##########################################################################
#
# pgAdmin 4 - PostgreSQL Tools
#
# Copyright (C) 2013 - 2024, The pgAdmin Development Team
# This software is released under the PostgreSQL License
#
##########################################################################
import logging
import subprocess
from datetime import datetime, timedelta, timezone
from threading import Lock

from flask import current_app

import config
from pgadmin.utils.driver import get_driver


class PasswordExec:

    lock = Lock()

    def __init__(self, cmd, host, port, username, expiration_seconds=None,
                 timeout=60):
        self.host = host
        self.port = port
        self.username = username
        self.cmd = cmd
        self.expiration_seconds = int(expiration_seconds) \
            if expiration_seconds is not None else None
        self.timeout = int(timeout)
        self.password = None
        self.last_result = None

    def get(self):
        if config.SERVER_MODE and not config.ENABLE_SERVER_PASS_EXEC_CMD:
            # Arbitrary shell execution on server is a security risk
            raise NotImplementedError('Passexec not available in server mode')
        driver = get_driver(config.PG_DEFAULT_DRIVER)
        self.cmd = str(self.cmd)
        self.cmd = self.cmd.replace('%HOSTNAME%', self.host)
        self.cmd = self.cmd.replace('%PORT%', str(self.port))
        self.cmd = self.cmd.replace('%USERNAME%',
                                    driver.qtIdent(None,self.username))
        with self.lock:
            if not self.password or self.is_expired():
                if not self.cmd:
                    return None
                current_app.logger.info('Calling passexec')
                now = datetime.now(timezone.utc)
                try:
                    p = subprocess.run(
                        self.cmd,
                        shell=True,
                        timeout=self.timeout,
                        capture_output=True,
                        text=True,
                        check=True,
                    )
                except subprocess.CalledProcessError as e:
                    if e.stderr:
                        self.create_logger().error(e.stderr)
                    raise

                current_app.logger.info('Passexec completed successfully')
                self.last_result = now
                self.password = p.stdout.strip()
            return self.password

    def is_expired(self):
        if self.expiration_seconds is None:
            return False
        return self.last_result is not None and\
            datetime.now(timezone.utc) - self.last_result \
            >= timedelta(seconds=self.expiration_seconds)

    def create_logger(self):
        logger = logging.getLogger('passexec')
        for h in current_app.logger.handlers:
            logger.addHandler(h)
        return logger