"""Common config for all the workflows."""
import base64
import logging
import os

from botocore.config import Config
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import serialization
from garcon_contrib.dynamo_feed_status import config as garcon_config

logger = logging.getLogger(__name__)

SNOWFLAKE_PRIVATE_KEY_PATH = os.environ.get('SNOWFLAKE_PRIVATE_KEY_PATH', '')
SNOWFLAKE_KEY_PASSPHRASE = os.environ.get('SNOWFLAKE_KEY_PASSPHRASE', '')

ENV = os.environ.get('Environment') or 'test'

if ENV == 'dev' and SNOWFLAKE_KEY_PASSPHRASE:
    # Snowflake key
    if not SNOWFLAKE_PRIVATE_KEY_PATH:
        SNOWFLAKE_PRIVATE_KEY_PATH = '{}/.ssh/snowflake/rsa_key.p8'.format(
            os.environ['HOME'])
    with open(SNOWFLAKE_PRIVATE_KEY_PATH, 'rb') as key:
        p_key = serialization.load_pem_private_key(
            key.read(),
            password=SNOWFLAKE_KEY_PASSPHRASE.encode(),
            backend=default_backend()
        )

    private_key = p_key.private_bytes(
        encoding=serialization.Encoding.DER,
        format=serialization.PrivateFormat.PKCS8,
        encryption_algorithm=serialization.NoEncryption())
else:
    private_key_str = os.environ.get('SNOWFLAKE_KEY')
    if private_key_str:
        private_key = base64.b64decode(private_key_str.encode('utf-8'))
    else:
        private_key = None

FILE_FORMAT_ARCHIVE_FROM_SNOWFLAKE = r"""
    FIELD_DELIMITER='\t'
    RECORD_DELIMITER='\n'
    COMPRESSION='GZIP'
    FIELD_OPTIONALLY_ENCLOSED_BY='"'
    TRIM_SPACE=TRUE"""


def merge_configs(c1, c2):
    """Merge two flat configs.

    Values from c1 get overridden by values from c2 if the keys collide.

    Args:
        c1 (dict): First config.
        c2 (dict): Second config.

    Returns:
        dict: Result dict containing merged result.
    """
    c1 = c1 or {}
    c2 = c2 or {}
    return {**c1, **c2}


# Default Snowflake connection parameters excluding credentials
SF_PARAMS = {
    'role': os.environ.get('SNOWFLAKE_ROLE'),
    'warehouse': os.environ.get('SNOWFLAKE_WAREHOUSE'),
    'db': os.environ.get('SNOWFLAKE_DATABASE'),
    'schema': os.environ.get('SNOWFLAKE_SCHEMA'),
    'ocsp_fail_open': False  # enforce OCSP checking
}

AWS_REGION = os.environ.get('AWS_REGION',
                            os.environ.get(
                                'AWS_DEFAULT_REGION', 'us-east-1'))

# common boto3 client config
BOTO3_CONFIG = Config(
    region_name=AWS_REGION,
)

DEFAULT_EXPECTED_BUCKET_OWNER = ('103233932089'
                                 if ENV in {'dev', 'local'}
                                 else '437795906767')
EXPECTED_BUCKET_OWNER = (os.environ.get('EXPECTED_BUCKET_OWNER')
                         or DEFAULT_EXPECTED_BUCKET_OWNER)

# Snowflake connection credentials
SF_CREDENTIALS = {
    'user': os.environ.get('SNOWFLAKE_USER'),
    'password': os.environ.get('SNOWFLAKE_PASSWORD'),
    'account': os.environ.get('SNOWFLAKE_ACCOUNT'),
    'private_key': private_key
}

SF_CONFIG = merge_configs(SF_PARAMS, SF_CREDENTIALS)

NEO4J_CONFIG = {
    'url': os.environ.get('NEO4J_URL'),
    'user': os.environ.get('NEO4J_USER'),
    'password': os.environ.get('NEO4J_PASSWORD'),
    'database': os.environ.get('NEO4J_DATABASE_NAME', 'graph.db'),
}

# autoconfig feed_status table if not set explicitly
if not garcon_config.feed_ingestion_table and ENV:
    garcon_config.feed_ingestion_table = f'{ENV}_feed_ingestion_status'
    logger.info(f'Autoconfigured dynamo_feed_status table '
                f'to {garcon_config.feed_ingestion_table}')