from fastapi import FastAPI, HTTPException
from starlette.responses import JSONResponse
from obspy.clients.fdsn import Client
from obspy.core.utcdatetime import UTCDateTime
import logging

# Configure logging
logging.basicConfig(level=logging.INFO)

# Initialize the FastAPI app
app = FastAPI(
    title="Earthquake Catalog API",
    description="An API to fetch earthquake data from the IRIS FDSN web service, ready for Hugging Face.",
    version="1.0.0",
)

# Initialize the IRIS FDSN client
try:
    client = Client("IRIS")
    logging.info("Successfully initialized IRIS FDSN client.")
except Exception as e:
    client = None
    logging.error(f"Could not initialize IRIS FDSN client on startup: {e}")

@app.get("/")
def greet_json():
    """
    A simple 'Hello World' endpoint.
    """
    return {"Hello": "World!", "message": "Go to /earthquakes to fetch data, or /docs for the API documentation.  Dayi"}

@app.get("/earthquakes")
async def get_earthquake_catalog():
    """
    Fetches earthquake data with a magnitude larger than 5.0
    from 2015-01-05 to 2016-03-05.
    """
    if not client:
        raise HTTPException(
            status_code=503, # Service Unavailable
            detail="The IRIS FDSN client is not available or failed to initialize.",
        )

    try:
        starttime = UTCDateTime("2015-01-05")
        endtime = UTCDateTime("2016-03-05")
        min_magnitude = 5.0

        logging.info(f"Fetching events from {starttime} to {endtime} with min magnitude {min_magnitude}.")
        catalog = client.get_events(
            starttime=starttime,
            endtime=endtime,
            minmagnitude=min_magnitude,
        )
        logging.info(f"Found {len(catalog)} events. Now processing.")

        earthquake_list = []
        # --- Key Change Start ---
        # Loop through each event and process it individually to prevent one bad event from crashing the app.
        for event in catalog:
            try:
                # Ensure the event has a preferred origin and magnitude
                if not event.preferred_origin() or not event.preferred_magnitude():
                    continue # Skip to the next event if essential data is missing

                origin = event.preferred_origin()
                magnitude = event.preferred_magnitude()

                # Safely extract the place description
                place = "N/A"
                if event.descriptions: # Check if the descriptions list exists and is not empty
                    place = event.descriptions[0].text

                earthquake_list.append({
                    "time": origin.time.isoformat(),
                    "latitude": origin.latitude,
                    "longitude": origin.longitude,
                    "depth_km": origin.depth / 1000.0 if origin.depth is not None else None,
                    "magnitude": magnitude.mag,
                    "magnitude_type": magnitude.magnitude_type,
                    "place": place,
                })
            except Exception as e:
                # If a single event fails, log it and continue with the others.
                logging.warning(f"Skipping one event due to a processing error: {e}")
                continue
        # --- Key Change End ---

        logging.info(f"Successfully processed {len(earthquake_list)} events.")
        return JSONResponse(content={"earthquakes": earthquake_list})

    except Exception as e:
        logging.error(f"A major error occurred during the request: {e}")
        raise HTTPException(
            status_code=500, # Internal Server Error
            detail=f"An internal error occurred: {e}",
        )