Turtle Move

local x,y = 0,0
local direction = "north"
local dirInstruct = ...

function testForAvailableFuel()
    for i = 1, 16 do
        turtle.select(i)
        if turtle.refuel(0) then
            return true
        end
    end
end

function fuel()
    if not turtle.getFuelLevel() <= math.floor(turtle.getFuelLimit()/2) or not testForAvailableFuel() then return end
    for i = 1, 16 do
        turtle.select(i)
        if turtle.refuel(0) then
            local halfStack = math.floor(turtle.getItemCount(i)/2)
            turtle.refuel(halfStack)
        end
    end
end

function forward(dirToGo)
    if dirToGo == "north" then
        y = y + 1
        if direction == "north" then
            turtle.forward()
        elseif direction == "south" then
            turtle.turnLeft()
            turtle.turnLeft()
            turtle.forward()
        elseif direction == "west" then
            turtle.turnRight()
            turtle.forward()
        elseif direction == "east" then
            turtle.turnLeft()
            turtle.forward()
        end
        direction = "north"
    elseif dirToGo == "east" then
        x = x + 1
        if direction == "north" then
            turtle.turnRight()
            turtle.forward()
        elseif direction == "west" then
            turtle.turnLeft()
            turtle.turnLeft()
            turtle.forward()
        elseif direction == "east" then
            turtle.forward()
        elseif direction == "south" then
            turtle.turnLeft()
            turtle.forward()
        end
        direction = "east"
    elseif dirToGo == "south" then
        y = y - 1
        if direction == "south" then
            turtle.forward()
        elseif direction == "north" then
            turtle.turnLeft()
            turtle.turnLeft()
            turtle.forward()
        elseif direction == "east" then
            turtle.turnRight()
            turtle.forward()
        elseif direction == "west" then
            turtle.turnLeft()
            turtle.forward()
        end
        direction = "south"
    elseif dirToGo == "west" then
        x = x - 1
        if direction == "west" then
            turtle.forward()
        elseif direction == "east" then
            turtle.turnLeft()
            turtle.turnLeft()
            turtle.forward()
        elseif direction == "south" then
            turtle.turnRight()
            turtle.forward()
        elseif direction == "north" then
            turtle.turnLeft()
            turtle.forward()
        end
        direction = "west"
    end
    fuel()
end

forward(dirInstruct)