Link between devices and gateways

[cdupont]

Currently, the API represent the link between a device and a gateway, e.g. "a device radio data has been received by a gateway". This link is represented as a field in Device data structure:

device: 
{
  id: XX
  gateway_id: YYY
}

It's not the best because:

• finding the devices connected to a gateway takes time, because you need to scan all the devices (thousands) and also verify the authorization.
• a device could be received by several gateways, this is not representable: gateway_id field has only one gateway.

[cdupont]

@j-forster what do you think could be a better representation?

[cdupont]

It's clearly a many-to-many relation. I see the following solutions:

1. create another table in the DB and new endpoint for "relationships": the list of links between devices and gateways.
2. add a new field "devices" in the gateway datastructure.

I think 1. would be overkill. I'm not sure we need to represent the radio link in a separate list. Especially because this is broadcast, so the link is not established.
2. seems better, as its really the gateway that "knows" the devices that are received.

The gateway API would be modified this way:

GET /gateways/XXX/devices -> get the list of devices received on this gateway
PUT /gateways/XXX/devices -> update the list of devices received on this gateway

The devices API is:

GET /devices/YYY/gateways -> get the list of gateways that receive this device (read only)