Split Trainer verifier into TrainerName and TrainerID

verify BDSP legality restrictions

Enforce nonzero TID/SID in Trainer Editor window (can use Block Data editor to set whatever without restriction, idc).

#3305

PKHeX.Core/Legality/Formatting/LegalityCheckStrings.cs

@@ -399,6 +399,7 @@ namespace PKHeX.Core
         public static string LOT_SID0 { get; set; } = "SID is zero.";
         public static string LOT_SID0Invalid { get; set; } = "SID should be 0.";
         public static string LOT_TID0 { get; set; } = "TID is zero.";
+        public static string LOT_IDInvalid { get; set; } = "TID and SID combination is not possible.";
 
         public static string LPIDEncryptWurmple { get; set; } = "Wurmple evolution Encryption Constant mismatch.";
         public static string LPIDEncryptZero { get; set; } = "Encryption Constant is not set.";

PKHeX.Core/Legality/LegalityAnalysis.cs

@@ -274,6 +274,7 @@ namespace PKHeX.Core
             Nickname.Verify(this);
             LanguageIndex.Verify(this);
             Trainer.Verify(this);
+            TrainerID.Verify(this);
             IndividualValues.Verify(this);
             EffortValues.Verify(this);
             Level.Verify(this);

PKHeX.Core/Legality/LegalityAnalyzers.cs

@@ -27,6 +27,7 @@
         public static readonly ContestStatVerifier Contest = new();
 
         public static readonly TrainerNameVerifier Trainer = new();
+        public static readonly TrainerIDVerifier TrainerID = new();
         public static readonly LevelVerifier Level = new();
         public static readonly MiscVerifier MiscValues = new();
         public static readonly TransferVerifier Transfer = new();

PKHeX.Core/Legality/Verifiers/TrainerIDVerifier.cs

@@ -0,0 +1,69 @@
+namespace PKHeX.Core
+{
+    /// <summary>
+    /// Verifies the <see cref="PKM.OT_Name"/>.
+    /// </summary>
+    public sealed class TrainerIDVerifier : Verifier
+    {
+        protected override CheckIdentifier Identifier => CheckIdentifier.Trainer;
+
+        public override void Verify(LegalityAnalysis data)
+        {
+            var pkm = data.pkm;
+            if (!TrainerNameVerifier.IsPlayerOriginalTrainer(data.EncounterMatch))
+                return; // already verified
+
+            if (pkm.BDSP)
+            {
+                if (pkm.TID == 0 && pkm.SID == 0) // Game loops to ensure a nonzero full-ID
+                {
+                    data.AddLine(GetInvalid(LegalityCheckStrings.LOT_IDInvalid));
+                    return;
+                }
+                if (pkm.TID == 0xFFFF && pkm.SID == 0x7FFF) // int.MaxValue cannot be yielded by Unity's Random.Range[min, max)
+                {
+                    data.AddLine(GetInvalid(LegalityCheckStrings.LOT_IDInvalid));
+                    return;
+                }
+            }
+            else if (pkm.VC && pkm.SID != 0)
+            {
+                data.AddLine(GetInvalid(LegalityCheckStrings.LOT_SID0Invalid));
+                return;
+            }
+
+            if (pkm.TID == 0 && pkm.SID == 0)
+            {
+                data.AddLine(Get(LegalityCheckStrings.LOT_IDs0, Severity.Fishy));
+            }
+            else if (pkm.TID == pkm.SID)
+            {
+                data.AddLine(Get(LegalityCheckStrings.LOT_IDEqual, Severity.Fishy));
+            }
+            else if (pkm.TID == 0)
+            {
+                data.AddLine(Get(LegalityCheckStrings.LOT_TID0, Severity.Fishy));
+            }
+            else if (pkm.SID == 0)
+            {
+                data.AddLine(Get(LegalityCheckStrings.LOT_SID0, Severity.Fishy));
+            }
+            else if (IsOTIDSuspicious(pkm.TID, pkm.SID))
+            {
+                data.AddLine(Get(LegalityCheckStrings.LOTSuspicious, Severity.Fishy));
+            }
+        }
+
+        public static bool IsOTIDSuspicious(int tid16, int sid16)
+        {
+            if (tid16 == 12345 && sid16 == 54321)
+                return true;
+
+            // 1234_123456 (SID7_TID7)
+            if (tid16 == 15040 && sid16 == 18831)
+                return true;
+
+            return false;
+        }
+    }
+}

PKHeX.Core/Legality/Verifiers/TrainerNameVerifier.cs

@@ -19,44 +19,15 @@ namespace PKHeX.Core
         public override void Verify(LegalityAnalysis data)
         {
             var pkm = data.pkm;
-            switch (data.EncounterMatch)
+            var enc = data.EncounterMatch;
-            {
+            if (!IsPlayerOriginalTrainer(enc))
-                case EncounterTrade:
+                return; // already verified
-                case MysteryGift {IsEgg: false}:
-                case EncounterStatic5N:
-                    return; // already verified
-            }
 
             var ot = pkm.OT_Name;
             if (ot.Length == 0)
                 data.AddLine(GetInvalid(LOTShort));
 
-            if (pkm.TID == 0 && pkm.SID == 0)
+            if (IsOTNameSuspicious(ot))
-            {
-                data.AddLine(Get(LOT_IDs0, Severity.Fishy));
-            }
-            else if (pkm.VC)
-            {
-                if (pkm.SID != 0)
-                    data.AddLine(GetInvalid(LOT_SID0Invalid));
-            }
-            else if (pkm.TID == pkm.SID)
-            {
-                data.AddLine(Get(LOT_IDEqual, Severity.Fishy));
-            }
-            else if (pkm.TID == 0)
-            {
-                data.AddLine(Get(LOT_TID0, Severity.Fishy));
-            }
-            else if (pkm.SID == 0)
-            {
-                data.AddLine(Get(LOT_SID0, Severity.Fishy));
-            }
-            else if (IsOTNameSuspicious(ot))
-            {
-                data.AddLine(Get(LOTSuspicious, Severity.Fishy));
-            }
-            else if (IsOTIDSuspicious(pkm.TID, pkm.SID))
             {
                 data.AddLine(Get(LOTSuspicious, Severity.Fishy));
             }
@@ -82,6 +53,14 @@ namespace PKHeX.Core
             }
         }
 
+        internal static bool IsPlayerOriginalTrainer(IEncounterable enc) => enc switch
+        {
+            EncounterTrade { HasTrainerName: true } => true,
+            MysteryGift { IsEgg: false } => true,
+            EncounterStatic5N => true,
+            _ => false,
+        };
+
         public static bool IsEdgeCaseLength(PKM pkm, IEncounterTemplate e, string ot)
         {
             if (e.EggEncounter)
@@ -160,18 +139,6 @@ namespace PKHeX.Core
             return false;
         }
 
-        public static bool IsOTIDSuspicious(int tid16, int sid16)
-        {
-            if (tid16 == 12345 && sid16 == 54321)
-                return true;
-
-            // 1234_123456 (SID7_TID7)
-            if (tid16 == 15040 && sid16 == 18831)
-                return true;
-
-            return false;
-        }
-
         public static bool ContainsTooManyNumbers(string str, int originalGeneration)
         {
             if (originalGeneration <= 3)