Outside light with PIR and fade-on/fade-off

[oliboli]

I wonder if anyone's done this before...

I have a conventional outdoor light fitting to which I want to add a PIR, timer and light level detector detector such that:

When it's dark the light comes on, but is dimmed.
After a certain time (e.g. midnight), the light goes off.
When the PIR trips, the light gets brighter.

Doesn't sound too tall an order so far, but I really want the light to fade smoothly between off, low and bright, preferably at a rate of my choice.

Am I being ridiculous, or is there a box out there that will do all this and, preferably, in a waterproof housing (as I don't have anywhere except a patress box to mount the device)?

Thanks

Oli