Minecraft ComputerCraft Modem DrawerController Pull From Barrels Above and Beyond

---
---Desc: A program which pulls items from connected barrels into a main storage drawer controller + attached drawers
---Difference between this Controller and pastebin.com/WhCSpiNr is Whitelisting Barrels, instead of Blacklisting
---This is considered an upgrade from the Modem Drawer Controller because:
---1. you don't need a modem for every drawer 2. operation is much faster
---

--By: hornedcommando

-- Define the controller peripheral
local controller = peripheral.wrap("storagedrawers:controller_0")
local occultism = peripheral.wrap("occultism:storage_controller_0")

-- Function to check if a drawer contains a specific item
local function findSlotForItem(itemName)
    local controllerContents = controller.list()
    for slot, item in pairs(controllerContents) do
        if item.name == itemName then
            return slot
        end
    end
    return nil
end

-- Function to push items from a single peripheral to the controller
local function pushItemsFromPeripheral(peripheralName)
    local peripheralDevice = peripheral.wrap(peripheralName)
    if not peripheralDevice then
        print("Peripheral " .. peripheralName .. " not found!")
        return false
    end

    if not peripheralDevice.list then
        print("Peripheral " .. peripheralName .. " does not have an inventory!")
        return false
    end

    local peripheralContents = peripheralDevice.list()
    if not peripheralContents or next(peripheralContents) == nil then
        print("Peripheral " .. peripheralName .. " is empty.")
        return true -- No items in peripheral, nothing to process
    end

    for slot, item in pairs(peripheralContents) do
        print("Processing item: " .. item.name .. " from slot: " .. slot)
        local targetSlot = findSlotForItem(item.name)

        -- If no specific slot for the item, find an empty one
        if not targetSlot then
            for i = 1, controller.size() do
                if not controller.getItemDetail(i) then
                    targetSlot = i
                    break
                end
            end
        end

        -- Attempt to push items to the controller
        if targetSlot then
            print("Pushing item: " .. item.name .. " to controller slot: " .. targetSlot)
            local success = peripheralDevice.pushItems(peripheral.getName(controller), slot, item.count, targetSlot)
            if success == 0 then
                print("Cannot push item to controller slot: " .. targetSlot .. " from peripheral " .. peripheralName .. "! Check storage capacity.")
                return false -- Failed push, continue checking other peripherals
            end
        else
            print("No slot available for item " .. item.name .. " in controller! Add or upgrade a drawer.")
            return false -- No slot available for this item
        end
    end
    return true -- Successfully processed all items in this peripheral
end

-- Main loop function
local function main()
    while true do
        local allSuccess = true

        for _, name in ipairs(peripheral.getNames()) do
            if peripheral.getType(name) == "minecraft:barrel" then
                print("Checking peripheral: " .. name)
                -- Try pushing items from the current peripheral
                local success = pushItemsFromPeripheral(name)
                if not success then
                    allSuccess = false -- Mark as false if any peripheral fails
                end
            end
        end

        -- Since this can pull a whole chest at once i've made the wait fairly long
        -- IMPORTANT: if the program cannot keep up with your inputs reduce the wait
        if allSuccess then
            print("All peripherals processed successfully. Waiting 60 seconds before next check.")
            os.sleep(60) -- Wait 60 seconds before checking again
        else
            print("Some peripherals failed to process. Retrying in 2 seconds.")
            os.sleep(10) -- Short delay to allow immediate retry if a peripheral fails
        end
    end
end

-- Start the main function
main()