#!/usr/bin/env python3

import functools
import logging
import os
import pdb
import sys
import traceback

# This module is commonly used by others in here and should avoid
# taking any unnecessary dependencies back on them.

from argparse_utils import ActionNoYes
import config


logger = logging.getLogger(__name__)

args = config.add_commandline_args(
    f'Bootstrap ({__file__})',
    'Args related to python program bootstrapper and Swiss army knife')
args.add_argument(
    '--debug_unhandled_exceptions',
    action=ActionNoYes,
    default=False,
    help='Break into pdb on top level unhandled exceptions.'
)


def handle_uncaught_exception(
        exc_type,
        exc_value,
        exc_traceback):
    if issubclass(exc_type, KeyboardInterrupt):
        sys.__excepthook__(exc_type, exc_value, exc_traceback)
        return
    logger.exception(f'Unhandled top level {exc_type}',
                     exc_info=(exc_type, exc_value, exc_traceback))
    traceback.print_exception(exc_type, exc_value, exc_traceback)
    if config.config['debug_unhandled_exceptions']:
        logger.info("Invoking the debugger...")
        pdb.pm()


def initialize(entry_point):

    """Remember to initialize config and logging before running main."""
    @functools.wraps(entry_point)
    def initialize_wrapper(*args, **kwargs):
        sys.excepthook = handle_uncaught_exception
        config.parse(entry_point.__globals__['__file__'])

        import logging_utils
        logging_utils.initialize_logging(logging.getLogger())

        config.late_logging()

        logger.debug(f'Starting {entry_point.__name__} (program entry point)')

        ret = None
        import timer
        with timer.Timer() as t:
            ret = entry_point(*args, **kwargs)
        logger.debug(
            f'{entry_point.__name__} (program entry point) returned {ret}.'
        )

        walltime = t()
        (utime, stime, cutime, cstime, elapsed_time) = os.times()
        logger.debug(f'\n'
                     f'user: {utime}s\n'
                     f'system: {stime}s\n'
                     f'child user: {cutime}s\n'
                     f'child system: {cstime}s\n'
                     f'elapsed: {elapsed_time}s\n'
                     f'walltime: {walltime}s\n')
        if ret != 0:
            logger.info(f'Exit {ret}')
        else:
            logger.debug(f'Exit {ret}')
        sys.exit(ret)
    return initialize_wrapper