# Author: Andrieiev Danil Maksimovich
# danssg08@gmail.com | https://github.com/DanilAndreev

# Here declared bridge functions for storing rainbow table in PostgreSQL database.
import psycopg2

CONNECTION = psycopg2.connect(
    host="localhost",
    database="postgres",
    user="postgres",
    password="postgres",
    port=5432
)


def get_from_table(end_word: str) -> list:
    """
    get_from_table - function, designed to get records from rainbow table by end_word.

    :param end_word: End word in chain.
    :return: Start words of the chain with input end_word.
    """
    cursor = CONNECTION.cursor()
    try:
        cursor.execute("select start_word from rainbow_table where end_word = %s", [end_word])
        return [x[0] for x in cursor.fetchall()]
    except Exception as exception:
        print("Error reading from table:", exception)
    finally:
        cursor.close()


def add_to_table(start_word: str, end_word: str) -> bool:
    """
    add_to_table

    :param start_word: Start word of the chain.
    :param end_word: End word of the chain.
    :return: True if record was saved and False if not.
    """
    cursor = CONNECTION.cursor()
    try:
        cursor.execute("insert into rainbow_table (start_word, end_word) values (%s, %s)", (start_word, end_word))
        CONNECTION.commit()
        return True
    except Exception as exception:
        print("Failed to push:", start_word, exception)
        CONNECTION.rollback()
        return False
    finally:
        cursor.close()