import os
import sys

try:
    import psycopg
except ImportError:
    sys.stderr.write("Missing dependency: install with `python -m pip install psycopg[binary]`\n")
    sys.exit(1)

DSN = os.environ.get("SUPABASE_DB_URL")
if not DSN:
    sys.stderr.write("SUPABASE_DB_URL environment variable is not set.\n")
    sys.exit(1)

try:
    with psycopg.connect(DSN, autocommit=True) as conn:
        with conn.cursor() as cur:
            cur.execute("select 1;")
            row = cur.fetchone()
            print("Query result:", row[0] if row else None)
except Exception as exc:
    sys.stderr.write(f"Connection failed: {exc}\n")
    sys.exit(1)