#!/usr/libexec/platform-python
# 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.

"""Migrate an undercloud's stack data to use ephemeral Heat. Queries for
existing stacks and exports necessary data from the stack to the default
consistent working directory before backing up and dropping the heat database.
"""

import argparse
import logging
import os
import subprocess
import tarfile
import tempfile
import time
import yaml

from heatclient.client import Client
import keystoneauth1
import openstack
from tripleo_common.utils import plan as plan_utils


LOG = logging.getLogger('undercloud')
ROLE_DATA_MAP_FILE = ('/var/lib/tripleo-config/'
                      'overcloud-stack-role-data-file-map.yaml')


def parse_args():
    parser = argparse.ArgumentParser(
        description="Upgrade an undercloud for ephemeral Heat.")

    parser.add_argument(
        '--cloud', '-c',
        default='undercloud',
        help='The name of the cloud used for the OpenStack connection.')
    parser.add_argument(
        '--stack', '-s',
        action='append',
        help='The stack(s) to migrate to using ephemeral Heat. Can be '
             'specified multiple times. If not specified, all stacks '
             'will be migrated')
    parser.add_argument(
        '--working-dir', '-w',
        help='Directory to use for saving stack state. '
             'Defaults to ~/overcloud-deploy/<stack>')

    return parser.parse_args()


def database_exists():
    """Check if the heat database exists.

    :return: True if the heat database exists, otherwise False
    :rtype: bool
    """
    output = subprocess.check_output([
        'sudo', 'podman', 'exec', '-u', 'root', 'mysql',
        'mysql', '-e', 'show databases like "heat"'
    ])
    return 'heat' in str(output)


def backup_db(backup_dir):
    """Backup the heat database to the specified directory

    :param backup_dir: The directory to store the backup
    :type backup_dir: str
    :return: Database tarfile backup path
    :rtype: str
    """
    heat_dir = os.path.join(backup_dir, 'heat-launcher')
    if not os.path.isdir(heat_dir):
        os.makedirs(heat_dir)
    db_path = os.path.join(heat_dir, 'heat-db.sql')
    LOG.info("Backing up heat database to {}".format(db_path))
    with open(db_path, 'w') as out:
        subprocess.run([
            'sudo', 'podman', 'exec', '-u', 'root',
            'mysql', 'mysqldump', 'heat'], stdout=out,
            check=True)
    os.chmod(db_path, 0o600)

    tf_name = '{}-{}.tar.bzip2'.format(db_path, time.time())
    tf = tarfile.open(tf_name, 'w:bz2')
    tf.add(db_path, os.path.basename(db_path))
    tf.close()
    LOG.info("Created tarfile {}".format(tf_name))

    return tf_name


def _decode(encoded):
    """Decode a string into utf-8

    :param encoded: Encoded string
    :type encoded: string
    :return: Decoded string
    :rtype: string
    """
    if not encoded:
        return ""
    decoded = encoded.decode('utf-8')
    if decoded.endswith('\n'):
        decoded = decoded[:-1]
    return decoded


def _get_ctlplane_vip():
    """Get the configured ctlplane VIP

    :return: ctlplane VIP
    :rtype: string
    """
    return _decode(subprocess.check_output(
        ['sudo', 'hiera', 'controller_virtual_ip']))


def _get_ctlplane_ip():
    """Get the configured ctlplane IP

    :return: ctlplane IP
    :rtype: string
    """
    return _decode(subprocess.check_output(
        ['sudo', 'hiera', 'ctlplane']))


def _make_stack_dirs(stacks, working_dir):
    """Create stack directory if it does not already exist

    :stacks: List of overcloud stack names
    :type stacks: list
    :working_dir: Path to working directly
    :type working_dir: str
    :return: None
    """
    for stack in stacks:
        stack_dir = os.path.join(working_dir, stack)
        if not os.path.exists(stack_dir):
            os.makedirs(stack_dir)


def _log_and_raise(msg):
    """Log error message and raise Exception

    :msg: Message string that will be logged, and added in Exception
    :type msg: str
    :return: None
    """
    LOG.error(msg)
    raise Exception(msg)


def _get_role_data_file(heat, stack, fd, temp_file_path):
    """Get the role data file for a stack

    :param heat: Heat client
    :type heat: heatclient.client.Client
    :param stack: Stack name to query for passwords
    :type stack: str
    :fd: File descriptor
    :type fd: int
    :temp_file_path: Path to role data temp file
    :type temp_file_path: str
    :return: Path to the role data file
    :rtype:: str
    """
    try:
        _stack = heat.get_stack(stack)
        stack_outputs = {i['output_key']: i['output_value']
                         for i in _stack.outputs}
        roles_data = stack_outputs[
            'TripleoHeatTemplatesJinja2RenderingDataSources']['roles_data']

        with os.fdopen(fd, 'w') as tmp:
            tmp.write(yaml.safe_dump(roles_data))

        roles_data_file = temp_file_path
    except KeyError:
        if not os.path.isfile(ROLE_DATA_MAP_FILE):
            _log_and_raise("Overcloud stack role data mapping file: {} was "
                           "not found.".format(ROLE_DATA_MAP_FILE))

        with open(ROLE_DATA_MAP_FILE, 'r') as f:
            data = yaml.safe_load(f.read())

        roles_data_file = data.get(stack)
        if not roles_data_file or not os.path.isfile(roles_data_file):
            _log_and_raise("Roles data file: {} for stack {} not found."
                           .format(roles_data_file, stack))

    return roles_data_file


def drop_db():
    """Drop the heat database and heat users

    :return: None
    :rtype: None
    """
    LOG.info("Dropping Heat database")
    subprocess.check_call([
        'sudo', 'podman', 'exec', '-u', 'root',
        'mysql', 'mysql', 'heat', '-e',
        'drop database if exists heat'])
    LOG.info("Dropping Heat users")
    subprocess.check_call([
        'sudo', 'podman', 'exec', '-u', 'root',
        'mysql', 'mysql', '-e',
        'drop user if exists \'heat\'@\'{}\''.format(_get_ctlplane_ip())])
    subprocess.check_call([
        'sudo', 'podman', 'exec', '-u', 'root',
        'mysql', 'mysql', '-e',
        'drop user if exists \'heat\'@\'{}\''.format(_get_ctlplane_vip())])
    subprocess.check_call([
        'sudo', 'podman', 'exec', '-u', 'root',
        'mysql', 'mysql', '-e',
        'drop user if exists \'heat\'@\'%\''])


def export_passwords(heat, stack, stack_dir):
    """Export passwords from an existing stack and write them in Heat
    environment file format to the specified directory.

    :param cloud: Heat client
    :type cloud: heatclient.client.Client
    :param stack: Stack name to query for passwords
    :type stack: str
    :param stack_dir: Directory to save the generated Heat environment
        containing the password values.
    :type stack_dir: str
    :return: None
    :rtype: None
    """
    passwords_path = os.path.join(
        stack_dir, "tripleo-{}-passwords.yaml".format(stack))
    LOG.info("Exporting passwords for stack %s to %s"
             % (stack, passwords_path))
    passwords = plan_utils.generate_passwords(heat=heat, container=stack)
    password_params = dict(parameter_defaults=passwords)
    with open(passwords_path, 'w') as f:
        f.write(yaml.safe_dump(password_params))
    os.chmod(passwords_path, 0o600)


def export_networks(stack, stack_dir):
    """Export networks from an existing stack and write network data file.

    :param stack: Stack name to query for networks
    :type stack: str
    :param stack_dir: Directory to save the generated network data file
        containing the stack network definitions.
    :type stack_dir: str
    :return: None
    :rtype: None
    """
    network_data_path = os.path.join(
        stack_dir, "tripleo-{}-network-data.yaml".format(stack))
    LOG.info("Exporting network from stack %s to %s"
             % (stack, network_data_path))
    subprocess.check_call(['openstack', 'overcloud', 'network', 'extract',
                           '--stack', stack, '--output', network_data_path,
                           '--yes'])
    os.chmod(network_data_path, 0o600)


def export_network_virtual_ips(stack, stack_dir):
    """Export network virtual IPs from an existing stack and write network
    vip data file.

    :param stack: Stack name to query for networks
    :type stack: str
    :param stack_dir: Directory to save the generated data file
        containing the stack virtual IP definitions.
    :type stack_dir: str
    :return: None
    :rtype: None
    """
    vip_data_path = os.path.join(
        stack_dir, "tripleo-{}-virtual-ips.yaml".format(stack))
    LOG.info("Exporting network virtual IPs from stack %s to %s"
             % (stack, vip_data_path))
    subprocess.check_call(['openstack', 'overcloud', 'network', 'vip',
                           'extract', '--stack', stack, '--output',
                           vip_data_path, '--yes'])
    os.chmod(vip_data_path, 0o600)


def export_provisioned_nodes(heat, stack, stack_dir):
    """Export provisioned nodes from an existing stack and write baremetal
    deployment definition file.

    :param cloud: Heat client
    :type cloud: heatclient.client.Client
    :param stack: Stack name to query for networks
    :type stack: str
    :param stack_dir: Directory to save the generated data file
        containing the stack baremetal deployment definitions.
    :type stack_dir: str
    :return: None
    :rtype: None
    """
    fd, temp_file_path = tempfile.mkstemp()
    try:
        roles_data_file = _get_role_data_file(heat, stack, fd, temp_file_path)
        bm_deployment_path = os.path.join(
            stack_dir, "tripleo-{}-baremetal-deployment.yaml".format(stack))
        LOG.info("Exporting provisioned nodes from stack %s to %s"
                 % (stack, bm_deployment_path))
        subprocess.check_call(['openstack', 'overcloud', 'node', 'extract',
                               'provisioned', '--stack', stack, '--roles-file',
                               roles_data_file, '--output',
                               bm_deployment_path, '--yes'])
        os.chmod(bm_deployment_path, 0o600)
    finally:
        os.remove(temp_file_path)


def main():
    logging.basicConfig()
    LOG.setLevel(logging.INFO)
    args = parse_args()

    sudo_user = os.environ.get('SUDO_USER')

    if not args.working_dir:
        if sudo_user:
            user_home = '~{}'.format(sudo_user)
        else:
            user_home = '~'

        working_dir = os.path.join(
            os.path.expanduser(user_home),
            'overcloud-deploy')
    else:
        working_dir = args.working_dir
    if not os.path.isdir(working_dir):
        os.makedirs(working_dir)

    try:
        conn = openstack.connection.from_config(cloud=args.cloud)
        heat = conn.orchestration
        _heatclient = Client('1', endpoint=conn.endpoint_for('orchestration'),
                             token=conn.auth_token)
    except keystoneauth1.exceptions.catalog.EndpointNotFound:
        LOG.error("No Heat endpoint found, won't migrate any "
                  "existing stack data.")
        raise

    try:
        stacks = args.stack or [s.name for s in heat.stacks()]
    except openstack.exceptions.HttpException:
        LOG.warning("No connection to Heat available, won't migrate any "
                    "existing stack data.")
        stacks = []

    # Make stack directories in the working directory if they don't not exist
    _make_stack_dirs(stacks, working_dir)

    for stack in stacks:
        stack_dir = os.path.join(working_dir, stack)
        export_networks(stack, stack_dir)
        export_network_virtual_ips(stack, stack_dir)
        export_provisioned_nodes(heat, stack, stack_dir)

    if database_exists():
        backup_dir = os.path.join(
            working_dir,
            'undercloud-upgrade-ephemeral-heat')
        db_tar_path = backup_db(backup_dir)
    else:
        LOG.warning("No database found to backup.")
        db_tar_path = None

    for stack in stacks:
        stack_dir = os.path.join(working_dir, stack)
        if db_tar_path:
            # Symlink to the existing db backup
            os.symlink(db_tar_path,
                os.path.join(stack_dir, os.path.basename(db_tar_path)))
        export_passwords(_heatclient, stack, stack_dir)

    if database_exists():
        drop_db()

    # Chown all files to original user if running under sudo
    if sudo_user:
        subprocess.run([
            'chown', '-R', '{}:{}'.format(sudo_user, sudo_user),
            working_dir],
            check=True)


if __name__ == '__main__':
    main()