I have found these sentences, "If I were you, I would have enjoyed my vacation.", "If I were you, I would have explained what happened." So I think the structure of "If I were...., I would have p.p..." is also possible. Do you agree with the grammar? I really hope to hear from you again. Thank you so much as usual.
Like Raymott, I would use If I were you there. However, I would not deduce a rule If I were ... I would have pp. It works for If I were you, but it's a special case because I can't be you at you any time. You can't say
If I were there, I would have spoken to her.