quarrysetup

local tArgs = { ... }
if #tArgs ~= 2 then
    print( "Usage: bridge <length> <direction of landmark (L, R, B)>" )
    return
end

-- Set length with user input
local length = tonumber( tArgs[1] )
if length < 1 then
    print( "Bridge length must be positive" )
    return
end

-- Check that there are <length>
-- blocks provided in slot 9
--local numblocks = turtle.getItemCount(9)
--if numblocks < length then
--  print("Please place at least "..length.." building blocks in slot 9")
--  return
--end

-- Place a block underneath
-- the turtle to build bridge
function putblockdown()
    if not (turtle.detectDown()) then
        turtle.select(9)
        turtle.placeDown()
    end
end

-- Place Landmark in front
function placelm()
    if tArgs[2] == "R" then
        if not (turtle.detect()) then
            turtle.turnRight()
            turtle.forward()
            turtle.select(9)
            turtle.placeDown()
            turtle.back()
            turtle.select(10)
            turtle.place()
            turtle.turnLeft()
        end
    end
if tArgs[2] == "L" then
        if not (turtle.detect()) then
            turtle.turnLeft()
            turtle.forward()
            turtle.select(9)
            turtle.placeDown()
            turtle.back()
            turtle.select(10)
            turtle.place()
            turtle.turnRight()
        end
    end
if tArgs[2] == "B" then
        if not (turtle.detect()) then
            turtle.turnRight()
            turtle.forward()
            turtle.select(9)
            turtle.placeDown()
            turtle.back()
            turtle.select(10)
            turtle.place()
            turtle.turnLeft()
            turtle.turnLeft()
            turtle.forward()
            turtle.select(9)
            turtle.placeDown()
            turtle.back()
            turtle.select(10)
            turtle.place()
            turtle.turnRight()
        end
    end
end

function backhome()
    x = length
    while x > 0 do
    -- putblockdown()
    turtle.back()
    x = x - 1
    end
end
-- Move forward <length> times
-- and build a bridge with
-- blocks provided in slot 9
local i = 0
while i < length do
    -- putblockdown()
    turtle.forward()
    i = i + 1
end

placelm()
backhome()

-- That's all, folks!
print("Built a bridge "..i.." blocks long")
return