Philip Seymour Hoffman -- Planning for Long Heroin Binge

Philip Seymour Hoffman was clearly prepping to use heroin for the long haul before he died, because we now know ... cops found approximately 50 heroin bags in the NYC apartment.

Law enforcement sources initially put the number of bags at 10 ... but now we know the number is 5 times that. Our sources say a number of the bags were full ... along with a number of unused needles. The upshot ... Hoffman was ready for a heroin binge.