drawerStockPileSwitch

local objDrawer = peripheral.find("storagedrawers:standard_drawers_1") -- Work only with the drawer 1x1
local objMonitor = peripheral.find("monitor") -- can be use with only one monitor
local fileName = "lastSignal.txt"
local sideOutput = "left"

local maxStack = 64 -- Place the max amount of itens per stack
local upgradeMultiplier = 1 -- how much the upgrade increase. If not have, leave at 1
local slot = 2 -- For drawer 1x1, aways will be 2

local minPercent = 0.20
local maxPercent = 0.80

local redstoneSignal = true

function main()
    shell.run("clear")

    returnMaxCapacityDrawer =  maxCapacityDrawer(objDrawer, upgradeMultiplier, maxStack)

    local currentCount = objDrawer.getItemDetail(slot).count

    local quantMin = returnMaxCapacityDrawer * minPercent
    local quantMax = returnMaxCapacityDrawer * maxPercent

    if objMonitor ~= nil then
        drawMonitor(objMonitor, currentCount, returnMaxCapacityDrawer)
    end

    local savedSignal = loadLastSignal(fileName)
    print("Value get from file: " .. tostring(savedSignal))
    redstoneSignal = savedSignal

    local returnSetRedstoneSignal = setRedstoneSignal(quantMin, quantMax, currentCount)

    if returnSetRedstoneSignal ~= nil then
        redstoneSignal = returnSetRedstoneSignal
        print("Signal change to: " .. tostring(redstoneSignal))
        saveLastSignal(fileName, redstoneSignal)
    end

    redstone.setOutput(sideOutput, redstoneSignal)
end

-- ==========================================================================
-- =============================== FUNCTIONS ================================
-- ==========================================================================

function maxCapacityDrawer(obj, multiplier, stack)
    local maxCount = obj.getItemDetail(slot).maxCount * stack
    maxCount = maxCount * multiplier
    return maxCount
end

function setRedstoneSignal(min, max, current)
    if current < min then
        return true
    end

    if current > max then
        return false
    end
end

function drawMonitor(monitor, currentItens, maxItens)
    monitor.setTextColor(colors.white)
    monitor.setBackgroundColor(colors.black)
    monitor.setTextScale(0.5)
    monitor.clear()

    monitor.setCursorPos(1,1)
    monitor.write("Itens: " .. currentItens)

    monitor.setCursorPos(1,2)
    monitor.write("Max Itens: " .. maxItens)
end

function loadLastSignal(name)
    if (fs.exists(name) == false) then
        saveLastSignal(name, redstoneSignal)
        return redstoneSignal
    else
        local file = fs.open(name,"r")
        local line = {}
        line = file.readLine()
        file.close()
        print("file readed")
        return line
    end
end

function saveLastSignal(name, content)
    local file = fs.open(name,"w")
    file.write(content)
    file.close()
    print("file writed")
end

function toBool(param)
    if param == "true" then
        return true
    end

    return false
end

-- ==========================================================================
-- ==========================================================================
while true do
    main()
    sleep(2)
end