""" Planetary Events Service - Calculate astronomical events using Skyfield Computes conjunctions, oppositions, and other events for major solar system bodies """ import logging from typing import List, Dict, Any, Optional from datetime import datetime, timedelta from skyfield.api import load, wgs84 from skyfield import almanac logger = logging.getLogger(__name__) class PlanetaryEventsService: """Service for calculating planetary astronomical events""" def __init__(self): """Initialize Skyfield ephemeris and timescale""" self.ts = None self.eph = None self._initialized = False def _ensure_initialized(self): """Lazy load ephemeris data (downloads ~30MB on first run)""" if not self._initialized: logger.info("Loading Skyfield ephemeris (DE421)...") self.ts = load.timescale() self.eph = load('de421.bsp') # Covers 1900-2050 self._initialized = True logger.info("Skyfield ephemeris loaded successfully") def get_planet_mapping(self) -> Dict[str, Dict[str, str]]: """ Map database body IDs to Skyfield names Returns: Dictionary mapping body_id to Skyfield ephemeris names """ return { '10': {'skyfield': 'sun', 'name': 'Sun', 'name_zh': '太阳'}, '199': {'skyfield': 'mercury', 'name': 'Mercury', 'name_zh': '水星'}, '299': {'skyfield': 'venus', 'name': 'Venus', 'name_zh': '金星'}, '399': {'skyfield': 'earth', 'name': 'Earth', 'name_zh': '地球'}, '301': {'skyfield': 'moon', 'name': 'Moon', 'name_zh': '月球'}, '499': {'skyfield': 'mars', 'name': 'Mars', 'name_zh': '火星'}, '599': {'skyfield': 'jupiter barycenter', 'name': 'Jupiter', 'name_zh': '木星'}, '699': {'skyfield': 'saturn barycenter', 'name': 'Saturn', 'name_zh': '土星'}, '799': {'skyfield': 'uranus barycenter', 'name': 'Uranus', 'name_zh': '天王星'}, '899': {'skyfield': 'neptune barycenter', 'name': 'Neptune', 'name_zh': '海王星'}, } def calculate_oppositions_conjunctions( self, body_ids: Optional[List[str]] = None, start_date: Optional[datetime] = None, end_date: Optional[datetime] = None, days_ahead: int = 365 ) -> List[Dict[str, Any]]: """ Calculate oppositions and conjunctions for specified bodies Args: body_ids: List of body IDs to calculate (default: all major planets) start_date: Start date (default: today) end_date: End date (default: start_date + days_ahead) days_ahead: Days to look ahead if end_date not specified Returns: List of event dictionaries """ self._ensure_initialized() # Set time range if start_date is None: start_date = datetime.utcnow() if end_date is None: end_date = start_date + timedelta(days=days_ahead) t0 = self.ts.utc(start_date.year, start_date.month, start_date.day) t1 = self.ts.utc(end_date.year, end_date.month, end_date.day) logger.info(f"Calculating planetary events from {start_date.date()} to {end_date.date()}") # Get planet mapping planet_map = self.get_planet_mapping() # Default to major planets (exclude Sun, Moon) if body_ids is None: body_ids = ['199', '299', '499', '599', '699', '799', '899'] # Earth as reference point earth = self.eph['earth'] events = [] for body_id in body_ids: if body_id not in planet_map: logger.warning(f"Body ID {body_id} not in planet mapping, skipping") continue planet_info = planet_map[body_id] skyfield_name = planet_info['skyfield'] try: planet = self.eph[skyfield_name] # Calculate oppositions and conjunctions f = almanac.oppositions_conjunctions(self.eph, planet) times, event_types = almanac.find_discrete(t0, t1, f) for ti, event_type in zip(times, event_types): event_time = ti.utc_datetime() # Convert timezone-aware datetime to naive UTC for database # Database expects TIMESTAMP (timezone-naive) event_time = event_time.replace(tzinfo=None) # event_type: 0 = conjunction, 1 = opposition is_conjunction = (event_type == 0) event_name = '合' if is_conjunction else '冲' event_type_en = 'conjunction' if is_conjunction else 'opposition' # Calculate separation angle earth_pos = earth.at(ti) planet_pos = planet.at(ti) separation = earth_pos.separation_from(planet_pos) # Create event data event = { 'body_id': body_id, 'title': f"{planet_info['name_zh']} {event_name} ({planet_info['name']} {event_type_en.capitalize()})", 'event_type': event_type_en, 'event_time': event_time, 'description': f"{planet_info['name_zh']}将发生{event_name}现象。" + (f"与地球的角距离约{separation.degrees:.2f}°。" if is_conjunction else "处于冲日位置，是观测的最佳时机。"), 'details': { 'event_subtype': event_name, 'separation_degrees': round(separation.degrees, 4), 'planet_name': planet_info['name'], 'planet_name_zh': planet_info['name_zh'], }, 'source': 'skyfield_calculation' } events.append(event) logger.debug(f"Found {event_type_en}: {planet_info['name']} at {event_time}") except KeyError: logger.error(f"Planet {skyfield_name} not found in ephemeris") except Exception as e: logger.error(f"Error calculating events for {body_id}: {e}") logger.info(f"Calculated {len(events)} planetary events") return events def calculate_planetary_distances( self, body_pairs: List[tuple], start_date: Optional[datetime] = None, end_date: Optional[datetime] = None, days_ahead: int = 365, threshold_degrees: float = 5.0 ) -> List[Dict[str, Any]]: """ Calculate close approaches between planet pairs Args: body_pairs: List of (body_id1, body_id2) tuples to check start_date: Start date end_date: End date days_ahead: Days to look ahead threshold_degrees: Only report if closer than this angle Returns: List of close approach events """ self._ensure_initialized() if start_date is None: start_date = datetime.utcnow() if end_date is None: end_date = start_date + timedelta(days=days_ahead) planet_map = self.get_planet_mapping() events = [] # Sample every day current = start_date while current <= end_date: t = self.ts.utc(current.year, current.month, current.day) for body_id1, body_id2 in body_pairs: if body_id1 not in planet_map or body_id2 not in planet_map: continue try: planet1 = self.eph[planet_map[body_id1]['skyfield']] planet2 = self.eph[planet_map[body_id2]['skyfield']] pos1 = planet1.at(t) pos2 = planet2.at(t) separation = pos1.separation_from(pos2) if separation.degrees < threshold_degrees: # Use naive UTC datetime for database event_time = current.replace(tzinfo=None) if hasattr(current, 'tzinfo') else current event = { 'body_id': body_id1, # Primary body 'title': f"{planet_map[body_id1]['name_zh']}与{planet_map[body_id2]['name_zh']}接近", 'event_type': 'close_approach', 'event_time': event_time, 'description': f"{planet_map[body_id1]['name_zh']}与{planet_map[body_id2]['name_zh']}的角距离约{separation.degrees:.2f}°，这是较为罕见的天象。", 'details': { 'body_id_secondary': body_id2, 'separation_degrees': round(separation.degrees, 4), 'planet1_name': planet_map[body_id1]['name'], 'planet2_name': planet_map[body_id2]['name'], }, 'source': 'skyfield_calculation' } events.append(event) except Exception as e: logger.error(f"Error calculating distance for {body_id1}-{body_id2}: {e}") current += timedelta(days=1) logger.info(f"Found {len(events)} close approach events") return events # Singleton instance planetary_events_service = PlanetaryEventsService()