Import LinuxCNC source tree

lib/python/mtc/mqtt_agent.py

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+# Copyright (C) 2026 LinuxCNC contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+
+# Optional MQTT transport following the standard MTConnect MQTT binding.
+#
+# Publishes the standard MTConnect response documents to the standard topics:
+#   <prefix>/Probe/<uuid>              (retained)
+#   <prefix>/Current/<uuid>           (at the sample interval)
+#   <prefix>/Sample/<uuid>            (when new observations arrive)
+#   <prefix>/Asset/<uuid>/<assetId>   (retained, on asset change)
+#
+# Reuses paho-mqtt, already used by src/hal/user_comps/mqtt-publisher.py.
+# Works with both paho-mqtt 1.x and 2.x.
+#
+# This is the vendor-neutral MTConnect binding only.  A retained Probe on
+# <prefix>/Probe/<uuid> is the standard discovery mechanism: an MTConnect
+# consumer subscribes and reconstructs the whole device from it.  (Home
+# Assistant support is a separate, optional bridge -- see the mtconnect-ha-bridge
+# contrib -- so that no other project's schema is baked into the core agent.)
+
+
+class MqttAgent:
+    def __init__(self, agent, broker="localhost", port=1883, prefix="MTConnect",
+                 username=None, password=None, client_id="linuxcnc-mtconnect"):
+        try:
+            import paho.mqtt.client as mqtt
+        except ModuleNotFoundError:
+            print("error: Missing Python module paho.mqtt.")
+            print("error: Arch: 'sudo pacman -S python-paho-mqtt'; "
+                  "Debian: 'sudo apt install python3-paho-mqtt'.")
+            raise
+        self.agent = agent
+        self.prefix = prefix.rstrip("/")
+        self.uuid = agent.config.uuid
+        self.connected = False   # broker link state, mirrored to a HAL pin
+        self._last_sample_seq = 1
+        self._last_asset_sig = None
+
+        # paho 2.x requires an explicit callback API version; 1.x has no such arg.
+        try:
+            self.client = mqtt.Client(mqtt.CallbackAPIVersion.VERSION1,
+                                      client_id=client_id)
+        except AttributeError:
+            self.client = mqtt.Client(client_id=client_id)
+        if username:
+            self.client.username_pw_set(username, password)
+        self.client.on_connect = self._on_connect
+        self.client.on_disconnect = self._on_disconnect
+        self.client.connect_async(broker, port, keepalive=60)
+        self.client.loop_start()
+        print("info: MQTT connecting to %s:%d as '%s' (prefix '%s')"
+              % (broker, port, username or "anonymous", self.prefix))
+
+    def _topic(self, kind, suffix=None):
+        base = "%s/%s/%s" % (self.prefix, kind, self.uuid)
+        return "%s/%s" % (base, suffix) if suffix else base
+
+    def _on_connect(self, client, userdata, flags, rc, *args):
+        self.connected = (rc == 0)
+        if rc == 0:
+            print("info: MQTT connected; publishing retained Probe to %s"
+                  % self._topic("Probe"))
+            self.publish_probe()
+            self.publish_assets()
+        else:
+            hint = {1: "unacceptable protocol version", 2: "identifier rejected",
+                    3: "broker unavailable", 4: "bad username or password",
+                    5: "not authorized (anonymous refused / bad credentials)"}
+            print("error: MQTT connect failed (rc=%s: %s)"
+                  % (rc, hint.get(int(rc) if str(rc).isdigit() else -1, "see broker log")))
+
+    def _on_disconnect(self, client, userdata, rc, *args):
+        self.connected = False
+        print("warning: MQTT disconnected (rc=%s)" % rc)
+
+    def publish_probe(self):
+        self.client.publish(self._topic("Probe"), self.agent.probe_document(),
+                            retain=True)
+
+    def publish_current(self):
+        self.client.publish(self._topic("Current"), self.agent.current_document())
+
+    def publish_sample(self):
+        first, nxt = self.agent.buffer.first_sequence, self.agent.buffer.next_sequence
+        if nxt <= self._last_sample_seq:
+            return
+        start = max(self._last_sample_seq, first)
+        self.client.publish(self._topic("Sample"),
+                            self.agent.sample_document(start, nxt - start))
+        self._last_sample_seq = nxt
+
+    def publish_assets(self):
+        assets = self.agent.source.tool_assets()
+        sig = tuple((a.asset_id, a.pocket, a.in_spindle) for a in assets)
+        if sig == self._last_asset_sig:
+            return
+        self._last_asset_sig = sig
+        doc = self.agent.assets_document()
+        for asset in assets:
+            self.client.publish(self._topic("Asset", asset.asset_id), doc,
+                                retain=True)
+
+    def stop(self):
+        self.client.loop_stop()
+        self.client.disconnect()