##############################################################################
# Copyright (c) 2016 Tim Rozet (trozet@redhat.com) 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 datetime
import distro
import json
import logging
import os
import pprint
import socket
import subprocess
import tarfile
import time
import urllib.error
import urllib.request
import urllib.parse
import yaml

from apex.common import exceptions as exc


def str2bool(var):
    if isinstance(var, bool):
        return var
    else:
        return var.lower() in ("true", "yes")


def parse_yaml(yaml_file):
    with open(yaml_file) as f:
        parsed_dict = yaml.safe_load(f)
        return parsed_dict


def dump_yaml(data, file):
    """
    Dumps data to a file as yaml
    :param data: yaml to be written to file
    :param file: filename to write to
    :return:
    """
    logging.debug("Writing file {} with "
                  "yaml data:\n{}".format(file, yaml.safe_dump(data)))
    with open(file, "w") as fh:
        yaml.safe_dump(data, fh, default_flow_style=False)


def dict_objects_to_str(dictionary):
        if isinstance(dictionary, list):
            tmp_list = []
            for element in dictionary:
                if isinstance(element, dict):
                    tmp_list.append(dict_objects_to_str(element))
                else:
                    tmp_list.append(str(element))
            return tmp_list
        elif not isinstance(dictionary, dict):
            if not isinstance(dictionary, bool):
                return str(dictionary)
            else:
                return dictionary
        return dict((k, dict_objects_to_str(v)) for
                    k, v in dictionary.items())


def run_ansible(ansible_vars, playbook, host='localhost', user='root',
                tmp_dir=None, dry_run=False):
    """
    Executes ansible playbook and checks for errors
    :param ansible_vars: dictionary of variables to inject into ansible run
    :param playbook: playbook to execute
    :param host: inventory file or string of target hosts
    :param user: remote user to run ansible tasks
    :param tmp_dir: temp directory to store ansible command
    :param dry_run: Do not actually apply changes
    :return: None
    """
    logging.info("Executing ansible playbook: {}".format(playbook))
    if not os.path.isfile(host):
        inv_host = "{},".format(host)
    else:
        inv_host = host
    if host == 'localhost':
        conn_type = 'local'
    else:
        conn_type = 'smart'
    ansible_command = ['ansible-playbook', '--become', '-i', inv_host,
                       '-u', user, '-c', conn_type, '-T', '30',
                       playbook, '-vv']
    if dry_run:
        ansible_command.append('--check')

    if isinstance(ansible_vars, dict) and ansible_vars:
        logging.debug("Ansible variables to be set:\n{}".format(
            pprint.pformat(ansible_vars)))
        ansible_command.append('--extra-vars')
        ansible_command.append(json.dumps(ansible_vars))
        if tmp_dir:
            ansible_tmp = os.path.join(tmp_dir,
                                       os.path.basename(playbook) + '.rerun')
            # FIXME(trozet): extra vars are printed without single quotes
            # so a dev has to add them manually to the command to rerun
            # the playbook.  Need to test if we can just add the single quotes
            # to the json dumps to the ansible command and see if that works
            with open(ansible_tmp, 'w') as fh:
                fh.write("ANSIBLE_HOST_KEY_CHECKING=FALSE {}".format(
                    ' '.join(ansible_command)))

    my_env = os.environ.copy()
    my_env['ANSIBLE_HOST_KEY_CHECKING'] = 'False'
    logging.info("Executing playbook...this may take some time")
    p = subprocess.Popen(ansible_command,
                         stdin=subprocess.PIPE,
                         stdout=subprocess.PIPE,
                         bufsize=1,
                         env=my_env,
                         universal_newlines=True)
    # read first line
    x = p.stdout.readline()
    # initialize task
    task = ''
    while x:
        # append lines to task
        task += x
        # log the line and read another
        x = p.stdout.readline()
        # deliver the task to info when we get a blank line
        if not x.strip():
            task += x
            logging.info(task.replace('\\n', '\n'))
            task = ''
            x = p.stdout.readline()
    # clean up and get return code
    p.stdout.close()
    rc = p.wait()
    if rc:
        # raise errors
        e = "Ansible playbook failed. See Ansible logs for details."
        logging.error(e)
        raise Exception(e)


def get_url_modified_date(url):
    """
    Returns the last modified date for an Tripleo image artifact
    :param url: URL to examine
    :return: datetime object of when artifact was last modified
    """
    try:
        u = urllib.request.urlopen(url)
    except urllib.error.URLError as e:
        logging.error("Failed to fetch target url. Error: {}".format(
            e.reason))
        raise

    metadata = u.info()
    headers = metadata.items()
    for header in headers:
        if isinstance(header, tuple) and len(header) == 2:
            if header[0] == 'Last-Modified':
                return datetime.datetime.strptime(header[1],
                                                  "%a, %d %b %Y %X GMT")


def fetch_upstream_and_unpack(dest, url, targets, fetch=True):
    """
    Fetches targets from a url destination and downloads them if they are
    newer.  Also unpacks tar files in dest dir.
    :param dest: Directory to download and unpack files to
    :param url: URL where target files are located
    :param targets: List of target files to download
    :param fetch: Whether or not to fetch latest from internet (boolean)
    :return: None
    """
    os.makedirs(dest, exist_ok=True)
    assert isinstance(targets, list)
    for target in targets:
        target_url = urllib.parse.urljoin(url, target)
        target_dest = os.path.join(dest, target)
        target_exists = os.path.isfile(target_dest)
        if fetch:
            download_target = True
        elif not target_exists:
            logging.warning("no-fetch requested but target: {} is not "
                            "cached, will download".format(target_dest))
            download_target = True
        else:
            logging.info("no-fetch requested and previous cache exists for "
                         "target: {}.  Will skip download".format(target_dest))
            download_target = False

        if download_target:
            logging.debug("Fetching and comparing upstream"
                          " target: \n{}".format(target_url))
        # Check if previous file and fetch we need to compare files to
        # determine if download is necessary
        if target_exists and download_target:
            logging.debug("Previous file found: {}".format(target_dest))
            target_url_date = get_url_modified_date(target_url)
            if target_url_date is not None:
                target_dest_mtime = os.path.getmtime(target_dest)
                target_url_mtime = time.mktime(target_url_date.timetuple())
                if target_url_mtime > target_dest_mtime:
                    logging.debug('URL target is newer than disk...will '
                                  'download')
                else:
                    logging.info('URL target does not need to be downloaded')
                    download_target = False
            else:
                logging.debug('Unable to find last modified url date')

        if download_target:
            urllib.request.urlretrieve(target_url, filename=target_dest)
            logging.info("Target downloaded: {}".format(target))
        if target.endswith(('.tar', 'tar.gz', 'tgz')):
            logging.info('Unpacking tar file')
            tar = tarfile.open(target_dest)
            tar.extractall(path=dest)
            tar.close()


def install_ansible():
    # we only install for CentOS/Fedora for now
    dist = distro.id()
    if 'centos' in dist:
        pkg_mgr = 'yum'
    elif 'fedora' in dist:
        pkg_mgr = 'dnf'
    else:
        return

    # yum python module only exists for 2.x, so use subprocess
    try:
        subprocess.check_call([pkg_mgr, '-y', 'install', 'ansible'])
    except subprocess.CalledProcessError:
        logging.warning('Unable to install Ansible')


def internet_connectivity():
    try:
        urllib.request.urlopen('http://opnfv.org', timeout=3)
        return True
    except (urllib.request.URLError, socket.timeout):
        logging.debug('No internet connectivity detected')
        return False


def open_webpage(url, timeout=5):
    try:
        response = urllib.request.urlopen(url, timeout=timeout)
        return response.read()
    except (urllib.request.URLError, socket.timeout) as e:
        logging.error("Unable to open URL: {}".format(url))
        raise exc.FetchException('Unable to open URL') from e


def edit_tht_env(env_file, section, settings):
    assert isinstance(settings, dict)
    with open(env_file) as fh:
        data = yaml.safe_load(fh)

    if section not in data.keys():
        data[section] = {}
    for setting, value in settings.items():
        data[section][setting] = value
    with open(env_file, 'w') as fh:
        yaml.safe_dump(data, fh, default_flow_style=False)
    logging.debug("Data written to env file {}:\n{}".format(env_file, data))


def unique(tmp_list):
    assert isinstance(tmp_list, list)
    uniq_list = []
    for x in tmp_list:
        if x not in uniq_list:
            uniq_list.append(x)
    return uniq_list


def bash_settings_to_dict(data):
    """
    Parses bash settings x=y and returns dict of key, values
    :param data: bash settings data in x=y format
    :return: dict of keys and values
    """
    return dict(item.split('=') for item in data.splitlines())


def fetch_properties(url):
    """
    Downloads OPNFV properties and returns a dictionary of the key, values
    :param url: URL of properties file
    :return: dict of k,v for each properties
    """
    if bool(urllib.parse.urlparse(url).scheme):
        logging.debug('Fetching properties from internet: {}'.format(url))
        return bash_settings_to_dict(open_webpage(url).decode('utf-8'))
    elif os.path.isfile(url):
        logging.debug('Fetching properties from file: {}'.format(url))
        with open(url, 'r') as fh:
            data = fh.read()
        return bash_settings_to_dict(data)
    else:
        logging.warning('Unable to fetch properties for: {}'.format(url))
        raise exc.FetchException('Unable determine properties location: '
                                 '{}'.format(url))