#
#    Copyright (C) 2014 Vaidas Jablonskis
#
#    Author: Vaidas Jablonskis <jablonskis@gmail.com>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License version 3, as
#    published by the Free Software Foundation.
#
#    This program 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 program.  If not, see <http://www.gnu.org/licenses/>.

import httpretty
import re

from base64 import b64encode, b64decode
from urlparse import urlparse

from cloudinit import settings
from cloudinit import helpers
from cloudinit.sources import DataSourceGCE

from .. import helpers as test_helpers

GCE_META = {
    'instance/id': '123',
    'instance/zone': 'foo/bar',
    'project/attributes/sshKeys': 'user:ssh-rsa AA2..+aRD0fyVw== root@server',
    'instance/hostname': 'server.project-foo.local',
    'instance/attributes/user-data': '/bin/echo foo\n',
}

GCE_META_PARTIAL = {
    'instance/id': '1234',
    'instance/hostname': 'server.project-bar.local',
    'instance/zone': 'bar/baz',
}

GCE_META_ENCODING = {
    'instance/id': '12345',
    'instance/hostname': 'server.project-baz.local',
    'instance/zone': 'baz/bang',
    'instance/attributes/user-data': b64encode('/bin/echo baz\n'),
    'instance/attributes/user-data-encoding': 'base64',
}

HEADERS = {'X-Google-Metadata-Request': 'True'}
MD_URL_RE = re.compile(
    r'http://metadata.google.internal./computeMetadata/v1/.*')


def _new_request_callback(gce_meta=None):
    if not gce_meta:
        gce_meta = GCE_META

    def _request_callback(method, uri, headers):
        url_path = urlparse(uri).path
        if url_path.startswith('/computeMetadata/v1/'):
            path = url_path.split('/computeMetadata/v1/')[1:][0]
        else:
            path = None
        if path in gce_meta:
            return (200, headers, gce_meta.get(path))
        else:
            return (404, headers, '')

    return _request_callback


class TestDataSourceGCE(test_helpers.HttprettyTestCase):

    def setUp(self):
        self.ds = DataSourceGCE.DataSourceGCE(
            settings.CFG_BUILTIN, None,
            helpers.Paths({}))
        super(TestDataSourceGCE, self).setUp()

    @httpretty.activate
    def test_connection(self):
        httpretty.register_uri(
            httpretty.GET, MD_URL_RE,
            body=_new_request_callback())

        success = self.ds.get_data()
        self.assertTrue(success)

        req_header = httpretty.last_request().headers
        self.assertDictContainsSubset(HEADERS, req_header)

    @httpretty.activate
    def test_metadata(self):
        httpretty.register_uri(
            httpretty.GET, MD_URL_RE,
            body=_new_request_callback())
        self.ds.get_data()

        self.assertEqual(GCE_META.get('instance/hostname'),
                         self.ds.get_hostname())

        self.assertEqual(GCE_META.get('instance/id'),
                         self.ds.get_instance_id())

        self.assertEqual(GCE_META.get('instance/zone'),
                         self.ds.availability_zone)

        self.assertEqual(GCE_META.get('instance/attributes/user-data'),
                         self.ds.get_userdata_raw())

        # we expect a list of public ssh keys with user names stripped
        self.assertEqual(['ssh-rsa AA2..+aRD0fyVw== root@server'],
                         self.ds.get_public_ssh_keys())

    # test partial metadata (missing user-data in particular)
    @httpretty.activate
    def test_metadata_partial(self):
        httpretty.register_uri(
            httpretty.GET, MD_URL_RE,
            body=_new_request_callback(GCE_META_PARTIAL))
        self.ds.get_data()

        self.assertEqual(GCE_META_PARTIAL.get('instance/id'),
                         self.ds.get_instance_id())

        self.assertEqual(GCE_META_PARTIAL.get('instance/hostname'),
                         self.ds.get_hostname())

    @httpretty.activate
    def test_metadata_encoding(self):
        httpretty.register_uri(
            httpretty.GET, MD_URL_RE,
            body=_new_request_callback(GCE_META_ENCODING))
        self.ds.get_data()

        decoded = b64decode(
            GCE_META_ENCODING.get('instance/attributes/user-data'))
        self.assertEqual(decoded, self.ds.get_userdata_raw())