human-controlled turret

turtle.select(2)
ref = turtle.refuel()
if ref == false then
  print("I couldn't find any kind of fuel! Have you put it in the 2nd slot?")
  sleep(2)
  os.reboot()
end
turtle.select(1)
print("GET READY...GO!")
print("Arrow keys, control arrow direction!")
print("A-D keys, turn the turtle!")
print("SPACE key, shoot!!")
print("Q key, quit!")
print("U key, + shoot charge!")
print("J key, - shoot charge!")
bow = peripheral.wrap("left")
xDir = 0
Pw = 0.1
yDir = 0
while true do
  event, key = os.pullEvent("key")
  if key == 57 then
    bow.shoot(Pw,xDir,yDir)
  elseif key == 30 then
    turtle.turnLeft()
  elseif key == 32 then
    turtle.turnRight()
  elseif key == 16 then
    os.reboot()
  elseif key == 200 then
    yDir = yDir + 1
  elseif key == 208 then
    yDir = yDir - 1
  elseif key == 203 then
    xDir = xDir - 1
  elseif key == 205 then
    xDir = xDir + 1
  elseif key == 22 then
    if Pw < 1 then
      Pw = Pw + 0.1
    end
  elseif key == 36 then
    if Pw > 0.1 then
      Pw = Pw - 0.1
    end
  end
end