Simplify Monster skills with Set instead of List

Doable now with MobSkillId records

src/main/java/net/server/channel/handlers/MoveLifeHandler.java

@@ -32,7 +32,6 @@ import server.maps.MapObject;
 import server.maps.MapObjectType;
 import server.maps.MapleMap;
 import tools.PacketCreator;
-import tools.Randomizer;
 import tools.exceptions.EmptyMovementException;
 
 import java.awt.*;
@@ -80,7 +79,6 @@ public final class MoveLifeHandler extends AbstractMovementPacketHandler {
         boolean isAttack = inRangeInclusive(rawActivity, 24, 41);
         boolean isSkill = inRangeInclusive(rawActivity, 42, 59);
 
-        MobSkill toUse = null;
         int useSkillId = 0, useSkillLevel = 0;
 
         MobSkill nextUse = null;
@@ -88,14 +86,12 @@ public final class MoveLifeHandler extends AbstractMovementPacketHandler {
 
         boolean nextMovementCouldBeSkill = !(isSkill || (pNibbles != 0));
 
-        int castPos;
         if (isSkill) {
             useSkillId = skillId;
             useSkillLevel = skillLv;
 
-            castPos = monster.getSkillPos(useSkillId, useSkillLevel);
+            if (monster.hasSkill(useSkillId, useSkillLevel)) {
-            if (castPos != -1) {
+                MobSkill toUse = MobSkillFactory.getMobSkill(MobSkillType.from(useSkillId), useSkillLevel);
-                toUse = MobSkillFactory.getMobSkill(MobSkillType.from(useSkillId), useSkillLevel);
 
                 if (monster.canUseSkill(toUse, true)) {
                     int animationTime = MonsterInformationProvider.getInstance().getMobSkillAnimationTime(toUse);
@@ -108,8 +104,7 @@ public final class MoveLifeHandler extends AbstractMovementPacketHandler {
                 }
             }
         } else {
-            castPos = (rawActivity - 24) / 2;
+            int castPos = (rawActivity - 24) / 2;
-
             int atkStatus = monster.canUseAttack(castPos, isSkill);
             if (atkStatus < 1) {
                 rawActivity = -1;
@@ -118,15 +113,11 @@ public final class MoveLifeHandler extends AbstractMovementPacketHandler {
         }
 
         int mobMp = monster.getMp();
-        if (nextMovementCouldBeSkill) {
+        if (nextMovementCouldBeSkill && monster.hasAnySkill()) {
-            int noSkills = monster.getNoSkills();
+            MobSkillId skillToUse = monster.getRandomSkill();
-            if (noSkills > 0) {
-                int rndSkill = Randomizer.nextInt(noSkills);
-
-                MobSkillId skillToUse = monster.getSkills().get(rndSkill);
             nextSkillId = skillToUse.type().getId();
             nextSkillLevel = skillToUse.level();
-                nextUse = MobSkillFactory.getMobSkill(MobSkillType.from(nextSkillId), nextSkillLevel);
+            nextUse = MobSkillFactory.getMobSkill(skillToUse.type(), skillToUse.level());
 
             if (!(nextUse != null && monster.canUseSkill(nextUse, false) && nextUse.getHP() >= (int) (((float) monster.getHp() / monster.getMaxHp()) * 100) && mobMp >= nextUse.getMpCon())) {
                 // thanks OishiiKawaiiDesu for noticing mobs trying to cast skills they are not supposed to be able
@@ -136,7 +127,6 @@ public final class MoveLifeHandler extends AbstractMovementPacketHandler {
                 nextUse = null;
             }
         }
-        }
 
         p.readByte();
         p.readInt(); // whatever
@@ -164,8 +154,8 @@ public final class MoveLifeHandler extends AbstractMovementPacketHandler {
             p.seek(movementDataStart);
 
             if (YamlConfig.config.server.USE_DEBUG_SHOW_RCVD_MVLIFE) {
-                log.debug("{} castPos: {}, rawAct: {}, opt: {}, skillId: {}, skillLv: {}, allowSkill: {}, mobMp: {}",
+                log.debug("{} rawAct: {}, opt: {}, skillId: {}, skillLv: {}, allowSkill: {}, mobMp: {}",
-                        isSkill ? "SKILL" : (isAttack ? "ATTCK" : ""), castPos, rawActivity, pOption, useSkillId,
+                        isSkill ? "SKILL" : (isAttack ? "ATTCK" : ""), rawActivity, pOption, useSkillId,
                         useSkillLevel, nextMovementCouldBeSkill, mobMp);
             }
 

src/main/java/server/life/LifeFactory.java

@@ -188,7 +188,7 @@ public class LifeFactory {
         Data monsterSkillInfoData = monsterInfoData.getChildByPath("skill");
         if (monsterSkillInfoData != null) {
             int i = 0;
-            List<MobSkillId> skills = new ArrayList<>();
+            Set<MobSkillId> skills = new HashSet<>();
             while (monsterSkillInfoData.getChildByPath(Integer.toString(i)) != null) {
                 int skillId = DataTool.getInt(i + "/skill", monsterSkillInfoData, 0);
                 int skillLv = DataTool.getInt(i + "/level", monsterSkillInfoData, 0);

src/main/java/server/life/Monster.java

@@ -1426,7 +1426,7 @@ public class Monster extends AbstractLoadedLife {
         return map.getAggroCoordinator();
     }
 
-    public List<MobSkillId> getSkills() {
+    public Set<MobSkillId> getSkills() {
         return stats.getSkills();
     }
 
@@ -1434,19 +1434,6 @@ public class Monster extends AbstractLoadedLife {
         return stats.hasSkill(skillId, level);
     }
 
-    public int getSkillPos(int skillId, int level) {
-        int pos = 0;
-        for (MobSkillId ms : this.getSkills()) {
-            if (ms.type().getId() == skillId && ms.level() == level) {
-                return pos;
-            }
-
-            pos++;
-        }
-
-        return -1;
-    }
-
     public boolean canUseSkill(MobSkill toUse, boolean apply) {
         if (toUse == null || isBuffed(MonsterStatus.SEAL_SKILL)) {
             return false;
@@ -1600,8 +1587,20 @@ public class Monster extends AbstractLoadedLife {
         }
     }
 
-    public int getNoSkills() {
+    public boolean hasAnySkill() {
-        return this.stats.getNoSkills();
+        return this.stats.getNoSkills() > 0;
+    }
+
+    public MobSkillId getRandomSkill() {
+        Set<MobSkillId> skills = stats.getSkills();
+        if (skills.size() == 0) {
+            return null;
+        }
+        // There is no simple way of getting a random element from a Set. Have to make do with this.
+        return skills.stream()
+                .skip(Randomizer.nextInt(skills.size()))
+                .findAny()
+                .orElse(null);
     }
 
     public boolean isFirstAttack() {

src/main/java/server/life/MonsterStats.java

@@ -41,7 +41,7 @@ public class MonsterStats {
     public Map<Element, ElementalEffectiveness> resistance = new HashMap<>();
     public List<Integer> revives = Collections.emptyList();
     public byte tagColor, tagBgColor;
-    public List<MobSkillId> skills = new ArrayList<>();
+    public Set<MobSkillId> skills = new HashSet<>();
     public Pair<Integer, Integer> cool = null;
     public BanishInfo banish = null;
     public List<loseItem> loseItem = null;
@@ -190,17 +190,12 @@ public class MonsterStats {
         this.tagBgColor = (byte) tagBgColor;
     }
 
-    public void setSkills(List<MobSkillId> skills) {
+    public void setSkills(Set<MobSkillId> skills) {
-        for (int i = this.skills.size(); i < skills.size(); i++) {
+        this.skills = skills;
-            this.skills.add(null);
-        }
-        for (int i = 0; i < skills.size(); i++) {
-            this.skills.set(i, skills.get(i));
-        }
     }
 
-    public List<MobSkillId> getSkills() {
+    public Set<MobSkillId> getSkills() {
-        return Collections.unmodifiableList(this.skills);
+        return Collections.unmodifiableSet(this.skills);
     }
 
     public int getNoSkills() {

src/main/java/tools/mapletools/MonsterStatFetcher.java

@@ -108,7 +108,7 @@ public class MonsterStatFetcher {
                 Data monsterSkillData = monsterInfoData.getChildByPath("skill");
                 if (monsterSkillData != null) {
                     int i = 0;
-                    List<MobSkillId> skills = new ArrayList<>();
+                    Set<MobSkillId> skills = new HashSet<>();
                     while (monsterSkillData.getChildByPath(Integer.toString(i)) != null) {
                         int skillId = DataTool.getInt(i + "/skill", monsterSkillData, 0);
                         MobSkillType type = MobSkillType.from(skillId);