bridge

local e = 1

function selectBlocks(s)
 if getBlockCount() ~= 0 then
  if tmp ~= nil then
   if tmp["name"] == "minecraft:netherrack" then
    local x = turtle.getItemCount()
    if x < 1 then
     turtle.select(s + 1)
    end
   end
  end
 else
  e = 2
 end
end

function bridge()
 turtle.dig()
 turtle.forward()
 turtle.digUp()
 turtle.placeDown()
 turtle.turnLeft()
 turtle.place()
 turtle.turnRight()
 turtle.turnRight()
 turtle.place()
 turtle.turnLeft()
end

function getBlockCount()
 local bc = 0
 local tmp
 for z = 1, 16, 1 do
  tmp = turtle.getItemDetail(t)
  if tmp ~= nil then
   if tmp["name"] == "minecraft:netherrack" then
    bc = bc + tmp["count"]
   end
  end
 end
 return bc
end

function equipPickaxe()
 local ed = 0
 local tmp
 shell.run("unequip", "left")
 shell.run("unequip", "right")
 for p = 1, 16, 1 do
  tmp = turtle.getItemDetail(p)
  if tmp ~= nil then
   if tmp["name"] == "minecraft:diamond_pickaxe" then
    turtle.equipLeft(p)
    ed = 1
   end
  end
 end
 if ed == 0 then
  e = 2
  print("Please put a Pickaxe into the Inventory")
 end
end

function doAll()
 shell.run("refuel", "all")
 equipPickaxe()
 turtle.select(1)
 while e == 1 do
  bridge()
  selectBlocks(turtle.getSelectedSlot())
 end
end

doAll()