# Copyright (c) 2016 Cisco and/or its affiliates.
# 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.

import shlex
from subprocess import Popen, PIPE, call
from multiprocessing import Pool
from tempfile import NamedTemporaryFile
from os.path import basename
from robot.api import logger
from robot.libraries.BuiltIn import BuiltIn
from ssh import SSH
from constants import Constants as con
from topology import NodeType

__all__ = ["SetupFramework"]


def pack_framework_dir():
    """Pack the testing WS into temp file, return its name."""

    tmpfile = NamedTemporaryFile(suffix=".tgz", prefix="openvpp-testing-")
    file_name = tmpfile.name
    tmpfile.close()

    proc = Popen(
        shlex.split("tar --exclude-vcs -zcf {0} .".format(file_name)),
        stdout=PIPE, stderr=PIPE)
    (stdout, stderr) = proc.communicate()

    logger.debug(stdout)
    logger.debug(stderr)

    return_code = proc.wait()
    if 0 != return_code:
        raise Exception("Could not pack testing framework.")

    return file_name


def copy_tarball_to_node(tarball, node):
    logger.console('Copying tarball to {0}'.format(node['host']))
    ssh = SSH()
    ssh.connect(node)

    ssh.scp(tarball, "/tmp/")


def extract_tarball_at_node(tarball, node):
    logger.console('Extracting tarball to {0} on {1}'.format(
        con.REMOTE_FW_DIR, node['host']))
    ssh = SSH()
    ssh.connect(node)

    cmd = 'sudo rm -rf {1}; mkdir {1} ; tar -zxf {0} -C {1}; ' \
        'rm -f {0}'.format(tarball, con.REMOTE_FW_DIR)
    (ret_code, stdout, stderr) = ssh.exec_command(cmd, timeout=30)
    if 0 != ret_code:
        logger.error('Unpack error: {0}'.format(stderr))
        raise Exception('Failed to unpack {0} at node {1}'.format(
            tarball, node['host']))


def create_env_directory_at_node(node):
    """Create fresh virtualenv to a directory, install pip requirements."""
    logger.console('Extracting virtualenv, installing requirements.txt '
                   'on {0}'.format(node['host']))
    ssh = SSH()
    ssh.connect(node)
    (ret_code, stdout, stderr) = ssh.exec_command(
            'cd {0} && rm -rf env && virtualenv env && '
            '. env/bin/activate && '
            'pip install -r requirements.txt'.format(con.REMOTE_FW_DIR), timeout=100)
    if 0 != ret_code:
        logger.error('Virtualenv creation error: {0}'.format(stdout + stderr))
        raise Exception('Virtualenv setup failed')
    else:
        logger.console('Virtualenv created on {0}'.format(node['host']))

def setup_node(args):
    tarball, remote_tarball, node = args
    copy_tarball_to_node(tarball, node)
    extract_tarball_at_node(remote_tarball, node)
    if node['type'] == NodeType.TG:
        create_env_directory_at_node(node)


def delete_local_tarball(tarball):
    call(shlex.split('sh -c "rm {0} > /dev/null 2>&1"'.format(tarball)))


class SetupFramework(object):
    """Setup suite run on topology nodes.

    Many VAT/CLI based tests need the scripts at remote hosts before executing
    them. This class packs the whole testing directory and copies it over
    to all nodes in topology under /tmp/
    """

    def __init__(self):
        pass

    def setup_framework(self, nodes):
        """Pack the whole directory and extract in temp on each node."""

        tarball = pack_framework_dir()
        msg = 'Framework packed to {0}'.format(tarball)
        logger.console(msg)
        logger.trace(msg)
        remote_tarball = "/tmp/{0}".format(basename(tarball))

        # Turn off loggining since we use multiprocessing
        log_level = BuiltIn().set_log_level('NONE')
        params = ((tarball, remote_tarball, node) for node in nodes.values())
        pool = Pool(processes=len(nodes))
        result = pool.map_async(setup_node, params)
        pool.close()
        pool.join()

        logger.info(
            'Executed node setups in parallel, waiting for processes to end')
        result.wait()

        logger.info('Results: {0}'.format(result.get()))

        # Turn on loggining
        BuiltIn().set_log_level(log_level)
        logger.trace('Test framework copied to all topology nodes')
        delete_local_tarball(tarball)