"""Helper functions related to Snowflake DB actions."""

from connectors import snowflake as snowdb
from utils.db_utils import run_query, zip_resultproxy_dict

from sql.select_all_distinct_single_field \
    import SELECT_ALL_DISTINCT_SINGLE_FIELD
from sql.select_all_single_field import \
    SELECT_ALL_SINGLE_FIELD
from sql.select_all_distinct_fields import SELECT_ALL_DISTINCT_FIELDS
from sql.select_all_fields import SELECT_ALL_FIELDS


@snowdb.db_session_wrap
def get_single_snowflake_field(session, field, table, distinct=False):
    """Get the value of a single field from snowflake.

    Args:
        session (SQLAlchemy):       Session from db wrapper
        field (str):                field name to retrieve
        table (str):                table name to query
        distinct (bool):            require distinct rows in result?

    Returns:
        dict

    """
    params = {
        'field_name': field,
        'table_name': table
    }

    sql = SELECT_ALL_DISTINCT_SINGLE_FIELD if distinct \
        else SELECT_ALL_SINGLE_FIELD

    query_results = run_query(session, sql=sql, params=params)

    results = zip_resultproxy_dict(query_results)

    return results


@snowdb.db_session_wrap
def get_snowflake_fields(session, field_list: list, table, distinct=False):
    """Get the value of a list of fields from snowflake.

    Args:
        session (SQLAlchemy):       Session from db wrapper
        field (list):               List of field names to retrieve
        table (str):                table name to query
        distinct (bool):            require distinct rows in result?

    Returns:
        dict

    """

    field_names = ','.join(list(field_list))
    params = {
        'field_names': field_names,
        'table_name': table
    }

    sql = SELECT_ALL_DISTINCT_FIELDS if distinct \
        else SELECT_ALL_FIELDS

    query_results = run_query(session, sql=sql, params=params)

    results = zip_resultproxy_dict(query_results)

    return results