from dagster import (
    sensor,
    SensorEvaluationContext,
    RunRequest,
    SkipReason,
    DefaultSensorStatus,
    AssetKey,
)
from dagster_duckdb import DuckDBResource

@sensor(
    name="gtfs_rt_vehicles_sensor",
    minimum_interval_seconds=60,
    asset_selection=["gtfs_rt_vehicles_downloads"],
    default_status=DefaultSensorStatus.RUNNING
)
def gtfs_rt_vehicles_sensor(
    context: SensorEvaluationContext,
    duckdb: DuckDBResource,
) -> list[RunRequest] | SkipReason:
    """
    Sensor that triggers gtfs_rt_vehicles_downloads every 60 seconds.
    Fetches feed metadata once and passes it to each partition run.
    """
    # Check if upstream asset has been materialized at least once
    upstream_asset_key = AssetKey("gtfs_rt_vehicles_partitions")
    latest_materialization = context.instance.get_latest_materialization_event(upstream_asset_key)

    if latest_materialization is None:
        return SkipReason(
            "Waiting for upstream asset 'gtfs_rt_vehicles_partitions' to be materialized. "
            "Run the upstream assets first."
        )

    try:
        with duckdb.get_connection() as conn:
            # Get all active feeds with their metadata in one query
            feeds = conn.execute("""
                SELECT feed_id, provider, producer_url
                FROM gtfs_rt_vehicles_metadata
                WHERE producer_url IS NOT NULL AND producer_url != ''
                ORDER BY feed_id
            """).fetchall()

            if not feeds:
                return SkipReason("No GTFS-RT vehicle feeds configured")

            # Create a RunRequest for each partition with metadata
            run_requests = [
                RunRequest(
                    partition_key=feed_id,
                    run_config={
                        "ops": {
                            "gtfs_rt_vehicles_downloads": {
                                "config": {
                                    "provider": provider,
                                    "producer_url": producer_url,
                                }
                            }
                        }
                    },
                    tags={
                        "feed_id": feed_id,
                        "sensor": "gtfs_rt_vehicles_sensor"
                    }
                )
                for feed_id, provider, producer_url in feeds
            ]

            context.log.info(f"Triggering downloads for {len(run_requests)} GTFS-RT vehicle feeds")

            return run_requests

    except Exception as e:
        # Handle case where table doesn't exist yet or other DB errors
        context.log.warning(f"Database query failed: {e}")
        return SkipReason(f"Database not ready or query failed: {e}")