#!/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

DOCUMENTATION = r'''
---
module: bigip_iapp_template
short_description: Manages TCL iApp templates on a BIG-IP.
description:
  - Manages TCL iApp templates on a BIG-IP. This module allows you to
    deploy iApp templates to the BIG-IP and manage their lifecycle. The
    conventional way to use this module is to import new iApps as needed,
    or by extracting the contents of the iApp archive that is provided at
    downloads.f5.com, and then importing all the iApps with this module.
    This module can also update existing iApps provided the source
    of the iApp changed while the name stayed the same. Note that
    this module does not reconfigure any services that may have been
    created using the C(bigip_iapp_service) module. iApps are normally
    not updated in production. Instead, new versions are deployed and then
    existing services are changed to consume that new template. As such,
    the ability to update templates in-place requires using the C(force) option.
version_added: "1.0.0"
options:
  force:
    description:
      - Specifies whether or not to force the uploading of an iApp. When
        C(true), the system force updates the iApp even if there are iApp services
        using it. This will not update the running service, use
        C(bigip_iapp_service) to do that. When C(false), the system updates the iApp
        only if there are no iApp services using the template.
    type: bool
  name:
    description:
      - The name of the iApp template you want to delete. This option
        is only available when specifying a C(state) of C(absent) and is
        provided as a way to delete templates that you may no longer have
        the source of.
    type: str
  content:
    description:
      - Sets the contents of an iApp template directly to the specified
        value. This is for simple values, but can be used with lookup
        plugins for anything complex or with formatting. C(content) must
        be provided when creating new templates.
    type: str
  state:
    description:
      - Whether the iApp template should exist or not.
    type: str
    choices:
      - present
      - absent
    default: present
  partition:
    description:
      - Device partition to manage resources on.
    type: str
    default: Common
extends_documentation_fragment: f5networks.f5_modules.f5
author:
  - Tim Rupp (@caphrim007)
  - Wojciech Wypior (@wojtek0806)
'''

EXAMPLES = r'''
- name: Add the iApp contained in template iapp.tmpl
  bigip_iapp_template:
    content: "{{ lookup('template', 'iapp.tmpl') }}"
    state: present
    provider:
      user: admin
      password: secret
      server: lb.mydomain.com
  delegate_to: localhost

- name: Update a template in place
  bigip_iapp_template:
    content: "{{ lookup('template', 'iapp-new.tmpl') }}"
    state: present
    provider:
      user: admin
      password: secret
      server: lb.mydomain.com
  delegate_to: localhost

- name: Update a template in place that has existing services created from it.
  bigip_iapp_template:
    content: "{{ lookup('template', 'iapp-new.tmpl') }}"
    force: true
    state: present
    provider:
      user: admin
      password: secret
      server: lb.mydomain.com
  delegate_to: localhost
'''

RETURN = r'''
# only common fields returned
'''

import re
import uuid
from datetime import datetime

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

from ..module_utils.bigip import F5RestClient
from ..module_utils.common import (
    F5ModuleError, AnsibleF5Parameters, transform_name, f5_argument_spec, fq_name
)
from ..module_utils.icontrol import (
    upload_file, tmos_version
)
from ..module_utils.teem import send_teem

try:
    from StringIO import StringIO
except ImportError:
    from io import StringIO


class Parameters(AnsibleF5Parameters):
    api_attributes = []

    returnables = []

    @property
    def name(self):
        if self._values['name']:
            return self._values['name']
        if self._values['content']:
            name = self._get_template_name()
            return name
        return None

    @property
    def content(self):
        if self._values['content'] is None:
            return None
        result = self._squash_template_name_prefix()
        result = self._replace_template_name(result)
        return result

    @property
    def checksum(self):
        return self._values['tmplChecksum']

    def _squash_template_name_prefix(self):
        """Removes the template name prefix

        This method removes that partition from the name
        in the iApp so that comparisons can be done properly and entries
        can be created properly when using REST.

        :return string
        """
        pattern = r'sys\s+application\s+template\s+/Common/'
        replace = 'sys application template '
        return re.sub(pattern, replace, self._values['content'])

    def _replace_template_name(self, template):
        """Replaces template name at runtime

        To allow us to do the switch-a-roo with temporary templates and
        checksum comparisons, we need to take the template provided to us
        and change its name to a temporary value so that BIG-IP will create
        a clone for us.

        :return string
        """
        pattern = r'sys\s+application\s+template\s+[^ ]+'

        if self._values['name']:
            name = self._values['name']
        else:
            name = self._get_template_name()

        replace = 'sys application template {0}'.format(fq_name(self.partition, name))
        return re.sub(pattern, replace, template)

    def _get_template_name(self):
        pattern = r'sys\s+application\s+template\s+(?P<path>\/[^\{}"\'*?|#]+\/)?(?P<name>[^\{}"\'*?|#]+)'
        matches = re.search(pattern, self._values['content'])
        try:
            result = matches.group('name').strip()
        except IndexError:
            result = None
        if result:
            return result
        raise F5ModuleError(
            "No template name was found in the template"
        )


class ApiParameters(Parameters):
    pass


class ModuleParameters(Parameters):
    pass


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

    def exec_module(self):
        start = datetime.now().isoformat()
        version = tmos_version(self.client)
        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.client, self.module, version)
        return result

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

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

    def create(self):
        if self.module.check_mode:
            return True
        self.create_on_device()
        if self.exists():
            return True
        else:
            raise F5ModuleError("Failed to create the iApp template")

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

    def update(self):
        self.have = self.read_current_from_device()

        if not self.templates_differ():
            return False

        if not self.want.force and self.template_in_use():
            return False

        if self.module.check_mode:
            return True

        self._remove_iapp_checksum()
        # The same process used for creating (load) can be used for updating
        self.create_on_device()
        self._generate_template_checksum_on_device()
        return True

    def exists(self):
        uri = "https://{0}:{1}/mgmt/tm/sys/application/template/{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 template_in_use(self):
        uri = "https://{0}:{1}/mgmt/tm/sys/application/service/".format(
            self.client.provider['server'],
            self.client.provider['server_port'],
        )

        name = fq_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

        if resp.status in [200, 201] or 'code' in response and response['code'] in [200, 201]:
            for item in response['items']:
                if item['template'] == name:
                    return True
            return False
        raise F5ModuleError(resp.content)

    def read_current_from_device(self):
        self._generate_template_checksum_on_device()
        uri = "https://{0}:{1}/mgmt/tm/sys/application/template/{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_iapp_checksum(self):
        """Removes the iApp tmplChecksum

        This is required for updating in place or else the load command will
        fail with a "AppTemplate ... content does not match the checksum"
        error.

        :return:
        """
        uri = "https://{0}:{1}/mgmt/tm/sys/application/template/{2}".format(
            self.client.provider['server'],
            self.client.provider['server_port'],
            transform_name(self.want.partition, self.want.name)
        )
        params = dict(tmplChecksum=None)

        resp = self.client.api.patch(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]:
            return True
        raise F5ModuleError(resp.content)

    def templates_differ(self):
        # BIG-IP can generate checksums of iApps, but the iApp needs to be
        # on the box to do this. Additionally, the checksum is MD5, but it
        # is not an MD5 of the entire content of the template. Instead, it
        # is a hash of some portion of the template that is unknown to me.
        #
        # The code below is responsible for uploading the provided template
        # under a unique name and creating a checksum for it so that that
        # checksum can be compared to the one of the existing template.
        #
        # Using this method we can compare the checksums of the existing
        # iApp and the iApp that the user is providing to the module.
        backup = self.want.name

        # Override whatever name may have been provided so that we can
        # temporarily create a new template to test checksums with
        self.want.update({
            'name': 'ansible-{0}'.format(str(uuid.uuid4()))
        })

        # Create and remove temporary template
        temp = self._get_temporary_template()

        # Set the template name back to what it was originally so that
        # any future operations only happen on the real template.
        self.want.update({
            'name': backup
        })
        if temp.checksum != self.have.checksum:
            return True
        return False

    def _get_temporary_template(self):
        self.create_on_device()
        temp = self.read_current_from_device()
        self.remove_from_device()
        return temp

    def _generate_template_checksum_on_device(self):
        command = 'tmsh generate sys application template {0} checksum'.format(
            self.want.name
        )
        params = dict(
            command="run",
            utilCmdArgs='-c "{0}"'.format(command)
        )
        uri = "https://{0}:{1}/mgmt/tm/util/bash".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]:
            return True
        raise F5ModuleError(resp.content)

    def upload_file_to_device(self, content, name):
        url = 'https://{0}:{1}/mgmt/shared/file-transfer/uploads'.format(
            self.client.provider['server'],
            self.client.provider['server_port']
        )
        try:
            upload_file(self.client, url, content, name)
        except F5ModuleError:
            raise F5ModuleError(
                "Failed to upload the file."
            )

    def create_on_device(self):
        remote_path = "/var/config/rest/downloads/{0}".format(self.want.name)
        load_command = 'tmsh load sys application template {0}'.format(remote_path)

        template = StringIO(self.want.content)
        self.upload_file_to_device(template, self.want.name)

        uri = "https://{0}:{1}/mgmt/tm/util/bash".format(
            self.client.provider['server'],
            self.client.provider['server_port']
        )
        params = dict(
            command="run",
            utilCmdArgs='-c "{0}"'.format(load_command)
        )

        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 'commandResult' in response:
                if 'Syntax Error' in response['commandResult']:
                    raise F5ModuleError(response['commandResult'])
                if 'ERROR' in response['commandResult']:
                    raise F5ModuleError(response['commandResult'])
            return True
        raise F5ModuleError(resp.content)

    def remove_from_device(self):
        uri = "https://{0}:{1}/mgmt/tm/sys/application/template/{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)


class ArgumentSpec(object):
    def __init__(self):
        self.supports_check_mode = True
        argument_spec = dict(
            name=dict(),
            state=dict(
                default='present',
                choices=['present', 'absent']
            ),
            force=dict(
                type='bool'
            ),
            content=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()
