from app import db


def import_data_from(file, table_name: str, without_header: bool = False):
    copy_sql = __copy_csv_sql(table_name, without_header)
    cursor = db.session.connection().connection.cursor()
    cursor.execute(f'DELETE FROM "{table_name}";')
    cursor.copy_expert(copy_sql, file)
    db.session.commit()


def update_data_from(file, table_name: str, without_header: bool = False):
    cursor = db.session.connection().connection.cursor()
    cursor.execute(f"""CREATE TEMP TABLE tmp_table (LIKE \"{table_name}\" INCLUDING ALL)""")
    copy_sql = __copy_csv_sql("tmp_table", without_header)
    cursor.copy_expert(copy_sql, file)
    cursor.execute(
        f"""
            INSERT INTO \"{table_name}\"
            SELECT *
            FROM tmp_table
            ON CONFLICT DO NOTHING;
        """
    )
    cursor.execute("DROP TABLE tmp_table")
    db.session.commit()


def __copy_csv_sql(table_name: str, without_header: False) -> str:
    copy_sql = f"COPY \"{table_name}\" FROM STDIN WITH CSV DELIMITER'\t' QUOTE E'\b' "
    if without_header:
        copy_sql = f"COPY \"{table_name}\" FROM STDIN WITH CSV HEADER DELIMITER'\t' QUOTE E'\b' "
    return copy_sql