baby digging

local MIN_FUEL = 300
local AUTO_REFUEL = true

local function  refuel()
    for i = 1, 16 do
        turtle.select(i)
        turtle.refuel()
    end
    turtle.select(1)
end

local function clearDrop()
    if AUTO_REFUEL and turtle.getFuelLevel() < MIN_FUEL then refuel() end
    for slot = 1, 16 do
        turtle.select(slot)
        turtle.dropDown()
    end
end

function  forward()
        while not turtle.forward() do
            turtle.attack()
            sleep(1)
        end
end
local function  up()
    while not turtle.up() do
        if not turtle.digUp() then
            turtle.attackUp()
            sleep(1)
        end
    end
    h = h+1
end

local function  down()
    while not turtle.down() do
        if not turtle.digDown() then
            turtle.attackDown()
            sleep(1)
        end
    end
    h = h-1
end

local function  left()
    turtle.turnLeft()
end

local function  right()
    turtle.turnRight()
end

local function around()
        right()
        right()
end

local function  returnWall()
    while true do
    local state, typeblock = turtle.inspect()
        if typeblock.name ~= 'minecraft:cobblestone' then
            forward()
        else
            right()
            break
        end
    end
end

local function  returnMatka()
    while true do
        forward()
    end
end

local function digHole()
        h = 0
        while true do
            local state, typeblock = turtle.inspectDown()
            if typeblock.name ~= 'minecraft:bedrock' then
                down()
                turtle.dig()
            else
                break
            end
        end
end

local function returnSurface()
    while h~=0 do
        turtle.dig()
        up()
    end
end

local function  main()
    os.setComputerLabel("BABY-"..os.getComputerID())
    term.clear()
    term.setCursorPos(1,1)
    print('Fuel level: ', turtle.getFuelLevel())
    print('Easy dig running!')
    peripheral.call('left','turnOn')
    peripheral.call('right','turnOn')
    refuel()
        if turtle.getFuelLevel() < MIN_FUEL then
            error('Fatal ERROR, put fuel in any slot end PRESS Ctrl+R!')
        end
    digHole()
    around()
    for i = 1, 4 do up()  end
    while turtle.detect() do turtle.dig() end
    forward()
    while true do
            local state, typeblock = turtle.inspectDown()
            if typeblock.name ~= 'minecraft:bedrock' then
                down()
            else
                break
            end
        end
    returnSurface()
    around()
    returnWall()
    clearDrop()
    returnMatka()
end

main()