"""Utility Functions for Models."""

from conflict_manager import config


def query_results_to_dict(query_results):
    """Convert query results in dict format.

    Args:
        query_results (ResultProxy): SQL Alchemy DB-API cursor wrapper.

    Returns:
        dict
    """
    results = []
    for row in query_results:
        results.append({key: row[key] for key in query_results.keys()})

    return results


def run_query(session, sql, account=None, params={}):
    """Run query with params.

    Expands table names and adds account info. Use these aliases within
    any query that is written:

    Alias                 | Substitution
    ---------------------------------------------------------------------
    {fact_conflict_table} | The fully qualified fact conflict table name
    {action_table}        | The fully qualified acount table
    {account_id}          | The vendor or subaccount id table field

    Args:
        session: SQLAlchemy session
        sql (str): SQL to run
        account (namedtuple): Account information (optional)
        params (dict): Parameters to add into query (handles SQL escaping)
    """
    aliases = {
        'fact_conflict_table': '{}.{}.fact_conflict'.format(
            config.FACTS_DATABASE, config.SNOWFLAKE_SCHEMA),
        'action_table': '{}.{}.action'.format(
            config.CONFLICT_MANAGER_DATABASE, config.SNOWFLAKE_SCHEMA),
        'track': '{}.track'.format(config.ART_RELATIONS_DATABASE_SCHEMA),
        'track_artist': '{}.track_artist'.format(
            config.ART_RELATIONS_DATABASE_SCHEMA),
        'releases': '{}.releases'.format(config.ART_RELATIONS_DATABASE_SCHEMA),
        'subaccount': '{}.subaccount'.format(
            config.ART_RELATIONS_DATABASE_SCHEMA),
        'conflict_status_table': '{}.{}.conflict_status'.format(
            config.CONFLICT_MANAGER_DATABASE, config.SNOWFLAKE_SCHEMA),
    }

    if account:
        aliases['account_id_field'] = '{}_id'.format(account.type)
        params['account_id'] = account.id

    return session.execute(sql.format(**aliases), params)


def get_total_records(results, offset, limit):
    """Try to get total records from pagination data.

    Args:
        results (list): List of items
        offset (int): Pagination offset
        limit (int): Pagination limit

    Returns:
        int, None
    """
    if len(results) > 0 and len(results) < limit:
        # This is the last page of results
        return offset + len(results)
    elif len(results) == 0 and offset == 0:
        # Total records is 0 when on the first page and there are no results
        return 0

    return None


def _validate_query_args(args):
    """Validate the presence of necessary arguments for filtering."""
    keys = list(args.copy().keys())
    return ('query' in keys and 'fields' in keys)