grammaticality - Had been vs was

Now this is confusing... I wanna know the difference between the following sentences:

If you were there, I would see you.

If you had been there, I would have seen you.

What's the difference between 'were' and 'had been'? And could we use 'were' instead of 'had been' in the 2nd sentence?

Answer

Scenario #1 - It is the present (now) and you are not here:

"If you were there, I would see you."

Scenario #2 - In the past and you were not there

"If you had been there, I would have seen you."

Scenario #3 - In the future

"If you are here tomorrow, I will see you."

In the first two cases, are counter-factual