From f99e4e54f3278ae093a553c471c1d4e59f827f6f Mon Sep 17 00:00:00 2001
From: Kurt <kwsch@users.noreply.github.com>
Date: Mon, 29 Jan 2024 17:41:12 -0800
Subject: [PATCH] Batch Editor: Combine simple & complex EC rand

Just pipe everything to the complicated EC pathway and allow it to select for biases. Swap input preferences to retain a proper EC for dudun/maus.
Closes #4179
---
 PKHeX.Core/Editing/Bulk/BatchMods.cs |  3 +--
 PKHeX.Core/Editing/CommonEdits.cs    | 23 +++++++++++++++--------
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/PKHeX.Core/Editing/Bulk/BatchMods.cs b/PKHeX.Core/Editing/Bulk/BatchMods.cs
index 87ae6f208..409d987b8 100644
--- a/PKHeX.Core/Editing/Bulk/BatchMods.cs
+++ b/PKHeX.Core/Editing/Bulk/BatchMods.cs
@@ -67,7 +67,6 @@ public static class BatchMods
         new ComplexSet(nameof(PKM.AbilityNumber), value => value.Length == 2 && value.StartsWith(CONST_SPECIAL), (pk, cmd) => pk.RefreshAbility(Convert.ToInt16(cmd.PropertyValue[1]) - 0x30)),
 
         // Random
-        new ComplexSet(nameof(PKM.EncryptionConstant), value => value == CONST_RAND, (pk, _) => pk.EncryptionConstant = Util.Rand32()),
         new ComplexSet(nameof(PKM.PID), value => value == CONST_RAND, (pk, _) => pk.PID = Util.Rand32()),
         new ComplexSet(nameof(PKM.Gender), value => value == CONST_RAND, (pk, _) => pk.SetPIDGender(pk.Gender)),
         new ComplexSet(PROP_EVS, value => value == CONST_RAND, (pk, _) => SetRandomEVs(pk)),
@@ -82,7 +81,7 @@ public static class BatchMods
         new ComplexSet(nameof(PKM.IsNicknamed), value => string.Equals(value, "false", StringComparison.OrdinalIgnoreCase), (pk, _) => pk.SetDefaultNickname()),
 
         // Complicated
-        new ComplexSet(nameof(PKM.EncryptionConstant), value => value.StartsWith(CONST_RAND), (pk, cmd) => pk.EncryptionConstant = CommonEdits.GetComplicatedEC(pk, option: cmd.PropertyValue[^1])),
+        new ComplexSet(nameof(PKM.EncryptionConstant), value => value.StartsWith(CONST_RAND), (pk, cmd) => pk.EncryptionConstant = CommonEdits.GetComplicatedEC(pk, option: (cmd.PropertyValue.Length == CONST_RAND.Length ? default : cmd.PropertyValue[^1]))),
     ];
 
     private static void SetRandomTeraType(PKM pk)
diff --git a/PKHeX.Core/Editing/CommonEdits.cs b/PKHeX.Core/Editing/CommonEdits.cs
index 0385a2ed8..dd250ee0f 100644
--- a/PKHeX.Core/Editing/CommonEdits.cs
+++ b/PKHeX.Core/Editing/CommonEdits.cs
@@ -440,7 +440,7 @@ public static string GetLocationString(this PKM pk, bool eggmet)
     /// <summary>
     /// Gets a <see cref="PKM.EncryptionConstant"/> to match the requested option.
     /// </summary>
-    public static uint GetComplicatedEC(ISpeciesForm pk, char option = ' ')
+    public static uint GetComplicatedEC(ISpeciesForm pk, char option = default)
     {
         var species = pk.Species;
         var form = pk.Form;
@@ -448,11 +448,11 @@ public static uint GetComplicatedEC(ISpeciesForm pk, char option = ' ')
     }
 
     /// <inheritdoc cref="GetComplicatedEC(ISpeciesForm,char)"/>
-    public static uint GetComplicatedEC(ushort species, byte form, char option = ' ')
+    public static uint GetComplicatedEC(ushort species, byte form, char option = default)
     {
         var rng = Util.Rand;
         uint rand = rng.Rand32();
-        uint mod = 1, noise = 0;
+        uint mod, noise;
         if (species is >= (int)Species.Wurmple and <= (int)Species.Dustox)
         {
             mod = 10;
@@ -462,13 +462,16 @@ public static uint GetComplicatedEC(ushort species, byte form, char option = ' '
         else if (species is (int)Species.Dunsparce or (int)Species.Dudunsparce or (int)Species.Tandemaus or (int)Species.Maushold)
         {
             mod = 100;
-            noise = option switch
+            noise = species switch
             {
-                '0' or '3' => 0u,
-                _ => species switch
+                // Retain requisite correlation to allow for evolving into this species too.
+                (int)Species.Dudunsparce => form == 1 ? 0 : (uint)rng.Next(1, 100), // 3 Segment
+                (int)Species.Maushold => form == 0 ? 0 : (uint)rng.Next(1, 100), // Family of 3
+
+                // Otherwise, check if one is preferred, and if not, just make it the more common outcome.
+                _ => option switch
                 {
-                    (int)Species.Dudunsparce when form == 1 => 0, // 3 Segment
-                    (int)Species.Maushold when form == 0 => 0, // Family of 3
+                    '0' or '3' => 0u,
                     _ => (uint)rng.Next(1, 100),
                 },
             };
@@ -478,6 +481,10 @@ public static uint GetComplicatedEC(ushort species, byte form, char option = ' '
             mod = 6;
             noise = (uint)(option - '0');
         }
+        else
+        {
+            return rand;
+        }
         return unchecked(rand - (rand % mod) + noise);
     }
 }