#!/usr/bin/env python
import argparse
import logging
import logging.config
import os
import sys

from rq import Queue
from rq.logutils import setup_loghandlers
from redis.exceptions import ConnectionError
from rq.contrib.legacy import cleanup_ghosts
from rq.scripts import add_standard_arguments, read_config_file, setup_default_arguments, setup_redis
from rq.utils import import_attribute

logger = logging.getLogger(__name__)


def parse_args():
    parser = argparse.ArgumentParser(description='Starts an RQ worker.')
    add_standard_arguments(parser)

    parser.add_argument('--burst', '-b', action='store_true', default=False, help='Run in burst mode (quit after all work is done)')
    parser.add_argument('--name', '-n', default=None, help='Specify a different name')
    parser.add_argument('--worker-class', '-w', action='store', default='rq.Worker', help='RQ Worker class to use')
    parser.add_argument('--path', '-P', default='.', help='Specify the import path.')
    parser.add_argument('--verbose', '-v', action='store_true', default=False, help='Show more output')
    parser.add_argument('--quiet', '-q', action='store_true', default=False, help='Show less output')
    parser.add_argument('--sentry-dsn', action='store', default=None, metavar='URL', help='Report exceptions to this Sentry DSN')
    parser.add_argument('--pid', action='store', default=None,
                        help='Write the process ID number to a file at the specified path')
    parser.add_argument('queues', nargs='*', help='The queues to listen on (default: \'default\')')

    return parser.parse_args()


def setup_loghandlers_from_args(args):
    if args.verbose and args.quiet:
        raise RuntimeError("Flags --verbose and --quiet are mutually exclusive.")

    if args.verbose:
        level = 'DEBUG'
    elif args.quiet:
        level = 'WARNING'
    else:
        level = 'INFO'
    setup_loghandlers(level)


def main():
    args = parse_args()

    if args.path:
        sys.path = args.path.split(':') + sys.path

    settings = {}
    if args.config:
        settings = read_config_file(args.config)

    setup_default_arguments(args, settings)

    # Worker specific default arguments
    if not args.queues:
        args.queues = settings.get('QUEUES', ['default'])

    if args.sentry_dsn is None:
        args.sentry_dsn = settings.get('SENTRY_DSN',
                                       os.environ.get('SENTRY_DSN', None))

    if args.pid:
        with open(os.path.expanduser(args.pid), "w") as fp:
            fp.write(str(os.getpid()))

    setup_loghandlers_from_args(args)
    setup_redis(args)

    cleanup_ghosts()
    w_class = import_attribute(args.worker_class)

    try:
        queues = list(map(Queue, args.queues))
        w = w_class(queues, name=args.name)

        # Should we configure Sentry?
        if args.sentry_dsn:
            from raven import Client
            from rq.contrib.sentry import register_sentry
            client = Client(args.sentry_dsn)
            register_sentry(client, w)

        w.work(burst=args.burst)
    except ConnectionError as e:
        print(e)
        sys.exit(1)