"""Config for rs2sf and s32sf workflow."""

import base64
from itertools import chain
import os

from snowflake_etl.conf import getconf


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: merge result dict.
    """
    c1 = c1 or {}
    c2 = c2 or {}
    return {k: v for k, v in chain(c1.items(), c2.items()) if v}


# 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')
}

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

# add optional private_key
private_key = os.environ.get('SNOWFLAKE_KEY')
if private_key:
    decoded_key = base64.b64decode(bytes(private_key, encoding='utf-8'))
    SF_CREDENTIALS['private_key'] = decoded_key

SF_CONFIG = merge_configs(SF_PARAMS, SF_CREDENTIALS)

_SF_CONF = getconf('snowflake')
SF_DEFAULT_QUERIES = _SF_CONF['queries']
SF_LOAD_STRATEGIES = _SF_CONF['load_strategies']
SF_DEFAULT_FILE_FORMAT = _SF_CONF['default_file_format']
SF_MYSQL_STDOUT_FILE_FORMAT = _SF_CONF['mysql_stdout_file_format']