#!/usr/bin/env python3
"""Example: Using the Skyfield Provider
This example shows how to use the Skyfield provider for fast,
offline astronomical calculations.
Features:
- 28-33x faster than Navy API (~25ms vs ~700ms)
- Offline calculations (after ephemeris download)
- Research-grade accuracy
- Supports moon phases and seasons
Limitations:
- Solar eclipses not supported (use Navy API)
- Rise/set times not yet implemented (use Navy API)
- Requires ephemeris files (~17-32 MB)
Setup:
python scripts/download_ephemeris.py --backend local
"""
import asyncio
from datetime import datetime
from chuk_mcp_celestial.providers import SkyfieldProvider
async def main():
print("=" * 70)
print("Skyfield Provider Example")
print("=" * 70)
# Create Skyfield provider with memory backend for demo
# In production, use "local" or "s3"
provider = SkyfieldProvider(
ephemeris_file="de421.bsp", # 17 MB, covers 1900-2050
storage_backend="local", # Use local filesystem
auto_download=True, # Download if not present
)
print("\n✓ Initialized Skyfield provider")
print(f" Ephemeris: {provider.ephemeris_file}")
print(f" Storage: {provider.storage_backend}")
print(f" Cache: {provider.cache_dir}")
# 1. Moon Phases (FAST!)
print("\n" + "=" * 70)
print("1. MOON PHASES - Next 12 phases (FAST!)")
print("=" * 70)
start_time = datetime.now()
phases = await provider.get_moon_phases("2024-12-1", num_phases=12)
elapsed = (datetime.now() - start_time).total_seconds() * 1000
print(f"\n⚡ Completed in {elapsed:.1f}ms (vs ~700ms for Navy API)")
print(f"\nAPI Version: {phases.apiversion}")
print(f"Starting from: {phases.year}-{phases.month:02d}-{phases.day:02d}")
print(f"Phases returned: {phases.numphases}\n")
for i, phase in enumerate(phases.phasedata, 1):
phase_emoji = {
"New Moon": "🌑",
"First Quarter": "🌓",
"Full Moon": "🌕",
"Last Quarter": "🌗",
}.get(phase.phase.value, "🌙")
print(
f"{i:2d}. {phase_emoji} {phase.phase.value:15s} - {phase.year}-{phase.month:02d}-{phase.day:02d} at {phase.time} UTC"
)
# 2. Full Year of Moon Phases
print("\n" + "=" * 70)
print("2. FULL YEAR OF MOON PHASES - All 48 phases in 2024")
print("=" * 70)
start_time = datetime.now()
year_phases = await provider.get_moon_phases("2024-1-1", num_phases=48)
elapsed = (datetime.now() - start_time).total_seconds() * 1000
print(f"\n⚡ Completed in {elapsed:.1f}ms")
print(" Navy API would take ~700ms (28x slower!)")
# Count each phase type
phase_counts = {}
for phase in year_phases.phasedata:
phase_counts[phase.phase.value] = phase_counts.get(phase.phase.value, 0) + 1
print("\nPhase distribution in 2024:")
for phase_name, count in sorted(phase_counts.items()):
print(f" {phase_name:15s}: {count}")
# 3. Earth Seasons (FAST!)
print("\n" + "=" * 70)
print("3. EARTH SEASONS - Equinoxes & Solstices 2024")
print("=" * 70)
start_time = datetime.now()
seasons = await provider.get_earth_seasons(2024, timezone=0, dst=False)
elapsed = (datetime.now() - start_time).total_seconds() * 1000
print(f"\n⚡ Completed in {elapsed:.1f}ms (vs ~800ms for Navy API)")
print(f"\nYear: {seasons.year}")
print(f"Timezone: UTC+{seasons.tz}")
print(f"Events: {len(seasons.data)}\n")
season_emoji = {
"March Equinox": "🌸", # Spring
"June Solstice": "☀️", # Summer
"September Equinox": "🍂", # Fall
"December Solstice": "❄️", # Winter
}
for event in seasons.data:
date_str = f"{event.year}-{event.month:02d}-{event.day:02d} {event.time}"
# Try to infer season name from month
season_name = ""
if event.month == 3:
season_name = "March Equinox"
elif event.month == 6:
season_name = "June Solstice"
elif event.month == 9:
season_name = "September Equinox"
elif event.month == 12:
season_name = "December Solstice"
emoji = season_emoji.get(season_name, "🌍")
print(f" {emoji} {event.phenom.value:12s} - {date_str} UTC")
# 4. Multi-year Seasons
print("\n" + "=" * 70)
print("4. MULTI-YEAR SEASONS - 2020-2025")
print("=" * 70)
start_time = datetime.now()
all_seasons = []
for year in range(2020, 2026):
year_seasons = await provider.get_earth_seasons(year)
all_seasons.append((year, year_seasons))
elapsed = (datetime.now() - start_time).total_seconds() * 1000
print(f"\n⚡ Completed 6 years in {elapsed:.1f}ms ({elapsed / 6:.1f}ms per year)")
print(" Navy API would take ~4800ms total (33x slower!)")
print(f"\nTotal events: {sum(len(s.data) for _, s in all_seasons)}")
# 5. Limitations Demo
print("\n" + "=" * 70)
print("5. LIMITATIONS - Features Not Supported")
print("=" * 70)
print("\n⚠️ The following features are NOT supported by Skyfield provider:")
print(" Use Navy API provider for these features.\n")
# Try solar eclipse (will raise NotImplementedError)
try:
await provider.get_solar_eclipse_by_date(date="2024-4-8", latitude=40.71, longitude=-74.01)
except NotImplementedError as e:
print(f" ❌ Solar eclipses: {e}")
# Try rise/set times (will raise NotImplementedError)
try:
await provider.get_sun_moon_data(date="2024-12-21", latitude=47.60, longitude=-122.33)
except NotImplementedError as e:
print(f" ❌ Sun/Moon rise/set: {e}")
print("\n" + "=" * 70)
print("✅ Skyfield Provider Demo Complete!")
print("=" * 70)
print("\nAdvantages:")
print(" ✓ 28-33x faster than Navy API")
print(" ✓ Offline calculations (after download)")
print(" ✓ Research-grade accuracy")
print(" ✓ No rate limits")
print(" ✓ Excellent for moon phases and seasons")
print("\nLimitations:")
print(" - Solar eclipses not supported")
print(" - Rise/set times not yet implemented")
print(" - Requires ephemeris files (~17-32 MB)")
print("\n💡 Tip: Use hybrid mode to get the best of both providers!")
if __name__ == "__main__":
asyncio.run(main())
