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

mqtt_demo/config.py

@@ -0,0 +1,117 @@
+"""Configuration — env-var driven.
+
+Two flavours:
+  * SharedConfig — MQTT broker, cert paths, HA prefix, timers. One per
+    process.
+  * ApplianceConfig — one per appliance the bridge is supervising. Keys
+    come from `APPLIANCE_<n>_*` env vars (1-indexed). The list of
+    appliances is `APPLIANCE_COUNT` entries long.
+
+.env in cwd hydrates os.environ at import time; docker-compose env wins
+over file contents."""
+import os
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Optional
+
+
+def _load_env_file(filename='.env'):
+    """If a .env-style file is present in cwd, hydrate os.environ from
+    it. Existing env wins so docker-compose `environment:` overrides
+    file contents."""
+    env_path = Path.cwd() / filename
+    if not env_path.exists():
+        return
+    for line in env_path.read_text().splitlines():
+        line = line.strip()
+        if not line or line.startswith('#') or '=' not in line:
+            continue
+        k, v = line.split('=', 1)
+        k = k.strip(); v = v.strip()
+        if k and k not in os.environ:
+            os.environ[k] = v
+
+
+_load_env_file('.env')
+
+
+def _resolve_cert(env_key, basename):
+    """Cert lookup: explicit env > /config/<basename> (Docker mount) >
+    ./certs/<basename> (bare-metal dev)."""
+    if os.getenv(env_key):
+        return Path(os.environ[env_key])
+    docker_path = Path('/config') / basename
+    if docker_path.exists():
+        return docker_path
+    return Path.cwd() / 'certs' / basename
+
+
+@dataclass(frozen=True)
+class SharedConfig:
+    """Process-wide config (MQTT, cert paths, intervals)."""
+    CERT_PATH: Path
+    KEY_PATH: Path
+    MQTT_BROKER: Optional[str]
+    MQTT_PORT: int
+    MQTT_USER: Optional[str]
+    MQTT_PASS: Optional[str]
+    HA_DISCOVERY_PREFIX: str
+    HEALTH_INTERVAL_S: int
+    PING_INTERVAL_S: int
+
+    @classmethod
+    def from_env(cls) -> 'SharedConfig':
+        return cls(
+            CERT_PATH=_resolve_cert('CERT_PATH', 'client_fullchain.pem'),
+            KEY_PATH=_resolve_cert('KEY_PATH',  'client.key'),
+            MQTT_BROKER=os.getenv('MQTT_BROKER'),
+            MQTT_PORT=int(os.getenv('MQTT_PORT', '1883')),
+            MQTT_USER=os.getenv('MQTT_USER') or None,
+            MQTT_PASS=os.getenv('MQTT_PASS') or None,
+            HA_DISCOVERY_PREFIX=os.getenv('HA_DISCOVERY_PREFIX',
+                                          'homeassistant'),
+            HEALTH_INTERVAL_S=int(os.getenv('HEALTH_INTERVAL_S', '60')),
+            PING_INTERVAL_S=int(os.getenv('PING_INTERVAL_S', '25')),
+        )
+
+
+@dataclass(frozen=True)
+class ApplianceConfig:
+    """Per-appliance runtime config.
+
+    Sourced from `APPLIANCE_<index>_*` env vars (1-indexed). `index` is
+    just a stable identifier for logs; it does not appear in MQTT
+    topics or HA discovery (those are keyed off `topic_prefix`)."""
+    index: int
+    klass: str              # 'dryer', 'oven', …
+    ip: str
+    ocf_port: Optional[int]  # None → descriptor.default_observe_port
+    topic_prefix: str
+    device_name: str
+
+    @classmethod
+    def from_env(cls, index: int) -> 'ApplianceConfig':
+        prefix = f'APPLIANCE_{index}_'
+        klass = os.getenv(prefix + 'CLASS')
+        if not klass:
+            raise ValueError(f"{prefix}CLASS not set")
+        ip = os.getenv(prefix + 'IP')
+        if not ip:
+            raise ValueError(f"{prefix}IP not set")
+        port_env = os.getenv(prefix + 'OCF_PORT')
+        port = int(port_env) if port_env else None
+        topic = os.getenv(prefix + 'TOPIC') or f'samsung_{klass}'
+        name = os.getenv(prefix + 'NAME') or f'Samsung {klass.title()}'
+        return cls(
+            index=index, klass=klass, ip=ip, ocf_port=port,
+            topic_prefix=topic, device_name=name,
+        )
+
+
+def load_appliances() -> list[ApplianceConfig]:
+    """Read APPLIANCE_COUNT and build the appliance list. At least one
+    is required."""
+    count = int(os.getenv('APPLIANCE_COUNT', '1'))
+    if count < 1:
+        raise ValueError("APPLIANCE_COUNT must be >= 1")
+    return [ApplianceConfig.from_env(i + 1) for i in range(count)]