#!/usr/bin/python
# -*- coding: utf-8 -*-

# (c) 2013, serge van Ginderachter <serge@vanginderachter.be>
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.

ANSIBLE_METADATA = {'status': ['preview'],
                    'supported_by': 'community',
                    'version': '1.0'}

DOCUMENTATION = '''
---
module: bigip_monitor_tcp
short_description: "Manages F5 BIG-IP LTM tcp monitors"
description:
  - "Manages F5 BIG-IP LTM tcp monitors via iControl SOAP API"
version_added: "1.4"
author:
  - Serge van Ginderachter (@srvg)
  - Tim Rupp (@caphrim007)
notes:
  - "Requires BIG-IP software version >= 11"
  - "F5 developed module 'bigsuds' required (see http://devcentral.f5.com)"
  - "Best run as a local_action in your playbook"
  - "Monitor API documentation: https://devcentral.f5.com/wiki/iControl.LocalLB__Monitor.ashx"
requirements:
  - bigsuds
options:
  state:
    description:
      - Monitor state
    required: false
    default: 'present'
    choices:
      - present
      - absent
  name:
    description:
      - Monitor name
    required: true
    default: null
    aliases:
      - monitor
  partition:
    description:
      - Partition for the monitor
    required: false
    default: 'Common'
  type:
    description:
      - The template type of this monitor template
    required: false
    default: 'tcp'
    choices:
      - TTYPE_TCP
      - TTYPE_TCP_ECHO
      - TTYPE_TCP_HALF_OPEN
  parent:
    description:
      - The parent template of this monitor template
    required: false
    default: 'tcp'
    choices:
      - tcp
      - tcp_echo
      - tcp_half_open
  parent_partition:
    description:
      - Partition for the parent monitor
    required: false
    default: 'Common'
  send:
    description:
      - The send string for the monitor call
    required: true
    default: none
  receive:
    description:
      - The receive string for the monitor call
    required: true
    default: none
  ip:
    description:
      - IP address part of the ipport definition. The default API setting
        is "0.0.0.0".
    required: false
    default: none
  port:
    description:
      - Port address part op the ipport definition. The default API
        setting is 0.
    required: false
    default: none
  interval:
    description:
      - The interval specifying how frequently the monitor instance
        of this template will run. By default, this interval is used for up and
        down states. The default API setting is 5.
    required: false
    default: none
  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. The default API setting
        is 16.
    required: false
    default: none
  time_until_up:
    description:
      - Specifies the amount of time in seconds after the first successful
        response before a node will be marked up. A value of 0 will cause a
        node to be marked up immediately after a valid response is received
        from the node. The default API setting is 0.
    required: false
    default: none
extends_documentation_fragment: f5
'''

EXAMPLES = '''
- name: Create TCP Monitor
  bigip_monitor_tcp:
    state: "present"
    server: "lb.mydomain.com"
    user: "admin"
    password: "secret"
    name: "my_tcp_monitor"
    type: "tcp"
    send: "tcp string to send"
    receive: "tcp string to receive"
  delegate_to: localhost

- name: Create TCP half open Monitor
  bigip_monitor_tcp:
    state: "present"
    server: "lb.mydomain.com"
    user: "admin"
    password: "secret"
    name: "my_tcp_monitor"
    type: "tcp"
    send: "tcp string to send"
    receive: "http string to receive"
  delegate_to: localhost

- name: Remove TCP Monitor
  bigip_monitor_tcp:
      state: "absent"
      server: "lb.mydomain.com"
      user: "admin"
      password: "secret"
      name: "my_tcp_monitor"
'''

TEMPLATE_TYPE = DEFAULT_TEMPLATE_TYPE = 'TTYPE_TCP'
TEMPLATE_TYPE_CHOICES = ['tcp', 'tcp_echo', 'tcp_half_open']
DEFAULT_PARENT = DEFAULT_TEMPLATE_TYPE_CHOICE = DEFAULT_TEMPLATE_TYPE.replace('TTYPE_', '').lower()


def check_monitor_exists(module, api, monitor, parent):
    # hack to determine if monitor exists
    result = False
    try:
        ttype = api.LocalLB.Monitor.get_template_type(template_names=[monitor])[0]
        parent2 = api.LocalLB.Monitor.get_parent_template(template_names=[monitor])[0]
        if ttype == TEMPLATE_TYPE and parent == parent2:
            result = True
        else:
            module.fail_json(msg='Monitor already exists, but has a different type (%s) or parent(%s)' % (ttype, parent))
    except bigsuds.OperationFailed as e:
        if "was not found" in str(e):
            result = False
        else:
            # genuine exception
            raise
    return result


def create_monitor(api, monitor, template_attributes):
    try:
        api.LocalLB.Monitor.create_template(
            templates=[{
                'template_name': monitor,
                'template_type': TEMPLATE_TYPE
            }],
            template_attributes=[template_attributes]
        )
    except bigsuds.OperationFailed as e:
        if "already exists" in str(e):
            return False
        else:
            # genuine exception
            raise
    return True


def delete_monitor(api, monitor):
    try:
        api.LocalLB.Monitor.delete_template(template_names=[monitor])
    except bigsuds.OperationFailed as e:
        # maybe it was deleted since we checked
        if "was not found" in str(e):
            return False
        else:
            # genuine exception
            raise
    return True


def check_string_property(api, monitor, str_property):
    try:
        template_prop = api.LocalLB.Monitor.get_template_string_property(
            [monitor], [str_property['type']]
        )[0]
        return str_property == template_prop
    except bigsuds.OperationFailed as e:
        # happens in check mode if not created yet
        if "was not found" in str(e):
            return True
        else:
            # genuine exception
            raise


def set_string_property(api, monitor, str_property):
    api.LocalLB.Monitor.set_template_string_property(
        template_names=[monitor],
        values=[str_property]
    )


def check_integer_property(api, monitor, int_property):
    try:
        return int_property == api.LocalLB.Monitor.get_template_integer_property(
            [monitor], [int_property['type']]
        )[0]
    except bigsuds.OperationFailed as e:
        # happens in check mode if not created yet
        if "was not found" in str(e):
            return True
        else:
            # genuine exception
            raise


def set_integer_property(api, monitor, int_property):
    api.LocalLB.Monitor.set_template_integer_property(
        template_names=[monitor],
        values=[int_property]
    )


def update_monitor_properties(api, module, monitor, template_string_properties, template_integer_properties):
    changed = False
    for str_property in template_string_properties:
        if str_property['value'] is not None and not check_string_property(api, monitor, str_property):
            if not module.check_mode:
                set_string_property(api, monitor, str_property)
            changed = True

    for int_property in template_integer_properties:
        if int_property['value'] is not None and not check_integer_property(api, monitor, int_property):
            if not module.check_mode:
                set_integer_property(api, monitor, int_property)
            changed = True

    return changed


def get_ipport(api, monitor):
    return api.LocalLB.Monitor.get_template_destination(template_names=[monitor])[0]


def set_ipport(api, monitor, ipport):
    try:
        api.LocalLB.Monitor.set_template_destination(
            template_names=[monitor], destinations=[ipport]
        )
        return True, ""

    except bigsuds.OperationFailed as e:
        if "Cannot modify the address type of monitor" in str(e):
            return False, "Cannot modify the address type of monitor if already assigned to a pool."
        else:
            # genuine exception
            raise


def main():
    argument_spec = f5_argument_spec()

    meta_args = dict(
        name=dict(required=True),
        type=dict(default=DEFAULT_TEMPLATE_TYPE_CHOICE, choices=TEMPLATE_TYPE_CHOICES),
        parent=dict(default=DEFAULT_PARENT),
        parent_partition=dict(default='Common'),
        send=dict(required=False),
        receive=dict(required=False),
        ip=dict(required=False),
        port=dict(required=False, type='int'),
        interval=dict(required=False, type='int'),
        timeout=dict(required=False, type='int'),
        time_until_up=dict(required=False, type='int', default=0)
    )
    argument_spec.update(meta_args)

    module = AnsibleModule(
        argument_spec=argument_spec,
        supports_check_mode=True
    )

    if module.params['validate_certs']:
        import ssl
        if not hasattr(ssl, 'SSLContext'):
            module.fail_json(msg='bigsuds does not support verifying certificates with python < 2.7.9.  Either update python or set validate_certs=False on the task')

    server = module.params['server']
    server_port = module.params['server_port']
    user = module.params['user']
    password = module.params['password']
    state = module.params['state']
    partition = module.params['partition']
    validate_certs = module.params['validate_certs']

    parent_partition = module.params['parent_partition']
    name = module.params['name']
    type = 'TTYPE_' + module.params['type'].upper()
    parent = fq_name(parent_partition, module.params['parent'])
    monitor = fq_name(partition, name)
    send = module.params['send']
    receive = module.params['receive']
    ip = module.params['ip']
    port = module.params['port']
    interval = module.params['interval']
    timeout = module.params['timeout']
    time_until_up = module.params['time_until_up']

    # tcp monitor has multiple types, so overrule
    global TEMPLATE_TYPE
    TEMPLATE_TYPE = type

    # end monitor specific stuff

    api = bigip_api(server, user, password, validate_certs, port=server_port)
    monitor_exists = check_monitor_exists(module, api, monitor, parent)

    # ipport is a special setting
    if monitor_exists:
        # make sure to not update current settings if not asked
        cur_ipport = get_ipport(api, monitor)
        if ip is None:
            ip = cur_ipport['ipport']['address']
        if port is None:
            port = cur_ipport['ipport']['port']
    else:
        # use API defaults if not defined to create it
        if interval is None:
            interval = 5
        if timeout is None:
            timeout = 16
        if ip is None:
            ip = '0.0.0.0'
        if port is None:
            port = 0
        if send is None:
            send = ''
        if receive is None:
            receive = ''

    # define and set address type
    if ip == '0.0.0.0' and port == 0:
        address_type = 'ATYPE_STAR_ADDRESS_STAR_PORT'
    elif ip == '0.0.0.0' and port != 0:
        address_type = 'ATYPE_STAR_ADDRESS_EXPLICIT_PORT'
    elif ip != '0.0.0.0' and port != 0:
        address_type = 'ATYPE_EXPLICIT_ADDRESS_EXPLICIT_PORT'
    else:
        address_type = 'ATYPE_UNSET'

    ipport = {
        'address_type': address_type,
        'ipport': {
            'address': ip,
            'port': port
        }
    }

    template_attributes = {
        'parent_template': parent,
        'interval': interval,
        'timeout': timeout,
        'dest_ipport': ipport,
        'is_read_only': False,
        'is_directly_usable': True
    }

    # monitor specific stuff
    if type == 'TTYPE_TCP':
        template_string_properties = [
            {
                'type': 'STYPE_SEND',
                'value': send
            },
            {
                'type': 'STYPE_RECEIVE',
                'value': receive
            }
        ]
    else:
        template_string_properties = []

    template_integer_properties = [
        {
            'type': 'ITYPE_INTERVAL',
            'value': interval
        },
        {
            'type': 'ITYPE_TIMEOUT',
            'value': timeout
        },
        {
            'type': 'ITYPE_TIME_UNTIL_UP',
            'value': time_until_up
        }
    ]

    # main logic, monitor generic

    try:
        result = {'changed': False}  # default

        if state == 'absent':
            if monitor_exists:
                if not module.check_mode:
                    # possible race condition if same task
                    # on other node deleted it first
                    result['changed'] |= delete_monitor(api, monitor)
                else:
                    result['changed'] |= True
        else:
            # check for monitor itself
            if not monitor_exists:
                if not module.check_mode:
                    # again, check changed status here b/c race conditions
                    # if other task already created it
                    result['changed'] |= create_monitor(api, monitor, template_attributes)
                else:
                    result['changed'] |= True

            # check for monitor parameters
            # whether it already existed, or was just created, now update
            # the update functions need to check for check mode but
            # cannot update settings if it doesn't exist which happens in check mode
            result['changed'] |= update_monitor_properties(api, module, monitor,
                                                           template_string_properties,
                                                           template_integer_properties)

            # we just have to update the ipport if monitor already exists and it's different
            if monitor_exists and cur_ipport != ipport:
                set_ipport(api, monitor, ipport)
                result['changed'] |= True
            # else: monitor doesn't exist (check mode) or ipport is already ok
    except Exception as e:
        module.fail_json(msg="received exception: %s" % e)

    module.exit_json(**result)

# import module snippets
from ansible.module_utils.basic import *
from ansible.module_utils.f5 import *

if __name__ == '__main__':
    main()
