#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# Copyright: (c) 2018, F5 Networks Inc.
# GNU General Public License v3.0 (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)

from __future__ import absolute_import, division, print_function
__metaclass__ = type

ANSIBLE_METADATA = {'metadata_version': '1.1',
                    'status': ['preview'],
                    'supported_by': 'certified'}

DOCUMENTATION = r'''
---
module: bigip_monitor_external
short_description: Manages external LTM monitors on a BIG-IP
description:
  - Manages external LTM monitors on a BIG-IP.
version_added: 2.6
options:
  name:
    description:
      - Specifies the name of the monitor.
    required: True
  description:
    description:
      - The description of the monitor.
    version_added: 2.7
  parent:
    description:
      - The parent template of this monitor template. Once this value has
        been set, it cannot be changed. By default, this value is the C(http)
        parent on the C(Common) partition.
    default: /Common/external
  arguments:
    description:
      - Specifies any command-line arguments that the script requires.
  ip:
    description:
      - IP address part of the IP/port definition. If this parameter is not
        provided when creating a new monitor, then the default value will be
        '*'.
  port:
    description:
      - Port address part of the IP/port definition. If this parameter is not
        provided when creating a new monitor, then the default value will be
        '*'. Note that if specifying an IP address, a value between 1 and 65535
        must be specified.
  external_program:
    description:
      - Specifies the name of the file for the monitor to use. In order to reference
        a file, you must first import it using options on the System > File Management > External
        Monitor Program File List > Import screen. The BIG-IP system automatically
        places the file in the proper location on the file system.
  interval:
    description:
      - The interval specifying how frequently the monitor instance of this
        template will run. If this parameter is not provided when creating
        a new monitor, then the default value will be 5. This value B(must)
        be less than the C(timeout) value.
  timeout:
    description:
      - The number of seconds in which the node or service must respond to
        the monitor request.
      - If the target responds within the set time period, it is considered up.
      - If the target does not respond within the set time period, it is considered
        down.
      - You can change this number to any number you want, however, it should be
        3 times the interval number of seconds plus 1 second.
      - If this parameter is not provided when creating a new monitor, then the
        default value will be C(16).
  variables:
    description:
      - Specifies any variables that the script requires.
      - Note that double quotes in values will be suppressed.
  partition:
    description:
      - Device partition to manage resources on.
    default: Common
  state:
    description:
      - When C(present), ensures that the monitor exists.
      - When C(absent), ensures the monitor is removed.
    default: present
    choices:
      - present
      - absent
extends_documentation_fragment: f5
author:
  - Tim Rupp (@caphrim007)
  - Wojciech Wypior (@wojtek0806)
'''

EXAMPLES = r'''
- name: Create an external monitor
  bigip_monitor_external:
    name: foo
    password: secret
    server: lb.mydomain.com
    state: present
    user: admin
  delegate_to: localhost

- name: Create an external monitor with variables
  bigip_monitor_external:
    name: foo
    timeout: 10
    variables:
      var1: foo
      var2: bar
    password: secret
    server: lb.mydomain.com
    state: present
    user: admin
  delegate_to: localhost

- name: Add a variable to an existing set
  bigip_monitor_external:
    name: foo
    timeout: 10
    variables:
      var1: foo
      var2: bar
      cat: dog
    password: secret
    server: lb.mydomain.com
    state: present
    user: admin
  delegate_to: localhost
'''

RETURN = r'''
parent:
  description: New parent template of the monitor.
  returned: changed
  type: string
  sample: external
description:
  description: The description of the monitor.
  returned: changed
  type: str
  sample: Important Monitor
ip:
  description: The new IP of IP/port definition.
  returned: changed
  type: string
  sample: 10.12.13.14
interval:
  description: The new interval in which to run the monitor check.
  returned: changed
  type: int
  sample: 2
timeout:
  description: The new timeout in which the remote system must respond to the monitor.
  returned: changed
  type: int
  sample: 10
'''

import re

from ansible.module_utils.basic import AnsibleModule
from ansible.module_utils.basic import env_fallback
from ansible.module_utils.six import iteritems

try:
    from library.module_utils.network.f5.bigip import F5RestClient
    from library.module_utils.network.f5.common import F5ModuleError
    from library.module_utils.network.f5.common import AnsibleF5Parameters
    from library.module_utils.network.f5.common import cleanup_tokens
    from library.module_utils.network.f5.common import fq_name
    from library.module_utils.network.f5.common import f5_argument_spec
    from library.module_utils.network.f5.common import transform_name
    from library.module_utils.network.f5.common import exit_json
    from library.module_utils.network.f5.common import fail_json
    from library.module_utils.network.f5.common import compare_dictionary
    from library.module_utils.network.f5.ipaddress import is_valid_ip
except ImportError:
    from ansible.module_utils.network.f5.bigip import F5RestClient
    from ansible.module_utils.network.f5.common import F5ModuleError
    from ansible.module_utils.network.f5.common import AnsibleF5Parameters
    from ansible.module_utils.network.f5.common import cleanup_tokens
    from ansible.module_utils.network.f5.common import fq_name
    from ansible.module_utils.network.f5.common import f5_argument_spec
    from ansible.module_utils.network.f5.common import transform_name
    from ansible.module_utils.network.f5.common import compare_dictionary
    from ansible.module_utils.network.f5.common import exit_json
    from ansible.module_utils.network.f5.common import fail_json
    from ansible.module_utils.network.f5.ipaddress import is_valid_ip


class Parameters(AnsibleF5Parameters):
    api_map = {
        'defaultsFrom': 'parent',
        'apiRawValues': 'variables',
        'run': 'external_program',
        'args': 'arguments',
    }

    api_attributes = [
        'defaultsFrom', 'interval', 'timeout', 'destination', 'run', 'args',
        'description',
    ]

    returnables = [
        'parent', 'ip', 'port', 'interval', 'timeout', 'variables', 'external_program',
        'arguments', 'description',
    ]

    updatables = [
        'destination', 'interval', 'timeout', 'variables', 'external_program',
        'arguments', 'description',
    ]

    @property
    def destination(self):
        if self.ip is None and self.port is None:
            return None
        destination = '{0}:{1}'.format(self.ip, self.port)
        return destination

    @destination.setter
    def destination(self, value):
        ip, port = value.split(':')
        self._values['ip'] = ip
        self._values['port'] = port

    @property
    def interval(self):
        if self._values['interval'] is None:
            return None

        # Per BZ617284, the BIG-IP UI does not raise a warning about this.
        # So I do
        if 1 > int(self._values['interval']) > 86400:
            raise F5ModuleError(
                "Interval value must be between 1 and 86400"
            )
        return int(self._values['interval'])

    @property
    def timeout(self):
        if self._values['timeout'] is None:
            return None
        return int(self._values['timeout'])

    @property
    def ip(self):
        if self._values['ip'] is None:
            return None
        if self._values['ip'] in ['*', '0.0.0.0']:
            return '*'
        elif is_valid_ip(self._values['ip']):
            return self._values['ip']
        else:
            raise F5ModuleError(
                "The provided 'ip' parameter is not an IP address."
            )

    @property
    def port(self):
        if self._values['port'] is None:
            return None
        elif self._values['port'] == '*':
            return '*'
        return int(self._values['port'])

    @property
    def parent(self):
        if self._values['parent'] is None:
            return None
        result = fq_name(self.partition, self._values['parent'])
        return result

    @property
    def type(self):
        return 'external'


class ApiParameters(Parameters):
    @property
    def variables(self):
        if self._values['variables'] is None:
            return None
        pattern = r'^userDefined\s(?P<key>.*)'
        result = {}
        for k, v in iteritems(self._values['variables']):
            matches = re.match(pattern, k)
            if not matches:
                raise F5ModuleError(
                    "Unable to find the variable 'key' in the API payload."
                )
            key = matches.group('key')
            result[key] = v
        return result


class ModuleParameters(Parameters):
    @property
    def variables(self):
        if self._values['variables'] is None:
            return None
        result = {}
        for k, v in iteritems(self._values['variables']):
            result[k] = str(v).replace('"', '')
        return result

    @property
    def external_program(self):
        if self._values['external_program'] is None:
            return None
        return fq_name(self.partition, self._values['external_program'])


class Changes(Parameters):
    def to_return(self):
        result = {}
        try:
            for returnable in self.returnables:
                result[returnable] = getattr(self, returnable)
            result = self._filter_params(result)
        except Exception:
            pass
        return result


class UsableChanges(Changes):
    pass


class ReportableChanges(Changes):
    pass


class Difference(object):
    def __init__(self, want, have=None):
        self.want = want
        self.have = have

    def compare(self, param):
        try:
            result = getattr(self, param)
            return result
        except AttributeError:
            return self.__default(param)

    def __default(self, param):
        attr1 = getattr(self.want, param)
        try:
            attr2 = getattr(self.have, param)
            if attr1 != attr2:
                return attr1
        except AttributeError:
            return attr1

    @property
    def parent(self):
        if self.want.parent != self.have.parent:
            raise F5ModuleError(
                "The parent monitor cannot be changed"
            )

    @property
    def destination(self):
        if self.want.ip is None and self.want.port is None:
            return None
        if self.want.port is None:
            self.want.update({'port': self.have.port})
        if self.want.ip is None:
            self.want.update({'ip': self.have.ip})

        if self.want.port in [None, '*'] and self.want.ip != '*':
            raise F5ModuleError(
                "Specifying an IP address requires that a port number be specified"
            )

        if self.want.destination != self.have.destination:
            return self.want.destination

    @property
    def interval(self):
        if self.want.timeout is not None and self.want.interval is not None:
            if self.want.interval >= self.want.timeout:
                raise F5ModuleError(
                    "Parameter 'interval' must be less than 'timeout'."
                )
        elif self.want.timeout is not None:
            if self.have.interval >= self.want.timeout:
                raise F5ModuleError(
                    "Parameter 'interval' must be less than 'timeout'."
                )
        elif self.want.interval is not None:
            if self.want.interval >= self.have.timeout:
                raise F5ModuleError(
                    "Parameter 'interval' must be less than 'timeout'."
                )
        if self.want.interval != self.have.interval:
            return self.want.interval

    @property
    def variables(self):
        if self.want.variables is None:
            return None
        if self.have.variables is None:
            return dict(
                variables=self.want.variables
            )
        result = dict()
        different = compare_dictionary(self.want.variables, self.have.variables)
        if not different:
            return None

        for k, v in iteritems(self.want.variables):
            if k in self.have.variables and v != self.have.variables[k]:
                result[k] = v
            elif k not in self.have.variables:
                result[k] = v
        for k, v in iteritems(self.have.variables):
            if k not in self.want.variables:
                result[k] = "none"
        if result:
            result = dict(
                variables=result
            )
            return result


class ModuleManager(object):
    def __init__(self, *args, **kwargs):
        self.module = kwargs.get('module', None)
        self.client = kwargs.get('client', None)
        self.want = ModuleParameters(params=self.module.params)
        self.have = ApiParameters()
        self.changes = UsableChanges()

    def _set_changed_options(self):
        changed = {}
        for key in Parameters.returnables:
            if getattr(self.want, key) is not None:
                changed[key] = getattr(self.want, key)
        if changed:
            self.changes = UsableChanges(params=changed)

    def _update_changed_options(self):
        diff = Difference(self.want, self.have)
        updatables = Parameters.updatables
        changed = dict()
        for k in updatables:
            change = diff.compare(k)
            if change is None:
                continue
            else:
                if isinstance(change, dict):
                    changed.update(change)
                else:
                    changed[k] = change
        if changed:
            self.changes = UsableChanges(params=changed)
            return True
        return False

    def should_update(self):
        result = self._update_changed_options()
        if result:
            return True
        return False

    def exec_module(self):
        changed = False
        result = dict()
        state = self.want.state

        if state == "present":
            changed = self.present()
        elif state == "absent":
            changed = self.absent()

        reportable = ReportableChanges(params=self.changes.to_return())
        changes = reportable.to_return()
        result.update(**changes)
        result.update(dict(changed=changed))
        self._announce_deprecations(result)
        return result

    def _announce_deprecations(self, result):
        warnings = result.pop('__warnings', [])
        for warning in warnings:
            self.client.module.deprecate(
                msg=warning['msg'],
                version=warning['version']
            )

    def present(self):
        if self.exists():
            return self.update()
        else:
            return self.create()

    def exists(self):
        uri = "https://{0}:{1}/mgmt/tm/ltm/monitor/external/{2}".format(
            self.client.provider['server'],
            self.client.provider['server_port'],
            transform_name(self.want.partition, self.want.name)
        )
        resp = self.client.api.get(uri)
        try:
            response = resp.json()
        except ValueError:
            return False
        if resp.status == 404 or 'code' in response and response['code'] == 404:
            return False
        return True

    def update(self):
        self.have = self.read_current_from_device()
        if not self.should_update():
            return False
        if self.module.check_mode:
            return True
        self.update_on_device()
        return True

    def remove(self):
        if self.module.check_mode:
            return True
        self.remove_from_device()
        if self.exists():
            raise F5ModuleError("Failed to delete the resource.")
        return True

    def create(self):
        self._set_changed_options()
        self._set_default_creation_values()
        if self.module.check_mode:
            return True
        self.create_on_device()
        return True

    def _set_default_creation_values(self):
        if self.want.timeout is None:
            self.want.update({'timeout': 16})
        if self.want.interval is None:
            self.want.update({'interval': 5})
        if self.want.ip is None:
            self.want.update({'ip': '*'})
        if self.want.port is None:
            self.want.update({'port': '*'})

    def create_on_device(self):
        params = self.changes.api_params()
        params['name'] = self.want.name
        params['partition'] = self.want.partition
        uri = "https://{0}:{1}/mgmt/tm/ltm/monitor/external/".format(
            self.client.provider['server'],
            self.client.provider['server_port']
        )
        resp = self.client.api.post(uri, json=params)
        try:
            response = resp.json()
        except ValueError as ex:
            raise F5ModuleError(str(ex))

        if 'code' in response and response['code'] in [400, 403]:
            if 'message' in response:
                raise F5ModuleError(response['message'])
            else:
                raise F5ModuleError(resp.content)

        if self.want.variables:
            self.set_variable_on_device(self.want.variables)

    def set_variable_on_device(self, commands):
        command = ' '.join(['user-defined {0} \\\"{1}\\\"'.format(k, v) for k, v in iteritems(commands)])
        command = 'tmsh modify ltm monitor external {0} {1}'.format(self.want.name, command)
        uri = "https://{0}:{1}/mgmt/tm/util/bash".format(
            self.client.provider['server'],
            self.client.provider['server_port'],
        )
        args = dict(
            command='run',
            utilCmdArgs='-c "{0}"'.format(command)
        )
        resp = self.client.api.post(uri, json=args)
        try:
            response = resp.json()
        except ValueError as ex:
            raise F5ModuleError(str(ex))
        if 'code' in response and response['code'] == 400:
            if 'message' in response:
                raise F5ModuleError(response['message'])
            else:
                raise F5ModuleError(resp.content)

    def update_on_device(self):
        params = self.changes.api_params()
        if params:
            uri = "https://{0}:{1}/mgmt/tm/ltm/monitor/external/{2}".format(
                self.client.provider['server'],
                self.client.provider['server_port'],
                transform_name(self.want.partition, self.want.name)
            )
            resp = self.client.api.patch(uri, json=params)
            try:
                response = resp.json()
            except ValueError as ex:
                raise F5ModuleError(str(ex))

            if 'code' in response and response['code'] == 400:
                if 'message' in response:
                    raise F5ModuleError(response['message'])
                else:
                    raise F5ModuleError(resp.content)
        if self.changes.variables:
            self.set_variable_on_device(self.changes.variables)

    def absent(self):
        if self.exists():
            return self.remove()
        return False

    def remove_from_device(self):
        uri = "https://{0}:{1}/mgmt/tm/ltm/monitor/external/{2}".format(
            self.client.provider['server'],
            self.client.provider['server_port'],
            transform_name(self.want.partition, self.want.name)
        )
        resp = self.client.api.delete(uri)
        if resp.status == 200:
            return True

    def read_current_from_device(self):
        uri = "https://{0}:{1}/mgmt/tm/ltm/monitor/external/{2}".format(
            self.client.provider['server'],
            self.client.provider['server_port'],
            transform_name(self.want.partition, self.want.name)
        )
        resp = self.client.api.get(uri)
        try:
            response = resp.json()
        except ValueError as ex:
            raise F5ModuleError(str(ex))

        if 'code' in response and response['code'] == 400:
            if 'message' in response:
                raise F5ModuleError(response['message'])
            else:
                raise F5ModuleError(resp.content)
        return ApiParameters(params=response)


class ArgumentSpec(object):
    def __init__(self):
        self.supports_check_mode = True
        argument_spec = dict(
            name=dict(required=True),
            parent=dict(default='/Common/external'),
            description=dict(),
            arguments=dict(),
            ip=dict(),
            port=dict(type='int'),
            external_program=dict(),
            interval=dict(type='int'),
            timeout=dict(type='int'),
            state=dict(
                default='present',
                choices=['present', 'absent']
            ),
            variables=dict(type='dict'),
            partition=dict(
                default='Common',
                fallback=(env_fallback, ['F5_PARTITION'])
            )
        )
        self.argument_spec = {}
        self.argument_spec.update(f5_argument_spec)
        self.argument_spec.update(argument_spec)


def main():
    spec = ArgumentSpec()

    module = AnsibleModule(
        argument_spec=spec.argument_spec,
        supports_check_mode=spec.supports_check_mode,
    )

    client = F5RestClient(**module.params)

    try:
        mm = ModuleManager(module=module, client=client)
        results = mm.exec_module()
        cleanup_tokens(client)
        exit_json(module, results, client)
    except F5ModuleError as ex:
        cleanup_tokens(client)
        fail_json(module, ex, client)


if __name__ == '__main__':
    main()
