import os, json, logging, datetime as dt
import azure.functions as func
from azure.storage.blob import BlobServiceClient

# Source storage (same one your trigger points to)
BLOB_CONN = os.environ["BLOB_CONN"]        # set as App Setting
CONTAINER = "bank-logs"                    # container your trigger uses

def main(blob: func.InputStream):
    # 1) Log to App Insights (if configured)
    logging.info("BlobIngest fired: name=%s len=%d", blob.name, blob.length)

    # 2) Write a marker blob so we can *see* it fired from Storage itself
    svc = BlobServiceClient.from_connection_string(BLOB_CONN)
    marker_name = f"intesa/_diag/processed-{dt.datetime.utcnow().strftime('%Y%m%dT%H%M%S')}.txt"
    payload = {
        "source": blob.name,
        "length": blob.length,
        "seen_at_utc": dt.datetime.utcnow().isoformat() + "Z"
    }
    svc.get_blob_client(CONTAINER, marker_name).upload_blob(
        json.dumps(payload).encode("utf-8"),
        overwrite=True
    )