Confusing phrases: I was to go. vs I was to have gone.

[allthewayanime]

I am confused about the following phrases. Please help me.

1. I was to go.
2. I was to have gone

Please provide the completed details of above sentences and grammar structure.

[Tdol]

What's your confusion? What do you see as the difference?

[allthewayanime]

I don't know if 'I was to go' implies a past action as 'I was to have gone'.

[5jj]

Perhaps if you could provide the full sentences in which you first met these structures, our explanations might be more useful for you.