--roadBuilder

currentFacing = 0
currentlySelectedSlot = 1
fuelLevelToRefuelAt = 5
initBlocksCount = 0
minSlot = 1
maxSlot = 16


currentY = 0

args = { ... }

minimumDown = 2

BLOCK_PILLAR = 1
BLOCK_GLASS = 3
BLOCK_WALL = 1
BLOCK_WALLSTAIRS = 2
BLOCK_LAMP = 4

function main()
  if #args > 0 then
    local length = tonumber(args[1])
    initBlocks()
    for i=1,length,1 do
      makePart()
    end
  else
    print("Usage: road <length>")
  end
end

function makePart()
  for i=1,3,1 do
    case(false)
  end
  go("forward",true)
  go("down",true)
  pillar()
  go("up",true)
  turnLeft()
  turnLeft()
  go("forward",true)
  turnLeft()
  turnLeft()
  case(false)
  case(true)
  case(false)
  for i=1,3,1 do
    case(false)
  end
end

function case(lamp)
  if lamp then
    replaceBlock(BLOCK_LAMP,"down")
  else
    replaceBlock(BLOCK_WALL,"down")
  end
  turnRight()
  go("forward",true)
  replaceBlock(BLOCK_WALL,"down")
  go("forward",true)

  go("up",true)
  replaceBlock(BLOCK_WALL,"down")
  go("forward",true)
  go("down",true)
  go("down",true)
  turnRight()
  turnRight()
  go("down",true)
  go("forward",true)
  replaceBlock(BLOCK_WALLSTAIRS,"up")
  turnRight()
  turnRight()
  go("forward",true)
  turnRight()
  turnRight()
  go("up",true)
  go("up",true)
  go("up",true)
  go("forward",true)
  go("up",true)
  replaceBlock(BLOCK_GLASS,"down")
  go("up",true)
  replaceBlock(BLOCK_WALL,"down")
  go("up",true)
  replaceBlock(BLOCK_WALLSTAIRS,"down")
  go("forward",true)
  replaceBlock(BLOCK_WALL,"down")
  go("forward",true)
  replaceBlock(BLOCK_GLASS,"down")
  go("forward",true)
  replaceBlock(BLOCK_WALL,"down")
  go("forward",true)
  go("forward",true)
  turnRight()
  turnRight()
  go("down",true)
  replaceBlock(BLOCK_WALLSTAIRS,"forward")
  go("down",true)
  replaceBlock(BLOCK_WALL,"forward")
  go("down",true)
  replaceBlock(BLOCK_GLASS,"forward")
  go("down",true)
  replaceBlock(BLOCK_WALL,"forward")
  go("down",true)
  go("forward",true)
  replaceBlock(BLOCK_WALL,"forward")
  turnRight()
  turnRight()
  go("forward",true)
  turnRight()
  turnRight()
  go("down",true)
  go("forward",true)
  replaceBlock(BLOCK_WALLSTAIRS,"up")
  turnLeft()
  turnLeft()
  go("forward",true)
  go("up",true)
  turnRight()
  go("forward",true)
  go("up",true)
  turnRight()
  go("forward",true)
  go("forward",true)
  go("forward",true)
  turnLeft()
end

function pillar()
  for i=1,minimumDown,1 do
    currentY  = currentY - 1
    go("down",true)
  end
  repeat
    currentY  = currentY - 1
    go("down",true)
  until not isEmpty("down")
  while currentY < 0 do
    go("up",true)
    replaceBlock(BLOCK_PILLAR,"down")
    turnLeft()
    go("forward",true)
    replaceBlock(BLOCK_PILLAR,"down")
    turnLeft()
    turnLeft()
    go("forward",true)
    go("forward",true)
    replaceBlock(BLOCK_PILLAR,"down")
    turnRight()
    turnRight()
    go("forward",true)
    turnRight()
    currentY = currentY + 1
  end
  turnRight()
  go("forward",true)
  turnLeft()
  go("forward",true)
  turnLeft()
  replaceBlock(BLOCK_PILLAR,"down")
  go("forward",true)
  replaceBlock(BLOCK_PILLAR,"down")
  go("forward",true)
  replaceBlock(BLOCK_PILLAR,"down")
  turnLeft()
  go("forward",true)
  go("forward",true)
  turnLeft()
  replaceBlock(BLOCK_PILLAR,"down")
  go("forward",true)
  replaceBlock(BLOCK_PILLAR,"down")
  go("forward",true)
  replaceBlock(BLOCK_PILLAR,"down")
  turnLeft()
  turnLeft()
  go("forward",true)
  turnRight()
  go("forward",true)
end



function replaceBlock(id, direction)
  if not isEmpty(direction) then
    dig(direction)
  end
  placeBlock(id, direction)
end

function placeBlock(id, direction)
  local slotNum = GetBlock(id)
  local result = false
  while slotNum == 0 do
    selectSlot(id)
    awaitFix("I have no blocks as in selected slot")
    slotNum = GetBlock(id)
  end
  ensureFuel()
  selectSlot(slotNum)
  if direction=="up" then
     result = turtle.placeUp()
  elseif direction=="down" then
     result = turtle.placeDown()
  else
     result = turtle.place()
  end
  return result
end

function GetBlock(id)
  if turtle.getItemCount(id) > 1 then
    return id
  else
    selectSlot(id)
    for i=minSlot,maxSlot,1 do
      if turtle.getItemCount(i) > 0 then
        if turtle.compareTo(i) then
          return i
        end
      end
    end
  end
  return 0
end


function ___initBlocks()
  if initBlocksCount==0 then
    selectSlot(1)
    while turtle.getItemCount(currentlySelectedSlot)~=0 do
      initBlocksCount = initBlocksCount + 1
      selectSlot(currentlySelectedSlot + 1)
    end
  end
  if initBlocksCount==0 then
    return false
  end
  minSlot = initBlocksCount + 1
  maxSlot = 15
end


function initBlocks()
  initBlocksCount = 4
  minSlot = initBlocksCount
  maxSlot = 15
end

function isEmpty(side)
    local result = false
    if side=="up" then
      result = not turtle.detectUp()
    elseif side=="down" then
      result = not turtle.detectDown()
    else
      result = not turtle.detect()
    end
    return result
end

--select slot
function selectSlot(x)
  if x<1 then
    x = 1
  elseif x > 16 then
    x = 16
  end
  turtle.select(x)
  currentlySelectedSlot = x
end


--Check fuel, refueling from inventory special slot or not
function ensureFuel()
  -- Determine whether a refuel is required
  local fuelLevel = turtle.getFuelLevel()
  if (fuelLevel ~= "unlimited") then
    if (fuelLevel < fuelLevelToRefuelAt) then
      -- Need to refuel
      selectSlot(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
        awaitFix("I want more fuel!")
      elseif (fuelItems == 1) then
        --load fuel from another slot
    local fueled = false
    local fromSlot = initBlocksCount + 1
        for i=fromSlot,15,1 do
          selectSlot(i)
      if (turtle.compareTo(16)) then
        print("Refueling from not fuel slot: "+i)
        turtle.refuel(1)
        turtle.transferTo(16)
        fueled = true
          end
        end
        if not fueled then
          print("completely out of fuel!")
        end
      else --fuelItems > 1
        print("Time to refueling!")
        turtle.refuel(1)
      end
    end
  end
end


--turns
function turnFacing(facing)
  while facing ~= currentFacing do
    turnRight()
  end
end

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

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

-- BOOL dig direction with retries
function dig(direction)
  local result = false
  local tries = 0
  selectSlot(1)
  while (not result) and (tries < 10) do
    ensureFuel()
    if direction=="up" then
        result = turtle.digUp()
    elseif direction=="down" then
        result = turtle.digDown()
    else
        result = turtle.dig()
    end
    tries = tries + 1
  end
  if not result then
    print ("can't dig in "..direction)
  end
  return result
end

--go direction with breaking blocks and refueling
function go(direction, allowDig)
    if direction=="right" then
      turnRight()
      direction="forward"
    end
    if direction=="left" then
      turnLeft()
      direction="forward"
    end
    if direction=="forward" then
       while turtle.detect() do
         if allowDig then
           ensureFuel()
           turtle.dig()
         else
           awaitFix("can't forward")
         end
       end

       while not turtle.forward() do
         ensureFuel()
         turtle.dig()
       end
    end
    if direction=="up" then
       while turtle.detectUp() do
         if allowDig then
           ensureFuel()
           turtle.digUp()
         else
           awaitFix("can't up")
         end
       end
       while not turtle.up() do
           ensureFuel()
           turtle.digUp()
       end
    end
    if direction=="down" then
       while turtle.detectDown() do
         if allowDig then
           ensureFuel()
           turtle.digDown()
         else
           awaitFix("can't down")
         end
       end
        while not turtle.down() do
           ensureFuel()
           turtle.digDown()
       end
    end
end

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



main() --execute ALL