turtle

local home = {x = -208, y = 65, z = 197}

local function goHomeByGPS(turned)
    local function travel(dist, positive)
        if ((math.abs(dist) == dist) and positive) or ((math.abs(dist) ~= dist) and not positive) then
            print("Heading in the right direction!")
        else
            print("Eek, wrong way!")
            turtle.turnLeft()
            turtle.turnLeft()
            turtle.forward()
            turtle.forward()
            print("There we go!")
        end
        print("I need to travel "..math.abs(dist)-1)
        print("Press a key to continue...")
        os.pullEvent("key")
        for i = 1, math.abs(dist)-1 do
            if not turtle.forward() then
                if turned then
                    return false
                end
                turtle.turnLeft()
                local ret = goHomeByGPS(true)
                return ret
            end
        end
        turtle.turnLeft()
        return goHomeByGPS()
    end

    local initX, initY, initZ = gps.locate()
    local diffX = (initX - home.x)*-1
    local diffY  = (initY - home.y)*-1
    local diffZ = (initZ - home.z)*-1
    print("I'm X:"..diffX.." and Z:"..diffZ.." away from home!")
    if (diffX == 0) and (diffZ == 0) then
        if math.abs(diffY) == diffY then
            for i = 1, diffY do
                turtle.up()
            end
        else
            for i = 1, math.abs(diffY) do
                turtle.down()
            end
        end
            print("I should be home!")
            local initX, initY, initZ = gps.locate()
            if home.x == initX and home.y == initY and home.z == initZ then
                print("Now, time to re-orientate...")
                for i = 1, 3 do
                    turtle.forward()
                    local x = gps.locate()
                    turtle.back()
                    if x > home.x then
                        print("Alright, I'm home! Awesome!")
                        return true
                    end
                    turtle.turnLeft()
                end
                print("I should 100% be theoretically home")
                return true
            else
                print("Ah crap, I miscalculated :/")
                print("Well, I'm screwed")
                return false
            end
    elseif turtle.forward() then
        secondX, _, secondZ = gps.locate()
        if secondX > initX then
            if diffX == 0 then
                print("Oh nope, im already in the right X position")
                turtle.back()
                turtle.turnLeft()
                local ret = goHomeByGPS()
            else
                return travel(diffX, true)
            end
        elseif secondX < initX then
            if diffX == 0 then
                print("Oh nope, im already in the right X position")
                turtle.back()
                turtle.turnLeft()
                local ret = goHomeByGPS()
            else
                return travel(diffX, false)
            end
        elseif secondZ > initZ then
            if diffZ == 0 then
                print("Oh nope, im already in the right Z position")
                turtle.back()
                turtle.turnLeft()
                local ret = goHomeByGPS()
            else
                return travel(diffZ, true)
            end
        elseif secondZ < initZ then
            if diffZ == 0 then
                print("Oh nope, im already in the right Z position")
                turtle.back()
                turtle.turnLeft()
                local ret = goHomeByGPS()
            else
                return travel(diffZ, false)
            end
        end
    elseif turtle.back() then
        print("Wait, lemmi just turn around")
        turtle.forward()
        turtle.turnLeft()
        turtle.turnLeft()
        local ret = goHomeByGPS()
        return ret
    elseif turned then
        print("Crap, I'm stuck!")
        print("D: Turtle is sad")
        return false
    else
        print("Friggen wall...")
        turtle.turnLeft()
        local ret = goHomeByGPS()
        return ret
    end
end
print(goHomeByGPS())