refactor: extract mqtt_demo/ — move bridge, config, logger, appliance descriptors

mqtt_demo/logger.py

@@ -0,0 +1,70 @@
+"""Stdout logging — works correctly under Docker's PYTHONUNBUFFERED=1.
+
+Two logger families share the root handler:
+  * `samsung_appliance` (and its children) for module-level lines —
+    DTLS warnings, generic startup chatter, MQTT plumbing.
+  * `<class>.<serial>` for per-appliance bridge lines — e.g.
+    `dryer.<serial>`. Each PushBridge gets its own such logger
+    via bridge_logger() once the seed reveals the appliance's serial.
+
+Both trees propagate to the root logger, which is the one with the
+StreamHandler, so the same format applies everywhere.
+
+WARNING lines render yellow, ERROR red, when colour is enabled. Set
+`NO_COLOR=1` in the environment to fall back to plain text (e.g. when
+writing logs to a file)."""
+import logging
+import os
+import sys
+
+
+_LEVEL_COLOURS = {
+    logging.WARNING:  '\033[33m',   # yellow
+    logging.ERROR:    '\033[31m',   # red
+    logging.CRITICAL: '\033[1;31m', # bold red
+}
+_RESET = '\033[0m'
+
+
+def _colour_enabled() -> bool:
+    return 'NO_COLOR' not in os.environ
+
+
+class _LevelColourFormatter(logging.Formatter):
+    """Wraps the rendered line in an ANSI colour for WARNING+ levels.
+    INFO/DEBUG pass through unchanged so the bulk of the log stays
+    readable and a yellow line draws the eye."""
+
+    def __init__(self, fmt: str, datefmt: str, use_colour: bool):
+        super().__init__(fmt=fmt, datefmt=datefmt)
+        self.use_colour = use_colour
+
+    def format(self, record: logging.LogRecord) -> str:
+        line = super().format(record)
+        if not self.use_colour:
+            return line
+        colour = _LEVEL_COLOURS.get(record.levelno)
+        if colour is None:
+            return line
+        return f"{colour}{line}{_RESET}"
+
+
+_handler = logging.StreamHandler(sys.stdout)
+_handler.setFormatter(_LevelColourFormatter(
+    fmt='%(asctime)s  %(levelname)-5s  %(name)-26s  %(message)s',
+    datefmt='%H:%M:%S',
+    use_colour=_colour_enabled(),
+))
+
+logging.basicConfig(level=logging.INFO, handlers=[_handler], force=True)
+
+logger = logging.getLogger("samsung_appliance")
+
+
+def bridge_logger(klass: str, serial: str | None = None) -> logging.Logger:
+    """Return a top-level logger tagged with the appliance class and,
+    once known, the serial. Pre-seed callers pass serial=None and get
+    e.g. `dryer`; post-seed callers pass the serial and get e.g.
+    `dryer.<serial>`."""
+    name = f"{klass}.{serial}" if serial else klass
+    return logging.getLogger(name)