#!/usr/bin/python
#
# (c) Cisco Systems, 2014
#
# This module 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.
#
# This software 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 this software. If not, see <http://www.gnu.org/licenses/>.

DOCUMENTATION = '''
---
module: neutron_sec_group
short_description: Create, Remove or Update Openstack security groups
description:
   - Create, Remove or Update Openstack security groups
options:
   login_username:
     description:
        - login username to authenticate to keystone
        - If unspecified, the OS_USERNAME environment variable is used
     required: true
   login_password:
     description:
        - Password of login user
        - If unspecified, the OS_PASSWORD environment variable is used
     required: true
   login_tenant_name:
     description:
        - The tenant name of the login user
        - If unspecified, the OS_TENANT_NAME environment variable is used
     required: false
   login_tenant_id:
     description:
        - The tenant id of the login user
        - If unspecified, the OS_TENANT_ID environment variable is used
     required: false
   auth_url:
     description:
        - The keystone url for authentication
        - If unspecified, the OS_AUTH_URL environment variable is used
     required: false
     default: 'http://127.0.0.1:5000/v2.0/'
   region_name:
     description:
        - Name of the region
     required: false
     default: None
   state:
     description:
        - Indicate desired state of the security group. 'append' will
	  add rules only, without deleting rules that are not listed.
     choices: ['present', 'absent', 'append']
     default: present
   name:
     description:
        - Name to be given to the security group
     required: true
     default: None
   tenant_name:
     description:
        - Name of the tenant for which the security group has to be created,
          if none, the security group would be created for the login tenant.
     required: false
     default: None
   rules:
      description:
         - "List of security group rules. Available parameters of a rule:
         direction, port_range_min, port_range_max, ethertype, protocol,
         remote_ip_prefix|remote_group_id|remote_group_name"
      required: false
      default: none
requirements: ["neutronclient", "keystoneclient"]
'''

EXAMPLES = '''
# Creates a security group with a number of rules
neutron_sec_group:
  login_username: "demo"
  login_password: "password"
  login_tenant_name: "demo"
  auth_url: "http://127.0.0.1:5000/v2.0"
  name: "sg-test"
  description: "Description of the security group"
  state: "present"
  rules:
    - direction: "ingress"
      port_range_min: "80"
      port_range_max: "80"
      ethertype: "IPv4"
      protocol: "tcp"
      remote_ip_prefix: "10.0.0.1/24"
    - direction: "ingress"
      port_range_min: "22"
      port_range_max: "22"
      ethertype: "IPv4"
      protocol: "tcp"
      remote_ip_prefix: "10.0.0.1/24"
    - direction: "ingress"
      port_range_min: "22"
      port_range_max: "22"
      ethertype: "IPv4"
      protocol: "tcp"
      remote_group_id: UUID_OF_GROUP
    - direction: "ingress"
      port_range_min: "22"
      port_range_max: "22"
      ethertype: "IPv4"
      protocol: "tcp"
      remote_group_name: 'default'
'''

try:
    import neutronclient.v2_0.client
    import keystoneclient.v2_0.client
    from neutronclient.common import exceptions
except ImportError:
    print "failed=True msg='neutronclient and keystoneclient are required'"


def main():
    """
    Main function - entry point. The magic starts here ;-)
    """
    module = AnsibleModule(
        argument_spec=dict(
            auth_url=dict(default=None, required=False),
            login_username=dict(default=None, required=False),
            login_password=dict(default=None, required=False),
            login_tenant_name=dict(default=None, required=False),
            login_tenant_id=dict(default=None, required=False),
            name=dict(required=True),
            description=dict(default=None),
            region_name=dict(default=None),
            rules=dict(default=None),
            tenant_name=dict(required=False),
            state=dict(default='present', choices=['present', 'absent', 'append'])
        ),
        supports_check_mode=True
    )
    # Grab configuration from environment or params for openstack
    for item in (
            'auth_url',
            'login_tenant_name',
            'login_username',
            'login_password',
            'login_tenant_id'
    ):
        if not module.params[item]:
            module.params[item] = os.environ.get(
                'OS_{0}'.format(item.upper().replace('LOGIN_', ''))
            )

    network_client = _get_network_client(module.params)
    identity_client = _get_identity_client(module.params)

    try:
        # Get id of security group (as a result check whether it exists)
        tenant_id = _get_tenant_id(module, identity_client)

        params = {
            'name': module.params['name'],
            'tenant_id': tenant_id,
            'fields': 'id',
        }

        sec_groups = network_client.list_security_groups(**params)['security_groups']
        if len(sec_groups) > 1:
            raise exceptions.NeutronClientNoUniqueMatch(resource='security_group', name=params['name'])
        elif len(sec_groups) == 0:
            sec_group_exists = False
        else:
            sec_group = sec_groups[0]
            sec_group_exists = True

        # state=present -> create or update depending on whether sg exists.
        if module.params['state'] == 'present' or module.params['state'] == 'append':
            # UPDATE
            if sec_group_exists:
                changed, sg = _update_sg(module, network_client, sec_group, tenant_id)
                if changed:
                    module.exit_json(sec_group=sg, updated=True, changed=changed)
                else:
                    module.exit_json(sec_group=sg, changed=changed)
            # CREATE
            else:
                sg = _create_sg(module, network_client, tenant_id)
                module.exit_json(sec_group=sg, created=True, changed=True)
        # DELETE
        elif module.params['state'] == 'absent' and sec_group_exists:
            _delete_sg(module, network_client, sec_group)
            module.exit_json(changed=True)

        module.exit_json(changed=False)

    except exceptions.Unauthorized as exc:
        module.fail_json(msg="Authentication error: %s" % str(exc))
    except Exception as exc:
        module.fail_json(msg="Error: %s" % str(exc))


def _delete_sg(module, network_client, sec_group):
    """
    Deletes a security group.
    :param module: module to get security group params from.
    :param network_client: network client to use.
    :param sec_group: security group to delete.
    """
    if module.check_mode:
        return
    network_client.delete_security_group(sec_group['id'])


def _create_sg(module, network_client, tenant_id):
    """
    Creates a security group.
    :param module: module to get security group params from.
    :param network_client: network client to use.
    :param: identity_client: identity_client used if an admin performs the
    operation for a different tenant.
    :return: newly created security group.
    """
    if module.check_mode:
        return None

    data = {
        'security_group': {
            'name': module.params['name'],
            'description': module.params['description'],
            'tenant_id': tenant_id
        }
    }

    sg = network_client.create_security_group(data)
    sg = sg['security_group']

    changed, sg = _update_sg(module, network_client, sg, tenant_id)
    return sg


def _update_sg(module, network_client, sg, tenant_id):
    """
    Updates a security group.
    :param module: module to get updated security group param from.
    :param network_client: network client to use.
    :param sg: security group that needs to be updated.
    :return: True/False, the updated security group.
    """
    changed = False
    sg = network_client.show_security_group(sg['id'])
    sg = sg['security_group']

    # We only allow description updating, no name updating
    if module.params['description'] \
        and not module.params['description'] == sg['description'] \
        and module.check_mode:

        changed = True
    elif module.params['description'] \
        and not module.params['description'] == sg['description'] \
        and not module.check_mode:
        body = {
            'security_group': {
                'description': module.params['description']
            }
        }
        sg = network_client.update_security_group(sg['id'], body)
        sg = sg['security_group']
        changed = True

    if module.params['rules'] is not None:
        rules_changed = _update_sg_rules(module, network_client, sg,
                                         module.params['rules'], tenant_id)
        changed |= rules_changed

    return changed, sg


def _update_sg_rules(module, network_client, sg, wanted_rules, tenant_id):
    """
    Updates rules of a security group.
    """

    changed = False
    existing_rules = sg['security_group_rules']

    #check ok
    ok_rules = []
    for new_rule in wanted_rules:
        # Ugly: define tenant also here so that matches
        new_rule['tenant_id'] = sg['tenant_id']
        # protocol is in lowercase
        if 'protocol' in new_rule:
            new_rule['protocol'] = new_rule['protocol'].lower()

        matched_id = None
        for old_rule in existing_rules:
            clean_new_rule = new_rule.copy()
            clean_old_rule = old_rule.copy()
            old_id = clean_old_rule.pop('id')
            clean_old_rule.pop('security_group_id')
            for key in clean_old_rule.keys():
                if key not in clean_new_rule:
                    clean_new_rule[key] = None
                    continue
                value = clean_new_rule[key]
                if isinstance(value, (str, unicode)) and value.isdigit() and \
                    key != 'tenant_id':
                    clean_new_rule[key] = int(value)
            if cmp(clean_old_rule, clean_new_rule) == 0:
                matched_id = old_id
                break

        if matched_id:
            new_rule['done'] = True
            ok_rules.append(matched_id)

    #apply new first
    new_rules = [rule for rule in wanted_rules if 'done' not in rule]
    if len(new_rules):
        if not module.check_mode:
            sg = _create_sg_rules(network_client, sg, new_rules, tenant_id)
        changed = True

    #then delete not ok if not append
    if module.params['state'] != 'append':
        for rule in existing_rules:
            if rule['id'] in ok_rules:
                continue
            if not module.check_mode:
                sg = network_client.delete_security_group_rule(rule['id'])
	    changed = True

    return changed


def _create_sg_rules(network_client, sg, rules, tenant_id):
    """
    Creates a set of security group rules in a given security group.
    :param network_client: network client to use to create rules.
    :param sg: security group to create rules in.
    :param rules: rules to create.
    :return: the updated security group.
    """
    if rules:
        for rule in rules:
            if 'remote_group_name' in rule:
                rule['remote_group_id'] = _get_security_group_id(network_client,
                                                                 rule['remote_group_name'],
                                                                 tenant_id)
                rule.pop('remote_group_name', None)
            rule['tenant_id'] = sg['tenant_id']
            rule['security_group_id'] = sg['id']
            data = {
                'security_group_rule': rule
            }
            network_client.create_security_group_rule(data)

        # fetch security group again to show end result
        return network_client.show_security_group(sg['id'])['security_group']
    return sg


def _get_security_group_id(network_client, group_name, tenant_id):
    """
    Lookup the UUID for a named security group. This provides the ability to
    specify a SourceGroup via remote_group_id.

    http://docs.openstack.org/openstack-ops/content/security_groups.html

    This will return the first match to a group name.
    :param network_client: network client ot use to lookup group_id
    :param group_name: The name of the security group to lookup
    """

    params = {
        'name': group_name,
        'tenant_id': tenant_id,
        'fields': 'id'
    }

    return network_client.list_security_groups(**params)['security_groups'][0]['id']


def _get_tenant_id(module, identity_client):
    """
    Returns the tenant_id, given tenant_name.
    if tenant_name is not specified in the module params uses login_tenant_name
    if tenant_name is not specified and login_tenant_id is defined, it uses that.
    :param identity_client: identity_client used to get the tenant_id from its
           name.
    :param module_params: module parameters.
    """
    if not module.params['tenant_name']:
        if module.params['login_tenant_id']:
            return module.params['login_tenant_id']

        # Use token to get ID to avoid using "admin"/internal call
        return identity_client.tenant_id
    else:
        return _get_tenant(identity_client, module.params['tenant_name']).id


def _get_tenant(identity_client, tenant_name):
    """
    Returns the tenant, given the tenant_name.
    :param identity_client: identity client to use to do the required requests.
    :param tenant_name: name of the tenant.
    :return: tenant for which the name was given.
    """
    tenants = identity_client.tenants.list()
    tenant = next((t for t in tenants if t.name == tenant_name), None)
    if not tenant:
        raise Exception("Tenant with name '%s' not found." % tenant_name)

    return tenant


def _get_network_client(module_params):
    """
    :param module_params: module params containing the openstack credentials
    used to authenticate.
    :return: a neutron client.
    """
    client = neutronclient.v2_0.client.Client(
        username=module_params.get('login_username'),
        password=module_params.get('login_password'),
        tenant_name=module_params.get('login_tenant_name'),
        auth_url=module_params.get('auth_url'),
        region_name=module_params.get('region_name'))

    return client


def _get_identity_client(module_params):
    """
    :param module_params: module params containing the openstack credentials
    used to authenticate.
    :return: a keystone client.
    """
    client = keystoneclient.v2_0.client.Client(
        username=module_params.get('login_username'),
        password=module_params.get('login_password'),
        tenant_name=module_params.get('login_tenant_name'),
        auth_url=module_params.get('auth_url'),
        region_name=module_params.get('region_name'))

    return client


# Let's get the party started!
from ansible.module_utils.basic import *

main()