#!/usr/bin/env python3
import logging
import sys
import importlib
import argparse
import os

from etcd3.exceptions import ConnectionFailedError

from uncloud.common import settings
from uncloud import UncloudException
from uncloud.common.cli import resolve_otp_credentials


def exception_hook(exc_type, exc_value, exc_traceback):
    logging.getLogger(__name__).error(
        'Uncaught exception',
        exc_info=(exc_type, exc_value, exc_traceback)
    )


sys.excepthook = exception_hook

# the components that use etcd
ETCD_COMPONENTS = ['api', 'scheduler', 'host', 'filescanner',
                   'imagescanner', 'metadata', 'configure', 'hack']

ALL_COMPONENTS = ETCD_COMPONENTS.copy()
ALL_COMPONENTS.append('cli')


if __name__ == '__main__':
    # Setting up root logger
    logger = logging.getLogger()
    logger.setLevel(logging.DEBUG)

    arg_parser = argparse.ArgumentParser()
    subparsers = arg_parser.add_subparsers(dest='command')

    parent_parser = argparse.ArgumentParser(add_help=False)
    parent_parser.add_argument('--debug', '-d', action='store_true', default=False,
                               help='More verbose logging')
    parent_parser.add_argument('--conf-dir', '-c', help='Configuration directory',
                               default=os.path.expanduser('~/uncloud'))

    etcd_parser = argparse.ArgumentParser(add_help=False)
    etcd_parser.add_argument('--etcd-host', dest='etcd_url')
    etcd_parser.add_argument('--etcd-port')
    etcd_parser.add_argument('--etcd-ca-cert', help='CA that signed the etcd certificate')
    etcd_parser.add_argument('--etcd-cert-cert', help='Path to client certificate')
    etcd_parser.add_argument('--etcd-cert-key', help='Path to client certificate key')

    for component in ALL_COMPONENTS:
        mod = importlib.import_module('uncloud.{}.main'.format(component))
        parser = getattr(mod, 'arg_parser')

        if component in ETCD_COMPONENTS:
            subparsers.add_parser(name=parser.prog, parents=[parser, parent_parser, etcd_parser])
        else:
            subparsers.add_parser(name=parser.prog, parents=[parser, parent_parser])

    arguments = vars(arg_parser.parse_args())
    etcd_arguments = [key for key, value in arguments.items() if key.startswith('etcd_') and value]
    etcd_arguments = {
        'etcd': {
            key.replace('etcd_', ''): arguments[key]
            for key in etcd_arguments
        }
    }
    if not arguments['command']:
        arg_parser.print_help()
    else:
        # Initializing Settings and resolving otp_credentials
        # It is neccessary to resolve_otp_credentials after argument parsing is done because
        # previously we were reading config file which was fixed to ~/uncloud/uncloud.conf and
        # providing the default values for --name, --realm and --seed arguments from the values
        # we read from file. But, now we are asking user about where the config file lives. So,
        # to providing default value is not possible before parsing arguments. So, we are doing
        # it after..
        settings.settings = settings.Settings(arguments['conf_dir'], seed_value=etcd_arguments)
        resolve_otp_credentials(arguments)

        name = arguments.pop('command')
        mod = importlib.import_module('uncloud.{}.main'.format(name))
        main = getattr(mod, 'main')

        try:
            main(arguments)
        except UncloudException as err:
            logger.error(err)
        except ConnectionFailedError:
            logger.error('Cannot connect to etcd')
        except Exception as err:
            logger.exception(err)