How to manage user-based access to a mesh wi-fi network

The company I work for is trying to build a solution that will allow for user-based access to a wi-fi mesh network similar to the way this works in some Shopping centers and Hotels.

Scenario:

1. we generate users and allocate bandwidth(usage plan) to the user through some interface(could be CLI or ideally REST API)
2. any device that user logs in with will be allocated to his/her account
3. ideally, the bandwidth to be shared across all allocated devices in order to never exceed the total bandwidth from the usage plan
4. ability to remotely control the system(create/modify/suspend users, change usage plans) and pull the usage data on a per allocated device
5. the user is free to walk around without the need to reconnect to the network as we will place a necessary number of access points around the area

Problem:

1. we were not able to find an out-of-the-box solution that can support these requirements except for Cisco Meraki which is insanely expensive and not economical for us

Question:

1. does anyone know an open-source software that may help us to achieve these scenarios or at least a few of them if not all?

Any thoughts are highly appreciated.

​

Thank you!