#!/usr/bin/env python2
# vim: expandtab:tabstop=4:shiftwidth=4

import argparse
import ConfigParser
import os
import sys
import subprocess
import traceback


class Cluster(object):
    """
    Provide Command, Control and Configuration (c3) Interface for OpenShift Clusters
    """

    def __init__(self):
        # setup ansible ssh environment
        if 'ANSIBLE_SSH_ARGS' not in os.environ:
            os.environ['ANSIBLE_SSH_ARGS'] = (
                '-o ForwardAgent=yes '
                '-o StrictHostKeyChecking=no '
                '-o UserKnownHostsFile=/dev/null '
                '-o ControlMaster=auto '
                '-o ControlPersist=600s '
            )
            # Because of `UserKnownHostsFile=/dev/null`
            # our `.ssh/known_hosts` file most probably misses the ssh host public keys
            # of our servers.
            # In that case, ansible serializes the execution of ansible modules
            # because we might be interactively prompted to accept the ssh host public keys.
            # Because of `StrictHostKeyChecking=no` we know that we won't be prompted
            # So, we don't want our modules execution to be serialized.
            os.environ['ANSIBLE_HOST_KEY_CHECKING'] = 'False'
            # TODO: A more secure way to proceed would consist in dynamically
            # retrieving the ssh host public keys from the IaaS interface

    def get_deployment_type(self, args):
        """
        Get the deployment_type based on the environment variables and the
        command line arguments
        :param args: command line arguments provided by the user
        :return: string representing the deployment type
        """
        deployment_type = 'origin'
        if args.deployment_type:
            deployment_type = args.deployment_type
        elif 'OS_DEPLOYMENT_TYPE' in os.environ:
            deployment_type = os.environ['OS_DEPLOYMENT_TYPE']
        return deployment_type


    def create(self, args):
        """
        Create an OpenShift cluster for given provider
        :param args: command line arguments provided by user
        """
        env = {'cluster_id': args.cluster_id,
               'deployment_type': self.get_deployment_type(args)}
        playbook = "playbooks/{}/openshift-cluster/launch.yml".format(args.provider)
        inventory = self.setup_provider(args.provider)

        env['num_masters'] = args.masters
        env['num_nodes'] = args.nodes
        env['num_infra'] = args.infra
        env['num_etcd'] = args.etcd

        self.action(args, inventory, env, playbook)

    def terminate(self, args):
        """
        Destroy OpenShift cluster
        :param args: command line arguments provided by user
        """
        env = {'cluster_id': args.cluster_id,
               'deployment_type': self.get_deployment_type(args)}
        playbook = "playbooks/{}/openshift-cluster/terminate.yml".format(args.provider)
        inventory = self.setup_provider(args.provider)

        self.action(args, inventory, env, playbook)

    def list(self, args):
        """
        List VMs in cluster
        :param args: command line arguments provided by user
        """
        env = {'cluster_id': args.cluster_id,
               'deployment_type': self.get_deployment_type(args)}
        playbook = "playbooks/{}/openshift-cluster/list.yml".format(args.provider)
        inventory = self.setup_provider(args.provider)

        self.action(args, inventory, env, playbook)

    def config(self, args):
        """
        Configure or reconfigure OpenShift across clustered VMs
        :param args: command line arguments provided by user
        """
        env = {'cluster_id': args.cluster_id,
               'deployment_type': self.get_deployment_type(args)}
        playbook = "playbooks/{}/openshift-cluster/config.yml".format(args.provider)
        inventory = self.setup_provider(args.provider)

        self.action(args, inventory, env, playbook)

    def update(self, args):
        """
        Update to latest OpenShift across clustered VMs
        :param args: command line arguments provided by user
        """
        env = {'cluster_id': args.cluster_id,
               'deployment_type': self.get_deployment_type(args)}
        playbook = "playbooks/{}/openshift-cluster/update.yml".format(args.provider)
        inventory = self.setup_provider(args.provider)

        self.action(args, inventory, env, playbook)

    def service(self, args):
        """
        Make the same service call across all nodes in the cluster
        :param args: command line arguments provided by user
        """
        env = {'cluster_id': args.cluster_id,
               'deployment_type': self.get_deployment_type(args),
               'new_cluster_state': args.state}

        playbook = "playbooks/{}/openshift-cluster/service.yml".format(args.provider)
        inventory = self.setup_provider(args.provider)

        self.action(args, inventory, env, playbook)

    def setup_provider(self, provider):
        """
        Setup ansible playbook environment
        :param provider: command line arguments provided by user
        :return: path to inventory for given provider
        """
        config = ConfigParser.ConfigParser()
        if 'gce' == provider:
            gce_ini_default_path = os.path.join(
                'inventory/gce/hosts/gce.ini')
            gce_ini_path = os.environ.get('GCE_INI_PATH', gce_ini_default_path)
            if os.path.exists(gce_ini_path): 
                config.readfp(open(gce_ini_path))

                for key in config.options('gce'):
                    os.environ[key] = config.get('gce', key)

            inventory = '-i inventory/gce/hosts'
        elif 'aws' == provider:
            config.readfp(open('inventory/aws/hosts/ec2.ini'))

            for key in config.options('ec2'):
                os.environ[key] = config.get('ec2', key)

            inventory = '-i inventory/aws/hosts'

            key_vars = ['AWS_ACCESS_KEY_ID', 'AWS_SECRET_ACCESS_KEY']
            key_missing = [key for key in key_vars if key not in os.environ]

            boto_conf_files = ['~/.aws/credentials', '~/.boto']
            conf_exists = lambda conf: os.path.isfile(os.path.expanduser(conf))
            boto_configs = [conf for conf in boto_conf_files if conf_exists(conf)]

            if len(key_missing) > 0 and len(boto_configs) == 0:
                raise ValueError("PROVIDER aws requires {} environment variable(s). See README_AWS.md".format(key_missing))

        elif 'libvirt' == provider:
            inventory = '-i inventory/libvirt/hosts'
        elif 'openstack' == provider:
            inventory = '-i inventory/openstack/hosts'
        else:
            # this code should never be reached
            raise ValueError("invalid PROVIDER {}".format(provider))

        return inventory

    def action(self, args, inventory, env, playbook):
        """
        Build ansible-playbook command line and execute
        :param args: command line arguments provided by user
        :param inventory: derived provider library
        :param env: environment variables for kubernetes
        :param playbook: ansible playbook to execute
        """

        verbose = ''
        if args.verbose > 0:
            verbose = '-{}'.format('v' * args.verbose)

        if args.option:
            for opt in args.option:
                k, v = opt.split('=', 1)
                env['cli_' + k] = v

        ansible_env = '-e \'{}\''.format(
            ' '.join(['%s=%s' % (key, value) for (key, value) in env.items()])
        )

        command = 'ansible-playbook {} {} {} {}'.format(
            verbose, inventory, ansible_env, playbook
        )

        if args.profile:
            command = 'ANSIBLE_CALLBACK_PLUGINS=ansible-profile/callback_plugins ' + command

        if args.verbose > 1:
            command = 'time {}'.format(command)

        if args.verbose > 0:
            sys.stderr.write('RUN [{}]\n'.format(command))
            sys.stderr.flush()

        try:
            subprocess.check_call(command, shell=True)
        except subprocess.CalledProcessError as exc:
            raise ActionFailed("ACTION [{}] failed: {}"
                               .format(args.action, exc))


class ActionFailed(Exception):
    """
    Raised when action failed.
    """
    pass


if __name__ == '__main__':
    """
    User command to invoke ansible playbooks in a "known" environment

    Reads ~/.openshift-ansible for default configuration items
      [DEFAULT]
      validate_cluster_ids = False
      cluster_ids = marketing,sales
      providers = gce,aws,libvirt,openstack
    """

    environment = ConfigParser.SafeConfigParser({
        'cluster_ids': 'marketing,sales',
        'validate_cluster_ids': 'False',
        'providers': 'gce,aws,libvirt,openstack',
    })

    path = os.path.expanduser("~/.openshift-ansible")
    if os.path.isfile(path):
        environment.read(path)

    cluster = Cluster()

    parser = argparse.ArgumentParser(
        description='Python wrapper to ensure proper environment for OpenShift ansible playbooks',
    )
    parser.add_argument('-v', '--verbose', action='count',
                        help='Multiple -v options increase the verbosity')
    parser.add_argument('--version', action='version', version='%(prog)s 0.3')

    meta_parser = argparse.ArgumentParser(add_help=False)
    providers = environment.get('DEFAULT', 'providers').split(',')
    meta_parser.add_argument('provider', choices=providers, help='provider')

    if environment.get('DEFAULT', 'validate_cluster_ids').lower() in ("yes", "true", "1"):
        meta_parser.add_argument('cluster_id', choices=environment.get('DEFAULT', 'cluster_ids').split(','),
                                 help='prefix for cluster VM names')
    else:
        meta_parser.add_argument('cluster_id', help='prefix for cluster VM names')

    meta_parser.add_argument('-t', '--deployment-type',
                             choices=['origin', 'online', 'enterprise'],
                             help='Deployment type. (default: origin)')
    meta_parser.add_argument('-T', '--product-type',
                             choices=['openshift', 'atomic-enterprise'],
                             help='Product type. (default: openshift)')
    meta_parser.add_argument('-o', '--option', action='append',
                             help='options')

    meta_parser.add_argument('-p', '--profile', action='store_true',
                             help='Enable playbook profiling')

    action_parser = parser.add_subparsers(dest='action', title='actions',
                                          description='Choose from valid actions')

    create_parser = action_parser.add_parser('create', help='Create a cluster',
                                             parents=[meta_parser])
    create_parser.add_argument('-m', '--masters', default=1, type=int,
                               help='number of masters to create in cluster')
    create_parser.add_argument('-n', '--nodes', default=2, type=int,
                               help='number of nodes to create in cluster')
    create_parser.add_argument('-i', '--infra', default=1, type=int,
                               help='number of infra nodes to create in cluster')
    create_parser.add_argument('-e', '--etcd', default=0, type=int,
                               help='number of external etcd hosts to create in cluster')
    create_parser.set_defaults(func=cluster.create)

    config_parser = action_parser.add_parser('config',
                                             help='Configure or reconfigure a cluster',
                                             parents=[meta_parser])
    config_parser.set_defaults(func=cluster.config)

    terminate_parser = action_parser.add_parser('terminate',
                                                help='Destroy a cluster',
                                                parents=[meta_parser])
    terminate_parser.add_argument('-f', '--force', action='store_true',
                                  help='Destroy cluster without confirmation')
    terminate_parser.set_defaults(func=cluster.terminate)

    update_parser = action_parser.add_parser('update',
                                             help='Update OpenShift across cluster',
                                             parents=[meta_parser])
    update_parser.add_argument('-f', '--force', action='store_true',
                               help='Update cluster without confirmation')
    update_parser.set_defaults(func=cluster.update)

    list_parser = action_parser.add_parser('list', help='List VMs in cluster',
                                           parents=[meta_parser])
    list_parser.set_defaults(func=cluster.list)

    service_parser = action_parser.add_parser('service', help='service for openshift across cluster',
                                              parents=[meta_parser])
    # choices are the only ones valid for the ansible service module: http://docs.ansible.com/service_module.html
    service_parser.add_argument('state', choices=['started', 'stopped', 'restarted', 'reloaded'],
                                help='make service call across cluster')
    service_parser.set_defaults(func=cluster.service)

    args = parser.parse_args()

    if 'terminate' == args.action and not args.force:
        answer = raw_input("This will destroy the ENTIRE {} environment. Are you sure? [y/N] ".format(args.cluster_id))
        if answer not in ['y', 'Y']:
            sys.stderr.write('\nACTION [terminate] aborted by user!\n')
            exit(1)

    if 'update' == args.action and not args.force:
        answer = raw_input(
            "This is destructive and could corrupt {} environment. Continue? [y/N] ".format(args.cluster_id))
        if answer not in ['y', 'Y']:
            sys.stderr.write('\nACTION [update] aborted by user!\n')
            exit(1)

    try:
        args.func(args)
    except Exception as exc:
        if args.verbose:
            traceback.print_exc(file=sys.stderr)
        else:
            print >>sys.stderr, exc
        exit(1)