# Copyright 2018 Open Source Robotics Foundation, Inc.
#
# 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.

from ros2cli.node.direct import DirectNode
from ros2cli.node.strategy import add_arguments
from ros2cli.node.strategy import NodeStrategy

from ros2lifecycle.api import call_get_available_transitions
from ros2lifecycle.api import call_get_transition_graph
from ros2lifecycle.api import get_node_names
from ros2lifecycle.verb import VerbExtension

from ros2node.api import get_absolute_node_name
from ros2node.api import NodeNameCompleter


class ListVerb(VerbExtension):
    """Output a list of available transitions."""

    def add_arguments(self, parser, cli_name):  # noqa: D102
        add_arguments(parser)
        arg = parser.add_argument(
            'node_name', help='Name of the ROS node')
        arg.completer = NodeNameCompleter(
            include_hidden_nodes_key='include_hidden_nodes')
        parser.add_argument(
            '--include-hidden-nodes', action='store_true',
            help='Consider hidden nodes as well')
        parser.add_argument(
            '-a', '--all', action='store_true',
            help='Display all existing transitions')
        parser.add_argument(
            '--timeout', metavar='N', type=float,
            help='Maximum time to wait for response in seconds '
                 '(default: waits indefinitely)')

    def main(self, *, args):  # noqa: D102
        with NodeStrategy(args) as node:
            node_names = get_node_names(
                node=node, include_hidden_nodes=args.include_hidden_nodes)

        node_name = get_absolute_node_name(args.node_name)
        if node_name not in {n.full_name for n in node_names}:
            return 'Node not found'

        with DirectNode(args) as node:
            if args.all:
                transitions = call_get_transition_graph(
                    node=node, states={node_name: None}, timeout=args.timeout)
            else:
                transitions = call_get_available_transitions(
                    node=node, states={node_name: None}, timeout=args.timeout)
            transitions = transitions[node_name]
            if isinstance(transitions, Exception):
                return 'Exception while calling service of node ' \
                    f"'{args.node_name}': {transitions}"
            for t in transitions:
                print(
                    f'- {t.transition.label} [{t.transition.id}]\n'
                    f'\tStart: {t.start_state.label}\n'
                    f'\tGoal: {t.goal_state.label}')
