feat/improve: create "custom loot" for monsters

This has two different options:
Adding "global" items that can drop on any monster (it is disabled by default)

Add specific items for each monster, without having to modify each monster's script. This allows a certain freedom to work with loot, without having to edit each script.

Added "const ref" to getBestiaryList, avoid copying large bestiary map.

Improved "registerLoot" function to avoid code duplication.
Removed "bad" code in "closeContainer", this may crash if the container is used (it is removed right before)

New lua function "getMonsterTypeByName".

data/scripts/lib/register_monster_type.lua

@@ -344,140 +344,88 @@ function SortLootByChance(loot)
 	end)
 end
 
-registerMonsterType.loot = function(mtype, mask)
-	if type(mask.loot) == "table" then
-		SortLootByChance(mask.loot)
-		local lootError = false
-		for _, loot in pairs(mask.loot) do
-			local parent = Loot()
-			if loot.name then
-				if not parent:setIdFromName(loot.name) then
-					lootError = true
-				end
-			else
-				if not isInteger(loot.id) or loot.id < 1 then
-					lootError = true
-				end
-				parent:setId(loot.id)
-			end
-			if loot.subType or loot.charges then
-				parent:setSubType(loot.subType or loot.charges)
-			else
-				local lType = ItemType(loot.name and loot.name or loot.id)
-				if lType and lType:getCharges() > 1 then
-					parent:setSubType(lType:getCharges())
-				end
-			end
-			if loot.chance then
-				parent:setChance(loot.chance)
-			end
-			if loot.minCount then
-				parent:setMinCount(loot.minCount)
-			end
-			if loot.maxCount then
-				parent:setMaxCount(loot.maxCount)
-			end
-			if loot.aid or loot.actionId then
-				parent:setActionId(loot.aid or loot.actionId)
-			end
-			if loot.text or loot.description then
-				parent:setText(loot.text or loot.description)
-			end
-			if loot.name then
-				parent:setNameItem(loot.name)
-			end
-			if loot.article then
-				parent:setArticle(loot.article)
-			end
-			if loot.attack then
-				parent:setAttack(loot.attack)
-			end
-			if loot.defense then
-				parent:setDefense(loot.defense)
-			end
-			if loot.extraDefense or loot.extraDef then
-				parent:setExtraDefense(loot.extraDefense or loot.extraDef)
-			end
-			if loot.armor then
-				parent:setArmor(loot.armor)
+local function configureLootAttributes(lootObject, lootProperties)
+	if lootProperties.subType or lootProperties.charges then
+		lootObject:setSubType(lootProperties.subType or lootProperties.charges)
+	else
+		local itemType = ItemType(lootProperties.name and lootProperties.name or lootProperties.itemId)
+		if itemType and itemType:getCharges() > 1 then
+			lootObject:setSubType(itemType:getCharges())
+		end
+	end
+
+	lootObject:setChance(lootProperties.chance or 0)
+	lootObject:setMinCount(lootProperties.minCount or 0)
+	lootObject:setMaxCount(lootProperties.maxCount or 0)
+	lootObject:setActionId(lootProperties.aid or lootProperties.actionId or 0)
+	lootObject:setText(lootProperties.text or lootProperties.description or "")
+	lootObject:setNameItem(lootProperties.name or "")
+	lootObject:setArticle(lootProperties.article or "")
+	lootObject:setAttack(lootProperties.attack or 0)
+	lootObject:setDefense(lootProperties.defense or 0)
+	lootObject:setExtraDefense(lootProperties.extraDefense or lootProperties.extraDef or 0)
+	lootObject:setArmor(lootProperties.armor or 0)
+	lootObject:setShootRange(lootProperties.shootRange or lootProperties.range or 0)
+	lootObject:setUnique(lootProperties.unique or false)
+end
+
+local function addChildrenLoot(parent, childrenLoot)
+	SortLootByChance(childrenLoot)
+	for _, child in pairs(childrenLoot) do
+		local childLoot = Loot()
+		if child.name then
+			if not childLoot:setIdFromName(child.name) then
+				return true
 			end
-			if loot.shootRange or loot.range then
-				parent:setShootRange(loot.shootRange or loot.range)
+		else
+			if not isInteger(child.id) or child.id < 1 then
+				return true
 			end
-			if loot.unique then
-				parent:setUnique(loot.unique)
+			childLoot:setId(child.id)
+		end
+		configureLootAttributes(childLoot, child)
+		parent:addChildLoot(childLoot)
+	end
+	return false
+end
+
+function MonsterType:createLoot(lootTable)
+	SortLootByChance(lootTable)
+	local lootError = false
+
+	for _, loot in pairs(lootTable) do
+		local parent = Loot()
+		if loot.name then
+			if not parent:setIdFromName(loot.name) then
+				lootError = true
 			end
-			if loot.child then
-				SortLootByChance(loot.child)
-				for _, children in pairs(loot.child) do
-					local child = Loot()
-					if children.name then
-						if not child:setIdFromName(children.name) then
-							lootError = true
-						end
-					else
-						if not isInteger(children.id) or children.id < 1 then
-							lootError = true
-						end
-						child:setId(children.id)
-					end
-					if children.subType or children.charges then
-						child:setSubType(children.subType or children.charges)
-					else
-						local cType = ItemType(children.name and children.name or children.id)
-						if cType and cType:getCharges() > 1 then
-							child:setSubType(cType:getCharges())
-						end
-					end
-					if children.chance then
-						child:setChance(children.chance)
-					end
-					if children.minCount then
-						child:setMinCount(children.minCount)
-					end
-					if children.maxCount then
-						child:setMaxCount(children.maxCount)
-					end
-					if children.aid or children.actionId then
-						child:setActionId(children.aid or children.actionId)
-					end
-					if children.text or children.description then
-						child:setText(children.text or children.description)
-					end
-					if loot.name then
-						child:setNameItem(loot.name)
-					end
-					if children.article then
-						child:setArticle(children.article)
-					end
-					if children.attack then
-						child:setAttack(children.attack)
-					end
-					if children.defense then
-						child:setDefense(children.defense)
-					end
-					if children.extraDefense or children.extraDef then
-						child:setExtraDefense(children.extraDefense or children.extraDef)
-					end
-					if children.armor then
-						child:setArmor(children.armor)
-					end
-					if children.shootRange or children.range then
-						child:setShootRange(children.shootRange or children.range)
-					end
-					if children.unique then
-						child:setUnique(children.unique)
-					end
-					parent:addChildLoot(child)
-				end
+		else
+			if not isInteger(loot.id) or loot.id < 1 then
+				lootError = true
 			end
-			mtype:addLoot(parent)
+			parent:setId(loot.id)
 		end
-		if lootError then
-			logger.warn("[registerMonsterType.loot] - Monster: {} loot could not correctly be load", mtype:name())
+
+		configureLootAttributes(parent, loot)
+
+		if loot.child and addChildrenLoot(parent, loot.child) then
+			lootError = true
 		end
+
+		self:addLoot(parent)
+	end
+
+	if lootError then
+		logger.warn("[MonsterType:createLoot] - Monster: {} loot could not be loaded correctly", self:getName())
 	end
 end
+
+registerMonsterType.loot = function(mtype, mask)
+	if type(mask.loot) == "table" then
+		mtype:createLoot(mask.loot)
+	end
+end
+
 local playerElements = { COMBAT_PHYSICALDAMAGE, COMBAT_ENERGYDAMAGE, COMBAT_EARTHDAMAGE, COMBAT_FIREDAMAGE, COMBAT_ICEDAMAGE, COMBAT_HOLYDAMAGE, COMBAT_DEATHDAMAGE }
 registerMonsterType.elements = function(mtype, mask)
 	local min = configManager.getNumber(configKeys.MIN_ELEMENTAL_RESISTANCE)

data/scripts/systems/custom_monster_loot.lua

@@ -0,0 +1,74 @@
+-- Drops custom loot for all monsters
+local allLootConfig = {
+	--{ id = 6526, chance = 100000 }, -- Example of loot (100% chance)
+}
+
+-- Custom loot for specific monsters (this has the same usage options as normal monster loot)
+local customLootConfig = {
+	["Dragon"] = { items = {
+		{ name = "platinum coin", chance = 1000, maxCount = 1 },
+	} },
+}
+
+-- Global loot addition for all monsters
+local callback = EventCallback("MonsterOnDropLootCustom")
+
+function callback.monsterOnDropLoot(monster, corpse)
+	if not monster or not corpse then
+		return
+	end
+	local player = Player(corpse:getCorpseOwner())
+	if not player or not player:canReceiveLoot() then
+		return
+	end
+	corpse:addLoot(monster:generateCustomLoot())
+end
+
+-- Register the callback only if there is loot to be dropped
+if #allLootConfig > 0 then
+	callback:register()
+end
+
+function Monster:generateCustomLoot()
+	local mType = self:getType()
+	if not mType then
+		return {}
+	end
+
+	local loot = {}
+
+	for _, lootInfo in ipairs(allLootConfig) do
+		local roll = math.random(1, 10000)
+		if roll <= lootInfo.chance then
+			if loot[lootInfo.id] then
+				loot[lootInfo.id].count = loot[lootInfo.id].count + 1
+			else
+				loot[lootInfo.id] = { count = 1 }
+			end
+		end
+	end
+
+	return loot
+end
+
+local customMonsterLoot = GlobalEvent("CreateCustomMonsterLoot")
+
+function customMonsterLoot.onStartup()
+	for monsterName, _ in pairs(customLootConfig) do
+		local mtype = Game.getMonsterTypeByName(monsterName)
+		if mtype then
+			local lootTable = customLootConfig[mtype:getName()]
+			if not lootTable then
+				logger.error("[customMonsterLoot.onStartup] - No custom loot found for monster: {}", self:getName())
+				return
+			end
+
+			if #lootTable.items > 0 then
+				mtype:createLoot(lootTable.items)
+				logger.debug("[customMonsterLoot.onStartup] - Custom loot registered for monster: {}", mtype:getName())
+			end
+		end
+	end
+end
+
+customMonsterLoot:register()

src/creatures/monsters/monsters.cpp

@@ -345,9 +345,7 @@ void Monsters::clear() {
 std::shared_ptr<MonsterType> Monsters::getMonsterType(const std::string &name, bool silent /* = false*/) const {
 	std::string lowerCaseName = asLowerCaseString(name);
 	if (auto it = monsters.find(lowerCaseName);
-	    it != monsters.end()
-	    // We will only return the MonsterType if it match the exact name of the monster
-	    && it->first.find(lowerCaseName) != std::basic_string<char>::npos) {
+	    it != monsters.end()) {
 		return it->second;
 	}
 	if (!silent) {

src/creatures/players/player.cpp

@@ -976,8 +976,6 @@ void Player::closeContainer(uint8_t cid) {
 		removeEmptyRewards();
 	}
 	openContainers.erase(it);
-	if (container && container->getID() == ITEM_BROWSEFIELD) {
-	}
 }
 
 void Player::removeEmptyRewards() {

src/game/game.cpp

@@ -456,7 +456,7 @@ void Game::loadBoostedCreature() {
 	}
 
 	const auto oldRace = result->getNumber<uint16_t>("raceid");
-	const auto monsterlist = getBestiaryList();
+	const auto &monsterlist = getBestiaryList();
 
 	struct MonsterRace {
 		uint16_t raceId { 0 };

src/io/iobestiary.cpp

@@ -193,7 +193,7 @@ uint16_t IOBestiary::getBestiaryRaceUnlocked(const std::shared_ptr<Player> &play
 	}
 
 	uint16_t count = 0;
-	std::map<uint16_t, std::string> besty_l = g_game().getBestiaryList();
+	const std::map<uint16_t, std::string> &besty_l = g_game().getBestiaryList();
 
 	for (const auto &it : besty_l) {
 		const auto mtype = g_monsters().getMonsterType(it.second);

src/io/ioprey.cpp

@@ -146,7 +146,7 @@ void TaskHuntingSlot::reloadMonsterGrid(std::vector<uint16_t> blackList, uint32_
 	// Disabling task hunting system if the server have less then 36 registered monsters on bestiary because:
 	// - Impossible to generate random lists without duplications on slots.
 	// - Stress the server with unnecessary loops.
-	std::map<uint16_t, std::string> bestiary = g_game().getBestiaryList();
+	const std::map<uint16_t, std::string> &bestiary = g_game().getBestiaryList();
 	if (bestiary.size() < 36) {
 		return;
 	}
@@ -574,7 +574,7 @@ void IOPrey::initializeTaskHuntOptions() {
 	}
 
 	msg.addByte(0xBA);
-	std::map<uint16_t, std::string> bestiaryList = g_game().getBestiaryList();
+	const std::map<uint16_t, std::string> &bestiaryList = g_game().getBestiaryList();
 	msg.add<uint16_t>(static_cast<uint16_t>(bestiaryList.size()));
 	std::for_each(bestiaryList.begin(), bestiaryList.end(), [&msg](auto mType) {
 		const auto mtype = g_monsters().getMonsterType(mType.second);

src/lua/functions/core/game/game_functions.cpp

@@ -84,6 +84,24 @@ int GameFunctions::luaGameCreateNpcType(lua_State* L) {
 	return NpcTypeFunctions::luaNpcTypeCreate(L);
 }
 
+int GameFunctions::luaGameGetMonsterTypeByName(lua_State* L) {
+	if (!isString(L, 1)) {
+		reportErrorFunc("First argument must be a string");
+		return 1;
+	}
+
+	const auto name = getString(L, 1);
+	const auto &mType = g_monsters().getMonsterType(name);
+	if (!mType) {
+		reportErrorFunc(fmt::format("MonsterType with name {} not found", name));
+		return 1;
+	}
+
+	pushUserdata<MonsterType>(L, mType);
+	setMetatable(L, -1, "MonsterType");
+	return 1;
+}
+
 int GameFunctions::luaGameGetSpectators(lua_State* L) {
 	// Game.getSpectators(position[, multifloor = false[, onlyPlayer = false[, minRangeX = 0[, maxRangeX = 0[, minRangeY = 0[, maxRangeY = 0]]]]]])
 	const Position &position = getPosition(L, 1);

src/lua/functions/core/game/game_functions.hpp

@@ -24,6 +24,7 @@ class GameFunctions final : LuaScriptInterface {
 
 		registerMethod(L, "Game", "createNpcType", GameFunctions::luaGameCreateNpcType);
 		registerMethod(L, "Game", "createMonsterType", GameFunctions::luaGameCreateMonsterType);
+		registerMethod(L, "Game", "getMonsterTypeByName", GameFunctions::luaGameGetMonsterTypeByName);
 
 		registerMethod(L, "Game", "getSpectators", GameFunctions::luaGameGetSpectators);
 
@@ -100,6 +101,7 @@ class GameFunctions final : LuaScriptInterface {
 private:
 	static int luaGameCreateMonsterType(lua_State* L);
 	static int luaGameCreateNpcType(lua_State* L);
+	static int luaGameGetMonsterTypeByName(lua_State* L);
 
 	static int luaGameGetSpectators(lua_State* L);