goto

-- north=1, east=2, south=3, west=4

local ox, oy, oz = nil, nil, nil
local endx, endy, endz = nil, nil, nil
local stuck = 0


function getpos()
   rednet.open("right")
   cx, cy, cz = gps.locate(1)
end

getpos()


print("Wohin solls gehen?")
write("x: ")
nx = read()

write("y: ")
ny = read()

write("z: ")
nz = read()

write("In welche Richtung gucken (1-4)?")
ndirect = read()

function directto(x)
   while ndirect ~= direct do
      turtle.turnRight()
      if direct ~= 4 then
         direct = direct + 1
      else
         direct = 1
      end
   end

function gox1()
   if cx < nx then
      directto(1)
      if turtle.forward() then
         cx = cx - 1
         gox1()
      else
         gox3()
      end
   end
end

function gox3()
   if cx > nx then
      directto(3)
      if turtle.forward() then
         cx = cx +1
         gox3()
      else
         goz2()
      end
   end
end

function goz2()
   if cz < nz then
      directto(2)
      if turtle.forward() then
         cz = cz + 1
         goz2()
      else
         goz4()
      end
   end
end

function goz4()
   if cz > nz then
      directto(4)
      if turtle.forward() then
         cz = cz - 1
         goz4()
      else
         goyu()
      end
   end
end

function goyu()
   if cy < ny then
      if turtle.up() then
         cy = cy + 1
         goyu()
      else
         goyd()
      end
   end
end

function goyd()
   if cy > ny then
      if turtle.down() then
         cy = cy -1
         goyd()
      else
         chegfuel()
      end
   end
end

function chegfuel()
   if turtle.getFuelLevel > 0 and stuck = 0 then
      if turtle.up() then
         gox1()
      elseif stuck < 1
         stuck = 1
         os.sleep(5)
         gox1()
      end
   else
      if turtle.getFuelLevel = 0 then
         print("I need more fuel!")
         while turtle.getFuelLevel = 0 do
            os.sleep(5)
            turtle.refuel()
         end
         gox1()
      else
         print("Help my I'm stuck!")
         print("Shut down the programm.")
      end
   end
end


if not nx then
   nx = cx
end
if not ny then
   ny = cx
end
if not nz then
   nz = cz
end

shell.run("skyside")
if direct ~= nil then
   gox1()
   getpos()
   gox1()
end