Turn android into server to livestream its own camera and serial data

In my project, I need to turn an old android into a web server. I need to be able to access live video from this phone **and** be able to send/receive data to/from a mobile app. Data received from the app will be sent via serial to an Arduino to carry out a respective task, and likewise data received by the Arduino will be sent to the app. After a lot of Googling, I still can't figure out a solution. How can I accomplish this?