# =============================================================================
# config.py - Leak Detection System v2 (Pi 4 Model B) settings — non-secret defaults
#
# Operational/secret values such as server URL / API_KEY / device identifier are loaded from config_local.py.
# config_local.py is excluded from commits via .gitignore.
#   Setup:  cp config_local.example.py config_local.py  → fill in with real values
# =============================================================================

# ─────────────────────────────────────────────
# Sensor GPIO settings (BCM numbering — same as Pi 4 40-pin header)
#   GPIO17 = physical pin 11 on the 40-pin header
# ─────────────────────────────────────────────
SENSORS = [
    {"id": 1, "gpio": 17, "name": "Sensor 1 (Server Room)"},
    # Add more sensors below if present (BCM numbering)
    # {"id": 2, "gpio": 27, "name": "Sensor 2 (Machine Room)"},  # physical pin 13
    # {"id": 3, "gpio": 22, "name": "Sensor 3 (Restroom)"},  # physical pin 15
]

# Sensor active-level setting
# When using the e-con 5C-08 resistive sensor + 10MΩ pull-down:
#   Dry: GPIO = LOW(0)  → ACTIVE_LOW = False
#   Leak: GPIO = HIGH(1)
ACTIVE_LOW = False

# GPIO internal pull-resistor setting
# Must stay False (PUD_OFF)!
# Enabling the internal pull-down (50kΩ) keeps the line from going HIGH even on a leak, causing detection failure.
# → Use only the external 10MΩ pull-down resistor
USE_INTERNAL_PULL = False  # True = PUD_DOWN, False = PUD_OFF

# ─────────────────────────────────────────────
# Interval settings
# ─────────────────────────────────────────────
REPORT_INTERVAL = 600       # Normal-state periodic report interval (sec) = 10 min
                            # Must be shorter than the server's HEARTBEAT_TIMEOUT_SEC (default 1200 sec)
                            # to avoid offline false positives (600 sec = offline after 2 missed reports).
LEAK_REPORT_INTERVAL = 10   # Re-report interval while a leak is detected (sec)
DEBOUNCE_MS = 500           # Debounce time (ms) — set generously due to high impedance

# Confirm-read debounce: an edge alone never changes state. After an edge the pin is
# re-read CONFIRM_READS times, CONFIRM_INTERVAL_SEC apart; ALL reads must agree with the
# new state or the event is discarded as noise. Real water persists; sub-second EMI
# blips on the 10MΩ high-impedance line (server-room noise) do not.
# Total confirmation latency ≈ CONFIRM_READS × CONFIRM_INTERVAL_SEC ≈ 0.9 sec.
CONFIRM_READS = 3           # Consecutive identical reads required to accept a change
CONFIRM_INTERVAL_SEC = 0.3  # Delay between confirmation reads (sec)

# ─────────────────────────────────────────────
# Log settings
# ─────────────────────────────────────────────
LOG_FILE = "/var/log/leak_sensor.log"
LOG_MAX_BYTES = 5 * 1024 * 1024  # 5MB
LOG_BACKUP_COUNT = 3

# ─────────────────────────────────────────────
# Retry settings
# ─────────────────────────────────────────────
HTTP_TIMEOUT = 10           # HTTP request timeout (sec)
HTTP_RETRY_COUNT = 3        # Retry count
HTTP_RETRY_DELAY = 5        # Retry delay (sec)

# ─────────────────────────────────────────────
# Camera settings
#   Pi 4 = 15-pin (1.0mm pitch) standard CSI, Zero 2 W = 22-pin (0.5mm pitch) CSI →
#   ribbon/camera board not compatible (needs a Pi 4 15-pin ribbon or a 15↔22 adapter).
#   Capture uses rpicam-still (Bookworm) / libcamera-still (Bullseye).
# ─────────────────────────────────────────────
CAMERA_ENABLED = True       # Set to False to skip capture/upload
PHOTO_WIDTH = 640           # Capture resolution (width)
PHOTO_HEIGHT = 480          # Capture resolution (height)
PHOTO_QUALITY = 60          # JPEG quality (1-100, 60 ≈ 50-80KB)

# ─────────────────────────────────────────────
# Load operational/secret values (fail closed)
#   If config_local.py is missing, stop immediately with a clear error
#   instead of wrongly starting with placeholder/hardcoded secrets.
# ─────────────────────────────────────────────
try:
    from config_local import (   # noqa: F401  (leak_sensor.py re-imports from config)
        API_URL,
        API_KEY,
        PHOTO_UPLOAD_URL,
        DEVICE_ID,
        DEVICE_LOCATION,
    )
except ImportError as e:
    raise RuntimeError(
        "config_local.py not found. "
        "Run `cp config_local.example.py config_local.py`, then fill in the real server URL / API_KEY / "
        "device info. (Never commit secret values.)"
    ) from e

# ─────────────────────────────────────────────
# Optional override — per-device values can be overridden in config_local.py.
#   Editing the tracked file (config.py) per device causes deployment drift, so
#   define SENSORS in config_local.py for a new site node (e.g. sensor_id 3).
# ─────────────────────────────────────────────
try:
    from config_local import SENSORS  # noqa: F811 — per-device sensor list override
except ImportError:
    pass  # use the default above if config_local has no SENSORS

# SENSORS format validation (fail closed) — prevents an override typo/format error from
# silently starting with a wrong sensor_id (e.g. default 1) and overwriting another site's state.
if not isinstance(SENSORS, list) or not SENSORS:
    raise RuntimeError("SENSORS must be a non-empty list (check config_local.py).")
_ids, _gpios = set(), set()
for _s in SENSORS:
    if not (isinstance(_s, dict)
            and isinstance(_s.get("id"), int) and 1 <= _s["id"] <= 255
            and isinstance(_s.get("gpio"), int)
            and isinstance(_s.get("name"), str) and _s["name"]):
        raise RuntimeError(
            f"SENSORS entry format error: {_s!r} — id(int 1..255)/gpio(int)/name(str) required."
        )
    if _s["id"] in _ids or _s["gpio"] in _gpios:
        raise RuntimeError(f"SENSORS duplicate id/gpio: {_s!r}")
    _ids.add(_s["id"])
    _gpios.add(_s["gpio"])
del _ids, _gpios