from datetime import datetime, timedelta, timezone
from pathlib import Path
from typing import Literal

from pydantic import Field
from pydantic_settings import BaseSettings

CST = timezone(timedelta(hours=8))


def now_cst() -> datetime:
    """Return current time in CST (UTC+8) as naive datetime for SQLite."""
    return datetime.now(CST).replace(tzinfo=None)

# Project root directory (where config.py lives → parent = app/ → parent = project root)
_PROJECT_ROOT = Path(__file__).resolve().parent.parent
_DEFAULT_DB_PATH = _PROJECT_ROOT / "badge_admin.db"


class Settings(BaseSettings):
    APP_NAME: str = "KKS Badge Management System"
    DATABASE_URL: str = Field(
        default=f"sqlite+aiosqlite:///{_DEFAULT_DB_PATH}",
        description="Database connection URL (absolute path for SQLite)",
    )
    TCP_HOST: str = "0.0.0.0"
    TCP_PORT: int = Field(default=5000, ge=1, le=65535)
    API_HOST: str = "0.0.0.0"
    API_PORT: int = Field(default=8088, ge=1, le=65535)
    DEBUG: bool = Field(default=False, description="Enable debug mode (SQL echo, verbose errors)")

    # API authentication
    API_KEY: str | None = Field(default=None, description="API key for authentication (None=disabled)")
    CORS_ORIGINS: str = Field(default="*", description="Comma-separated allowed CORS origins")

    # Rate limiting
    RATE_LIMIT_DEFAULT: str = Field(default="60/minute", description="Default rate limit")
    RATE_LIMIT_WRITE: str = Field(default="30/minute", description="Rate limit for write operations")

    # 高德地图 API (geocoding)
    AMAP_KEY: str | None = Field(default=None, description="高德地图 Web服务 key (逆地理编码/POI搜索)")
    AMAP_SECRET: str | None = Field(default=None, description="高德地图 Web服务安全密钥")
    AMAP_HARDWARE_KEY: str | None = Field(default=None, description="高德地图智能硬件定位 key (基站/WiFi定位)")
    AMAP_HARDWARE_SECRET: str | None = Field(default=None, description="高德地图智能硬件定位安全密钥 (与 HARDWARE_KEY 配对)")

    # Geocoding
    GEOCODING_DEFAULT_IMEI: str = Field(default="868120334031363", description="Default IMEI for AMAP geocoding API")
    GEOCODING_CACHE_SIZE: int = Field(default=10000, description="Max geocoding cache entries")

    # Track query limit
    TRACK_MAX_POINTS: int = Field(default=10000, description="Maximum points returned by track endpoint")

    # Fence auto-attendance
    FENCE_CHECK_ENABLED: bool = Field(default=True, description="Enable automatic fence attendance check on location report")
    FENCE_LBS_TOLERANCE_METERS: int = Field(default=200, description="Extra tolerance (meters) for LBS locations in fence check")
    FENCE_WIFI_TOLERANCE_METERS: int = Field(default=100, description="Extra tolerance (meters) for WiFi locations in fence check")
    FENCE_MIN_INSIDE_SECONDS: int = Field(default=60, description="Minimum seconds between fence attendance transitions (debounce)")

    # Data retention
    DATA_RETENTION_DAYS: int = Field(default=90, description="Days to keep location/heartbeat/alarm/attendance/bluetooth records")
    DATA_CLEANUP_INTERVAL_HOURS: int = Field(default=24, description="Hours between automatic cleanup runs")

    model_config = {"env_file": ".env", "env_file_encoding": "utf-8", "extra": "ignore"}


settings = Settings()