Detecting light as a particle or a wave
depends on how coherent ( i.e. how predictable ) it is.

For example, given an ideal laser showing a diffraction pattern
in famous double-slit experiment:

A. The frequency / energy is fully predictable;
i.e. it's Fully a wave.

B. You can't detect ( not even in theory )
which of the two slits it might've passed through;
i.e. it's Not a particle.

Semi-coherent ( i.e. semi-predictable ) light
is detectable as a semi-particle, semi-wave.

Randomness is ignorance; it exists only in the mind.
No matter what else is or isn't known,
metaphysically, we “ know ” the cosmos is fully causal.