#!/usr/bin/env python
# Copyright 2012 Hewlett-Packard Development Company, L.P.
# Copyright 2013 OpenStack Foundation
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

import logging
import logging.config
import os
import signal
import sys
import threading
import traceback


def stack_dump_handler(signum, frame):
    signal.signal(signal.SIGUSR2, signal.SIG_IGN)
    log_str = ""
    threads = {}
    for t in threading.enumerate():
        threads[t.ident] = t
    for thread_id, stack_frame in sys._current_frames().items():
        thread = threads.get(thread_id)
        if thread:
            thread_name = thread.name
        else:
            thread_name = 'Unknown'
        label = '%s (%s)' % (thread_name, thread_id)
        log_str += "Thread: %s\n" % label
        log_str += "".join(traceback.format_stack(stack_frame))
    log = logging.getLogger("nodepool.stack_dump")
    log.debug(log_str)
    signal.signal(signal.SIGUSR2, stack_dump_handler)


class NodepoolApp(object):

    def __init__(self):
        self.args = None

    def setup_logging(self):
        if self.args.logconfig:
            fp = os.path.expanduser(self.args.logconfig)
            if not os.path.exists(fp):
                raise Exception("Unable to read logging config file at %s" %
                                fp)
            logging.config.fileConfig(fp)
        else:
            logging.basicConfig(level=logging.DEBUG,
                                format='%(asctime)s %(levelname)s %(name)s: '
                                       '%(message)s')