From 450cde3fbe417bcd1d846b64bc60f4633394b762 Mon Sep 17 00:00:00 2001
From: Blaise Thompson <blaise@untzag.com>
Date: Fri, 23 Oct 2020 16:27:45 -0500
Subject: initial commit

---
 README.md       | 18 ++++++++++++
 write_influx.py | 91 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 109 insertions(+)
 create mode 100644 README.md
 create mode 100644 write_influx.py

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..e2e925d
--- /dev/null
+++ b/README.md
@@ -0,0 +1,18 @@
+# mqtt
+
+documentation and source code for departmental mqtt server
+
+hosted at https://mosquitto.chem.wisc.edu
+
+## mosquitto
+
+https://mosquitto.org/
+
+## influxdb
+
+https://www.influxdata.com/
+
+## bridge daemon
+
+`write_influx.py`
+
diff --git a/write_influx.py b/write_influx.py
new file mode 100644
index 0000000..240b10b
--- /dev/null
+++ b/write_influx.py
@@ -0,0 +1,91 @@
+from influxdb import InfluxDBClient
+import os
+import paho.mqtt.client as mqtt
+import time
+import pathlib
+import datetime
+from dataclasses import dataclass, field
+from typing import List, Dict
+
+
+class Topic(dict):
+
+    def __init__(self):
+        super().__init__()
+        self["__value__"] = None
+
+    def __getitem__(self, key):
+        try:
+            return super().__getitem__(key)
+        except KeyError:
+            out = Topic()
+            self[key] = out
+            return out
+
+
+homie = Topic()
+
+
+def on_connect(client, userdata, flags, rc):
+    print("Connected with result code " + str(rc))
+    client.subscribe("homie/#")
+
+
+def on_message(client, userdata, msg):
+    topics = msg.topic.split("/")
+    payload = msg.payload.decode()
+    # fill topic tree
+    here = homie
+    for t in topics[1:]:
+        here = here[t]
+    here["__value__"] = payload
+    # tags
+    tags = {}
+    tags["device_id"] = topics[1]
+    # case of device attribute
+    device_attributes = ["$homie", "$name", "$state", "$nodes", "$extensions", "$implementation"]
+    if len(topics) == 3 and topics[2] in device_attributes:
+        measurement = topics[2]
+        fields = {"value": payload}
+        write_point(measurement, tags, fields)
+    # case of device node property
+    elif len(topics) == 4:
+        measurement = topics[3]
+        tags["node"] = topics[2]
+        datatype = homie[topics[1]][topics[2]][topics[3]]["$datatype"]["__value__"]
+        print(datatype, datatype=="float")
+        if datatype == "float":
+            fields = {"value": float(payload)}
+        else:
+            raise KeyError
+        write_point(measurement, tags, fields)
+
+
+influx_client = InfluxDBClient('localhost', 8086, 'root', 'root', "homie")
+influx_client.create_database("homie")
+
+
+def write_point(measurement, tags, fields):
+    json = {}
+    json["measurement"] = measurement
+    json["tags"] = tags
+    json["fields"] = fields
+    try:
+        influx_client.write_points([json])
+    except Exception as e:
+        print(e)
+    print(json)
+
+
+
+client = mqtt.Client()
+client.on_connect = on_connect
+client.on_message = on_message
+
+client.connect("mosquitto.chem.wisc.edu", 1883, 60)
+
+# Blocking call that processes network traffic, dispatches callbacks and
+# handles reconnecting.
+# Other loop*() functions are available that give a threaded interface and a
+# manual interface.
+client.loop_forever()
-- 
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