I'd seperate all of the connections at the main light from each other (but leave everything else as it is) and then test / inspect to see which cable is which.
There should be a supply cable (you can test for this by meter, or by attaching a lamp holder to every cable end. When you restore power, only the supply will light up, and you will not be able to switch it off other than at the consumer unit. mark for identification. if there are two sets of live cables I would blame the drugs).
There should be a switching circuit - hopefully red blue yellow +E (twist both blue and yellow together at both ends) or red red +E, but possibly red & black +E which will make it harder to identify (If no meter, when you've found the supply - see above - connect each possible cable in turn to the supply as follows: supply red to test cable red, supply black to lampholder, test cable black to lampholder. if you get the correct cable the switch will turn the light on and off, if wrong cable the light may stay off (try switches in nearby areas at this point), stay on but dim - check house for other dim lights, if it is the spur you've found the spur cable, if another room (s), you've got the outgoing supply cable or be switched off and dim in which case you have the outgoing supply again.)
Once you've identified all of the cables, you need to connect the supply black to the spur black and to the outgoing supply/ies (if present) black. you need to connect the supply red to the/a switch circuit red and to the outgoing supply/ies (if present) red. you need to connect the switch circuit return (ie the other red, the blue& yellow or black as appropriate) to the spur red. you need to connect all of the earths together.
er, that's it. Good luck. If not sure any time, post or mail me back. I'm a.m.todd@lboro.ac.uk