Hello
Here in my company, we have developed a very complex ERP system. Part of this system is very rich in reports of the most varied degrees of complexity of information. The tool we chose to use in creating and reporting was Birt. I do not know if it would be very useful for you, because here in the company the classes that interact with Birt are all in PHP, it is our backend.
Birt has some chatty issues, such as changing the database connection that it will query to generate the report and everything else, but nothing that will disable the tool.
In this link you will find the basic information of the tool:
BIRT Home
It is worth mentioning that Birt is a tool until well spread, and for this reason you find solutions to problems, tips and tutorials without much difficulty.
I hope I have helped, good luck!