#!/usr/bin/env python
# This code is part of Ansible, but is an independent component.
# This particular file snippet, and this file snippet only, is BSD licensed.
# Modules you write using this snippet, which is embedded dynamically by Ansible
# still belong to the author of the module, and may assign their own license
# to the complete work.
#
# Copyright (c) 2014 Hewlett-Packard Development Company, L.P.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without modification,
# are permitted provided that the following conditions are met:
#
#    * Redistributions of source code must retain the above copyright
#      notice, this list of conditions and the following disclaimer.
#    * Redistributions in binary form must reproduce the above copyright notice,
#      this list of conditions and the following disclaimer in the documentation
#      and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
# USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

try:
    import glanceclient.v2.client as glanceclient
except ImportError:
    print("failed=True msg='module glanceclient is required for this module'")
try:
    from keystoneclient.v3 import client as ksclient
except ImportError:
    print(
        "failed=True msg='module keystoneclient is required for this module'"
    )

import hashlib
import os

try:
    from novaclient.v1_1 import client as nova_client
    from novaclient import exceptions
except ImportError:
    print("failed=True msg='module novaclient is required for this module'")

import time


DOCUMENTATION = '''
---
module: glance_download
short_description: Download file from Glance
description:
   - Return the requested file from Glance to a location defined by the user.
options:
   login_username:
     description:
        - login username to authenticate to keystone
     required: true
     default: admin
   login_password:
     description:
        - Password of login user
     required: true
     default: 'yes'
   login_tenant_name:
     description:
        - The tenant name of the login user
     required: true
     default: 'yes'
   auth_url:
     description:
        - The keystone url for authentication
     required: false
     default: 'http://127.0.0.1:35357/v2.0/'
   region_name:
     description:
        - Name of the region
     required: false
     default: None
   image_id:
     description:
        - Glance file ID that you wish to download.
     required: true
     default: None
   path:
     description:
        - Location where to save the file from Glance to
     required: true
     default: None
requirements: ["glanceclient"]
'''

EXAMPLES = '''
# Downloads a glance image to the defined path
- glance_download:
       login_username: admin
       login_password: admin
       login_tenant_name: admin
       image_id: 4f905f38-e52a-43d2-b6ec-754a13ffb529
       path: /tmp/4f905f38-e52a-43d2-b6ec-754a13ffb529.qcow2
'''


# The following openstack_ is a copy paste from an upcoming
# core module "lib/ansible/module_utils/openstack.py" Once that's landed,
# these should be replaced with a line at the bottom of the file:
# from ansible.module_utils.openstack import *
def openstack_argument_spec():
    # Consume standard OpenStack environment variables.
    # This is mainly only useful for ad-hoc command line operation as
    # in playbooks one would assume variables would be used appropriately
    OS_AUTH_URL = os.environ.get('OS_AUTH_URL', 'http://127.0.0.1:35357/v2.0/')
    OS_PASSWORD = os.environ.get('OS_PASSWORD', None)
    OS_REGION_NAME = os.environ.get('OS_REGION_NAME', None)
    OS_USERNAME = os.environ.get('OS_USERNAME', 'admin')
    OS_TENANT_NAME = os.environ.get('OS_TENANT_NAME', OS_USERNAME)

    spec = dict(
        login_username=dict(default=OS_USERNAME),
        auth_url=dict(default=OS_AUTH_URL),
        region_name=dict(default=OS_REGION_NAME),
        availability_zone=dict(default=None),
    )
    if OS_PASSWORD:
        spec['login_password'] = dict(default=OS_PASSWORD)
    else:
        spec['login_password'] = dict(required=True)
    if OS_TENANT_NAME:
        spec['login_tenant_name'] = dict(default=OS_TENANT_NAME)
    else:
        spec['login_tenant_name'] = dict(required=True)
    return spec


def _glance_get_image_checksum(glance, image_id):
    return glance.images.get(image_id).checksum


def _md5sum_file(path):
    try:
        with open(path) as file_object:
            checksum = hashlib.md5()
            while True:
                data = file_object.read(65535)
                if not data:
                    break
                checksum.update(data)
        return checksum.hexdigest()
    except Excption, e:
        print("Checksum operaction failed: %s" % e.message)


def _glance_download(module, glance, image_id, path):
    image_checksum = _glance_get_image_checksum(glance, image_id)
    if os.path.isfile(path):
        file_checksum = _md5sum_file(path)
        if image_checksum == file_checksum:
            module.exit_json(
                ansible_facts={
                    'returned_checksum': file_checksum
                }
            )
    try:
        file_data = glance.images.data(image_id)
        glanceclient.utils.save_image(file_data, path)
    except:
        module.fail_json(
            msg="Retrieval of image from Glance failed."
        )
    file_checksum = _md5sum_file(path)
    if image_checksum == file_checksum:
            module.exit_json(
                ansible_facts={
                    'returned_checksum': file_checksum
                }
            )
    else:
        module.fail_json(
            msg="Glance checksum %s != %s checksum %s" % (
                image_checksum,
                path,
                file_checksum
            )
        )


def main():
    argument_spec = openstack_argument_spec()
    argument_spec.update(dict(
        image_id=dict(required=True),
        path=dict(required=True)
    ))
    module = AnsibleModule(argument_spec=argument_spec)
    try:
        if '/v2.0' in module.params['auth_url']:
            module.params['auth_url'] = module.params['auth_url'].replace(
                '/v2.0',
                '/v3'
            )
        keystone = ksclient.Client(
            username=module.params['login_username'],
            password=module.params['login_password'],
            tenant=module.params['login_tenant_name'],
            auth_url=module.params['auth_url'],
            region_name=module.params['region_name']
        )
        keystone.authenticate()
    except:
        module.fail_json(
            msg="Failed to Authenticate to Keystone"
        )
    try:
        glance_endpoint = keystone.service_catalog.url_for(
            service_type='image',
            endpoint_type='publicURL'
        )
    except:
        module.fail_json(
            msg="Failed to retrieve image server URL"
        )
    try:
        glance = glanceclient.Client(
            endpoint=glance_endpoint,
            token=keystone.auth_token
        )
    except:
        module.fail_json(
            msg="Failed to connect to Glance"
        )

    _glance_download(
        module,
        glance,
        module.params['image_id'],
        module.params['path']
    )


from ansible.module_utils.basic import *
main()