Update nix build

Reduces database size

default.nix

@@ -1,10 +1,12 @@
 { python3 }:
 with python3.pkgs;
 buildPythonPackage rec {
-  name = "mqtt-config";
+  name = "mqtt-tools";
   src = ./.;
   propagatedBuildInputs = [ pyyaml paho-mqtt ];
   buildInputs = [ ];
   doCheck = false;
   shellHook = "";
+  pyproject = true;
+  build-system = [ setuptools ];
 }

mqtt-collect

@@ -7,17 +7,10 @@ import paho.mqtt.client
 import sqlite3
 import datetime
 
+MAX_VALUE_CACHE_SIZE = 1024
 
 def init_db(path, topics):
     db = sqlite3.connect(path)
-    c = db.cursor()
-    for topic in topics:
-        table = topic.replace('/', '_')
-        c.execute(
-            f'CREATE TABLE IF NOT EXISTS {table} (timestamp timestamp, value real)'
-        )
-
-    db.commit()
     return db
 
 
@@ -39,15 +32,37 @@ def main():
     def on_disconnect(client, userdata, rc):
         client.reconnect()
 
+    current_values = {}
+
     def on_message(client, userdata, msg):
         try:
             c = db.cursor()
             table = msg.topic.replace("/", "_")
             ts = datetime.datetime.now()
+            textual = {
+                b"on": 1.,
+                b"off": 0.,
+                b"yes": 1.,
+                b"no": 0.
+            }
+
+            if msg.payload.lower() in textual:
+                value = textual[msg.payload.lower()]
+            else:
                 value = float(msg.payload)
-            c.execute(f'INSERT INTO {table} VALUES (?, ?)', (ts, value))
+            print(f"{table}: {value} ")
-            c.execute(f'SELECT * from {table}')
+
+            if current_values.get(table, None) != value:
+                current_values[table] = value
+                if len(current_values) > MAX_VALUE_CACHE_SIZE:
+                    first_entry = current_values.keys().next()
+                    del current_values[first_entry]
+
+                c.execute(f'CREATE TABLE IF NOT EXISTS "{table}" '
+                          '(timestamp timestamp, value real)')
+                c.execute(f'INSERT INTO "{table}" VALUES (?, ?)', (ts, value))
                 db.commit()
+
         except Exception as e:
             print(f'Error writing to database: {e}')