extraFuncs - v2

extraFuncs = {
    pos = vector.new(0, 0, 0),
    dir = "N",
    gps = false
}

function extraFuncs:new(pos, dir, gps)
    setmetatable({}, extraFuncs)
    self.pos = pos
    self.dir = dir
    self.gps = gps
    return self
end

function extraFuncs:forward()
    if turtle.forward() == true then
        if self.dir == "N" then
            self.pos.y = self.pos.y - 1
        elseif self.dir == "S" then
            self.pos.y = self.pos.y + 1
        elseif self.dir == "E" then
            self.pos.x = self.pos.x + 1
        elseif self.dir == "W" then
            self.pos.x = self.pos.x - 1
        end
        return true
    else
        return false
    end
end

function extraFuncs:back()
    if turtle.back() == true then
        if self.dir == "N" then
            self.pos.y = self.pos.y + 1
        elseif self.dir == "S" then
            self.pos.y = self.pos.y - 1
        elseif self.dir == "E" then
            self.pos.x = self.pos.x - 1
        elseif self.dir == "W" then
            self.pos.x = self.pos.x + 1
        end
        return true
    else
        return false
    end
end

function extraFuncs:digForward()
    repeat turtle.dig() until turtle.forward() == true
    if self.dir == "N" then
            self.pos.y = self.pos.y - 1
        elseif self.dir == "S" then
                self.pos.y = self.pos.y + 1
        elseif self.dir == "E" then
                self.pos.x = self.pos.x + 1
        elseif self.dir == "W" then
                self.pos.x = self.pos.x - 1
        end
    return true
end

function extraFuncs:up()
    if turtle.up() == true then
        self.pos.z = self.pos.z + 1
        return true
    else
        return false
    end
end

function extraFuncs:digUp()
    repeat turtle.digUp() until turtle.up() == true
    self.pos.z = self.pos + 1
    return true
end

function extraFuncs:digDown()
    repeat turtle.digDown() until turtle.down() == true
    self.pos.z = self.pos.z - 1
    return true
end

function extraFuncs:down()
    if turtle.down() == true then
        self.pos.z = self.pos.z - 1
        return true
    else
        return false
    end
end

function extraFuncs:left()
    turtle.turnLeft()
    if self.dir == "N" then
        self.dir = "W"
    elseif self.dir == "W" then
        self.dir = "S"
    elseif self.dir == "S" then
        self.dir = "E"
    elseif self.dir == "E" then
        self.dir = "N"
    end
    return true
end

function extraFuncs:right()
    turtle.turnRight()
    if self.dir == "N" then
        self.dir = "E"
    elseif self.dir == "E" then
        self.dir = "S"
    elseif self.dir == "S" then
        self.dir = "W"
    elseif self.dir == "W" then
        self.dir = "N"
    end
    return true
end

function extraFuncs:has_modem()
    if peripheral.getType("right") == "modem" or peripheral.getType("left") ==
        "modem" then
        return true
    else
        return false
    end
end

function extraFuncs:get_gps()
    if self:has_modem() and self.gps then
        local this_new_position = vector.new(gps.locate(5))
        if not this_new_position.x then
            return "E:GPS failes"
        else
            self.pos = this_new_position:round()
            return this_new_position:round()
        end
    else
        return "E:No modem"
    end
end

function extraFuncs:get_dir()
    if self:has_modem() and self.gps then
        local first_scan = self:get_gps()
        if not first_scan.x then
            print(first_scan)
        else
            if turtle.forward() then
                local second_scan = self:get_gps()
                if second_scan.y ~= first_scan.y then
                    if first_scan.y > second_scan.y then
                        self.dir = "N"
                    else
                        self.dir = "S"
                    end
                elseif second_scan.x ~= first_scan.x then
                    if first_scan.x < second_scan.x then
                        self.dir = "E"
                    else
                        self.dir = "W"
                    end
                end
                turtle.back()
            elseif turtle.back() then
                local second_scan = self:get_gps()
                if second_scan.y ~= first_scan.y then
                    if first_scan.y > second_scan.y then
                        self.dir = "S"
                    else
                        self.dir = "N"
                    end
                elseif second_scan.x ~= first_scan.x then
                    if first_scan.x < second_scan.x then
                        self.dir = "W"
                    else
                        self.dir = "E"
                    end
                end
                turtle.forward()
            end
        end
            elseif not self.gps then
        local first_scan = self.pos
        if turtle.forward() then
            local second_scan = self.pos
            if second_scan.y ~= first_scan.y then
                if first_scan.y > second_scan.y then
                    self.dir = "N"
                else
                    self.dir = "S"
                end
            elseif second_scan.x ~= first_scan.x then
                if first_scan.x < second_scan.x then
                    self.dir = "E"
                else
                    self.dir = "W"
                end
            end
            turtle.back()
        elseif turtle.back() then
            local second_scan = self.pos
            if second_scan.y ~= first_scan.y then
                if first_scan.y > second_scan.y then
                    self.dir = "S"
                else
                    self.dir = "N"
                end
            elseif second_scan.x ~= first_scan.x then
                if first_scan.x < second_scan.x then
                    self.dir = "W"
                else
                    self.dir = "E"
                end
            end
            turtle.forward()
                end
                self:get_gps()
            else
                print("Error?")
            end
end

-- Read and save turtle position
function extraFuncs:read_pos()
    if not fs.exists("extraFuncs_turtlePosition") then
            io.write("Couldn't find the extraFuncs_turtlePosition folder, make one? Y/N")
            answer=io.read()
            if answer:lower()=="y" then
                print("creating extraFuncs_turtlePosition file")
                local h = fs.open("extraFuncs_turtlePosition", "w")
                h.writeLine(self.pos.x)
                h.writeLine(self.pos.y)
                h.writeLine(self.pos.z)
                h.writeLine(self.dir)
                h.close()
            elseif answer:lower()=="n" then
                error("Couldn't find the extraFuncs_turtlePosition folder")
            end
        else
            local h = fs.open("extraFuncs_turtlePosition", "r")
            self.pos.x = tonumber(h.readLine())
            self.pos.y = tonumber(h.readLine())
            self.pos.z = tonumber(h.readLine())
            self.dir = h.readLine()
            h.close()
            return true
        end
end

function extraFuncs:save_pos()
    if not fs.exists("extraFuncs_turtlePosition") then
        io.write("Couldn't find the extraFuncs_turtlePosition folder, make one? Y/N")
        answer=io.read()
        if answer:lower()=="y" then
            print("creating extraFuncs_turtlePosition file")
            local h = fs.open("extraFuncs_turtlePosition", "w")
            h.writeLine(self.pos.x)
            h.writeLine(self.pos.y)
            h.writeLine(self.pos.z)
            h.writeLine(self.dir)
            h.close()
        elseif answer:lower()=="n" then
            error("Couldn't find the extraFuncs_turtlePosition folder")
        end
    else
        local h = fs.open("extraFuncs_turtlePosition", "w")
        h.writeLine(self.pos.x)
        h.writeLine(self.pos.y)
        h.writeLine(self.pos.z)
        h.writeLine(self.dir)
        h.close()
        return true
    end
end