Split codewords into its own system (#37928)

* Split codewords into its own system

* Fix admin log

* Nuke unused code

* Fix formatting errors

* Fix tests

* Make the codeword system add itself if called when not active

* Put comment in right place.

* Review: Rename prototypes

* Review: Make codewords serializable

* Fix build

* Reviews: Change the system to not be a gamerule.

* Fix YAML Linter

* Fix test fail

* Remove unused import

Content.Server/Codewords/CodewordSystem.cs

@@ -0,0 +1,90 @@
+using System.Linq;
+using Content.Server.Administration.Logs;
+using Content.Server.GameTicking.Events;
+using Content.Shared.Database;
+using Robust.Shared.Map;
+using Robust.Shared.Prototypes;
+using Robust.Shared.Random;
+
+namespace Content.Server.Codewords;
+
+/// <summary>
+/// Gamerule that provides codewords for other gamerules that rely on them.
+/// </summary>
+public sealed class CodewordSystem : EntitySystem
+{
+    [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
+    [Dependency] private readonly IAdminLogManager _adminLogger = default!;
+    [Dependency] private readonly IRobustRandom _random = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+
+        SubscribeLocalEvent<RoundStartingEvent>(OnRoundStart);
+    }
+
+    private void OnRoundStart(RoundStartingEvent ev)
+    {
+        var manager = Spawn();
+        AddComp<CodewordManagerComponent>(manager);
+    }
+
+    /// <summary>
+    /// Retrieves codewords for the faction specified.
+    /// </summary>
+    public string[] GetCodewords(ProtoId<CodewordFactionPrototype> faction)
+    {
+        var query = EntityQueryEnumerator<CodewordManagerComponent>();
+        while (query.MoveNext(out  _, out var manager))
+        {
+            if (!manager.Codewords.TryGetValue(faction, out var codewordEntity))
+                return GenerateForFaction(faction, ref manager);
+
+            return Comp<CodewordComponent>(codewordEntity).Codewords;
+        }
+
+        Log.Warning("Codeword system not initialized. Returning empty array.");
+        // While throwing in this situation would be cool, that causes a test fail (in SpawnAndDeleteEntityCountTest)
+        // as the traitor codewords paper gets spawned in and calls this method,
+        // but the "start round" event never gets called in this test case.
+        return [];
+    }
+
+    private string[] GenerateForFaction(ProtoId<CodewordFactionPrototype> faction, ref CodewordManagerComponent manager)
+    {
+        var factionProto = _prototypeManager.Index<CodewordFactionPrototype>(faction.Id);
+
+        var codewords = GenerateCodewords(factionProto.Generator);
+        var codewordsContainer = EntityManager.Spawn(protoName:null, MapCoordinates.Nullspace);
+        EnsureComp<CodewordComponent>(codewordsContainer)
+            .Codewords = codewords;
+        manager.Codewords[faction] = codewordsContainer;
+        _adminLogger.Add(LogType.EventStarted, LogImpact.Low, $"Codewords generated for faction {faction}: {string.Join(", ", codewords)}");
+
+        return codewords;
+    }
+
+    /// <summary>
+    /// Generates codewords as specified by the <see cref="CodewordGeneratorPrototype"/> codeword generator.
+    /// </summary>
+    public string[] GenerateCodewords(ProtoId<CodewordGeneratorPrototype> generatorId)
+    {
+        var generator = _prototypeManager.Index(generatorId);
+
+        var codewordPool = new List<string>();
+        foreach (var dataset in generator.Words
+                     .Select(datasetPrototype => _prototypeManager.Index(datasetPrototype)))
+        {
+            codewordPool.AddRange(dataset.Values);
+        }
+
+        var finalCodewordCount = Math.Min(generator.Amount, codewordPool.Count);
+        var codewords = new string[finalCodewordCount];
+        for (var i = 0; i < finalCodewordCount; i++)
+        {
+            codewords[i] = Loc.GetString(_random.PickAndTake(codewordPool));
+        }
+        return codewords;
+    }
+}