For the analogCommand() function, BridgeClient is the type name for the client parameter. You only provide the type names for parameters when you define the function, not when you call it. The error message is complaining that you are also including the the type name while calling the function, which is wrong.
There are still many things wrong with the logic and structure of this sketch. For example, the loop() function is calling analogCommand() directly, yet neither loop() nor analogCommand() check to see if a client connection was made before reading from the client. This check is normally done in the process() function, but that function is not called - and that's a good thing because process() has many issues starting with reading from the client before checking for a connection, and recursively calling itself if there is a connection. Once there is a connection, this recursive call will cause an infinite loop that will quickly fill up the stack and crash the sketch. There is much more that is concerning about the design of this sketch.
It looks to me that you don't understand what the code is trying to do. You cannot write successful software by randomly copying some statements from here and there and putting them together. I suggest that you take a step back and try to break this project down into basic parts, figure out how each part works, and truly understand what it is doing. When you have each part working by itself as an independent sketch, and you know what the various statements are doing, only then should you try to combine them into a single sketch.
Please, take a step back to work out the small details and get comfortable with what is going on before you tackle such a complex project.