##############################################################################
# Copyright (c) 2017 NEC Corporation and others.
#
# All rights reserved. This program and the accompanying materials
# are made available under the terms of the Apache License, Version 2.0
# which accompanies this distribution, and is available at
# http://www.apache.org/licenses/LICENSE-2.0
##############################################################################

import collectd
import sys
from netifaces import interfaces, ifaddresses, AF_INET
from datetime import datetime
import json
import requests
import time
from requests.exceptions import ConnectionError

from keystoneauth1 import loading
from keystoneauth1 import session
from congressclient.v1 import client


def write_debug(str_write, write_type, compute_user):
    file_name = ('/home/%s/monitor.log' % compute_user)
    file_tmp = open(file_name, write_type)
    file_tmp.write( "%s" % str_write)
    file_tmp.close()


class DoctorMonitorCollectd(object):
    def __init__(self):
        self.control_ip = ''
        self.compute_user = ''
        self.compute_ip = ''
        self.host_name = ''
        self.inspector_type = ''
        self.inspector_url = ''
        self.os_auth_url = ''
        self.os_username = ''
        self.os_password = ''
        self.os_project_name = ''
        self.os_user_domain_name = ''
        self.os_user_domain_id = ''
        self.os_project_domain_name = ''
        self.os_project_domain_id = ''
        self.sess = ''
        self.auth = ''
        self.inspector_notified = 0
        self.start_notifications = 0
        self.monitor_type = 'sample'

    def config_func(self, config):
        for node in config.children:
            key = node.key.lower()
            val = node.values[0]

            if key == 'compute_host':
                self.host_name = val
            elif key == 'control_ip':
                self.control_ip = val
            elif key == 'compute_ip':
                self.compute_ip = val
            elif key == 'compute_user':
                self.compute_user = val
            elif key == 'inspector_type':
                self.inspector_type = val
            elif key == 'os_auth_url':
                self.os_auth_url = val
            elif key == 'os_username':
                self.os_username = val
            elif key == 'os_password':
                self.os_password = val
            elif key == 'os_project_name':
                self.os_project_name = val
            elif key == 'os_user_domain_name':
                self.os_user_domain_name = val
            elif key == 'os_user_domain_id':
                self.os_user_domain_id = val
            elif key == 'os_project_domain_name':
                self.os_project_domain_name = val
            elif key == 'os_project_domain_id':
                self.os_project_domain_id = val
            else:
                collectd.info('Unknown config key "%s"' % key)

    def init_collectd(self):
        write_debug("Compute node collectd monitor start at %s\n\n" % datetime.now().isoformat(), "w", self.compute_user)

        if self.inspector_type == 'sample':
            self.inspector_url = ('http://%s:12345/events' % self.control_ip)
        elif self.inspector_type == 'congress':
            loader = loading.get_plugin_loader('password')
            self.auth = loader.load_from_options(auth_url=self.os_auth_url,
                        username=self.os_username,
                        password=self.os_password,
                        project_name=self.os_project_name,
                        user_domain_name=self.os_user_domain_name,
                        user_domain_id=self.os_user_domain_id,
                        project_domain_name=self.os_project_domain_name,
                        project_domain_id=self.os_project_domain_id)
            self.sess=session.Session(auth=self.auth)
            congress = client.Client(session=self.sess, service_type='policy')
            ds = congress.list_datasources()['results']
            doctor_ds = next((item for item in ds if item['driver'] == 'doctor'),
                         None)

            congress_endpoint = congress.httpclient.get_endpoint(auth=self.auth)
            self.inspector_url = ('%s/v1/data-sources/%s/tables/events/rows' %
                              (congress_endpoint, doctor_ds['id']))
        else:
            sys.exit()
        self.start_notifications = 1


    def notify_inspector(self):
        event_type = "compute.host.down"
        payload = [
            {
                 'id': ("monitor_%s_id1" % self.monitor_type),
                 'time': datetime.now().isoformat(),
                 'type': event_type,
                 'details': {
                     'hostname': self.host_name,
                     'status': 'down',
                     'monitor': ("monitor_%s" % self.monitor_type),
                     'monitor_event_id': ("monitor_%s_event1" % self.monitor_type)
                 },
             },
        ]
        data = json.dumps(payload)
        self.inspector_notified = 1

        if self.inspector_type == 'sample':
            headers = {'content-type': 'application/json'}
            try:
                requests.post(self.inspector_url, data=data, headers=headers)
            except ConnectionError as err:
                print err
        elif self.inspector_type == 'congress':
            # TODO(umar) enhance for token expiry case
            headers = {
                'Content-Type': 'application/json',
                'Accept': 'application/json',
                'X-Auth-Token': self.sess.get_token()
            }
            requests.put(self.inspector_url, data=data, headers=headers)


    def handle_notif(self, notification, data=None):
        if (notification.severity == collectd.NOTIF_FAILURE or
            notification.severity == collectd.NOTIF_WARNING):
            if (self.start_notifications == 1 and self.inspector_notified == 0):
                write_debug("Received down notification: doctor monitor detected at %s\n" % time.time(), "a", self.compute_user)
                self.notify_inspector()

        elif notification.severity == collectd.NOTIF_OKAY:
            collectd.info("Interface status: UP again %s\n" % time.time())
        else:
            collectd.info("Unknown notification severity %s\n" % notification.severity)


monitor = DoctorMonitorCollectd()

collectd.register_config(monitor.config_func)
collectd.register_init(monitor.init_collectd)
collectd.register_notification(monitor.handle_notif)