"""KFS Smart Farm — configuration. Every value can be overridden with an environment variable."""
import os
from pathlib import Path

BASE_DIR = Path(__file__).resolve().parent


def env(name, default):
    return os.environ.get(name, default)


SECRET_KEY = env("SF_SECRET_KEY", "change-me-in-production")      # Flask session signing
NODE_API_KEY = env("SF_NODE_API_KEY", "kfs-farm-node-key")         # sent by the ESP32 nodes in X-API-Key
ADMIN_USER = env("SF_ADMIN_USER", "admin")
ADMIN_PASSWORD = env("SF_ADMIN_PASSWORD", "kfs-farm-2026")         # change before the field deployment!

DB_PATH = Path(env("SF_DB_PATH", str(BASE_DIR / "farm.db")))
MODEL_PATH = Path(env("SF_MODEL_PATH", str(BASE_DIR.parent / "ai" / "outputs" / "irrigation_model.joblib")))

# Farm location (Faculty of Agriculture — Kafr El-Sheikh University)
FARM_LAT = float(env("SF_FARM_LAT", "31.1047"))
FARM_LON = float(env("SF_FARM_LON", "30.9436"))

# Decision threshold for the irrigation model (session 16: chosen with the agronomist from the FN/FP costs)
IRRIGATION_THRESHOLD = float(env("SF_IRRIGATION_THRESHOLD", "0.4"))

# Capacitive sensor calibration: soil_moisture_pct (0 % = dry, 100 % = water) -> volumetric water content
VWC_AT_0_PCT = float(env("SF_VWC_AT_0", "0.15"))
VWC_AT_100_PCT = float(env("SF_VWC_AT_100", "0.45"))

# Alert rules (session 18)
SOIL_DRY_PCT = float(env("SF_SOIL_DRY_PCT", "30"))        # irrigate below this
SOIL_WET_PCT = float(env("SF_SOIL_WET_PCT", "75"))        # never irrigate above this
AIR_HOT_C = float(env("SF_AIR_HOT_C", "38"))              # heat stress alert
GREENHOUSE_HUMID_PCT = float(env("SF_GH_HUMID_PCT", "90"))  # fungal disease risk -> turn the fan on
NODE_OFFLINE_MIN = int(env("SF_NODE_OFFLINE_MIN", "15"))
BATTERY_LOW_V = float(env("SF_BATTERY_LOW_V", "3.5"))
PUMP_MAX_MIN = int(env("SF_PUMP_MAX_MIN", "30"))           # safety: maximum pump run time

# Notifications (optional)
TELEGRAM_TOKEN = env("SF_TELEGRAM_TOKEN", "")
TELEGRAM_CHAT_ID = env("SF_TELEGRAM_CHAT_ID", "")