[DA] Improve per-device addressing and topic/channel decoding strategies

Add more details about per-device decoding to the `WanBusStrategy`, and
exercise a few topic/channel decodings, including edge cases.

Examples:

- myrealm/acme/area-42/foo-70b3d57ed005dac6
- myrealm/d/123e4567-e89b-12d3-a456-426614174000
- myrealm/dt/acme-area42-eui70b3d57ed005dac6
- myrealm/dt/eui-70b3d57ed005dac6
- myrealm/dt/acme-area42-eui70b3d57ed005dac6
- myrealm/dt/acme-area42-eui70b3d57ed005dac6-suffix
- myrealm/dt/myrealm-acme-area42-eui70b3d57ed005dac6
- mqttkit-1/d
- myrealm/dt

kotori/daq/strategy/wan.py

@@ -10,8 +10,8 @@ class WanBusStrategy(StrategyBase):
 
     # Regular expression pattern for decoding MQTT topic address segments.
     channel_matcher            = re.compile(r'^(?P<realm>.+?)/(?P<network>.+?)/(?P<gateway>.+?)/(?P<node>.+?)(?:/(?P<slot>.+?))?$')
-    device_matcher_dashed_topo = re.compile(r'^(?P<realm>.+?)/dt/(?P<device>.+?)(?:/(?P<slot>.+?))?$')
-    device_matcher_generic     = re.compile(r'^(?P<realm>.+?)/d/(?P<device>.+?)(?:/(?P<slot>.+?))?$')
+    device_matcher_dashed_topo = re.compile(r'^(?P<realm>.+?)/dt/(?P<device>.+?)/(?:(?P<slot>.+?))$')
+    device_matcher_generic     = re.compile(r'^(?P<realm>.+?)/d/(?P<device>.+?)/(?:(?P<slot>.+?))$')
 
     def topic_to_topology(self, topic):
         """
@@ -59,6 +59,8 @@ def topic_to_topology(self, topic):
 
         # Decode the topic.
         address = None
+
+        # Try to match the per-device pattern.
         m = self.device_matcher_generic.match(topic)
         if m:
             address = SmartMunch(m.groupdict())
@@ -68,21 +70,41 @@ def topic_to_topology(self, topic):
                 address.node = address.device
                 del address.device
 
+        # Try to match the per-device pattern with dashed topology encoding for topics.
         if address is None:
             m = self.device_matcher_dashed_topo.match(topic)
             if m:
                 address = SmartMunch(m.groupdict())
                 if "device" in address:
                     segments = address.device.split("-")
+
+                    # Compensate "too few segments": Fill up with "default" at the front.
+                    missing_segments = 3 - len(segments)
+                    segments = ["default"] * missing_segments + segments
+
+                    # When the first topic path fragment is equal to the realm, we assume a
+                    # slight misconfiguration, and ignore the first decoded segment completely.
+                    if segments[0] == address.realm:
+                        segments = segments[1:]
+
+                    # Compensate "too many segments": Merge trailing segments.
+                    if len(segments) > 3:
+                        segments = segments[:2] + ["-".join(segments[2:])]
+
+                    # Destructure three components / segments.
                     address.network, address.gateway, address.node = segments
+
+                    # Do not propagate the `device` slot. It either has been
+                    # dissolved, or it was propagated into the `node` slot.
                     del address.device
 
+        # Try to match the classic path-based WAN topic encoding scheme.
         if address is None:
             m = self.channel_matcher.match(topic)
             if m:
                 address = SmartMunch(m.groupdict())
 
-        return address or {}
+        return address
 
     @classmethod
     def topology_to_storage(self, topology, message_type=None):

pytest.ini

@@ -43,3 +43,4 @@ markers =
     hiveeyes: Tests for vendor hiveeyes.
     legacy: Tests for legacy endpoints and such.
     device: Device-based addressing.
+    strategy: Transformation strategies.

test/settings/mqttkit.py

@@ -40,6 +40,8 @@ class TestSettings:
     device_influx_measurement_sensors = 'default_123e4567_e89b_12d3_a456_426614174000_sensors'
     device_mqtt_topic_generic      = 'mqttkit-1/d/123e4567-e89b-12d3-a456-426614174000/data.json'
     device_mqtt_topic_dashed_topo  = 'mqttkit-1/dt/itest-foo-bar/data.json'
+    device_http_path_generic       = '/mqttkit-1/d/123e4567-e89b-12d3-a456-426614174000/data'
+    device_http_path_dashed_topo   = '/mqttkit-1/dt/itest-foo-bar/data'
 
 
 settings = TestSettings

test/test_wan_strategy.py

@@ -0,0 +1,166 @@
+# -*- coding: utf-8 -*-
+# (c) 2023 Andreas Motl <andreas@getkotori.org>
+import pytest
+
+from kotori.daq.strategy.wan import WanBusStrategy
+from kotori.util.common import SmartMunch
+
+
+@pytest.mark.strategy
+def test_wan_strategy_channel():
+    """
+    Verify the classic WAN topology decoding, using a channel-based addressing scheme.
+    """
+    strategy = WanBusStrategy()
+    topology = strategy.topic_to_topology("myrealm/acme/area-42/foo-70b3d57ed005dac6/data.json")
+    assert topology == SmartMunch(
+        {
+            "realm": "myrealm",
+            "network": "acme",
+            "gateway": "area-42",
+            "node": "foo-70b3d57ed005dac6",
+            "slot": "data.json",
+        }
+    )
+
+
+@pytest.mark.strategy
+def test_wan_strategy_device_generic_success():
+    """
+    Verify the per-device WAN topology decoding, using a generic device identifier.
+    """
+    strategy = WanBusStrategy()
+    topology = strategy.topic_to_topology("myrealm/d/123e4567-e89b-12d3-a456-426614174000/data.json")
+    assert topology == SmartMunch(
+        {
+            "realm": "myrealm",
+            "network": "devices",
+            "gateway": "default",
+            "node": "123e4567-e89b-12d3-a456-426614174000",
+            "slot": "data.json",
+        }
+    )
+
+
+@pytest.mark.strategy
+def test_wan_strategy_device_dashed_topo_basic():
+    """
+    Verify the per-device WAN topology decoding, using a dashed device identifier, which translates to the topology.
+    """
+    strategy = WanBusStrategy()
+    topology = strategy.topic_to_topology("myrealm/dt/acme-area42-eui70b3d57ed005dac6/data.json")
+    assert topology == SmartMunch(
+        {
+            "realm": "myrealm",
+            "network": "acme",
+            "gateway": "area42",
+            "node": "eui70b3d57ed005dac6",
+            "slot": "data.json",
+        }
+    )
+
+
+@pytest.mark.strategy
+def test_wan_strategy_device_dashed_topo_too_few_components():
+    """
+    Verify the per-device WAN topology decoding, using a dashed device identifier with too few components.
+    The solution is to pad the segments with `default` labels at the front.
+
+    This specific test uses a vanilla TTN device identifier.
+    """
+    strategy = WanBusStrategy()
+    topology = strategy.topic_to_topology("myrealm/dt/eui-70b3d57ed005dac6/data.json")
+    assert topology == SmartMunch(
+        {
+            "realm": "myrealm",
+            "network": "default",
+            "gateway": "eui",
+            "node": "70b3d57ed005dac6",
+            "slot": "data.json",
+        }
+    )
+
+
+@pytest.mark.strategy
+def test_wan_strategy_device_dashed_topo_three_components():
+    """
+    Verify the per-device WAN topology decoding, using a dashed device identifier with exactly three components.
+    This topic will be decoded as-is.
+    """
+    strategy = WanBusStrategy()
+    topology = strategy.topic_to_topology("myrealm/dt/acme-area42-eui70b3d57ed005dac6/data.json")
+    assert topology == SmartMunch(
+        {
+            "realm": "myrealm",
+            "network": "acme",
+            "gateway": "area42",
+            "node": "eui70b3d57ed005dac6",
+            "slot": "data.json",
+        }
+    )
+
+
+@pytest.mark.strategy
+def test_wan_strategy_device_dashed_topo_too_many_components_merge_suffixes():
+    """
+    Verify the per-device WAN topology decoding, using a dashed device identifier with too many components.
+    The solution is to merge all trailing segments into the `node` slot, re-joining them with `-`.
+    """
+    strategy = WanBusStrategy()
+    topology = strategy.topic_to_topology("myrealm/dt/acme-area42-eui70b3d57ed005dac6-suffix/data.json")
+    assert topology == SmartMunch(
+        {
+            "realm": "myrealm",
+            "network": "acme",
+            "gateway": "area42",
+            "node": "eui70b3d57ed005dac6-suffix",
+            "slot": "data.json",
+        }
+    )
+
+
+@pytest.mark.strategy
+def test_wan_strategy_device_dashed_topo_too_many_components_redundant_realm():
+    """
+    Verify the per-device WAN topology decoding, using a dashed device identifier with too many components.
+
+    This is an edge case where the first addressing component actually equals the realm.
+    Strictly, it is a misconfiguration, but we pretend to be smart, and ignore that,
+    effectively not using the redundant information, and ignoring the `myrealm-` prefix
+    within the device identifier slot altogether.
+
+    Cheers, @thiasB.
+    """
+    strategy = WanBusStrategy()
+    topology = strategy.topic_to_topology("myrealm/dt/myrealm-acme-area42-eui70b3d57ed005dac6/data.json")
+    assert topology == SmartMunch(
+        {
+            "realm": "myrealm",
+            "network": "acme",
+            "gateway": "area42",
+            "node": "eui70b3d57ed005dac6",
+            "slot": "data.json",
+        }
+    )
+
+
+@pytest.mark.strategy
+def test_wan_strategy_device_generic_empty():
+    """
+    Verify the per-device WAN topology decoding, using a generic device identifier with no components.
+    Topic-to-topology decoding should return `None`.
+    """
+    strategy = WanBusStrategy()
+    topology = strategy.topic_to_topology("myrealm/d/data.json")
+    assert topology is None
+
+
+@pytest.mark.strategy
+def test_wan_strategy_device_dashed_topo_empty():
+    """
+    Verify the per-device WAN topology decoding, using a dashed device identifier with no components.
+    Topic-to-topology decoding should return `None`.
+    """
+    strategy = WanBusStrategy()
+    topology = strategy.topic_to_topology("myrealm/dt/data.json")
+    assert topology is None