#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# (c) 2015, René Moser <mail@renemoser.net>
#
# 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 = {'metadata_version': '1.0',
                    'status': ['stableinterface'],
                    'supported_by': 'community'}


DOCUMENTATION = '''
---
module: cs_sshkeypair
short_description: Manages SSH keys on Apache CloudStack based clouds.
description:
    - Create, register and remove SSH keys.
    - If no key was found and no public key was provided and a new SSH
      private/public key pair will be created and the private key will be returned.
version_added: '2.0'
author: "René Moser (@resmo)"
options:
  name:
    description:
      - Name of public key.
    required: true
  domain:
    description:
      - Domain the public key is related to.
    required: false
    default: null
  account:
    description:
      - Account the public key is related to.
    required: false
    default: null
  project:
    description:
      - Name of the project the public key to be registered in.
    required: false
    default: null
  state:
    description:
      - State of the public key.
    required: false
    default: 'present'
    choices: [ 'present', 'absent' ]
  public_key:
    description:
      - String of the public key.
    required: false
    default: null
extends_documentation_fragment: cloudstack
'''

EXAMPLES = '''
# create a new private / public key pair:
- cs_sshkeypair:
    name: linus@example.com
  delegate_to: localhost
  register: key
- debug:
    msg: 'Private key is {{ key.private_key }}'

# remove a public key by its name:
- cs_sshkeypair:
    name: linus@example.com
    state: absent
  delegate_to: localhost

# register your existing local public key:
- cs_sshkeypair:
    name: linus@example.com
    public_key: "{{ lookup('file', '~/.ssh/id_rsa.pub') }}"
  delegate_to: localhost
'''

RETURN = '''
---
id:
  description: UUID of the SSH public key.
  returned: success
  type: string
  sample: a6f7a5fc-43f8-11e5-a151-feff819cdc9f
name:
  description: Name of the SSH public key.
  returned: success
  type: string
  sample: linus@example.com
fingerprint:
  description: Fingerprint of the SSH public key.
  returned: success
  type: string
  sample: "86:5e:a3:e8:bd:95:7b:07:7c:c2:5c:f7:ad:8b:09:28"
private_key:
  description: Private key of generated SSH keypair.
  returned: changed
  type: string
  sample: "-----BEGIN RSA PRIVATE KEY-----\nMII...8tO\n-----END RSA PRIVATE KEY-----\n"
'''

try:
    import sshpubkeys
    HAS_LIB_SSHPUBKEYS = True
except ImportError:
    HAS_LIB_SSHPUBKEYS = False

from ansible.module_utils.basic import AnsibleModule
from ansible.module_utils.cloudstack import (
    AnsibleCloudStack,
    CloudStackException,
    cs_required_together,
    cs_argument_spec
)


class AnsibleCloudStackSshKey(AnsibleCloudStack):

    def __init__(self, module):
        super(AnsibleCloudStackSshKey, self).__init__(module)
        self.returns = {
            'privatekey': 'private_key',
            'fingerprint': 'fingerprint',
        }
        self.ssh_key = None

    def register_ssh_key(self, public_key):
        ssh_key = self.get_ssh_key()
        args = self._get_common_args()
        name = self.module.params.get('name')

        res = None
        if not ssh_key:
            self.result['changed'] = True
            args['publickey'] = public_key
            if not self.module.check_mode:
                args['name'] = name
                res = self.cs.registerSSHKeyPair(**args)
        else:
            fingerprint = self._get_ssh_fingerprint(public_key)
            if ssh_key['fingerprint'] != fingerprint:
                self.result['changed'] = True
                if not self.module.check_mode:
                    # delete the ssh key with matching name but wrong fingerprint
                    args['name'] = name
                    self.cs.deleteSSHKeyPair(**args)

            elif ssh_key['name'].lower() != name.lower():
                self.result['changed'] = True
                if not self.module.check_mode:
                    # delete the ssh key with matching fingerprint but wrong name
                    args['name'] = ssh_key['name']
                    self.cs.deleteSSHKeyPair(**args)
                    # First match for key retrievment will be the fingerprint.
                    # We need to make another lookup if there is a key with identical name.
                    self.ssh_key = None
                    ssh_key = self.get_ssh_key()
                    if ssh_key['fingerprint'] != fingerprint:
                        args['name'] = name
                        self.cs.deleteSSHKeyPair(**args)

            if not self.module.check_mode and self.result['changed']:
                args['publickey'] = public_key
                args['name'] = name
                res = self.cs.registerSSHKeyPair(**args)

        if res and 'keypair' in res:
            ssh_key = res['keypair']

        return ssh_key

    def create_ssh_key(self):
        ssh_key = self.get_ssh_key()
        if not ssh_key:
            self.result['changed'] = True
            args = self._get_common_args()
            args['name'] = self.module.params.get('name')
            if not self.module.check_mode:
                res = self.cs.createSSHKeyPair(**args)
                ssh_key = res['keypair']
        return ssh_key

    def remove_ssh_key(self, name=None):
        ssh_key = self.get_ssh_key()
        if ssh_key:
            self.result['changed'] = True
            args = self._get_common_args()
            args['name'] = name or self.module.params.get('name')
            if not self.module.check_mode:
                self.cs.deleteSSHKeyPair(**args)
        return ssh_key

    def _get_common_args(self):
        return {
            'domainid': self.get_domain('id'),
            'account': self.get_account('name'),
            'projectid': self.get_project('id')
        }

    def get_ssh_key(self):
        if not self.ssh_key:
            public_key = self.module.params.get('public_key')
            if public_key:
                # Query by fingerprint of the public key
                args_fingerprint = self._get_common_args()
                args_fingerprint['fingerprint'] = self._get_ssh_fingerprint(public_key)
                ssh_keys = self.cs.listSSHKeyPairs(**args_fingerprint)
                if ssh_keys and 'sshkeypair' in ssh_keys:
                    self.ssh_key = ssh_keys['sshkeypair'][0]
            # When key has not been found by fingerprint, use the name
            if not self.ssh_key:
                args_name = self._get_common_args()
                args_name['name'] = self.module.params.get('name')
                ssh_keys = self.cs.listSSHKeyPairs(**args_name)
                if ssh_keys and 'sshkeypair' in ssh_keys:
                    self.ssh_key = ssh_keys['sshkeypair'][0]
        return self.ssh_key

    def _get_ssh_fingerprint(self, public_key):
        key = sshpubkeys.SSHKey(public_key)
        return key.hash()


def main():
    argument_spec = cs_argument_spec()
    argument_spec.update(dict(
        name=dict(required=True),
        public_key=dict(),
        domain=dict(),
        account=dict(),
        project=dict(),
        state=dict(choices=['present', 'absent'], default='present'),
    ))

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

    if not HAS_LIB_SSHPUBKEYS:
        module.fail_json(msg="python library sshpubkeys required: pip install sshpubkeys")

    try:
        acs_sshkey = AnsibleCloudStackSshKey(module)
        state = module.params.get('state')
        if state in ['absent']:
            ssh_key = acs_sshkey.remove_ssh_key()
        else:
            public_key = module.params.get('public_key')
            if public_key:
                ssh_key = acs_sshkey.register_ssh_key(public_key)
            else:
                ssh_key = acs_sshkey.create_ssh_key()

        result = acs_sshkey.get_result(ssh_key)

    except CloudStackException as e:
        module.fail_json(msg='CloudStackException: %s' % str(e))

    module.exit_json(**result)


if __name__ == '__main__':
    main()
