import duckdb
from contextlib import contextmanager

@contextmanager
def get_duckdb_connection():
    """Context manager ensures connection cleanup."""
    con = duckdb.connect()
    try:
        con.execute("INSTALL httpfs; LOAD httpfs;")
        yield con
    finally:
        con.close()

# Configure and query
with get_duckdb_connection() as con:
    # S3 configuration
    con.execute("""
        SET s3_region='us-east-1';
        SET s3_access_key_id='AKIA...';
        SET s3_secret_access_key='...';
        -- For temporary creds: SET s3_session_token='...'
        -- For S3-compatible: SET s3_endpoint='http://minio:9000';
    """)

    # Query Parquet directly
    df = con.sql("""
        SELECT category, SUM(value) as total
        FROM read_parquet('s3://bucket/data/*.parquet')
        WHERE date >= '2024-01-01'
        GROUP BY category
    """).pl()

    # Read from GCS (configure via environment or default credentials)
    df = con.sql("SELECT * FROM read_csv('gs://bucket/data.csv')").pl()

import os
os.environ['AWS_ACCESS_KEY_ID'] = 'AKIA...'
os.environ['AWS_SECRET_ACCESS_KEY'] = '...'
os.environ['AWS_REGION'] = 'us-east-1'

# DuckDB HTTPFS reads these automatically on first use
import duckdb
con = duckdb.connect()
con.execute("INSTALL httpfs; LOAD httpfs;")
df = con.sql("SELECT * FROM read_parquet('s3://bucket/data.parquet')").pl()

import fsspec
import duckdb

# Register GCS (or any fsspec protocol)
duckdb.register_filesystem(fsspec.filesystem('gcs'))

# Now use gcs:// URIs natively
df = duckdb.sql("""
    SELECT * FROM read_parquet('gcs://bucket/data.parquet')
""").pl()

import duckdb

with duckdb.connect() as con:
    # Export table to S3
    con.sql("""
        COPY (SELECT * FROM my_table)
        TO 's3://bucket/output.parquet'
        (FORMAT PARQUET)
    """)

    # Import from S3
    con.sql("""
        CREATE TABLE imported AS
        SELECT * FROM read_parquet('s3://bucket/input.parquet')
    """)

import duckdb

with duckdb.connect() as con:
    con.execute("INSTALL delta; LOAD delta;")

    # Query Delta table
    df = con.sql("""
        SELECT * FROM delta_scan('s3://bucket/delta-table/')
        WHERE date >= '2024-01-01'
    """).pl()

    # Time travel (read specific version)
    df = con.sql("""
        SELECT * FROM delta_scan('s3://bucket/delta-table/', version => 5)
    """).pl()

# ✅ DO: Use context manager
with duckdb.connect("analytics.db") as con:
    con.sql("CREATE TABLE ...")

# ❌ DON'T: Leak connections
con = duckdb.connect("analytics.db")
con.sql("...")  # Never closed → leak

# ✅ DO: If you must, manually close
con = duckdb.connect("analytics.db")
try:
    con.sql("...")
finally:
    con.close()