refactor AI system

src/lib/ecs/system/ai/AttackEvaluator.cpp

@@ -0,0 +1,71 @@
+#include "AttackEvaluator.h"
+
+#include <vector>
+
+#include <QVector2D>
+
+#include "AttackBehavior.h"
+#include "BehaviorScores.h"
+#include "BehaviorTargeting.h"
+#include "EntityAdmin.h"
+#include "FactionComponent.h"
+#include "HealthComponent.h"
+#include "PositionComponent.h"
+#include "SensorRangeComponent.h"
+#include "tracing.h"
+
+void AttackEvaluator::evaluate(EntityAdmin& admin)
+{
+    TRACE();
+    const std::vector<CombatantInfo> combatants = buildCombatants(admin);
+
+    admin.forEach<AttackBehavior, PositionComponent, FactionComponent,
+                  SensorRangeComponent, HealthComponent>(
+        [&](entt::entity e, AttackBehavior& attack, const PositionComponent& pos,
+            const FactionComponent& faction, const SensorRangeComponent& sensor,
+            const HealthComponent& health)
+        {
+            const float range = sensor.value_tiles;
+
+            // Validate current target: still valid, still in range.
+            bool targetValid = false;
+            if (attack.currentTarget)
+            {
+                const entt::entity t = *attack.currentTarget;
+                if (admin.isValid(t) && admin.hasAll<PositionComponent>(t))
+                {
+                    const float dist =
+                        (admin.get<PositionComponent>(t).value - pos.value).length();
+                    if (dist <= range) { targetValid = true; }
+                }
+            }
+
+            // Acquire nearest valid target if needed.
+            if (!targetValid)
+            {
+                attack.currentTarget = std::nullopt;
+                float bestDist = range;
+                for (const CombatantInfo& c : combatants)
+                {
+                    if (c.entity == e) { continue; }
+                    const bool isValidTarget =
+                        faction.isEnemy ? !c.isEnemy : c.isEnemy;
+                    if (!isValidTarget) { continue; }
+
+                    const float dist = (c.position - pos.value).length();
+                    if (dist < bestDist)
+                    {
+                        bestDist = dist;
+                        attack.currentTarget = c.entity;
+                    }
+                }
+            }
+
+            const bool healthy =
+                (health.maxHp > 0.0f)
+                && (health.hp / health.maxHp >= BehaviorScores::kLowHpFraction);
+            attack.score = (healthy && attack.currentTarget)
+                ? BehaviorScores::kAttack
+                : BehaviorScores::kInactive;
+        });
+}