-- Advanced NPC System by Jiddo

if Modules == nil then
    -- default words for greeting and ungreeting the npc. Should be a table containing all such words.
    FOCUS_GREETWORDS = {"hi", "hello"}
    FOCUS_FAREWELLWORDS = {"bye", "farewell"}

    -- The words for requesting trade window.
    SHOP_TRADEREQUEST = {"trade"}

    -- The word for accepting/declining an offer. CAN ONLY CONTAIN ONE FIELD! Should be a table with a single string value.
    SHOP_YESWORD = {"yes"}
    SHOP_NOWORD = {"no"}

    -- Pattern used to get the amount of an item a player wants to buy/sell.
    PATTERN_COUNT = "%d+"

    -- Constants used to separate buying from selling.
    SHOPMODULE_SELL_ITEM = 1
    SHOPMODULE_BUY_ITEM = 2
    SHOPMODULE_BUY_ITEM_CONTAINER = 3

    -- Constants used for shop mode. Notice: addBuyableItemContainer is working on all modes
    SHOPMODULE_MODE_TALK = 1 -- Old system used before client version 8.2: sell/buy item name
    SHOPMODULE_MODE_TRADE = 2 -- Trade window system introduced in client version 8.2
    SHOPMODULE_MODE_BOTH = 3 -- Both working at one time

    -- Used shop mode
    SHOPMODULE_MODE = SHOPMODULE_MODE_BOTH

    Modules = {
        parseableModules = {}
    }

    StdModule = {}

    -- These callback function must be called with parameters.npcHandler = npcHandler in the parameters table or they will not work correctly.
    -- Notice: The members of StdModule have not yet been tested. If you find any bugs, please report them to me.
    -- Usage:
        -- keywordHandler:addKeyword({"offer"}, StdModule.say, {npcHandler = npcHandler, text = "I sell many powerful melee weapons."})
    function StdModule.say(cid, message, keywords, parameters, node)
        local npcHandler = parameters.npcHandler
        if npcHandler == nil then
            error("StdModule.say called without any npcHandler instance.")
        end
        local onlyFocus = (parameters.onlyFocus == nil or parameters.onlyFocus == true)
        if not npcHandler:isFocused(cid) and onlyFocus then
            return false
        end

        local parseInfo = {[TAG_PLAYERNAME] = Player(cid):getName()}
        npcHandler:say(npcHandler:parseMessage(parameters.text or parameters.message, parseInfo), cid, parameters.publicize and true)
        if parameters.reset then
            npcHandler:resetNpc(cid)
        elseif parameters.moveup ~= nil then
            npcHandler.keywordHandler:moveUp(cid, parameters.moveup)
        end

        return true
    end

    --Usage:
        -- local node1 = keywordHandler:addKeyword({"promot"}, StdModule.say, {npcHandler = npcHandler, text = "I can promote you for 20000 gold coins. Do you want me to promote you?"})
        -- node1:addChildKeyword({"yes"}, StdModule.promotePlayer, {npcHandler = npcHandler, cost = 20000, level = 20}, text = "Congratulations! You are now promoted.")
        -- node1:addChildKeyword({"no"}, StdModule.say, {npcHandler = npcHandler, text = "Allright then. Come back when you are ready."}, reset = true)
    function StdModule.promotePlayer(cid, message, keywords, parameters, node)
        local npcHandler = parameters.npcHandler
        if npcHandler == nil then
            error("StdModule.promotePlayer called without any npcHandler instance.")
        end

        if not npcHandler:isFocused(cid) then
            return false
        end

        local player = Player(cid)
        if player:isPremium() or not parameters.premium then
            local promotion = player:getVocation():getPromotion()
            if player:getStorageValue(STORAGEVALUE_PROMOTION) == 1 then
                npcHandler:say("You are already promoted!", cid)
            elseif player:getLevel() < parameters.level then
                npcHandler:say("I am sorry, but I can only promote you once you have reached level " .. parameters.level .. ".", cid)
            elseif not player:removeMoney(parameters.cost) then
                if player:getBankBalance() < parameters.cost then
                    npcHandler:say("You do not have enough money!", cid)
                else
                    player:setBankBalance(player:getBankBalance() - parameters.cost)
                    player:sendTextMessage(MESSAGE_INFO_DESCR, ("Bank Account: %d gold has been withdrawn from your account for this purchase. Your account balance is %d gold coins."):format(parameters.cost, player:getBankBalance()))
                end
            else
                npcHandler:say(parameters.text, cid)
                player:setVocation(promotion)
                player:setStorageValue(STORAGEVALUE_PROMOTION, 1)
            end
        else
            npcHandler:say("You need a premium account in order to get promoted.", cid)
        end
        npcHandler:resetNpc(cid)
        return true
    end

    function StdModule.learnSpell(cid, message, keywords, parameters, node)
        local npcHandler = parameters.npcHandler
        if npcHandler == nil then
            error("StdModule.learnSpell called without any npcHandler instance.")
        end

        if not npcHandler:isFocused(cid) then
            return false
        end

        local player = Player(cid)
        if player:isPremium() or not parameters.premium then
            if player:hasLearnedSpell(parameters.spellName) then
                npcHandler:say("You already know this spell.", cid)
            elseif not player:canLearnSpell(parameters.spellName) then
                npcHandler:say("You cannot learn this spell.", cid)
            elseif not player:removeMoney(parameters.price) then
                if player:getBankBalance() < parameters.price then
                    npcHandler:say("You do not have enough money, this spell costs " .. parameters.price .. " gold.", cid)
                else
                    player:setBankBalance(player:getBankBalance() - parameters.price)
                    player:sendTextMessage(MESSAGE_INFO_DESCR, ("Bank Account: %d gold has been withdrawn from your account for this purchase. Your account balance is %d gold coins."):format(parameters.price, player:getBankBalance()))
                end
            else
                npcHandler:say("You have learned " .. parameters.spellName .. ".", cid)
                player:learnSpell(parameters.spellName)
            end
        else
            npcHandler:say("You need a premium account in order to buy " .. parameters.spellName .. ".", cid)
        end
        npcHandler:resetNpc(cid)
        return true
    end

    function StdModule.bless(cid, message, keywords, parameters, node)
        local npcHandler = parameters.npcHandler
        if npcHandler == nil then
            error("StdModule.bless called without any npcHandler instance.")
        end

        if not npcHandler:isFocused(cid) or getWorldType() == WORLD_TYPE_PVP_ENFORCED then
            return false
        end

        local player = Player(cid)
        if player:isPremium() or not parameters.premium then
            if player:hasBlessing(parameters.bless) then
                npcHandler:say("Gods have already blessed you with this blessing!", cid)
            elseif not player:removeMoney(parameters.cost) then
                if player:getBankBalance() < parameters.cost then
                    npcHandler:say("You don't have enough money for blessing.", cid)
                else
                    player:setBankBalance(player:getBankBalance() - parameters.cost)
                    player:sendTextMessage(MESSAGE_INFO_DESCR, ("Bank Account: %d gold has been withdrawn from your account for this purchase. Your account balance is %d gold coins."):format(parameters.cost, player:getBankBalance()))
                end
            else
                player:addBlessing(parameters.bless)
                npcHandler:say("You have been blessed by one of the five gods!", cid)
            end
        else
            npcHandler:say("You need a premium account in order to be blessed.", cid)
        end
        npcHandler:resetNpc(cid)
        return true
    end

    function StdModule.travel(cid, message, keywords, parameters, node)
        local npcHandler = parameters.npcHandler
        if npcHandler == nil then
            error("StdModule.travel called without any npcHandler instance.")
        end

        if not npcHandler:isFocused(cid) then
            return false
        end

        local player = Player(cid)
        if player:isPremium() or not parameters.premium then
            if player:isPzLocked() then
                npcHandler:say("First get rid of those blood stains! You are not going to ruin my vehicle!", cid)
            elseif parameters.level and player:getLevel() < parameters.level then
                npcHandler:say("You must reach level " .. parameters.level .. " before I can let you go there.", cid)
            elseif not player:removeMoney(parameters.cost) then
                if player:getBankBalance() < parameters.cost then
                    npcHandler:say("You don't have enough money.", cid)
                else
                    player:setBankBalance(player:getBankBalance() - parameters.cost)
                    player:sendTextMessage(MESSAGE_INFO_DESCR, ("Bank Account: %d gold has been withdrawn from your account for this purchase. Your account balance is %d gold coins."):format(parameters.cost, player:getBankBalance()))
                end
            else
                npcHandler:say(parameters.msg or "Set the sails!", cid)
                npcHandler:releaseFocus(cid)

                local destination = Position(parameters.destination)
                local position = player:getPosition()
                player:teleportTo(destination)

                position:sendMagicEffect(CONST_ME_TELEPORT)
                destination:sendMagicEffect(CONST_ME_TELEPORT)
            end
        else
            npcHandler:say("I'm sorry, but you need a premium account in order to travel onboard our ships.", cid)
        end
        npcHandler:resetNpc(cid)
        return true
    end

    FocusModule = {
        npcHandler = nil
    }

    -- Creates a new instance of FocusModule without an associated NpcHandler.
    function FocusModule:new()
        local obj = {}
        setmetatable(obj, self)
        self.__index = self
        return obj
    end

    -- Inits the module and associates handler to it.
    function FocusModule:init(handler)
        self.npcHandler = handler
        for i, word in pairs(FOCUS_GREETWORDS) do
            local obj = {}
            obj[#obj + 1] = word
            obj.callback = FOCUS_GREETWORDS.callback or FocusModule.messageMatcher
            handler.keywordHandler:addKeyword(obj, FocusModule.onGreet, {module = self})
        end

        for i, word in pairs(FOCUS_FAREWELLWORDS) do
            local obj = {}
            obj[#obj + 1] = word
            obj.callback = FOCUS_FAREWELLWORDS.callback or FocusModule.messageMatcher
            handler.keywordHandler:addKeyword(obj, FocusModule.onFarewell, {module = self})
        end

        return true
    end

    -- Greeting callback function.
    function FocusModule.onGreet(cid, message, keywords, parameters)
        parameters.module.npcHandler:onGreet(cid)
        return true
    end

    -- UnGreeting callback function.
    function FocusModule.onFarewell(cid, message, keywords, parameters)
        if parameters.module.npcHandler:isFocused(cid) then
            parameters.module.npcHandler:onFarewell(cid)
            return true
        else
            return false
        end
    end

    -- Custom message matching callback function for greeting messages.
    function FocusModule.messageMatcher(keywords, message)
        for i, word in pairs(keywords) do
            if type(word) == "string" then
                if string.find(message, word) and not string.find(message, "[%w+]" .. word) and not string.find(message, word .. "[%w+]") then
                    return true
                end
            end
        end
        return false
    end

    KeywordModule = {
        npcHandler = nil
    }
    -- Add it to the parseable module list.
    Modules.parseableModules["module_keywords"] = KeywordModule

    function KeywordModule:new()
        local obj = {}
        setmetatable(obj, self)
        self.__index = self
        return obj
    end

    function KeywordModule:init(handler)
        self.npcHandler = handler
        return true
    end

    -- Parses all known parameters.
    function KeywordModule:parseParameters()
        local ret = NpcSystem.getParameter("keywords")
        if ret ~= nil then
            self:parseKeywords(ret)
        end
    end

    function KeywordModule:parseKeywords(data)
        local n = 1
        for keys in string.gmatch(data, "[^;]+") do
            local i = 1

            local keywords = {}
            for temp in string.gmatch(keys, "[^,]+") do
                keywords[#keywords + 1] = temp
                i = i + 1
            end

            if i ~= 1 then
                local reply = NpcSystem.getParameter("keyword_reply" .. n)
                if reply ~= nil then
                    self:addKeyword(keywords, reply)
                else
                    print("[Warning : " .. Npc():getName() .. "] NpcSystem:", "Parameter '" .. "keyword_reply" .. n .. "' missing. Skipping...")
                end
            else
                print("[Warning : " .. Npc():getName() .. "] NpcSystem:", "No keywords found for keyword set #" .. n .. ". Skipping...")
            end

            n = n + 1
        end
    end

    function KeywordModule:addKeyword(keywords, reply)
        self.npcHandler.keywordHandler:addKeyword(keywords, StdModule.say, {npcHandler = self.npcHandler, onlyFocus = true, text = reply, reset = true})
    end

    TravelModule = {
        npcHandler = nil,
        destinations = nil,
        yesNode = nil,
        noNode = nil,
    }

    -- Add it to the parseable module list.
    Modules.parseableModules["module_travel"] = TravelModule

    function TravelModule:new()
        local obj = {}
        setmetatable(obj, self)
        self.__index = self
        return obj
    end

    function TravelModule:init(handler)
        self.npcHandler = handler
        self.yesNode = KeywordNode:new(SHOP_YESWORD, TravelModule.onConfirm, {module = self})
        self.noNode = KeywordNode:new(SHOP_NOWORD, TravelModule.onDecline, {module = self})
        self.destinations = {}
        return true
    end

    -- Parses all known parameters.
    function TravelModule:parseParameters()
        local ret = NpcSystem.getParameter("travel_destinations")
        if ret ~= nil then
            self:parseDestinations(ret)

            self.npcHandler.keywordHandler:addKeyword({"destination"}, TravelModule.listDestinations, {module = self})
            self.npcHandler.keywordHandler:addKeyword({"where"}, TravelModule.listDestinations, {module = self})
            self.npcHandler.keywordHandler:addKeyword({"travel"}, TravelModule.listDestinations, {module = self})

        end
    end

    function TravelModule:parseDestinations(data)
        for destination in string.gmatch(data, "[^;]+") do
            local i = 1

            local name = nil
            local x = nil
            local y = nil
            local z = nil
            local cost = nil
            local premium = false

            for temp in string.gmatch(destination, "[^,]+") do
                if i == 1 then
                    name = temp
                elseif i == 2 then
                    x = tonumber(temp)
                elseif i == 3 then
                    y = tonumber(temp)
                elseif i == 4 then
                    z = tonumber(temp)
                elseif i == 5 then
                    cost = tonumber(temp)
                elseif i == 6 then
                    premium = temp == "true"
                else
                    print("[Warning : " .. getCreatureName(getNpcCid()) .. "] NpcSystem:", "Unknown parameter found in travel destination parameter.", temp, destination)
                end
                i = i + 1
            end

            if name ~= nil and x ~= nil and y ~= nil and z ~= nil and cost ~= nil then
                self:addDestination(name, {x=x, y=y, z=z}, cost, premium)
            else
                print("[Warning : " .. Npc():getName() .. "] NpcSystem:", "Parameter(s) missing for travel destination:", name, x, y, z, cost, premium)
            end
        end
    end

    function TravelModule:addDestination(name, position, price, premium)
        self.destinations[#self.destinations + 1] = name

        local parameters = {
            cost = price,
            destination = position,
            premium = premium,
            module = self
        }
        local keywords = {}
        keywords[#keywords + 1] = name

        local keywords2 = {}
        keywords2[#keywords2 + 1] = "bring me to " .. name
        local node = self.npcHandler.keywordHandler:addKeyword(keywords, TravelModule.travel, parameters)
        self.npcHandler.keywordHandler:addKeyword(keywords2, TravelModule.bringMeTo, parameters)
        node:addChildKeywordNode(self.yesNode)
        node:addChildKeywordNode(self.noNode)

        if npcs_loaded_travel[getNpcCid()] == nil then
            npcs_loaded_travel[getNpcCid()] = getNpcCid()
            self.npcHandler.keywordHandler:addKeyword({'yes'}, TravelModule.onConfirm, {module = self})
            self.npcHandler.keywordHandler:addKeyword({'no'}, TravelModule.onDecline, {module = self})
        end
    end

    function TravelModule.travel(cid, message, keywords, parameters, node)
        local module = parameters.module
        if not module.npcHandler:isFocused(cid) then
            return false
        end

        local npcHandler = module.npcHandler

        shop_destination[cid] = parameters.destination
        shop_cost[cid] = parameters.cost
        shop_premium[cid] = parameters.premium
        shop_npcuid[cid] = getNpcCid()

        local cost = parameters.cost
        local destination = parameters.destination
        local premium = parameters.premium

        module.npcHandler:say("Do you want to travel to " .. keywords[1] .. " for " .. cost .. " gold coins?", cid)
        return true
    end


 function TravelModule.onConfirm(cid, message, keywords, parameters, node)
        local module = parameters.module
        if not module.npcHandler:isFocused(cid) then
            return false
        end

        if shop_npcuid[cid] ~= Npc().uid then
            return false
        end

        local npcHandler = module.npcHandler

        local cost = shop_cost[cid]
        local destination = Position(shop_destination[cid])

        local player = Player(cid)
        if player:isPremium() or not shop_premium[cid] then
            if player:isPzLocked() then
                npcHandler:say("Get out of there with this blood.", cid)
                npcHandler:resetNpc(cid)
                return true
            end

            if not player:removeMoney(cost) then
                if player:getBankBalance() < cost then
                    npcHandler:say("You do not have enough money!", cid)
                    npcHandler:resetNpc(cid)
                    return true
                else
                    player:setBankBalance(player:getBankBalance() - cost)
                    player:sendTextMessage(MESSAGE_INFO_DESCR, ("Bank Account: %d gold has been withdrawn from your account for this purchase. Your account balance is %d gold coins."):format(cost, player:getBankBalance()))
                    print("testing")
                end
            end

            npcHandler:say("It was a pleasure doing business with you.", cid)
            npcHandler:releaseFocus(cid)

            local position = player:getPosition()
            player:teleportTo(destination)

            position:sendMagicEffect(CONST_ME_TELEPORT)
            destination:sendMagicEffect(CONST_ME_TELEPORT)
        else
            npcHandler:say("I can only allow premium players to travel there.", cid)
        end

        npcHandler:resetNpc(cid)
        return true
    end

    -- onDecline keyword callback function. Generally called when the player sais "no" after wanting to buy an item.
    function TravelModule.onDecline(cid, message, keywords, parameters, node)
        local module = parameters.module
        if not module.npcHandler:isFocused(cid) or shop_npcuid[cid] ~= getNpcCid() then
            return false
        end
        local parentParameters = node:getParent():getParameters()
        local parseInfo = { [TAG_PLAYERNAME] = Player(cid):getName() }
        local msg = module.npcHandler:parseMessage(module.npcHandler:getMessage(MESSAGE_DECLINE), parseInfo)
        module.npcHandler:say(msg, cid)
        module.npcHandler:resetNpc(cid)
        return true
    end

    function TravelModule.bringMeTo(cid, message, keywords, parameters, node)
        local module = parameters.module
        if not module.npcHandler:isFocused(cid) then
            return false
        end

        local cost = parameters.cost
        local destination = Position(parameters.destination)

        local player = Player(cid)
        if player:isPremium() or not parameters.premium then
            if player:removeMoney(cost) then
                local position = player:getPosition()
                player:teleportTo(destination)

                position:sendMagicEffect(CONST_ME_TELEPORT)
                destination:sendMagicEffect(CONST_ME_TELEPORT)
            else
                if player:getBankBalance() >= cost then
                    player:setBankBalance(player:getBankBalance() - cost)
                    player:sendTextMessage(MESSAGE_INFO_DESCR, ("Bank Account: %d gold has been withdrawn from your account for this purchase. Your account balance is %d gold coins."):format(cost, player:getBankBalance()))
                    local position = player:getPosition()
                    player:teleportTo(destination)

                    position:sendMagicEffect(CONST_ME_TELEPORT)
                    destination:sendMagicEffect(CONST_ME_TELEPORT)
                end
            end
        end
        return true
    end

    function TravelModule.listDestinations(cid, message, keywords, parameters, node)
        local module = parameters.module
        if not module.npcHandler:isFocused(cid) then
            return false
        end

        local msg = "I can bring you to "
        --local i = 1
        local maxn = #module.destinations
        for i, destination in pairs(module.destinations) do
            msg = msg .. destination
            if i == maxn - 1 then
                msg = msg .. " and "
            elseif i == maxn then
                msg = msg .. "."
            else
                msg = msg .. ", "
            end
            i = i + 1
        end

        module.npcHandler:say(msg, cid)
        module.npcHandler:resetNpc(cid)
        return true
    end

    ShopModule = {
        npcHandler = nil,
        yesNode = nil,
        noNode = nil,
        noText = "",
        maxCount = 100,
        amount = 0
    }

    -- Add it to the parseable module list.
    Modules.parseableModules["module_shop"] = ShopModule

    -- Creates a new instance of ShopModule
    function ShopModule:new()
        local obj = {}
        setmetatable(obj, self)
        self.__index = self
        return obj
    end

    -- Parses all known parameters.
    function ShopModule:parseParameters()
        local ret = NpcSystem.getParameter("shop_buyable")
        if ret ~= nil then
            self:parseBuyable(ret)
        end

        local ret = NpcSystem.getParameter("shop_sellable")
        if ret ~= nil then
            self:parseSellable(ret)
        end

        local ret = NpcSystem.getParameter("shop_buyable_containers")
        if ret ~= nil then
            self:parseBuyableContainers(ret)
        end
    end

    -- Parse a string contaning a set of buyable items.
    function ShopModule:parseBuyable(data)
        for item in string.gmatch(data, "[^;]+") do
            local i = 1

            local name = nil
            local itemid = nil
            local cost = nil
            local subType = nil
            local realName = nil

            for temp in string.gmatch(item, "[^,]+") do
                if i == 1 then
                    name = temp
                elseif i == 2 then
                    itemid = tonumber(temp)
                elseif i == 3 then
                    cost = tonumber(temp)
                elseif i == 4 then
                    subType = tonumber(temp)
                elseif i == 5 then
                    realName = temp
                else
                    print("[Warning : " .. Npc():getName() .. "] NpcSystem:", "Unknown parameter found in buyable items parameter.", temp, item)
                end
                i = i + 1
            end

            local it = ItemType(itemid)
            if subType == nil and it:getCharges() ~= 0 then
                subType = it:getCharges()
            end

            if SHOPMODULE_MODE == SHOPMODULE_MODE_TRADE then
                if itemid ~= nil and cost ~= nil then
                    if subType == nil and it:isFluidContainer() then
                        print("[Warning : " .. Npc():getName() .. "] NpcSystem:", "SubType missing for parameter item:", item)
                    else
                        self:addBuyableItem(nil, itemid, cost, subType, realName)
                    end
                else
                    print("[Warning : " .. Npc():getName() .. "] NpcSystem:", "Parameter(s) missing for item:", itemid, cost)
                end
            else
                if name ~= nil and itemid ~= nil and cost ~= nil then
                    if subType == nil and it:isFluidContainer() then
                        print("[Warning : " .. Npc():getName() .. "] NpcSystem:", "SubType missing for parameter item:", item)
                    else
                        local names = {}
                        names[#names + 1] = name
                        self:addBuyableItem(names, itemid, cost, subType, realName)
                    end
                else
                    print("[Warning : " .. Npc():getName() .. "] NpcSystem:", "Parameter(s) missing for item:", name, itemid, cost)
                end
            end
        end
    end

    -- Parse a string contaning a set of sellable items.
    function ShopModule:parseSellable(data)
        for item in string.gmatch(data, "[^;]+") do
            local i = 1

            local name = nil
            local itemid = nil
            local cost = nil
            local realName = nil
            local subType = nil

            for temp in string.gmatch(item, "[^,]+") do
                if i == 1 then
                    name = temp
                elseif i == 2 then
                    itemid = tonumber(temp)
                elseif i == 3 then
                    cost = tonumber(temp)
                elseif i == 4 then
                    realName = temp
                elseif i == 5 then
                    subType = tonumber(temp)
                else
                    print("[Warning : " .. Npc():getName() .. "] NpcSystem:", "Unknown parameter found in sellable items parameter.", temp, item)
                end
                i = i + 1
            end

            if SHOPMODULE_MODE == SHOPMODULE_MODE_TRADE then
                if itemid ~= nil and cost ~= nil then
                    self:addSellableItem(nil, itemid, cost, realName, subType)
                else
                    print("[Warning : " .. Npc():getName() .. "] NpcSystem:", "Parameter(s) missing for item:", itemid, cost)
                end
            else
                if name ~= nil and itemid ~= nil and cost ~= nil then
                    local names = {}
                    names[#names + 1] = name
                    self:addSellableItem(names, itemid, cost, realName, subType)
                else
                    print("[Warning : " .. Npc():getName() .. "] NpcSystem:", "Parameter(s) missing for item:", name, itemid, cost)
                end
            end
        end
    end

    -- Parse a string contaning a set of buyable items.
    function ShopModule:parseBuyableContainers(data)
        for item in string.gmatch(data, "[^;]+") do
            local i = 1

            local name = nil
            local container = nil
            local itemid = nil
            local cost = nil
            local subType = nil
            local realName = nil

            for temp in string.gmatch(item, "[^,]+") do
                if i == 1 then
                    name = temp
                elseif i == 2 then
                    itemid = tonumber(temp)
                elseif i == 3 then
                    itemid = tonumber(temp)
                elseif i == 4 then
                    cost = tonumber(temp)
                elseif i == 5 then
                    subType = tonumber(temp)
                elseif i == 6 then
                    realName = temp
                else
                    print("[Warning : " .. Npc():getName() .. "] NpcSystem:", "Unknown parameter found in buyable items parameter.", temp, item)
                end
                i = i + 1
            end

            if name ~= nil and container ~= nil and itemid ~= nil and cost ~= nil then
                if subType == nil and ItemType(itemid):isFluidContainer() then
                    print("[Warning : " .. Npc():getName() .. "] NpcSystem:", "SubType missing for parameter item:", item)
                else
                    local names = {}
                    names[#names + 1] = name
                    self:addBuyableItemContainer(names, container, itemid, cost, subType, realName)
                end
            else
                print("[Warning : " .. Npc():getName() .. "] NpcSystem:", "Parameter(s) missing for item:", name, container, itemid, cost)
            end
        end
    end

    -- Initializes the module and associates handler to it.
    function ShopModule:init(handler)
        self.npcHandler = handler
        self.yesNode = KeywordNode:new(SHOP_YESWORD, ShopModule.onConfirm, {module = self})
        self.noNode = KeywordNode:new(SHOP_NOWORD, ShopModule.onDecline, {module = self})
        self.noText = handler:getMessage(MESSAGE_DECLINE)

        if SHOPMODULE_MODE ~= SHOPMODULE_MODE_TALK then
            for i, word in pairs(SHOP_TRADEREQUEST) do
                local obj = {}
                obj[#obj + 1] = word
                obj.callback = SHOP_TRADEREQUEST.callback or ShopModule.messageMatcher
                handler.keywordHandler:addKeyword(obj, ShopModule.requestTrade, {module = self})
            end
        end

        return true
    end

    -- Custom message matching callback function for requesting trade messages.
    function ShopModule.messageMatcher(keywords, message)
        for i, word in pairs(keywords) do
            if type(word) == "string" then
                if string.find(message, word) and not string.find(message, "[%w+]" .. word) and not string.find(message, word .. "[%w+]") then
                    return true
                end
            end
        end

        return false
    end

    -- Resets the module-specific variables.
    function ShopModule:reset()
        self.amount = 0
    end

    -- Function used to match a number value from a string.
    function ShopModule:getCount(message)
        local ret = 1
        local b, e = string.find(message, PATTERN_COUNT)
        if b ~= nil and e ~= nil then
            ret = tonumber(string.sub(message, b, e))
        end

        if ret <= 0 then
            ret = 1
        elseif ret > self.maxCount then
            ret = self.maxCount
        end

        return ret
    end

    -- Adds a new buyable item.
    --  names = A table containing one or more strings of alternative names to this item. Used only for old buy/sell system.
    --  itemid = The itemid of the buyable item
    --  cost = The price of one single item
    --  subType - The subType of each rune or fluidcontainer item. Can be left out if it is not a rune/fluidcontainer. Default value is 1.
    --  realName - The real, full name for the item. Will be used as ITEMNAME in MESSAGE_ONBUY and MESSAGE_ONSELL if defined. Default value is nil (getItemName will be used)
    function ShopModule:addBuyableItem(names, itemid, cost, itemSubType, realName)
        if SHOPMODULE_MODE ~= SHOPMODULE_MODE_TALK then
            if itemSubType == nil then
                itemSubType = 1
            end

            local shopItem = self:getShopItem(itemid, itemSubType)
            if shopItem == nil then
                self.npcHandler.shopItems[#self.npcHandler.shopItems + 1] = {id = itemid, buy = cost, sell = -1, subType = itemSubType, name = realName or ItemType(itemid):getName()}
            else
                shopItem.buy = cost
            end
        end

        if names ~= nil and SHOPMODULE_MODE ~= SHOPMODULE_MODE_TRADE then
            for i, name in pairs(names) do
                local parameters = {
                        itemid = itemid,
                        cost = cost,
                        eventType = SHOPMODULE_BUY_ITEM,
                        module = self,
                        realName = realName or ItemType(itemid):getName(),
                        subType = itemSubType or 1
                    }

                keywords = {}
                keywords[#keywords + 1] = "buy"
                keywords[#keywords + 1] = name
                local node = self.npcHandler.keywordHandler:addKeyword(keywords, ShopModule.tradeItem, parameters)
                node:addChildKeywordNode(self.yesNode)
                node:addChildKeywordNode(self.noNode)
            end
        end

        if npcs_loaded_shop[getNpcCid()] == nil then
            npcs_loaded_shop[getNpcCid()] = getNpcCid()
            self.npcHandler.keywordHandler:addKeyword({'yes'}, ShopModule.onConfirm, {module = self})
            self.npcHandler.keywordHandler:addKeyword({'no'}, ShopModule.onDecline, {module = self})
        end
    end

    function ShopModule:getShopItem(itemId, itemSubType)
        if ItemType(itemId):isFluidContainer() then
            for i = 1, #self.npcHandler.shopItems do
                local shopItem = self.npcHandler.shopItems[i]
                if shopItem.id == itemId and shopItem.subType == itemSubType then
                    return shopItem
                end
            end
        else
            for i = 1, #self.npcHandler.shopItems do
                local shopItem = self.npcHandler.shopItems[i]
                if shopItem.id == itemId then
                    return shopItem
                end
            end
        end
        return nil
    end

    -- Adds a new buyable container of items.
    --  names = A table containing one or more strings of alternative names to this item.
    --  container = Backpack, bag or any other itemid of container where bought items will be stored
    --  itemid = The itemid of the buyable item
    --  cost = The price of one single item
    --  subType - The subType of each rune or fluidcontainer item. Can be left out if it is not a rune/fluidcontainer. Default value is 1.
    --  realName - The real, full name for the item. Will be used as ITEMNAME in MESSAGE_ONBUY and MESSAGE_ONSELL if defined. Default value is nil (getItemName will be used)
    function ShopModule:addBuyableItemContainer(names, container, itemid, cost, subType, realName)
        if names ~= nil then
            for i, name in pairs(names) do
                local parameters = {
                        container = container,
                        itemid = itemid,
                        cost = cost,
                        eventType = SHOPMODULE_BUY_ITEM_CONTAINER,
                        module = self,
                        realName = realName or ItemType(itemid):getName(),
                        subType = subType or 1
                    }

                keywords = {}
                keywords[#keywords + 1] = "buy"
                keywords[#keywords + 1] = name
                local node = self.npcHandler.keywordHandler:addKeyword(keywords, ShopModule.tradeItem, parameters)
                node:addChildKeywordNode(self.yesNode)
                node:addChildKeywordNode(self.noNode)
            end
        end
    end

    -- Adds a new sellable item.
    --  names = A table containing one or more strings of alternative names to this item. Used only by old buy/sell system.
    --  itemid = The itemid of the sellable item
    --  cost = The price of one single item
    --  realName - The real, full name for the item. Will be used as ITEMNAME in MESSAGE_ONBUY and MESSAGE_ONSELL if defined. Default value is nil (getItemName will be used)
    function ShopModule:addSellableItem(names, itemid, cost, realName, itemSubType)
        if SHOPMODULE_MODE ~= SHOPMODULE_MODE_TALK then
            if itemSubType == nil then
                itemSubType = 0
            end

            local shopItem = self:getShopItem(itemid, itemSubType)
            if shopItem == nil then
                self.npcHandler.shopItems[#self.npcHandler.shopItems + 1] = {id = itemid, buy = -1, sell = cost, subType = itemSubType, name = realName or getItemName(itemid)}
            else
                shopItem.sell = cost
            end
        end

        if names ~= nil and SHOPMODULE_MODE ~= SHOPMODULE_MODE_TRADE then
            for i, name in pairs(names) do
                local parameters = {
                    itemid = itemid,
                    cost = cost,
                    eventType = SHOPMODULE_SELL_ITEM,
                    module = self,
                    realName = realName or getItemName(itemid)
                }

                keywords = {}
                keywords[#keywords + 1] = "sell"
                keywords[#keywords + 1] = name

                local node = self.npcHandler.keywordHandler:addKeyword(keywords, ShopModule.tradeItem, parameters)
                node:addChildKeywordNode(self.yesNode)
                node:addChildKeywordNode(self.noNode)
            end
        end
    end

    -- onModuleReset callback function. Calls ShopModule:reset()
    function ShopModule:callbackOnModuleReset()
        self:reset()
        return true
    end

    -- Callback onBuy() function. If you wish, you can change certain Npc to use your onBuy().
    function ShopModule:callbackOnBuy(cid, itemid, subType, amount, ignoreCap, inBackpacks)
        local player = Player(cid)
        local shopItem = self:getShopItem(itemid, subType)
        if shopItem == nil then
            error("[ShopModule.onBuy] shopItem == nil")
            return false
        end

        if shopItem.buy == -1 then
            error("[ShopModule.onSell] attempt to buy a non-buyable item")
            return false
        end

        local backpack = 1988
        local totalCost = amount * shopItem.buy
        if inBackpacks then
            totalCost = isItemStackable(itemid) == TRUE and totalCost + 20 or totalCost + (math.max(1, math.floor(amount / getContainerCapById(backpack))) * 20)
        end

        local parseInfo = {
            [TAG_PLAYERNAME] = getPlayerName(cid),
            [TAG_ITEMCOUNT] = amount,
            [TAG_TOTALCOST] = totalCost,
            [TAG_ITEMNAME] = shopItem.name
        }

        local useBankBalance = false
        if getPlayerMoney(cid) < totalCost then
            if player:getBankBalance() < totalCost then
                local msg = self.npcHandler:getMessage(MESSAGE_NEEDMONEY)
                msg = self.npcHandler:parseMessage(msg, parseInfo)
                doPlayerSendCancel(cid, msg)
                return false
            else
                useBankBalance = true
            end
        end

        local subType = shopItem.subType or 1
        local a, b = doNpcSellItem(cid, itemid, amount, subType, ignoreCap, inBackpacks, backpack)
        if a < amount then
            local msgId = MESSAGE_NEEDMORESPACE
            if a == 0 then
                msgId = MESSAGE_NEEDSPACE
            end

            local msg = self.npcHandler:getMessage(msgId)
            parseInfo[TAG_ITEMCOUNT] = a
            msg = self.npcHandler:parseMessage(msg, parseInfo)
            doPlayerSendCancel(cid, msg)
            self.npcHandler.talkStart[cid] = os.time()

            if a > 0 then
                if useBankBalance then
                    local cost = ((a * shopItem.buy) + (b * 20))
                    player:setBankBalance(player:getBankBalance() - cost)
                    player:sendTextMessage(MESSAGE_INFO_DESCR, ("Bank Account: %d gold has been withdrawn from your account for this purchase. Your account balance is %d gold coins."):format(cost, player:getBankBalance()))
                else
                    doPlayerRemoveMoney(cid, ((a * shopItem.buy) + (b * 20)))
                end
                return true
            end

            return false
        else
            local msg = self.npcHandler:getMessage(MESSAGE_BOUGHT)
            msg = self.npcHandler:parseMessage(msg, parseInfo)
            doPlayerSendTextMessage(cid, MESSAGE_INFO_DESCR, msg)
            if useBankBalance then
                player:setBankBalance(player:getBankBalance() - totalCost)
                player:sendTextMessage(MESSAGE_INFO_DESCR, ("Bank Account: %d gold has been withdrawn from your account for this purchase. Your account balance is %d gold coins."):format(totalCost, player:getBankBalance()))
            else
                doPlayerRemoveMoney(cid, totalCost)
            end
            self.npcHandler.talkStart[cid] = os.time()
            return true
        end
    end

    -- Callback onSell() function. If you wish, you can change certain Npc to use your onSell().
    function ShopModule:callbackOnSell(cid, itemid, subType, amount, ignoreEquipped, _)
        local shopItem = self:getShopItem(itemid, subType)
        if shopItem == nil then
            error("[ShopModule.onSell] items[itemid] == nil")
            return false
        end

        if shopItem.sell == -1 then
            error("[ShopModule.onSell] attempt to sell a non-sellable item")
            return false
        end

        local parseInfo = {
            [TAG_PLAYERNAME] = getPlayerName(cid),
            [TAG_ITEMCOUNT] = amount,
            [TAG_TOTALCOST] = amount * shopItem.sell,
            [TAG_ITEMNAME] = shopItem.name
        }

        if not isItemFluidContainer(itemid) then
            subType = -1
        end

        if doPlayerRemoveItem(cid, itemid, amount, subType, ignoreEquipped) then
            local msg = self.npcHandler:getMessage(MESSAGE_SOLD)
            msg = self.npcHandler:parseMessage(msg, parseInfo)
            doPlayerSendTextMessage(cid, MESSAGE_INFO_DESCR, msg)
            doPlayerAddMoney(cid, amount * shopItem.sell)
            self.npcHandler.talkStart[cid] = os.time()
            return true
        else
            local msg = self.npcHandler:getMessage(MESSAGE_NEEDITEM)
            msg = self.npcHandler:parseMessage(msg, parseInfo)
            doPlayerSendCancel(cid, msg)
            self.npcHandler.talkStart[cid] = os.time()
            return false
        end
    end

    -- Callback for requesting a trade window with the NPC.
    function ShopModule.requestTrade(cid, message, keywords, parameters, node)
        local module = parameters.module
        if not module.npcHandler:isFocused(cid) then
            return false
        end

        if not module.npcHandler:onTradeRequest(cid) then
            return false
        end

        local itemWindow = {}
        for i = 1, #module.npcHandler.shopItems do
            itemWindow[#itemWindow + 1] = module.npcHandler.shopItems[i]
        end

        if itemWindow[1] == nil then
            local parseInfo = { [TAG_PLAYERNAME] = getPlayerName(cid) }
            local msg = module.npcHandler:parseMessage(module.npcHandler:getMessage(MESSAGE_NOSHOP), parseInfo)
            module.npcHandler:say(msg, cid)
            return true
        end

        local parseInfo = { [TAG_PLAYERNAME] = getPlayerName(cid) }
        local msg = module.npcHandler:parseMessage(module.npcHandler:getMessage(MESSAGE_SENDTRADE), parseInfo)
        openShopWindow(cid, itemWindow,
            function(cid, itemid, subType, amount, ignoreCap, inBackpacks) module.npcHandler:onBuy(cid, itemid, subType, amount, ignoreCap, inBackpacks) end,
            function(cid, itemid, subType, amount, ignoreCap, inBackpacks) module.npcHandler:onSell(cid, itemid, subType, amount, ignoreCap, inBackpacks) end)
        module.npcHandler:say(msg, cid)
        return true
    end

    -- onConfirm keyword callback function. Sells/buys the actual item.
    function ShopModule.onConfirm(cid, message, keywords, parameters, node)
        local player = Player(cid)
        local module = parameters.module
        if not module.npcHandler:isFocused(cid) or shop_npcuid[cid] ~= getNpcCid() then
            return false
        end
        shop_npcuid[cid] = 0

        local parentParameters = node:getParent():getParameters()
        local parseInfo = {
            [TAG_PLAYERNAME] = getPlayerName(cid),
            [TAG_ITEMCOUNT] = shop_amount[cid],
            [TAG_TOTALCOST] = shop_cost[cid] * shop_amount[cid],
            [TAG_ITEMNAME] = shop_rlname[cid]
        }

        if shop_eventtype[cid] == SHOPMODULE_SELL_ITEM then
            local ret = doPlayerSellItem(cid, shop_itemid[cid], shop_amount[cid], shop_cost[cid] * shop_amount[cid])
            if ret == true then
                local msg = module.npcHandler:getMessage(MESSAGE_ONSELL)
                msg = module.npcHandler:parseMessage(msg, parseInfo)
                module.npcHandler:say(msg, cid)
            else
                local msg = module.npcHandler:getMessage(MESSAGE_MISSINGITEM)
                msg = module.npcHandler:parseMessage(msg, parseInfo)
                module.npcHandler:say(msg, cid)
            end
        elseif shop_eventtype[cid] == SHOPMODULE_BUY_ITEM then
            local cost = shop_cost[cid] * shop_amount[cid]
            local useBankBalance = false
            if getPlayerMoney(cid) < cost then
                if player:getBankBalance() < cost then
                    local msg = module.npcHandler:getMessage(MESSAGE_MISSINGMONEY)
                    msg = module.npcHandler:parseMessage(msg, parseInfo)
                    module.npcHandler:say(msg, cid)
                    return false
                else
                    useBankBalance = true
                end
            end

            local a, b = doNpcSellItem(cid, shop_itemid[cid], shop_amount[cid], shop_subtype[cid], false, false, 1988)
            if a < shop_amount[cid] then
                local msgId = MESSAGE_NEEDMORESPACE
                if a == 0 then
                    msgId = MESSAGE_NEEDSPACE
                end

                local msg = module.npcHandler:getMessage(msgId)
                msg = module.npcHandler:parseMessage(msg, parseInfo)
                module.npcHandler:say(msg, cid)
                if a > 0 then
                    if not useBankBalance then
                        doPlayerRemoveMoney(cid, a * shop_cost[cid])
                    else
                        player:setBankBalance(player:getBankBalance() - a * shop_cost[cid])
                        player:sendTextMessage(MESSAGE_INFO_DESCR, ("Bank Account: %d gold has been withdrawn from your account for this purchase. Your account balance is %d gold coins."):format(a * shop_cost[cid], player:getBankBalance()))
                    end

                    if shop_itemid[cid] == ITEM_PARCEL then
                        doNpcSellItem(cid, ITEM_LABEL, shop_amount[cid], shop_subtype[cid], true, false, 1988)
                    end
                    return true
                end
                return false
            else
                local msg = module.npcHandler:getMessage(MESSAGE_ONBUY)
                msg = module.npcHandler:parseMessage(msg, parseInfo)
                module.npcHandler:say(msg, cid)

                if not useBankBalance then
                    doPlayerRemoveMoney(cid, cost)
                else
                    player:setBankBalance(player:getBankBalance() - a * shop_cost[cid])
                    player:sendTextMessage(MESSAGE_INFO_DESCR, ("Bank Account: %d gold has been withdrawn from your account for this purchase. Your account balance is %d gold coins."):format(a * shop_cost[cid], player:getBankBalance()))
                end

                if shop_itemid[cid] == ITEM_PARCEL then
                    doNpcSellItem(cid, ITEM_LABEL, shop_amount[cid], shop_subtype[cid], true, false, 1988)
                end
                return true
            end
        elseif shop_eventtype[cid] == SHOPMODULE_BUY_ITEM_CONTAINER then
            local ret = doPlayerBuyItemContainer(cid, shop_container[cid], shop_itemid[cid], shop_amount[cid], shop_cost[cid] * shop_amount[cid], shop_subtype[cid])
            if ret == true then
                local msg = module.npcHandler:getMessage(MESSAGE_ONBUY)
                msg = module.npcHandler:parseMessage(msg, parseInfo)
                module.npcHandler:say(msg, cid)
            else
                local msg = module.npcHandler:getMessage(MESSAGE_MISSINGMONEY)
                msg = module.npcHandler:parseMessage(msg, parseInfo)
                module.npcHandler:say(msg, cid)
            end
        end

        module.npcHandler:resetNpc(cid)
        return true
    end

    -- onDecline keyword callback function. Generally called when the player sais "no" after wanting to buy an item.
    function ShopModule.onDecline(cid, message, keywords, parameters, node)
        local module = parameters.module
        if not module.npcHandler:isFocused(cid) or shop_npcuid[cid] ~= getNpcCid() then
            return false
        end
        shop_npcuid[cid] = 0

        local parentParameters = node:getParent():getParameters()
        local parseInfo = {
            [TAG_PLAYERNAME] = getPlayerName(cid),
            [TAG_ITEMCOUNT] = shop_amount[cid],
            [TAG_TOTALCOST] = shop_cost[cid] * shop_amount[cid],
            [TAG_ITEMNAME] = shop_rlname[cid]
        }

        local msg = module.npcHandler:parseMessage(module.noText, parseInfo)
        module.npcHandler:say(msg, cid)
        module.npcHandler:resetNpc(cid)
        return true
    end

    -- tradeItem callback function. Makes the npc say the message defined by MESSAGE_BUY or MESSAGE_SELL
    function ShopModule.tradeItem(cid, message, keywords, parameters, node)
        local module = parameters.module
        if not module.npcHandler:isFocused(cid) then
            return false
        end

        if not module.npcHandler:onTradeRequest(cid) then
            return true
        end

        local count = module:getCount(message)
        module.amount = count

        shop_amount[cid] = module.amount
        shop_cost[cid] = parameters.cost
        shop_rlname[cid] = parameters.realName
        shop_itemid[cid] = parameters.itemid
        shop_container[cid] = parameters.container
        shop_npcuid[cid] = getNpcCid()
        shop_eventtype[cid] = parameters.eventType
        shop_subtype[cid] = parameters.subType

        local parseInfo = {
            [TAG_PLAYERNAME] = getPlayerName(cid),
            [TAG_ITEMCOUNT] = shop_amount[cid],
            [TAG_TOTALCOST] = shop_cost[cid] * shop_amount[cid],
            [TAG_ITEMNAME] = shop_rlname[cid]
        }

        if shop_eventtype[cid] == SHOPMODULE_SELL_ITEM then
            local msg = module.npcHandler:getMessage(MESSAGE_SELL)
            msg = module.npcHandler:parseMessage(msg, parseInfo)
            module.npcHandler:say(msg, cid)
        elseif shop_eventtype[cid] == SHOPMODULE_BUY_ITEM then
            local msg = module.npcHandler:getMessage(MESSAGE_BUY)
            msg = module.npcHandler:parseMessage(msg, parseInfo)
            module.npcHandler:say(msg, cid)
        elseif shop_eventtype[cid] == SHOPMODULE_BUY_ITEM_CONTAINER then
            local msg = module.npcHandler:getMessage(MESSAGE_BUY)
            msg = module.npcHandler:parseMessage(msg, parseInfo)
            module.npcHandler:say(msg, cid)
        end
        return true
    end
end