses);
+
+        public bool Equals(Player p)
+        {
+            return Id == p.Id;
+        }
+
+        public static PlayerDto Create(Player p)
+        {
+            return new PlayerDto
+            {
+                Id = p.Id,
+                Name = p.Name,
+                Image = p.Image
+            };
+        }
+    }
+}