#!/usr/bin/env python
""" Detect running daemons then configure and start the agent.
"""

import argparse
import logging
import os
import platform
import pwd
import socket
import subprocess
import sys
import yaml

import agent_config
import detection.plugins.apache as apache
import detection.plugins.ceilometer as ceilometer
import detection.plugins.cinder as cinder
import detection.plugins.glance as glance
import detection.plugins.kafka_consumer as kafka_consumer
import detection.plugins.keystone as keystone
import detection.plugins.libvirt as libvirt
import detection.plugins.mon as mon
import detection.plugins.mysql as mysql
import detection.plugins.network as network
import detection.plugins.neutron as neutron
import detection.plugins.nova as nova
import detection.plugins.rabbitmq as rabbitmq
import detection.plugins.swift as swift
import detection.plugins.zookeeper as zookeeper
import service.sysv as sysv

# List of all detection plugins to run
DETECTION_PLUGINS = [apache.Apache, ceilometer.Ceilometer, cinder.Cinder,
                     glance.Glance, kafka_consumer.Kafka, keystone.Keystone,
                     libvirt.Libvirt, mon.MonAPI, mon.MonPersister, mon.MonThresh,
                     mysql.MySQL, network.Network, neutron.Neutron, nova.Nova,
                     rabbitmq.RabbitMQ, swift.Swift, zookeeper.Zookeeper]
# Map OS to service type
OS_SERVICE_MAP = {'Linux': sysv.SysV}

log = logging.getLogger(__name__)


def main(argv=None):
    parser = argparse.ArgumentParser(description='Detect running daemons then configure and start the agent.',
                                     formatter_class=argparse.ArgumentDefaultsHelpFormatter)
    parser.add_argument(
        '-u', '--username', help="Username used for keystone authentication", required=True)
    parser.add_argument(
        '-p', '--password', help="Password used for keystone authentication", required=True)
    parser.add_argument('--keystone_url', help="Keystone url", required=True)
    parser.add_argument('--monasca_url', help="Monasca API url", required=True)
    parser.add_argument('--insecure', help="Set whether certificates are used for Keystone authentication", required=False, default=False)
    parser.add_argument('--project_name', help="Project name for keystone authentication", required=False, default='')
    parser.add_argument('--project_domain_id', help="Project domain id for keystone authentication", required=False, default='')
    parser.add_argument('--project_domain_name', help="Project domain name for keystone authentication", required=False, default='')
    parser.add_argument('--project_id', help="Keystone project id  for keystone authentication", required=False, default='')
    parser.add_argument('--ca_file', help="Sets the path to the ca certs file if using certificates. " +
                                          "Required only if insecure is set to False", required=False, default='')
    parser.add_argument('--config_dir', help="Configuration directory", default='/etc/monasca/agent')
    parser.add_argument('--dimensions', help="Additional dimensions to set for all metrics. A comma seperated list " +
                                             "of name/value pairs, 'name:value,name2:value2'")
    parser.add_argument('--log_dir', help="monasca-agent log directory", default='/var/log/monasca/agent')
    parser.add_argument(
        '--template_dir', help="Alternative template directory", default='/usr/local/share/monasca/agent')
    parser.add_argument('--headless', help="Run in a non-interactive mode", action="store_true")
    parser.add_argument('--overwrite',
                        help="Overwrite existing plugin configuration. " +
                             "The default is to merge. Agent.conf is always overwritten.",
                        action="store_true")
    parser.add_argument('--skip_enable', help="By default the service is enabled, " +
                                              "which requires the script run as root. Set this to skip that step.",
                        action="store_true")
    parser.add_argument('--user', help="User name to run monasca-agent as", default='monasca-agent')
    parser.add_argument('-s', '--service', help="Service this node is associated with, added as a dimension.")
    parser.add_argument('--amplifier', help="Integer for the number of additional measurements to create. " +
                                            "Additional measurements contain the 'amplifier' dimension. " +
                                            "Useful for load testing; not for production use.", default=0, required=False)
    parser.add_argument('-v', '--verbose', help="Verbose Output", action="store_true")
    args = parser.parse_args()

    if args.verbose:
        logging.basicConfig(level=logging.DEBUG, format="%(levelname)s: %(message)s")
    else:
        logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")

    # Detect os
    detected_os = platform.system()
    if detected_os == 'Linux':
        linux_flavor = platform.linux_distribution()[0]
        if 'Ubuntu' or 'debian' in linux_flavor:
            for package in ['coreutils', 'sysstat']:
                #Check for required dependencies for system checks
                try:
                    output = subprocess.check_output('dpkg -s {}'.format(package),
                                                     stderr=subprocess.STDOUT,
                                                     shell=True)
                except subprocess.CalledProcessError:
                    log.warn("*** {} package is not installed! ***".format(package) +
                             "\nNOTE: If you do not install the {} ".format(package) +
                             "package, you will not receive all of the standard " +
                             "operating system type metrics!")
        else:
            pass
    elif detected_os == 'Darwin':
        print("Mac OS is not currently supported by the Monasca Agent")
        sys.exit()
    elif detected_os == 'Windows':
        print("Windows is not currently supported by the Monasca Agent")
        sys.exit()
    else:
        print("{0} is not currently supported by the Monasca Agent".format(detected_os))

    # Service enable, includes setup of users/config directories so must be
    # done before configuration
    agent_service = OS_SERVICE_MAP[detected_os](os.path.join(args.template_dir, 'monasca-agent.init'),
                                                args.config_dir,
                                                args.log_dir, username=args.user)
    if not args.skip_enable:
        agent_service.enable()

    gid = pwd.getpwnam(args.user).pw_gid
    # Write the main agent.conf - Note this is always overwritten
    log.info('Configuring base Agent settings.')
    agent_conf_path = os.path.join(args.config_dir, 'agent.conf')
    with open(os.path.join(args.template_dir, 'agent.conf.template'), 'r') as agent_template:
        with open(agent_conf_path, 'w') as agent_conf:
            # Join service in with the dimensions
            if args.service:
                if args.dimensions is None:
                    args.dimensions = 'service:' + args.service
                else:
                    args.dimensions = ','.join([args.dimensions, 'service:' + args.service])
            agent_conf.write(agent_template.read().format(args=args, hostname=socket.getfqdn()))
    os.chown(agent_conf_path, 0, gid)
    os.chmod(agent_conf_path, 0o640)
    # Link the supervisor.conf
    supervisor_path = os.path.join(args.config_dir, 'supervisor.conf')
    if os.path.exists(supervisor_path):
        os.remove(supervisor_path)
    os.symlink(os.path.join(args.template_dir, 'supervisor.conf'), supervisor_path)

    # Run through detection and config building for the plugins
    plugin_config = agent_config.Plugins()
    for detect_class in DETECTION_PLUGINS:
        detect = detect_class(args.template_dir, args.overwrite)
        if detect.available:
            log.info('Configuring {0}'.format(detect.name))
            new_config = detect.build_config()
            plugin_config.merge(new_config)

        # todo add option to install dependencies

    # Write out the plugin config
    for key, value in plugin_config.iteritems():
        # todo if overwrite is set I should either warn or just delete any config files not in the new config
        # todo add the ability to show a diff before overwriting or merging config
        config_path = os.path.join(args.config_dir, 'conf.d', key + '.yaml')
        # merge old and new config, new has precedence
        if (not args.overwrite) and os.path.exists(config_path):
            with open(config_path, 'r') as config_file:
                old_config = yaml.load(config_file.read())
            if old_config is not None:
                agent_config.deep_merge(old_config, value)
                value = old_config
        with open(config_path, 'w') as config_file:
            os.chmod(config_path, 0o640)
            os.chown(config_path, 0, gid)
            config_file.write(yaml.safe_dump(value, encoding='utf-8', allow_unicode=True))

    # Now that the config is build start the service
    try:
        agent_service.start(restart=True)
    except subprocess.CalledProcessError:
        log.error('The service did not startup correctly see %s' % args.log_dir)


if __name__ == "__main__":
    sys.exit(main())
