Fancy Remote Dispenser

local source = "turtle_2187"
local dispense_from = "minecraft:ironchest_iron_1508"
local monitor = peripheral.wrap "monitor_2978"
local button = "top"
local dispense_count = 16
local dispense_direction = "west"
local size = peripheral.call(dispense_from, "size")
local stack_size = 64
local display_name = "Melon"

local function mon_write(...)
    monitor.setTextScale(1)
    local oldterm = term.redirect(monitor)
    term.clear()
    term.setCursorPos(1, 1)
    write(...)
    term.redirect(oldterm)
end

local function fill_chest()
    while true do
        local current_contents = peripheral.call(dispense_from, "list")

        local item_count = 0
        local can_fill = true
        for slot = 1, size do
            local slot_contents = current_contents[slot]

            if slot_contents and slot_contents.count then
                item_count = item_count + slot_contents.count
            end
            if can_fill and (not slot_contents or slot_contents.count < stack_size) then
                print("Filling slot", slot)
                local source_contents = peripheral.call(source, "list")
                local moved
                for source_slot in pairs(source_contents) do
                    moved = peripheral.call(source, "pushItems", dispense_from, source_slot, nil, slot)
                end
                if moved then
                    print("Moved", moved, "items")
                else
                    print("Insufficient items in source")
                    can_fill = false
                end
            end
        end

        mon_write(("%dx %s stored\n\nPress button for %dx %s"):format(item_count, display_name, dispense_count, display_name))
        sleep(5)
    end
end

local function handle_button()
    while true do
        os.pullEvent "redstone"
        if redstone.getInput(button) then
            local contents = peripheral.call(dispense_from, "list")
            for slot, stack in pairs(contents) do
                if stack.count > dispense_count then
                    print("Dispensing", dispense_count, "from", slot, "to", dispense_direction)
                    peripheral.call(dispense_from, "drop", slot, dispense_count, dispense_direction)
                    break
                end
            end
        end
    end
end

parallel.waitForAll(handle_button, fill_chest)