"""Definition of connect function."""
from __future__ import annotations

import os

from minio import Minio


def connect(
) -> Minio:
    """Connect to MinIO server"""
    # ensure necessary env vars available
    necesasary_var_list = [
        'MINIO_ENDPOINT',
        'MINIO_ACCESS_KEY',
        'MINIO_SECRET_KEY',
        'MINIO_BUCKET_NAME',
    ]
    for env_var in necesasary_var_list:
        # ensure env var set
        assert (
            env_var in os.environ
        ), (
            f"environment variable not set: {env_var}"
        )
    # prepare arguments
    minio_endpoint = os.getenv('MINIO_ENDPOINT', default=None)
    assert isinstance(minio_endpoint, str)
    minio_access_key = os.getenv('MINIO_ACCESS_KEY', default=None)
    assert isinstance(minio_access_key, str)
    minio_secret_key = os.getenv('MINIO_SECRET_KEY', default=None)
    assert isinstance(minio_secret_key, str)
    minio_bucket_name = os.getenv('MINIO_BUCKET_NAME', default=None)
    assert isinstance(minio_bucket_name, str)
    # connect client
    client = Minio(
        endpoint=minio_endpoint,
        access_key=minio_access_key,
        secret_key=minio_secret_key,
        secure=False,
    )
    # ensure bucket exists
    if not client.bucket_exists(bucket_name=minio_bucket_name):
        client.make_bucket(bucket_name=minio_bucket_name)
    return client