# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
#
#    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.

"""
System-level utilities and helper functions.
"""

import inspect
import logging
import os
import random
import subprocess
import socket
import sys
from datetime import datetime

from nova import flags

FLAGS = flags.FLAGS


def fetchfile(url, target):
    logging.debug("Fetching %s" % url)
#    c = pycurl.Curl()
#    fp = open(target, "wb")
#    c.setopt(c.URL, url)
#    c.setopt(c.WRITEDATA, fp)
#    c.perform()
#    c.close()
#    fp.close()
    execute("curl %s -o %s" % (url, target))

def execute(cmd, input=None, addl_env=None):
    env = os.environ.copy()
    if addl_env:
        env.update(addl_env)
    obj = subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE,
        stdout=subprocess.PIPE, stderr=subprocess.PIPE, env=env)
    result = None
    if input != None:
        result = obj.communicate(input)
    else:
        result = obj.communicate()
    obj.stdin.close()
    if obj.returncode:
        logging.debug("Result was %s" % (obj.returncode))
    return result


def abspath(s):
    return os.path.join(os.path.dirname(__file__), s)


def default_flagfile(filename='nova.conf'):
    for arg in sys.argv:
        if arg.find('flagfile') != -1:
            break
    else:
        if not os.path.isabs(filename):
            # turn relative filename into an absolute path
            script_dir = os.path.dirname(inspect.stack()[-1][1])
            filename = os.path.abspath(os.path.join(script_dir, filename))
        if os.path.exists(filename):
            sys.argv = sys.argv[:1] + ['--flagfile=%s' % filename] + sys.argv[1:]


def debug(arg):
    logging.debug('debug in callback: %s', arg)
    return arg


def runthis(prompt, cmd):
    logging.debug("Running %s" % (cmd))
    logging.debug(prompt % (subprocess.call(cmd.split(" "))))


def generate_uid(topic, size=8):
    return '%s-%s' % (topic, ''.join([random.choice('01234567890abcdefghijklmnopqrstuvwxyz') for x in xrange(size)]))


def generate_mac():
    mac = [0x00, 0x16, 0x3e, random.randint(0x00, 0x7f),
           random.randint(0x00, 0xff), random.randint(0x00, 0xff)
           ]
    return ':'.join(map(lambda x: "%02x" % x, mac))


def last_octet(address):
    return int(address.split(".")[-1])


def get_my_ip():
    ''' returns the actual ip of the local machine.
    '''
    if getattr(FLAGS, 'fake_tests', None):
        return '127.0.0.1'
    csock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    csock.connect(('www.google.com', 80))
    (addr, port) = csock.getsockname()
    csock.close()
    return addr

def isotime(at=None):
    if not at:
        at = datetime.utcnow()
    return at.strftime("%Y-%m-%dT%H:%M:%SZ")