[Bug Fix] Aegolism Spell line stacking (#4399)

* fix stacking issues with Aegolism spell line

Issue: When casting buffing a player with aegolism spell line, who already has cleric AC, symbol and heroism spell, it would overwrite heorism buff and leave other two.

Aegolism spell line when applied when a client has Heroism spell line, AC spell line, and symbol spell line. Should overwrite the Heroism spell and fade the AC and Symbol buffs.

* Update spdat.cpp

common/spdat.cpp

@@ -2325,3 +2325,108 @@ bool IsCastNotStandingSpell(uint16 spell_id) {
 	*/
 	return spells[spell_id].cast_not_standing;
 }
+
+bool IsAegolismSpell(uint16 spell_id) {
+
+	if (!IsValidSpell(spell_id)) {
+		return 0;
+	}
+
+	bool has_max_hp = false;
+	bool has_current_hp = false;
+	bool has_ac = false;
+
+	for (int i = 0; i < EFFECT_COUNT; ++i) {
+
+		if (i == 0 && spells[spell_id].effect_id[i] != SE_StackingCommand_Block) {
+			return 0;
+		}
+
+		if (i == 1 && spells[spell_id].effect_id[i] == SE_TotalHP) {
+			has_max_hp = true;
+		}
+
+		if (i == 2 && spells[spell_id].effect_id[i] == SE_CurrentHPOnce) {
+			has_current_hp = true;
+		}
+
+		if (i == 3 && spells[spell_id].effect_id[i] == SE_ArmorClass) {
+			has_ac = true;
+		}
+
+		if (i == 4 && spells[spell_id].effect_id[i] != SE_StackingCommand_Overwrite) {
+			return 0;
+		}
+	}
+
+	if (has_max_hp && has_current_hp && has_ac) {
+		return 1;
+	}
+	return 0;
+}
+
+
+bool AegolismStackingIsSymbolSpell(uint16 spell_id) {
+	
+	/*
+		This is hardcoded to be specific to the type of HP buffs that are removed if a mob has an Aegolism buff.
+	*/
+
+	if (!IsValidSpell(spell_id)) {
+		return 0;
+	}
+
+	bool has_max_hp = false;
+	bool has_current_hp = false;
+
+	for (int i = 0; i < EFFECT_COUNT; ++i) {
+
+		if ((i < 2 && spells[spell_id].effect_id[i] != SE_CHA) ||
+			i > 3 && spells[spell_id].effect_id[i] != SE_Blank) {
+			return 0;;
+		}
+
+		if (i == 2 && spells[spell_id].effect_id[i] == SE_TotalHP) {
+			has_max_hp = true;
+		}
+
+		if (i == 3 && spells[spell_id].effect_id[i] == SE_CurrentHPOnce) {
+			has_current_hp = true;
+		}
+	}
+
+	if (has_max_hp && has_current_hp) {
+		return 1;
+	}
+
+	return 0;
+}
+
+bool AegolismStackingIsArmorClassSpell(uint16 spell_id) {
+	/*
+		This is hardcoded to be specific to the type of AC buffs that are removed if a mob has an Aegolism buff.
+	*/
+	if (!IsValidSpell(spell_id)) {
+		return 0;
+	}
+
+	bool has_ac = false;
+
+	for (int i = 0; i < EFFECT_COUNT; ++i) {
+
+		if ((i < 3 && spells[spell_id].effect_id[i] != SE_CHA) ||
+			i > 3 && spells[spell_id].effect_id[i] != SE_Blank) {
+			return 0;
+		}
+
+		if (i == 3 && spells[spell_id].effect_id[i] == SE_ArmorClass) {
+			has_ac = true;
+		}
+	}
+
+	if (has_ac) {
+		return 1;
+	}
+
+	return 0;
+}

common/spdat.h

@@ -1625,5 +1625,8 @@ bool IsSpellUsableInThisZoneType(uint16 spell_id, uint8 zone_type);
 const char *GetSpellName(uint16 spell_id);
 int GetSpellStatValue(uint16 spell_id, const char* stat_identifier, uint8 slot = 0);
 bool IsCastRestrictedSpell(uint16 spell_id);
+bool IsAegolismSpell(uint16 spell_id);
+bool AegolismStackingIsSymbolSpell(uint16 spell_id);
+bool AegolismStackingIsArmorClassSpell(uint16 spell_id);
 
 #endif

zone/spells.cpp

@@ -3743,6 +3743,18 @@ int Mob::AddBuff(Mob *caster, uint16 spell_id, int duration, int32 level_overrid
 		}
 	}
 
+	//remove associated buffs for certain live spell lines
+	if (IsAegolismSpell(spell_id)) {
+		int buff_count = GetMaxBuffSlots();
+		for (int slot = 0; slot < buff_count; slot++) {
+			if (IsValidSpell(buffs[slot].spellid)) {
+				if (AegolismStackingIsSymbolSpell(buffs[slot].spellid) || AegolismStackingIsArmorClassSpell(buffs[slot].spellid)) {
+					BuffFadeBySlot(slot);
+				}
+			}
+		}
+	}
+
 	buffs[emptyslot].spellid = spell_id;
 	buffs[emptyslot].casterlevel = caster_level;
 	if (caster && !caster->IsAura()) // maybe some other things we don't want to ...