tier upgrade

[Yatozin]

just wondering if someone can help me with adding so that items can revert backwards on fails with a chance on this.

-- Tier Upgrader by Stigma: https://otland.net/threads/tfs-0-4-1-2-tier-upgrading-system.245047/
-- Converted to TFS 1.3 Revscriptsys by Stigma

local action = Action()

local config = {
    messages = {
        success = {
            text  = 'Upgrade!',
            talkType = TALKTYPE_MONSTER_SAY,
            effect   = CONST_ME_FIREWORK_RED
        },

        fail = {
            text  = 'Upgrade Failed.',
            talkType = TALKTYPE_MONSTER_SAY,
            effect   = CONST_ME_POFF
        },
    },

    gear = {
        -- [key id] = {tier = item tier, upgraderType = 'key, soil, crystal, etc (whatever you want it to say, there's no limit)', chance = upgrade chance}
        [2087] = {tier = 1, upgraderType = 'key', chance = 30,
            items = {
                -- [from id] = [to id]
                [2505] = 2492,
                [2160] = 2148
            }
        },
        [2088] = {tier = 2, upgraderType = 'key', chance = 80,
            items = {
                [2148] = 2160
            }
        }
    }
}

function action.onUse(player, item, fromPosition, target, toPosition, isHotkey)
    -- Using player's position if the target item is located in a container, otherwise use the item's position located on the map
    local pos = target:getPosition().x == 65535 and player:getPosition() or target:getPosition()
    -- Make sure the player is not attempting to target a creature
    if not target:isItem() then
        player:sendCancelMessage('You must select an item.')
        pos:sendMagicEffect(CONST_ME_POFF)
        return true
    end
    -- Attempt to get the config based on which key id the player is using
    local keyConfig = config.gear[item:getId()]
    -- Adding article to full item name if possible, ex: "a sword"
    local name  = (target:getArticle() ~= '') and string.format('%s %s', target:getArticle(), target:getName()) or target:getName()
    if keyConfig then
        -- Directly attempt to access the item id to upgrade to by indexing the item list with the target item's id
        local upgradeId = keyConfig.items[target:getId()]
        -- Prevent attempting to upgrade an item that isn't in config
        if not upgradeId then
            player:sendCancelMessage(string.format('You are unable to upgrade %s with a tier %d %s.', (name == '') and 'this' or name, keyConfig.tier, keyConfig.upgraderType))
            pos:sendMagicEffect(CONST_ME_POFF)
            return true
        end
        -- Prevent attempting to upgrade a stackable item that has more than 1 in it's stack
        if target:getCount() > 1 then
            player:sendCancelMessage('You may only upgrade this item one at a time.')
            pos:sendMagicEffect(CONST_ME_POFF)
            return true
        end
        -- Use the "success" table in config if the random value is less than or equal to the chance, otherwise use the "fail" table
        local confKey = (math.random(100) <= keyConfig.chance and 'success' or 'fail')
        local resultConfig = config.messages[confKey]
        pos:sendMagicEffect(resultConfig.effect)
        player:say(resultConfig.text, resultConfig.talkType)
        if confKey == 'success' then
            target:transform(upgradeId)
        end
        -- Make sure to remove only 1 item in the case the upgrader is a stackable item
        item:remove(1)
    end
    return true
end

-- Automatically register the key ids in config
for keyId, _ in pairs(config.gear) do
    action:id(keyId)
end
action:register() -- Enable the action for use