Consider next unit on planning retreat

src/fheroes2/ai/ai_battle.cpp

@@ -29,6 +29,7 @@
 #include <functional>
 #include <limits>
 #include <map>
+#include <memory>
 #include <numeric>
 #include <optional>
 #include <ostream>
@@ -39,6 +40,7 @@
 #include <utility>
 #include <vector>
 
+#include "army_troop.h"
 #include "artifact.h"
 #include "artifact_info.h"
 #include "battle.h"
@@ -68,6 +70,8 @@
 #include "spell_info.h"
 #include "spell_storage.h"
 
+class Army;
+
 namespace
 {
     const std::vector<int32_t> cellsUnderWallsIndexes = { 7, 28, 49, 72, 95 };
@@ -734,6 +738,45 @@ bool AI::BattlePlanner::isLimitOfTurnsExceeded( const Battle::Arena & arena, Bat
     return false;
 }
 
+std::optional<const Battle::Unit *> AI::BattlePlanner::findNextUnit( const Battle::Arena & arena, const Battle::Unit & currentUnit )
+{
+    const std::shared_ptr<const Battle::Units> order = arena.getOrderOfUnits();
+    const Battle::Units * units = order.get();
+
+    size_t i = 0;
+    const size_t count = units->size();
+    for ( ; i < count; i++ ) {
+        const Battle::Unit * unit = units->at( i );
+        if ( *unit == currentUnit ) {
+            break;
+        }
+    }
+    i++;
+    if ( i == count ) {
+        i = 0;
+    }
+
+    const Battle::Unit * next_unit = units->at( i );
+    assert( next_unit != nullptr );
+    return { next_unit };
+}
+
+bool AI::BattlePlanner::isPostponeRetreat( const Battle::Arena & arena, const Battle::Unit & currentUnit )
+{
+    const std::optional<const Battle::Unit *> maybeNextUnit = findNextUnit( arena, currentUnit );
+    if ( !maybeNextUnit.has_value() ) {
+        return false;
+    }
+    const Battle::Unit * nextUnit = maybeNextUnit.value();
+    assert( nextUnit != nullptr );
+
+    const Army * currentArmy = currentUnit.GetArmy();
+    const Army * nextArmy = nextUnit->GetArmy();
+
+    const bool isSameArmy = ( currentArmy != nullptr ) && ( currentArmy == nextArmy );
+    return isSameArmy && ( nextUnit->GetMorale() >= 0 );
+}
+
 Battle::Actions AI::BattlePlanner::planUnitTurn( Battle::Arena & arena, const Battle::Unit & currentUnit )
 {
     if ( currentUnit.Modes( Battle::SP_BERSERKER ) ) {
@@ -757,7 +800,7 @@ Battle::Actions AI::BattlePlanner::planUnitTurn( Battle::Arena & arena, const Ba
             Surrender
         };
 
-        const Outcome outcome = [this, &arena, actualHero]() {
+        const Outcome outcome = [this, &arena, actualHero, &currentUnit]() {
             if ( !_considerRetreat ) {
                 return Outcome::ContinueBattle;
             }
@@ -852,7 +895,7 @@ Battle::Actions AI::BattlePlanner::planUnitTurn( Battle::Arena & arena, const Ba
 
             // If the hero has valuable artifacts, he should retreat so that these artifacts do not end up at the disposal of the enemy, especially in the case of an
             // alliance war
-            if ( hasValuableArtifacts ) {
+            if ( hasValuableArtifacts && !isPostponeRetreat( arena, currentUnit ) ) {
                 return Outcome::Retreat;
             }
 
@@ -862,7 +905,7 @@ Battle::Actions AI::BattlePlanner::planUnitTurn( Battle::Arena & arena, const Ba
             }
 
             // Otherwise, if this hero is relatively experienced, then he should retreat so that he can be hired again later
-            if ( actualHero->getTotalPrimarySkillLevel() >= minHeroTotalPrimarySkillLevelForRetreat ) {
+            if ( ( actualHero->getTotalPrimarySkillLevel() >= minHeroTotalPrimarySkillLevelForRetreat ) && !( isPostponeRetreat( arena, currentUnit ) ) ) {
                 return Outcome::Retreat;
             }
 

src/fheroes2/ai/ai_battle.h

@@ -1,6 +1,6 @@
 /***************************************************************************
  *   fheroes2: https://github.com/ihhub/fheroes2                           *
- *   Copyright (C) 2024 - 2025                                             *
+ *   Copyright (C) 2024 - 2026                                             *
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
@@ -21,6 +21,7 @@
 #pragma once
 
 #include <cstdint>
+#include <optional>
 
 #include "color.h"
 
@@ -120,6 +121,9 @@ namespace AI
 
         static double getMeleeBestOutcome( Battle::Arena & arena, const Battle::Unit & currentUnit, const Battle::Units & enemies, BattleTargetPair & bestTarget );
 
+        static std::optional<const Battle::Unit *> findNextUnit( const Battle::Arena & arena, const Battle::Unit & currentUnit );
+        bool isPostponeRetreat( const Battle::Arena & arena, const Battle::Unit & currentUnit );
+
         // When this limit of turns without deaths is exceeded for an attacking AI-controlled hero,
         // the auto combat should be interrupted (one way or another)
         static const uint32_t MAX_TURNS_WITHOUT_DEATHS{ 50 };

src/fheroes2/battle/battle_arena.h

@@ -1,6 +1,6 @@
 /***************************************************************************
  *   fheroes2: https://github.com/ihhub/fheroes2                           *
- *   Copyright (C) 2019 - 2025                                             *
+ *   Copyright (C) 2019 - 2026                                             *
  *                                                                         *
  *   Free Heroes2 Engine: http://sourceforge.net/projects/fheroes2         *
  *   Copyright (C) 2010 by Andrey Afletdinov <fheroes2@gmail.com>          *
@@ -152,6 +152,11 @@ namespace Battle
         const Unit * GetTroopBoard( int32_t ) const;
 
         Unit * GetTroopUID( uint32_t );
+        std::shared_ptr<const Units> getOrderOfUnits() const
+        {
+            return _orderOfUnits;
+        }
+
         const Unit * GetTroopUID( uint32_t ) const;
 
         const SpellStorage & GetUsedSpells() const;