Minecraft testing movements

currentPositionx = 0
currentPositiony = 0
currentPositionz = 0
currentFacing = 0
currentlySelectedSlot = 1
fuelLevelToRefuelAt = 5

function main()
  pillarToZ(1, 3)
  lineToY(1, currentPositiony + 2)
  turnZero()
  safeForward()
  pillarToZ(1, 3)
  lineToY(1, currentPositiony + 2)
  turnZero()
  safeForward()
  pillarToZ(1, 3)
end

function lineToY(item, y)
  turnZero()
  while currentPositiony ~= y do
     if not turtle.detectDown() then
       safePlaceDown(item)
     end
     if y > currentPositiony then
        turnFacing(0)
        safeForward()
        safePlaceDown(item)
     elseif y < currentPositiony then
        turnFacing(2)
        safeForward()
        safePlaceDown(item)
     end
  end
end

function pillarToZ(item, z)
  goGround(128)
  safeUp()
  while currentPositionz < z do
    safePlaceDown(item)
    safeUp()
  end
end

function goGround(maximum)
  local current = 0;
  while not turtle.detectDown() do
    safeDown()
    current = current + 1
    if current >= maximum  then
        return true
    end
  end
  return true
end

function getItemPlace(item)
  while true do
    turtle.select(item)
    local skip = true
    for i = 1, 15 do
      if skip then
        if turtle.getItemCount(i)==0 then
          skip = false
        end
      else
        if turtle.getItemCount(i)~=0 then
          if turtle.compareTo(i) then
            print("Found material in "..tostring(i))
            return i
          end
        end
      end
    end
    awaitFix("No building materials! Refill with same as selected slot!")
  end
end

function ensureFuel()
  -- Determine whether a refuel is required
  local fuelLevel = turtle.getFuelLevel()
  if (fuelLevel ~= "unlimited") then
    if (fuelLevel < fuelLevelToRefuelAt) then
      -- Need to refuel
      turtle.select(16)
      currentlySelectedSlot = 16
      local fuelItems = turtle.getItemCount(16)
      -- Do we need to impact the emergency fuel to continue? (always
      -- keep one fuel item in slot 16)
      if (fuelItems == 0) then
        print("I want more fuel!")
      else
        turtle.refuel(1)
      end
    end
  end
end

function awaitFix(message)
    print("I have problem: " .. message)
    print("Please fix it and press Enter to continue")
    io.read()
end

function safePlaceFront(itemTest)
  item = getItemPlace(itemTest)
  ensureFuel()
  turtle.select(item)
  success = false
  while not success do
    success = turtle.place()
    if not success then
      awaitFix("Can't place in front")
    end
  end
end

function safePlaceDown(itemTest)
  item = getItemPlace(itemTest)
  ensureFuel()
  turtle.select(item)
  success = false
  while not success do
    success = turtle.placeDown()
    if not success then
      awaitFix("Can't place down")
    end
  end
end


function safePlaceUp(itemTest)
  item = getItemPlace(itemTest)
  ensureFuel()
  turtle.select(item)
  success = false
  while not success do
    success = turtle.placeUp()
    if not success then
      awaitFix("Can't place up")
    end
  end
end


function safeDigFront(item)
  ensureFuel()
  turtle.select(item)
  success = false
  while not success do
    success = turtle.dig()
    if not success then
      awaitFix("Can't dig in front")
    end
  end
end

function safeDigDown(item)
  ensureFuel()
  turtle.select(item)
  success = false
  while not success do
    success = turtle.digDown()
    if not success then
      awaitFix("Can't dig down")
    end
  end
end


function safeDigUp(item)
  ensureFuel()
  turtle.select(item)
  success = false
  while not success do
    success = turtle.digUp()
    if not success then
      awaitFix("Can't dig up")
    end
  end
end

function turnZero()
  while currentFacing ~= 0 do
    turnRightTrack()
  end
end

function turnFacing(facing)
  --todo: faster it
  while facing ~= currentFacing do
    turnRightTrack()
  end
end

function turnRightTrack()
  ensureFuel()
  turtle.turnRight()
  currentFacing = currentFacing + 1
  if currentFacing >= 4 then
    currentFacing = 0
  end
end

function turnLeftTrack()
  ensureFuel()
  turtle.turnLeft()
  currentFacing = currentFacing - 1
  if currentFacing < 0 then
    currentFacing = 3
  end
end

function safeForward()
  ensureFuel()
  success = false
  while not success do
    success = turtle.forward()
    if not success then
      awaitFix("Blocked attempting to move forward")
    end
  end
  if (currentFacing == 0) then
    currentPositiony = currentPositiony + 1
  elseif (currentFacing == 1) then
    currentPositionx = currentPositionx + 1
  elseif (currentFacing == 2) then
    currentPositiony = currentPositiony - 1
  elseif (currentFacing == 3) then
    currentPositionx = currentPositionx - 1
  else
    awaitFix("Oy we gotta into 101010022..")
  end
end

function safeBack()
  ensureFuel()
  success = false
  while not success do
    success = turtle.back()
    if not success then
      awaitFix("Blocked attempting to move back")
    end
  end
  if (currentFacing == 0) then
    currentPositiony = currentPositiony - 1
  elseif (currentFacing == 1) then
    currentPositionx = currentPositionx - 1
  elseif (currentFacing == 2) then
    currentPositiony = currentPositiony + 1
  elseif (currentFacing == 3) then
    currentPositionx = currentPositionx + 1
  else
    awaitFix("Oy we gotta into 101010022..")
  end
end

function safeUp()
  ensureFuel()
  success = false
  while not success do
    success = turtle.up()
    if not success then
      awaitFix("Blocked attempting to move up")
    end
  end
  currentPositionz = currentPositionz + 1
end

function safeDown()
  ensureFuel()
  success = false
  while not success do
    success = turtle.down()
    if not success then
      awaitFix("Blocked attempting to move down")
    end
  end
  currentPositionz = currentPositionz - 1
end

main()