#!/usr/bin/env python3

from datetime import datetime
from pathlib import Path

from psycopg2 import connect
from yaml import safe_load


base_directory = Path(__file__).parent.parent
data_directory = base_directory / "data"
configuration_file = data_directory / "config.yml"
archive_directory = data_directory / "archive"


if __name__ == "__main__":
    exit_code = 0
    try:
        # read config
        with configuration_file.open("r") as f:
            config = safe_load(f)
        # connect to database
        connection = connect(
            user = config["db"]["user"],
            password = config["db"]["password"],
            host = config["db"]["host"],
            port = config["db"]["port"],
            database = config["db"]["database"]
        )
        cur = connection.cursor()
        # copy data from database
        timestamp = datetime.now().strftime("%Y-%m-%d-%H%M%S")
        orders_archive_path = archive_directory / f"orders-archive-{timestamp}.csv"
        transactions_archive_path = archive_directory / f"transactions-archive-{timestamp}.csv"
        print(f"Copying data...")
        with orders_archive_path.open("w") as of:
            cur.copy_expert(
                "copy (select * from app_order) to STDOUT with csv delimiter ';'", of)
            print(str(orders_archive_path))
        with transactions_archive_path.open("w") as tf:
            cur.copy_expert(
                "copy (select * from app_registertransaction) to STDOUT with csv delimiter ';'", tf)
            print(str(transactions_archive_path))
        # delete data from database
        print("Deleting data from database...")
        cur.execute("delete from app_order;")
        cur.execute("delete from app_registertransaction;")
        connection.commit()
        print("done.")
    except (Error, Exception) as err:
        connection.rollback()
        print(f"An error occured while upgrading the database at {os.environ['PGDB_HOST']}:\n{err}")
        exit_code = 1
    finally:
        cur.close()
        connection.close()
        exit(exit_code)