# Copyright (c) 2022 Hai Cao, <t-haicao@microsoft.com>, Marcin Slowikowski (@msl0)
#
# 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 = """
---
name: azure_keyvault_secret
author:
    - Hai Cao (@tk5eq) <t-haicao@microsoft.com>
    - Marcin Slowikowski (@msl0)
version_added: '1.12.0'
requirements:
    - requests
    - azure
short_description: Read secret from Azure Key Vault.
description:
  - This lookup returns the content of secret saved in Azure Key Vault.
  - When ansible host is MSI enabled Azure VM, user don't need provide any credential to access to Azure Key Vault.
options:
    _terms:
        description: Secret name, version can be included like secret_name/secret_version.
        required: True
    vault_url:
        description: Url of Azure Key Vault.
        required: True
    tenant:
        aliases:
          - tenant_id
    use_msi:
        description:
          - MSI token autodiscover.
          - The default is to try MSI authentication first, then use auth_source, You can disable MSI entirely
            by setting this to False.
        default: true
    use_cli:
        description:
          - When I(use_cli=True), get the 'az login' credential authentication, default if false.
          - Deprecated, please use I(auth_source=cli) instead.
    cloud_type:
        description: Specify which cloud, such as C(azure), C(usgovcloudapi).
notes:
    - If version is not provided, this plugin will return the latest version of the secret.
    - If ansible is running on Azure Virtual Machine with MSI enabled, client_id, secret and tenant are not required.
    - For enabling MSI on Azure VM, please refer to this doc https://docs.microsoft.com/en-us/azure/active-directory/managed-service-identity/
    - After enabling MSI on Azure VM, remember to grant access of the Key Vault to the VM by adding a new Acess Policy in Azure Portal.
    - If MSI is not enabled on ansible host, it's required to provide a valid service principal which has access to the key vault.
    - To authenticate via service principal, pass client_id, secret and tenant or set environment variables
      AZURE_CLIENT_ID, AZURE_CLIENT_SECRET and AZURE_TENANT_ID.
    - Authentication via C(az login) is also supported. Set I(use_cli=true) when using Azure CLI.
    - To use a plugin from a collection, please reference the full namespace, collection name, and lookup plugin name that you want to use.

extends_documentation_fragment:
    - azure.azcollection.azure_plugin
"""

EXAMPLE = """
- name: Look up secret when azure cli login
  debug:
    msg: msg: "{{ lookup('azure.azcollection.azure_keyvault_secret', 'testsecret', vault_url=key_vault_uri, use_cli=true)}}"

- name: Look up secret with cloud type
  debug:
    msg: msg: "{{ lookup('azure.azcollection.azure_keyvault_secret', 'testsecret', cloud_type='usgovcloudapi', vault_url=key_vault_uri)}}"

- name: Look up secret when ansible host is MSI enabled Azure VM
  debug:
    msg: "the value of this secret is {{
        lookup(
          'azure.azcollection.azure_keyvault_secret',
          'testSecret/version',
          vault_url='https://yourvault.vault.azure.net'
        )
      }}"

- name: Look up secret when ansible host is general VM
  vars:
    url: 'https://yourvault.vault.azure.net'
    secretname: 'testSecret/version'
    client_id: '123456789'
    secret: 'abcdefg'
    tenant: 'uvwxyz'
  debug:
    msg: "the value of this secret is {{
        lookup(
          'azure.azcollection.azure_keyvault_secret',
          secretname,
          vault_url=url,
          client_id=client_id,
          secret=secret,
          tenant=tenant,
          use_msi=False
        )
      }}"

# Example below creates an Azure Virtual Machine with SSH public key from key vault using 'azure_keyvault_secret' lookup plugin.
- name: Create Azure VM
  hosts: localhost
  connection: local
  no_log: True
  vars:
    resource_group: myResourceGroup
    vm_name: testvm
    location: eastus
    ssh_key: "{{ lookup('azure.azcollection.azure_keyvault_secret','myssh_key') }}"
  - name: Create VM
    azure_rm_virtualmachine:
      resource_group: "{{ resource_group }}"
      name: "{{ vm_name }}"
      vm_size: Standard_DS1_v2
      admin_username: azureuser
      ssh_password_enabled: false
      ssh_public_keys:
        - path: /home/azureuser/.ssh/authorized_keys
          key_data: "{{ ssh_key }}"
      network_interfaces: "{{ vm_name }}"
      image:
        offer: 0001-com-ubuntu-server-focal
        publisher: Canonical
        sku: 20_04-lts
        version: latest
"""

RETURN = """
  _raw:
    description: secret content string
"""

from ansible_collections.azure.azcollection.plugins.module_utils.azure_rm_common import AzureRMAuth
from ansible.errors import AnsibleError
from ansible.plugins.lookup import LookupBase
from ansible.utils.display import Display
try:
    import logging
    import requests
    from azure.keyvault.secrets import SecretClient
    from azure.keyvault.secrets import SecretClient

except ImportError:
    pass

display = Display()

TOKEN_ACQUIRED = False

logger = logging.getLogger("azure.identity").setLevel(logging.ERROR)


class LookupModule(LookupBase):
    def lookup_secret_non_msi(self, terms, vault_url, auth_source):

        client_id = self.get_option('client_id')
        secret = self.get_option('secret')
        tenant = self.get_option('tenant')

        # Legacy use_cli will set auth_source to cli.
        if self.get_option('use_cli'):
            auth_source = 'cli'
        # If auth_source is auto but no client_id or secret passed in switch to cli
        if auth_source == 'auto':
            if any(v is None for v in [client_id, secret, tenant]):
                auth_source = 'cli'

        auth_options = dict(
            auth_source=auth_source,
            client_id=client_id,
            secret=secret,
            tenant=tenant,
            is_ad_resource=True
        )

        azure_auth = AzureRMAuth(**auth_options)

        client = SecretClient(vault_url, azure_auth.azure_credential_track2)

        ret = []
        for term in terms:
            try:
                secret_val = client.get_secret(term).value
                ret.append(secret_val)
            except Exception:
                raise AnsibleError('Failed to fetch secret ' + term + ' from ' + vault_url + '.')
        return ret

    def run(self, terms, variables, **kwargs):

        self.set_options(direct=kwargs)

        ret = []
        # Default auth_source is auto, but we still try MSI first unless explicitly disabled.
        auth_source = self.get_option('auth_source')
        vault_url = self.get_option('vault_url')
        use_msi = self.get_option('use_msi')
        TOKEN_ACQUIRED = False
        token = None

        token_params = {
            'api-version': '2018-02-01',
            'resource': 'https://vault.{0}.net'.format(self.get_option('cloud_type') or 'azure')
        }

        token_headers = {
            'Metadata': 'true'
        }

        if use_msi:
            try:
                token_res = requests.get('http://169.254.169.254/metadata/identity/oauth2/token',
                                         params=token_params,
                                         headers=token_headers,
                                         timeout=(3.05, 27))
                if token_res.ok:
                    token = token_res.json().get("access_token")
                    if token is not None:
                        TOKEN_ACQUIRED = True
                    else:
                        display.v('Successfully called MSI endpoint, but no token was available. Will use service principal if provided.')
                else:
                    display.v("Unable to query MSI endpoint, Error Code %s. Will use service principal if provided" % token_res.status_code)
            except Exception:
                display.v('Unable to fetch MSI token. Will use service principal if provided.')

        if vault_url is None:
            raise AnsibleError('Failed to get valid vault url.')
        if TOKEN_ACQUIRED:
            secret_params = {'api-version': '2016-10-01'}
            secret_headers = {'Authorization': 'Bearer ' + token}
            for term in terms:
                try:
                    secret_res = requests.get(vault_url + '/secrets/' + term, params=secret_params, headers=secret_headers)
                    ret.append(secret_res.json()["value"])
                except KeyError:
                    raise AnsibleError('Failed to fetch secret ' + term + ' from ' + vault_url + '.')
                except Exception:
                    raise AnsibleError('Failed to fetch secret ' + term + ' from ' + vault_url + ' via MSI endpoint.')
            return ret
        else:
            return self.lookup_secret_non_msi(terms, vault_url, auth_source)
