I would like to modify the authoryear citestyle in such a way that the first time a citation appears, a footnote giving the complete reference is added to the citation. The behavior would be similar to the standard verbose citestyle, only that, instead of creating a footnote entry for every citation, it uses the authoryear style everywhere, adding a footnote only the first time a citation appears -ideally in the chapter-.
I would like something like the following:
[...] as described by Sagan (1997)^1. Indeed, Sagan (1997) and Schulze-Makuch and Irwin (2004)^2 perfectly describe the feeling that we are trying to convey.
 Sagan, C., (1997). Pale blue dot: A vision of the human future in space. Random House Digital, Inc.
 Schulze-Makuch, D., & Irwin, L. N. (2004). Life in the Universe. Springer-Verlag.editions.
Your help is much appreciated