# This code is part of Ansible, but is an independent component.
# This particular file snippet, and this file snippet only, is BSD licensed.
# Modules you write using this snippet, which is embedded dynamically by Ansible
# still belong to the author of the module, and may assign their own license
# to the complete work.
#
# Copyright (c) 2015 Peter Sprygada, <psprygada@ansible.com>
#
# Redistribution and use in source and binary forms, with or without modification,
# are permitted provided that the following conditions are met:
#
#    * Redistributions of source code must retain the above copyright
#      notice, this list of conditions and the following disclaimer.
#    * Redistributions in binary form must reproduce the above copyright notice,
#      this list of conditions and the following disclaimer in the documentation
#      and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
# USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
from ansible.module_utils.basic import AnsibleModule
from ansible.module_utils.basic import env_fallback, get_exception
from ansible.module_utils.netcli import Cli, Command
from ansible.module_utils._text import to_native
from ansible.module_utils.six import iteritems

NET_TRANSPORT_ARGS = dict(
    host=dict(required=True),
    port=dict(type='int'),

    username=dict(fallback=(env_fallback, ['ANSIBLE_NET_USERNAME'])),
    password=dict(no_log=True, fallback=(env_fallback, ['ANSIBLE_NET_PASSWORD'])),
    ssh_keyfile=dict(fallback=(env_fallback, ['ANSIBLE_NET_SSH_KEYFILE']), type='path'),

    authorize=dict(default=False, fallback=(env_fallback, ['ANSIBLE_NET_AUTHORIZE']), type='bool'),
    auth_pass=dict(no_log=True, fallback=(env_fallback, ['ANSIBLE_NET_AUTH_PASS'])),

    provider=dict(type='dict', no_log=True),
    transport=dict(choices=list()),

    timeout=dict(default=10, type='int')
)

NET_CONNECTION_ARGS = dict()

NET_CONNECTIONS = dict()


def _transitional_argument_spec():
    argument_spec = {}
    for key, value in iteritems(NET_TRANSPORT_ARGS):
        value['required'] = False
        argument_spec[key] = value
    return argument_spec


def to_list(val):
    if isinstance(val, (list, tuple)):
        return list(val)
    elif val is not None:
        return [val]
    else:
        return list()


class ModuleStub(object):
    def __init__(self, argument_spec, fail_json):
        self.params = dict()
        for key, value in argument_spec.items():
            self.params[key] = value.get('default')
        self.fail_json = fail_json


class NetworkError(Exception):

    def __init__(self, msg, **kwargs):
        super(NetworkError, self).__init__(msg)
        self.kwargs = kwargs


class Config(object):

    def __init__(self, connection):
        self.connection = connection

    def __call__(self, commands, **kwargs):
        lines = to_list(commands)
        return self.connection.configure(lines, **kwargs)

    def load_config(self, commands, **kwargs):
        commands = to_list(commands)
        return self.connection.load_config(commands, **kwargs)

    def get_config(self, **kwargs):
        return self.connection.get_config(**kwargs)

    def save_config(self):
        return self.connection.save_config()


class NetworkModule(AnsibleModule):

    def __init__(self, *args, **kwargs):
        connect_on_load = kwargs.pop('connect_on_load', True)

        argument_spec = NET_TRANSPORT_ARGS.copy()
        argument_spec['transport']['choices'] = NET_CONNECTIONS.keys()
        argument_spec.update(NET_CONNECTION_ARGS.copy())

        if kwargs.get('argument_spec'):
            argument_spec.update(kwargs['argument_spec'])
        kwargs['argument_spec'] = argument_spec

        super(NetworkModule, self).__init__(*args, **kwargs)

        self.connection = None
        self._cli = None
        self._config = None

        try:
            transport = self.params['transport'] or '__default__'
            cls = NET_CONNECTIONS[transport]
            self.connection = cls()
        except KeyError:
            self.fail_json(msg='Unknown transport or no default transport specified')
        except (TypeError, NetworkError):
            exc = get_exception()
            self.fail_json(msg=to_native(exc))

        if connect_on_load:
            self.connect()

    @property
    def cli(self):
        if not self.connected:
            self.connect()
        if self._cli:
            return self._cli
        self._cli = Cli(self.connection)
        return self._cli

    @property
    def config(self):
        if not self.connected:
            self.connect()
        if self._config:
            return self._config
        self._config = Config(self.connection)
        return self._config

    @property
    def connected(self):
        return self.connection._connected

    def _load_params(self):
        super(NetworkModule, self)._load_params()
        provider = self.params.get('provider') or dict()
        for key, value in provider.items():
            for args in [NET_TRANSPORT_ARGS, NET_CONNECTION_ARGS]:
                if key in args:
                    if self.params.get(key) is None and value is not None:
                        self.params[key] = value

    def connect(self):
        try:
            if not self.connected:
                self.connection.connect(self.params)
                if self.params['authorize']:
                    self.connection.authorize(self.params)
                self.log('connected to %s:%s using %s' % (self.params['host'],
                         self.params['port'], self.params['transport']))
        except NetworkError:
            exc = get_exception()
            self.fail_json(msg=to_native(exc))

    def disconnect(self):
        try:
            if self.connected:
                self.connection.disconnect()
            self.log('disconnected from %s' % self.params['host'])
        except NetworkError:
            exc = get_exception()
            self.fail_json(msg=to_native(exc))


def register_transport(transport, default=False):
    def register(cls):
        NET_CONNECTIONS[transport] = cls
        if default:
            NET_CONNECTIONS['__default__'] = cls
        return cls
    return register


def add_argument(key, value):
    NET_CONNECTION_ARGS[key] = value
