From 614ae6855b19bacb741c82df2bcd2e8c4d4566a7 Mon Sep 17 00:00:00 2001
From: Kurt <kaphotics@gmail.com>
Date: Thu, 25 Nov 2021 11:24:34 -0800
Subject: [PATCH] Allow ignored egg moves for v1.0 unpatched games

They didn't reference the TamagoWazaIgnore table until v1.1 lmao

mimic BDSP's index fetching and just grab the array of eggmoves directly to avoid the abstraction method's overhead

set evotree back to private because don't need direct access anymore
---
 .../EncounterSlot/EncounterSlot8b.cs          | 37 ++++++++++++-------
 .../Legality/Evolutions/EvolutionTree.cs      |  2 +-
 2 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/PKHeX.Core/Legality/Encounters/EncounterSlot/EncounterSlot8b.cs b/PKHeX.Core/Legality/Encounters/EncounterSlot/EncounterSlot8b.cs
index a290ec398..69c67f9c3 100644
--- a/PKHeX.Core/Legality/Encounters/EncounterSlot/EncounterSlot8b.cs
+++ b/PKHeX.Core/Legality/Encounters/EncounterSlot/EncounterSlot8b.cs
@@ -12,10 +12,13 @@ public sealed record EncounterSlot8b : EncounterSlot
         public override int Generation => 8;
         public bool IsUnderground => Area.Location is (>= 508 and <= 617);
         public bool IsMarsh => Area.Location is (>= 219 and <= 224);
+        public readonly bool IsBCAT;
 
-        public EncounterSlot8b(EncounterArea area, int species, int form, int min, int max) : base(area, species, form, min, max)
+        public EncounterSlot8b(EncounterArea area, int species, int form, int min, int max, bool isBCAT = false) : base(area, species, form, min, max)
         {
+            IsBCAT = isBCAT;
         }
+
         protected override void SetFormatSpecificData(PKM pk)
         {
             if (IsUnderground)
@@ -32,42 +35,48 @@ protected override void SetFormatSpecificData(PKM pk)
 
         public bool CanBeUndergroundMove(int move)
         {
-            var et = EvolutionTree.Evolves8b;
-            var sf = et.GetBaseSpeciesForm(Species, Form);
-            var species = sf & 0x7FF;
-            var form = sf >> 11;
-            if (IgnoreEggMoves.TryGetValue(species, out var exclude) && Array.IndexOf(exclude, move) != -1)
+            var et = PersonalTable.BDSP;
+            var sf = (PersonalInfoBDSP)et.GetFormEntry(Species, Form);
+            var species = sf.HatchSpecies;
+            if (IsBCAT && IgnoreEggMoves.TryGetValue(species, out var exclude) && Array.IndexOf(exclude, move) != -1)
                 return false;
 
-            var baseEgg = MoveEgg.GetEggMoves(8, species, form, Version);
-            return baseEgg.Length == 0 || Array.IndexOf(baseEgg, move) >= 0;
+            var baseEgg = Legal.EggMovesBDSP[species].Moves;
+            if (baseEgg.Length == 0)
+                return move == 0;
+            return Array.IndexOf(baseEgg, move) >= 0;
         }
 
         public bool GetBaseEggMove(out int move)
         {
-            var et = EvolutionTree.Evolves8b;
-            var sf = et.GetBaseSpeciesForm(Species, Form);
-            var species = sf & 0x7FF;
-            var form = sf >> 11;
+            var et = PersonalTable.BDSP;
+            var sf = (PersonalInfoBDSP)et.GetFormEntry(Species, Form);
+            var species = sf.HatchSpecies;
 
             int[] Exclude = IgnoreEggMoves.TryGetValue(species, out var exclude) ? exclude : Array.Empty<int>();
-            var baseEgg = MoveEgg.GetEggMoves(8, species, form, Version);
+            var baseEgg = Legal.EggMovesBDSP[species].Moves;
             if (baseEgg.Length == 0)
             {
                 move = 0;
                 return false;
             }
 
+            // Official method creates a new List<ushort>() with all the egg moves, removes all ignored, then picks a random index.
+            // We'll just loop instead to not allocate, and because it's a >50% chance the move won't be ignored, thus faster.
             var rnd = Util.Rand;
             while (true)
             {
                 var index = rnd.Next(baseEgg.Length);
                 move = baseEgg[index];
-                if (Array.IndexOf(Exclude, move) == -1)
+                if (IsBCAT && Array.IndexOf(Exclude, move) == -1)
                     return true;
             }
         }
 
+        /// <summary>
+        /// Unreferenced in v1.0, so all egg moves are possible for ROM encounters.
+        /// Since the Underground supports BCAT distributions, we will keep this around on the off chance they do utilize that method of distribution.
+        /// </summary>
         private static readonly Dictionary<int, int[]> IgnoreEggMoves = new()
         {
             {004, new[] {394}}, // Charmander
diff --git a/PKHeX.Core/Legality/Evolutions/EvolutionTree.cs b/PKHeX.Core/Legality/Evolutions/EvolutionTree.cs
index 387839add..b4a56a555 100644
--- a/PKHeX.Core/Legality/Evolutions/EvolutionTree.cs
+++ b/PKHeX.Core/Legality/Evolutions/EvolutionTree.cs
@@ -23,7 +23,7 @@ public sealed class EvolutionTree
         private static readonly EvolutionTree Evolves7 = new(Unpack("uu"), Gen7, PersonalTable.USUM, MaxSpeciesID_7_USUM);
         private static readonly EvolutionTree Evolves7b = new(Unpack("gg"), Gen7, PersonalTable.GG, MaxSpeciesID_7b);
         private static readonly EvolutionTree Evolves8 = new(Unpack("ss"), Gen8, PersonalTable.SWSH, MaxSpeciesID_8);
-        internal static readonly EvolutionTree Evolves8b = new(Unpack("bs"), Gen8, PersonalTable.BDSP, MaxSpeciesID_8b);
+        private static readonly EvolutionTree Evolves8b = new(Unpack("bs"), Gen8, PersonalTable.BDSP, MaxSpeciesID_8b);
 
         private static byte[] Get(string resource) => Util.GetBinaryResource($"evos_{resource}.pkl");
         private static byte[][] Unpack(string resource) => BinLinker.Unpack(Get(resource), resource);