#!/usr/bin/env python3

import os, sys

from pathlib import Path

from psycopg2 import connect
from psycopg2._psycopg import cursor as _cursor
from psycopg2._psycopg import connection as _connection
from psycopg2 import Error
from psycopg2 import IntegrityError
from psycopg2 import errorcodes


# setup or upgrade the database


def log(s, error=False):
    if error:
        print(f"{s}", file=sys.stderr)
    else:
        print(f"{s}", file=sys.stdout)


def execute_sql_statement(cursor:_cursor, connection:_connection, sql_statement):
    try:
        cursor.execute(sql_statement)
        connection.commit()
    except IntegrityError as ie:
        if ie.pgcode == errorcodes.UNIQUE_VIOLATION:
            log("Skipping one row that already exists.")
            connection.rollback()
        else:
            log(f"An integrity error occured:\n{ie}\nRolling back...", error=True)
            connection.rollback()
    except Error as e:
        log(f"An SQL statement failed while upgrading the database at {os.environ['PGDB_HOST']}:\n{e}", error=True)
        connection.rollback()


if __name__ == "__main__":

    exit_code = 0
    
    try:

        log("\nSetting up/upgrading database...")

        conn = connect(
            user = os.environ["PGDB_USER"],
            password = os.environ["PGDB_PASSWORD"],
            host = os.environ["PGDB_HOST"],
            port = os.environ["PGDB_PORT"],
            database = os.environ["PGDB_DB"]
        )

        cur = conn.cursor()


        # # # # #

        log("Not deleting register_balance. You can delete it via the Admin Panel (Globals -> register_balance), as it is no more used.")

        execute_sql_statement(cur, conn, """
            insert into app_global
            values ('global_message', 'Here you can set a global message that will be shown to every user.', 0.0, '');
        """)

        execute_sql_statement(cur, conn, """
            insert into app_global
            values ('admin_info', 'Here you can set am infotext that will be displayed on the admin panel.', 0.0, '');
        """)

        execute_sql_statement(cur, conn, """
            create or replace view app_userdeposits_view as
                select * from app_registertransaction
                where is_user_deposit = true;
        """)

        # # # # #


        # set app_version in file and database

        # database

        try:

            cur.execute("""
                select value from application_info
                where key = 'app_version';
            """)

            result = cur.fetchone()

            if result == None:

                cur.execute(f"""
                    insert into application_info values ('app_version', '{os.environ['APP_VERSION']}');
                """)

                conn.commit()

            else:

                cur.execute(f"""
                    update application_info set value = '{os.environ['APP_VERSION']}' where key = 'app_version';
                """)

                conn.commit()

        except Error as err:

            if err.pgcode == errorcodes.UNDEFINED_TABLE:

                try:

                    conn.rollback()

                    cur.execute("""
                        create table application_info (
                            key varchar(32) primary key,
                            value text
                        );
                    """)

                    cur.execute(f"""
                        insert into application_info values ('app_version', '{os.environ['APP_VERSION']}');
                    """)

                    conn.commit()

                except Error as err2:

                    log(f"An error occurred while setting app_version in table application_info: {err}", error=True)
                    exit_code = 1

            else:

                log(f"An error occurred while setting app_version in table application_info: {err}", error=True)
                exit_code = 1
        
        # file

        Path("./config/db_app_version.txt").write_text(os.environ["APP_VERSION"])
        log("done with db setup/upgrade.")

    except (Error, Exception) as err:

        log(f"An error occured while upgrading the database at {os.environ['PGDB_HOST']}:\n{err}", error=True)
        exit_code = 1

    finally:

        cur.close()
        conn.close()
        exit(exit_code)