from unittest import mock

import pytest

from cloudinit.config.cc_resolv_conf import generate_resolv_conf

EXPECTED_HEADER = """\

# Your system has been configured with 'manage-resolv-conf' set to true.

# As a result, cloud-init has written this file with configuration data

# that it has been provided. Cloud-init, by default, will write this file

# a single time (PER_ONCE).

#\n\n"""

class TestGenerateResolvConf:

    @mock.patch("cloudinit.config.cc_resolv_conf.templater.render_to_file")

    def test_default_target_fname_is_etc_resolvconf(self, m_render_to_file):

        generate_resolv_conf("templates/resolv.conf.tmpl", mock.MagicMock())

        assert [

            mock.call(mock.ANY, "/etc/resolv.conf", mock.ANY)

        ] == m_render_to_file.call_args_list

    @mock.patch("cloudinit.config.cc_resolv_conf.templater.render_to_file")

    def test_target_fname_is_used_if_passed(self, m_render_to_file):

        generate_resolv_conf(

            "templates/resolv.conf.tmpl", mock.MagicMock(), "/use/this/path"

        )

        assert [

            mock.call(mock.ANY, "/use/this/path", mock.ANY)

        ] == m_render_to_file.call_args_list

    # Patch in templater so we can assert on the actual generated content

    @mock.patch("cloudinit.templater.util.write_file")

    # Parameterise with the value to be passed to generate_resolv_conf as the

    # params parameter, and the expected line after the header as

    # expected_extra_line.

    @pytest.mark.parametrize(

        "params,expected_extra_line",

        [

            # No options

            ({}, None),

            # Just a true flag

            ({"options": {"foo": True}}, "options foo"),

            # Just a false flag

            ({"options": {"foo": False}}, None),

            # Just an option

            ({"options": {"foo": "some_value"}}, "options foo:some_value"),

            # A true flag and an option

            (

                {"options": {"foo": "some_value", "bar": True}},

                "options bar foo:some_value",

            ),

            # Two options

            (

                {"options": {"foo": "some_value", "bar": "other_value"}},

                "options bar:other_value foo:some_value",

            ),

            # Everything

            (

                {

                    "options": {

                        "foo": "some_value",

                        "bar": "other_value",

                        "baz": False,

                        "spam": True,

                    }

                },

                "options spam bar:other_value foo:some_value",

            ),

        ],

    )

    def test_flags_and_options(

        self, m_write_file, params, expected_extra_line

    ):

        generate_resolv_conf("templates/resolv.conf.tmpl", params)

        expected_content = EXPECTED_HEADER

        if expected_extra_line is not None:

            # If we have any extra lines, expect a trailing newline

            expected_content += "\n".join([expected_extra_line, ""])

        assert [

            mock.call(mock.ANY, expected_content, mode=mock.ANY)

        ] == m_write_file.call_args_list