#!/usr/bin/env python
# pylint: disable=C0103
# 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.

"""Euca add-on to use ajax console"""

import getopt
import os
import sys

# If ../nova/__init__.py exists, add ../ to Python search path, so that
# it will override what happens to be installed in /usr/(local/)lib/python...
possible_topdir = os.path.normpath(os.path.join(os.path.abspath(sys.argv[0]),
                                   os.pardir,
                                   os.pardir))
if os.path.exists(os.path.join(possible_topdir, 'nova', '__init__.py')):
    sys.path.insert(0, possible_topdir)

import boto
import nova
from boto.ec2.connection import EC2Connection
import euca2ools
from euca2ools import Euca2ool, InstanceValidationError, Util

usage_string = """
Retrieves a url to an ajax console terminal

euca-get-ajax-console [-h, --help] [--version] [--debug] instance_id

REQUIRED PARAMETERS

instance_id: unique identifier for the instance show the console output for.

OPTIONAL PARAMETERS

"""


# This class extends boto to add AjaxConsole functionality
class NovaEC2Connection(EC2Connection):

    def get_ajax_console(self, instance_id):
        """
        Retrieves a console connection for the specified instance.

        :type instance_id: string
        :param instance_id: The instance ID of a running instance on the cloud.

        :rtype: :class:`AjaxConsole`
        """

        class AjaxConsole:
            def __init__(self, parent=None):
                self.parent = parent
                self.instance_id = None
                self.url = None

            def startElement(self, name, attrs, connection):
                return None

            def endElement(self, name, value, connection):
                if name == 'instanceId':
                    self.instance_id = value
                elif name == 'url':
                    self.url = value
                else:
                    setattr(self, name, value)

        params = {}
        self.build_list_params(params, [instance_id], 'InstanceId')
        return self.get_object('GetAjaxConsole', params, AjaxConsole)
    pass


def override_connect_ec2(aws_access_key_id=None,
                         aws_secret_access_key=None, **kwargs):
    return NovaEC2Connection(aws_access_key_id,
                             aws_secret_access_key, **kwargs)

# override boto's connect_ec2 method, so that we can use NovaEC2Connection
# (This is for Euca2ools 1.2)
boto.connect_ec2 = override_connect_ec2

# Override Euca2ools' EC2Connection class (which it gets from boto)
# (This is for Euca2ools 1.3)
euca2ools.EC2Connection = NovaEC2Connection


def usage(status=1):
    print usage_string
    Util().usage()
    sys.exit(status)


def version():
    print Util().version()
    sys.exit()


def display_console_output(console_output):
    print console_output.instance_id
    print console_output.timestamp
    print console_output.output


def display_ajax_console_output(console_output):
    print console_output.url


def main():
    try:
        euca = Euca2ool()
    except Exception, e:
        print e
        usage()

    instance_id = None

    for name, value in euca.opts:
        if name in ('-h', '--help'):
            usage(0)
        elif name == '--version':
            version()
        elif name == '--debug':
            debug = True

    for arg in euca.args:
        instance_id = arg
        break

    if instance_id:
        try:
            euca.validate_instance_id(instance_id)
        except InstanceValidationError:
            print 'Invalid instance id'
            sys.exit(1)

        try:
            euca_conn = euca.make_connection()
        except Exception, e:
            print e.message
            sys.exit(1)
        try:
            console_output = euca_conn.get_ajax_console(instance_id)
        except Exception, ex:
            euca.display_error_and_exit('%s' % ex)

        display_ajax_console_output(console_output)
    else:
        print 'instance_id must be specified'
        usage()

if __name__ == "__main__":
    main()