What does this poem mean?

It is still the moon and border pass in Qin and Han dynasties, and the enemy has fought a protracted war.

Or the bright moon and the border pass in Qin and Han Dynasties, and Wan Li, who was guarding the border pass and fighting the enemy, has not returned yet.

If Wei Qing, who attacked Longcheng, and Li Guang, the flying general, were alive today, the Huns would not be allowed to go south to spend their horses in Yinshan.

If Li Guang, the flying general of Dragon City, was still here, he would never let the Huns go south to herd horses and spend the Yinshan Mountain.