# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

import fixtures
import logging
import os
import testtools
import yaml

from diskimage_builder.block_device.blockdevice \
    import BlockDevice


logger = logging.getLogger(__name__)


class TestConfig(testtools.TestCase):
    """Helper for setting up and reading a config"""
    def setUp(self):
        super(TestConfig, self).setUp()

        fs = '%(asctime)s %(levelname)s [%(name)s] %(message)s'
        self.log_fixture = self.useFixture(
            fixtures.FakeLogger(level=logging.DEBUG, format=fs))

        # reset all globals for each test.
        # XXX: remove globals :/
        import diskimage_builder.block_device.level2.mkfs
        diskimage_builder.block_device.level2.mkfs.file_system_labels = set()
        import diskimage_builder.block_device.level3.mount
        diskimage_builder.block_device.level3.mount.mount_points = {}
        diskimage_builder.block_device.level3.mount.sorted_mount_points = None

    def load_config_file(self, f):
        path = os.path.join(os.path.dirname(__file__),
                            'config', f)
        with open(path, 'r') as config:
            return yaml.safe_load(config)


class TestGraphGeneration(TestConfig):
    """Extra helper class for testing graph generation"""
    def setUp(self):
        super(TestGraphGeneration, self).setUp()

        self.fake_default_config = {
            'build-dir': '/fake',
            'image-size': '1000',
            'image-dir': '/fake',
            'mount-base': '/fake',
        }

        self.bd = BlockDevice(self.fake_default_config)


# NOTE: inherits from TestGraphGeneration for simplicity to get
# BlockDevice.plugin_manager object for _config_tree_to_diagraph.
# Config parsing can be moved separately (and not require a
# BlockDevice object) in a later change.
class TestConfigParsing(TestGraphGeneration):
    """Test parsing config file into a graph"""

    def test_config_bad_plugin(self):
        # Currently, configuration parsing does not notice a missing
        # plugin.  This is left as a stub
        return
        # config = self.load_config_file('bad_plugin.yaml')
        # self.assertRaises(BlockDeviceSetupException,
        #                  self.bd._config_tree_to_digraph,
        #                  config, self.bd.plugin_manager)

    # a graph should remain the same
    def test_graph(self):
        graph = self.load_config_file('simple_graph.yaml')
        parsed_graph = self.bd._config_tree_to_digraph(graph,
                                                       self.bd.plugin_manager)
        self.assertEqual(parsed_graph, graph)

    # equivalence of simple tree to graph
    def test_simple_tree(self):
        tree = self.load_config_file('simple_tree.yaml')
        graph = self.load_config_file('simple_graph.yaml')
        parsed_graph = self.bd.\
                       _config_tree_to_digraph(tree,
                                               self.bd.plugin_manager)
        self.assertItemsEqual(parsed_graph, graph)

    # equivalence of a deeper tree to graph
    def test_deep_tree(self):
        tree = self.load_config_file('deep_tree.yaml')
        graph = self.load_config_file('deep_graph.yaml')
        parsed_graph = self.bd.\
                       _config_tree_to_digraph(tree, self.bd.plugin_manager)
        self.assertItemsEqual(parsed_graph, graph)

    # equivalence of a complicated multi-partition tree to graph
    def test_multipart_tree(self):
        tree = self.load_config_file('multiple_partitions_tree.yaml')
        graph = self.load_config_file('multiple_partitions_graph.yaml')
        parsed_graph = self.bd._config_tree_to_digraph(tree,
                                                       self.bd.plugin_manager)
        logger.debug(parsed_graph)
        self.assertItemsEqual(parsed_graph, graph)


class TestCreateGraph(TestGraphGeneration):

    # Test digraph generation from deep_graph config file
    def test_deep_graph_generator(self):
        config = self.load_config_file('deep_graph.yaml')

        graph, call_order = self.bd.create_graph(config,
                                                 self.fake_default_config)

        call_order_list = [n.name for n in call_order]

        # manually created from deep_graph.yaml
        # Note unlike below, the sort here is stable because the graph
        # doesn't have multiple paths with only one partition
        call_order_names = ['image0', 'root', 'mkfs_root',
                            'mount_mkfs_root',
                            'fstab_mount_mkfs_root']

        self.assertListEqual(call_order_list, call_order_names)

    # Test multiple parition digraph generation
    def test_multiple_partitions_graph_generator(self):
        config = self.load_config_file('multiple_partitions_graph.yaml')

        graph, call_order = self.bd.create_graph(config,
                                                 self.fake_default_config)
        call_order_list = [n.name for n in call_order]

        # The sort creating call_order_list is unstable.

        # We want to ensure we see the "partitions" object in
        # root->var->var_log order
        root_pos = call_order_list.index('root')
        var_pos = call_order_list.index('var')
        var_log_pos = call_order_list.index('var_log')
        self.assertGreater(var_pos, root_pos)
        self.assertGreater(var_log_pos, var_pos)

        # Ensure mkfs happens after partition
        mkfs_root_pos = call_order_list.index('mkfs_root')
        self.assertLess(root_pos, mkfs_root_pos)
        mkfs_var_pos = call_order_list.index('mkfs_var')
        self.assertLess(var_pos, mkfs_var_pos)
        mkfs_var_log_pos = call_order_list.index('mkfs_var_log')
        self.assertLess(var_log_pos, mkfs_var_log_pos)