#!/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

DOCUMENTATION = r'''
---
module: bigip_gtm_monitor_external
short_description: Manages external GTM monitors on a BIG-IP
description:
  - Manages external GTM (now BIG-IP DNS) monitors on a BIG-IP.
version_added: "1.0.0"
options:
  name:
    description:
      - Specifies the name of the monitor.
    type: str
    required: True
  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.
    type: str
    default: "/Common/external"
  arguments:
    description:
      - Specifies any command-line arguments the script requires.
    type: str
  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
        '*'.
    type: str
  port:
    description:
      - Port address part of the IP/port definition. If this parameter is not
        provided when creating a new monitor, the default value will be
        '*'. Note that if specifying an IP address, you must use a value between 1 and 65535.
    type: str
  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.
    type: str
  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, the default value will be 30. This value B(must)
        be less than the C(timeout) value.
    type: int
  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
        to any number, 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, the default value will be 120.
    type: int
  variables:
    description:
      - Specifies any variables the script requires.
      - Double quotes in values will be suppressed.
    type: dict
  partition:
    description:
      - Device partition to manage resources on.
    type: str
    default: Common
  state:
    description:
      - When C(present), ensures the monitor exists.
      - When C(absent), ensures the monitor is removed.
    type: str
    choices:
      - present
      - absent
    default: present
extends_documentation_fragment: f5networks.f5_modules.f5
author:
  - Tim Rupp (@caphrim007)
  - Wojciech Wypior (@wojtek0806)
'''

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

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

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

RETURN = r'''
parent:
  description: New parent template of the monitor.
  returned: changed
  type: str
  sample: external
ip:
  description: The new IP of IP/port definition.
  returned: changed
  type: str
  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 os
import re
from datetime import datetime

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


from ..module_utils.bigip import F5RestClient
from ..module_utils.common import (
    F5ModuleError, AnsibleF5Parameters, transform_name, f5_argument_spec, fq_name
)
from ..module_utils.compare import compare_dictionary
from ..module_utils.icontrol import (
    module_provisioned, tmos_version
)
from ..module_utils.ipaddress import is_valid_ip
from ..module_utils.teem import send_teem


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

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

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

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

    @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
        if self._values['parent'].startswith('/'):
            parent = os.path.basename(self._values['parent'])
            result = '/{0}/{1}'.format(self.partition, parent)
        else:
            result = '/{0}/{1}'.format(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:
            raise
        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 = F5RestClient(**self.module.params)
        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 _announce_deprecations(self, result):
        warnings = result.pop('__warnings', [])
        for warning in warnings:
            self.client.module.deprecate(
                msg=warning['msg'],
                version=warning['version']
            )

    def _set_default_creation_values(self):
        if self.want.timeout is None:
            self.want.update({'timeout': 120})
        if self.want.interval is None:
            self.want.update({'interval': 30})
        if self.want.ip is None:
            self.want.update({'ip': '*'})
        if self.want.port is None:
            self.want.update({'port': '*'})

    def exec_module(self):
        start = datetime.now().isoformat()
        version = tmos_version(self.client)
        if not module_provisioned(self.client, 'gtm'):
            raise F5ModuleError(
                "GTM must be provisioned to use this module."
            )
        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)
        send_teem(start, self.module, version)
        return result

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

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

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

    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 monitor.")
        return True

    def exists(self):
        uri = "https://{0}:{1}/mgmt/tm/gtm/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 resp.status == 404 or 'code' in response and response['code'] == 404:
            return False
        if resp.status in [200, 201] or 'code' in response and response['code'] in [200, 201]:
            return True

        errors = [401, 403, 409, 500, 501, 502, 503, 504]

        if resp.status in errors or 'code' in response and response['code'] in errors:
            if 'message' in response:
                raise F5ModuleError(response['message'])
            else:
                raise F5ModuleError(resp.content)

    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/gtm/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 resp.status in [200, 201] or 'code' in response and response['code'] in [200, 201]:
            if self.want.variables:
                self.set_variable_on_device(self.want.variables)
            return True
        raise F5ModuleError(resp.content)

    def update_on_device(self):
        params = self.changes.api_params()
        if params:
            uri = "https://{0}:{1}/mgmt/tm/gtm/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 resp.status not in [200, 201] or 'code' in response and response['code'] not in [200, 201]:
                raise F5ModuleError(resp.content)
        if self.changes.variables:
            self.set_variable_on_device(self.changes.variables)

    def read_current_from_device(self):
        uri = "https://{0}:{1}/mgmt/tm/gtm/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 resp.status in [200, 201] or 'code' in response and response['code'] in [200, 201]:
            return ApiParameters(params=response)
        raise F5ModuleError(resp.content)

    def remove_from_device(self):
        uri = "https://{0}:{1}/mgmt/tm/gtm/monitor/external/{2}".format(
            self.client.provider['server'],
            self.client.provider['server_port'],
            transform_name(self.want.partition, self.want.name),
        )
        response = self.client.api.delete(uri)
        if response.status == 200:
            return True
        raise F5ModuleError(response.content)

    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 gtm 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 resp.status in [200, 201] or 'code' in response and response['code'] in [200, 201]:
            return True
        raise F5ModuleError(resp.content)


class ArgumentSpec(object):
    def __init__(self):
        self.supports_check_mode = True
        argument_spec = dict(
            name=dict(required=True),
            parent=dict(default='/Common/external'),
            arguments=dict(),
            ip=dict(),
            port=dict(),
            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,
    )

    try:
        mm = ModuleManager(module=module)
        results = mm.exec_module()
        module.exit_json(**results)
    except F5ModuleError as ex:
        module.fail_json(msg=str(ex))


if __name__ == '__main__':
    main()
