feat: add BasePower abstraction

PlayerPowers.cs

@@ -0,0 +1,42 @@
+using CounterStrikeSharp.API.Core;
+using Cs2SuperPowers.Powers;
+
+namespace Cs2SuperPowers;
+
+public class PlayerPowers
+{
+    private static PlayerPowers? _instance;
+    public static PlayerPowers Instance => _instance ??= new PlayerPowers();
+    
+    private readonly IDictionary<CCSPlayerController, ISuperPower> _superPowers 
+        = new Dictionary<CCSPlayerController, ISuperPower>();
+
+    public void RemovePower(CCSPlayerController player)
+    {
+        if (!_superPowers.TryGetValue(player, out var superPower)) return;
+        
+        superPower.UnassignFromPlayer(player);
+        _superPowers.Remove(player);
+    }
+    
+    public void AddPower(CCSPlayerController player, ISuperPower superPower, bool showMessages)
+    {
+        if (_superPowers.TryGetValue(player, out var existingSuperPower))
+        {
+            existingSuperPower.UnassignFromPlayer(player);
+            _superPowers.Remove(player);
+        };
+        
+        superPower.AssignToPlayer(player, showMessages);
+        _superPowers.Add(player, superPower);
+    }
+
+    public bool TryGetValue(CCSPlayerController attacker, out ISuperPower? power) 
+        => _superPowers.TryGetValue(attacker, out power);
+
+    public IEnumerable<(CCSPlayerController Player, ISuperPower Power)> GetAssignedPowers() 
+        => _superPowers.Select(x => (x.Key, x.Value));
+
+    public IEnumerable<CCSPlayerController> GetPlayersWithPower(ISuperPower power)
+        => GetAssignedPowers().Where(x => x.Power.Id == power.Id).Select(x => x.Player);
+}