Node is too generic, use RootNode

[jonsmirl]

These should be called RootNode to follow spec.

/* Create a Matter node */
node::config_t node_config;
node_t *node = node::create(&node_config, app_attribute_update_cb, NULL);

[jonsmirl]

Maybe like this, who is making the mandatory RootNode?

/* Create a Matter node */
node::config_t node_config;
node_t *node = node::create(&node_config, app_attribute_update_cb, NULL);

root_node::config_t root_node_config;
endpoint_t *endpoint = root_node::create(node, &root_node_config, ENDPOINT_FLAG_NONE);

on_off_switch::config_t switch_config;
endpoint_t *endpoint = on_off_switch::create(node, &switch_config, ENDPOINT_FLAG_NONE);

[chiragatal]

Node here is more of a generic term. And when node::create() is called, it internally adds the mandatory root_node on endpoint 0.

[jonsmirl]

Useful to explain the side effect of root_node creation via a comment in the example sources.

[chiragatal]

Yeah, it makes sense, now that you mention it. It is easy to get confused between node and root_node.

[jonsmirl]

Need to come up with different names for these various things...
BLE is using node too. Too many uses of the same word.

For a start...
node_t *node = node::get();
to
device_t *device = device::get();

Should that root_node be automatically created? How do you get a pointer to it to add optional clusters?

[chiragatal]

The root_node is being automatically created just to keep the application code simple and cover most of the use-cases. But if optional clusters are being added to root_node in a lot of use-cases, we can move the creation of root_node from the default node::create() and move that explicitly to the application.

With the current implementation, you can get the endpoint handle for the root node with this:

uint16_t root_node_endpoint_id = 0;
node_t *node = node::get();
endpoint_t *endpoint = endpoint::get(node, root_node_endpoint_id);

[dhrishi]

Updated the comment in the application to reflect the creation of Root Node device type in create API