#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# Copyright (c) 2017 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': 'community'}

DOCUMENTATION = r'''
---
module: bigip_provision
short_description: Manage BIG-IP module provisioning
description:
  - Manage BIG-IP module provisioning. This module will only provision at the
    standard levels of Dedicated, Nominal, and Minimum.
version_added: "2.4"
options:
  name:
    description:
      - The module to provision in BIG-IP.
    required: true
    choices:
      - am
      - afm
      - apm
      - asm
      - avr
      - fps
      - gtm
      - ilx
      - lc
      - ltm
      - pem
      - sam
      - swg
      - vcmp
    aliases:
      - module
  level:
    description:
      - Sets the provisioning level for the requested modules. Changing the
        level for one module may require modifying the level of another module.
        For example, changing one module to C(dedicated) requires setting all
        others to C(none). Setting the level of a module to C(none) means that
        the module is not activated.
    default: nominal
    choices:
      - dedicated
      - nominal
      - minimum
  state:
    description:
      - The state of the provisioned module on the system. When C(present),
        guarantees that the specified module is provisioned at the requested
        level provided that there are sufficient resources on the device (such
        as physical RAM) to support the provisioned module. When C(absent),
        de-provision the module.
    default: present
    choices:
      - present
      - absent
notes:
  - Requires the f5-sdk Python package on the host. This is as easy as pip
    install f5-sdk.
requirements:
  - f5-sdk >= 2.2.3
extends_documentation_fragment: f5
author:
  - Tim Rupp (@caphrim007)
'''

EXAMPLES = r'''
- name: Provision PEM at "nominal" level
  bigip_provision:
    server: lb.mydomain.com
    module: pem
    level: nominal
    password: secret
    user: admin
    validate_certs: no
  delegate_to: localhost

- name: Provision a dedicated SWG. This will unprovision every other module
  bigip_provision:
    server: lb.mydomain.com
    module: swg
    password: secret
    level: dedicated
    user: admin
    validate_certs: no
  delegate_to: localhost
'''

RETURN = r'''
level:
  description: The new provisioning level of the module.
  returned: changed
  type: string
  sample: minimum
'''

import time

from ansible.module_utils.f5_utils import AnsibleF5Client
from ansible.module_utils.f5_utils import AnsibleF5Parameters
from ansible.module_utils.f5_utils import HAS_F5SDK
from ansible.module_utils.f5_utils import F5ModuleError

try:
    from f5.bigip.contexts import TransactionContextManager
    from f5.sdk_exception import LazyAttributesRequired
    from ansible.module_utils.f5_utils import iControlUnexpectedHTTPError
except ImportError:
    HAS_F5SDK = False


class Parameters(AnsibleF5Parameters):
    api_attributes = ['level']

    returnables = ['level']

    updatables = ['level']

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

    def api_params(self):
        result = {}
        for api_attribute in self.api_attributes:
            if self.api_map is not None and api_attribute in self.api_map:
                result[api_attribute] = getattr(self, self.api_map[api_attribute])
            else:
                result[api_attribute] = getattr(self, api_attribute)
        result = self._filter_params(result)
        return result

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


class ModuleManager(object):
    def __init__(self, client):
        self.client = client
        self.have = None
        self.want = Parameters(self.client.module.params)
        self.changes = Parameters()

    def _update_changed_options(self):
        changed = {}
        for key in Parameters.updatables:
            if getattr(self.want, key) is not None:
                attr1 = getattr(self.want, key)
                attr2 = getattr(self.have, key)
                if attr1 != attr2:
                    changed[key] = attr1
        if changed:
            self.changes = Parameters(changed)
            return True
        return False

    def exec_module(self):
        if not HAS_F5SDK:
            raise F5ModuleError("The python f5-sdk module is required")

        changed = False
        result = dict()
        state = self.want.state

        try:
            if state == "present":
                changed = self.update()
            elif state == "absent":
                changed = self.absent()
        except iControlUnexpectedHTTPError as e:
            raise F5ModuleError(str(e))

        changes = self.changes.to_return()
        result.update(**changes)
        result.update(dict(changed=changed))
        return result

    def exists(self):
        provision = self.client.api.tm.sys.provision
        resource = getattr(provision, self.want.module)
        resource = resource.load()
        result = resource.attrs
        if str(result['level']) == 'none':
            return False
        return True

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

        self.update_on_device()
        self._wait_for_module_provisioning()

        if self.want.module == 'vcmp':
            self._wait_for_reboot()
            self._wait_for_module_provisioning()

        if self.want.module == 'asm':
            self._wait_for_asm_ready()
        return True

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

    def update_on_device(self):
        if self.want.level == 'dedicated':
            self.provision_dedicated_on_device()
        else:
            self.provision_non_dedicated_on_device()

    def provision_dedicated_on_device(self):
        params = self.want.api_params()
        tx = self.client.api.tm.transactions.transaction
        collection = self.client.api.tm.sys.provision.get_collection()
        resources = [x['name'] for x in collection if x['name'] != self.want.module]
        with TransactionContextManager(tx) as api:
            provision = api.tm.sys.provision
            for resource in resources:
                resource = getattr(provision, resource)
                resource = resource.load()
                resource.update(level='none')
            resource = getattr(provision, self.want.module)
            resource = resource.load()
            resource.update(**params)

    def provision_non_dedicated_on_device(self):
        params = self.want.api_params()
        provision = self.client.api.tm.sys.provision
        resource = getattr(provision, self.want.module)
        resource = resource.load()
        resource.update(**params)

    def read_current_from_device(self):
        provision = self.client.api.tm.sys.provision
        resource = getattr(provision, str(self.want.module))
        resource = resource.load()
        result = resource.attrs
        return Parameters(result)

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

    def remove(self):
        if self.client.check_mode:
            return True
        self.remove_from_device()
        self._wait_for_module_provisioning()

        # For vCMP, because it has to reboot, we also wait for mcpd to become available
        # before "moving on", or else the REST API would not be available and subsequent
        # Tasks would fail.
        if self.want.module == 'vcmp':
            self._wait_for_reboot()
            self._wait_for_module_provisioning()

        if self.exists():
            raise F5ModuleError("Failed to de-provision the module")
        return True

    def remove_from_device(self):
        provision = self.client.api.tm.sys.provision
        resource = getattr(provision, self.want.module)
        resource = resource.load()
        resource.update(level='none')

    def _wait_for_module_provisioning(self):
        # To prevent things from running forever, the hack is to check
        # for mprov's status twice. If mprov is finished, then in most
        # cases (not ASM) the provisioning is probably ready.
        nops = 0

        # Sleep a little to let provisioning settle and begin properly
        time.sleep(5)

        while nops < 3:
            try:
                if not self._is_mprov_running_on_device():
                    nops += 1
                else:
                    nops = 0
            except Exception:
                # This can be caused by restjavad restarting.
                try:
                    self.client.reconnect()
                except Exception:
                    pass
            time.sleep(5)

    def _is_mprov_running_on_device(self):
        # /usr/libexec/qemu-kvm is added here to prevent vcmp provisioning
        # from never allowing the mprov provisioning to succeed.
        #
        # It turns out that the 'mprov' string is found when enabling vcmp. The
        # qemu-kvm command that is run includes it.
        #
        # For example,
        #   /usr/libexec/qemu-kvm -rt-usecs 880 ... -mem-path /dev/mprov/vcmp -f5-tracing ...
        #
        try:
            output = self.client.api.tm.util.bash.exec_cmd(
                'run',
                utilCmdArgs='-c "ps aux | grep \'[m]prov\' | grep -v /usr/libexec/qemu-kvm"'
            )
            if hasattr(output, 'commandResult'):
                return True
        except Exception:
            pass
        return False

    def _wait_for_asm_ready(self):
        """Waits specifically for ASM

        On older versions, ASM can take longer to actually start up than
        all the previous checks take. This check here is specifically waiting for
        the Policies API to stop raising errors
        :return:
        """
        nops = 0
        while nops < 3:
            try:
                policies = self.client.api.tm.asm.policies_s.get_collection()
                if len(policies) >= 0:
                    nops += 1
                else:
                    nops = 0
            except Exception as ex:
                pass
            time.sleep(5)

    def _get_last_reboot(self):
        try:
            output = self.client.api.tm.util.bash.exec_cmd(
                'run',
                utilCmdArgs='-c "/usr/bin/last reboot | head -1"'
            )
            if hasattr(output, 'commandResult'):
                return str(output.commandResult)
        except Exception:
            pass
        return None

    def _wait_for_reboot(self):
        nops = 0

        last_reboot = self._get_last_reboot()

        # Sleep a little to let provisioning settle and begin properly
        time.sleep(5)

        while nops < 6:
            try:
                self.client.reconnect()
                next_reboot = self._get_last_reboot()
                if next_reboot is None:
                    nops = 0
                if next_reboot == last_reboot:
                    nops = 0
                else:
                    nops += 1
            except Exception as ex:
                # This can be caused by restjavad restarting.
                pass
            time.sleep(10)


class ArgumentSpec(object):
    def __init__(self):
        self.supports_check_mode = True
        self.argument_spec = dict(
            module=dict(
                required=True,
                choices=[
                    'afm', 'am', 'sam', 'asm', 'avr', 'fps',
                    'gtm', 'lc', 'ltm', 'pem', 'swg', 'ilx',
                    'apm', 'vcmp'
                ],
                aliases=['name']
            ),
            level=dict(
                default='nominal',
                choices=['nominal', 'dedicated', 'minimum']
            ),
            state=dict(
                default='present',
                choices=['present', 'absent']
            )
        )
        self.mutually_exclusive = [
            ['parameters', 'parameters_src']
        ]
        self.f5_product_name = 'bigip'


def main():
    if not HAS_F5SDK:
        raise F5ModuleError("The python f5-sdk module is required")

    spec = ArgumentSpec()

    client = AnsibleF5Client(
        argument_spec=spec.argument_spec,
        mutually_exclusive=spec.mutually_exclusive,
        supports_check_mode=spec.supports_check_mode,
        f5_product_name=spec.f5_product_name
    )

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


if __name__ == '__main__':
    main()