Light-activated lamp, cries out "Me too!" when other lights are turned on
I'm looking for some guidance. I have a plan to modify one of my lamps to brighten and dim based on the amount of light hitting it: Essentially, if I turn on a larger light, this lamp will turn on as well. As this is still simply an idea in my head, though, I plan to make it rather complicated and feature-rich.
Two main settings for the light: Absolute and Relative.
When in Absolute mode, the lamp will turn on and off based whether or not the amount of light hitting its photosensor surpasses the necessary threshold energy level (TEL). The TEL will be adjustable by the use of a small dial, so that as the TEL approaches 0, the lamp turns on regardless of any additional light, and as the TEL approaches Infinity (or, at least, the maximum amount of light the photosensor can detect), the lamp turns off. Of course, I'd plan on primarily keeping the TEL at the level at which the lamp only turns on when I've turned on another light in the room, but there are times when I'd want the lamp to be independent of other lighting.
When in Relative mode, the light would brighten and dim based on the relative amount of light hitting its photosensor, so that the more lights I have on around it, the brighter it gets. I'd like to be able to use the same dial from Absolute mode to calibrate the relative brightness of the lamp, but that may be overly complicated for the amount of benefit it provides. Additionally, it would be interesting to invert this relationship, so that as less light hits the photosensor, the brighter the lamp gets.
A next step could be to layer the exterior of the lamp with solar cells so that it can not only activate based on its environment, but actually power itself (at least partially) based on its environment. This is not as important as any other features.
I plan on developing this post with a diagramed model of how this would work, but first I'd like to iron out a few issues:
-How does a photosensor detecting light export information?
-Assuming the photosensor exports electricity, what does the sensor need to be hooked up to in order to become meaningful?
-How would I set TELs, and how could I set TELs with a controllable dial?
-How would I swap between Relative and Absolute modes? How could I add a switch in to do this easily?
-How would the lamp's own light effect the photosensor if the photosensor was positioned on an opaque lampshade?
-Has anyone else done this, or something similar, so that I could look to those projects as a model?
-What else do I need to know?
I'm not specifically asking for someone to answer every question for me, but I would greatly appreciate it if I could be pointed in the right direction towards resources that would help me figure out the technical aspects of this project. With the small amount of experience I have, I'd expect to have to do a lot of reading.
Thanks for any responses!