<sigh> That is water damage all right. Sounds extensive too.
I would be real careful about calling insurance right away.
They may total the camper and pay you out.
You might not get very much for a 2006.
You need to understand that water seeks its own level. It will run down cracks and seams; then puddle far from where the leak is. The damage in front may be from a leak (or blockage) at the air conditioner (for example).
Start at the top and work down looking for varying degrees of damage to try and locate the source. The wood will be black and spongy at site of the oldest damage. Calling your dealer for an inspection will also be very expensive because at 150 an hour just the estimate could run you a several hundred dollars. At this point you pretty much have nothing to lose by taking it apart yourself to see what you have to work with.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW