import launch_testing
import unittest
import os

from launch import LaunchDescription
from launch.actions import DeclareLaunchArgument, ExecuteProcess
from launch.substitutions import PathJoinSubstitution, LaunchConfiguration
from launch_ros.actions import Node
from launch.actions import IncludeLaunchDescription
from launch.substitutions import PathJoinSubstitution
from launch_ros.substitutions import FindPackageShare
from launch.launch_description_sources import PythonLaunchDescriptionSource



def generate_test_description():
    # This is necessary to get unbuffered output from the process under test
    proc_env = os.environ.copy()
    proc_env['PYTHONUNBUFFERED'] = '1'

    dut_process = ExecuteProcess(cmd=['/usr/bin/sleep', '5']) 
    pkg_dir = FindPackageShare('gazebo_ros')
    full_path = PathJoinSubstitution([pkg_dir] + ['launch', 'gazebo.launch.py'])

    gazebo_launch = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            full_path))

    return LaunchDescription([
        gazebo_launch,
        dut_process,

        launch_testing.actions.ReadyToTest(),
    ]), {'dut_process': dut_process}


class TestWait(unittest.TestCase):

    def test_wait_for_end(self, proc_output, proc_info, dut_process):
        # Wait until process ends
        proc_info.assertWaitForShutdown(process=dut_process, timeout=10)


@ launch_testing.post_shutdown_test()
class TestSuccessfulExit(unittest.TestCase):

    def test_exit_code(self, proc_info, dut_process):
        # Check that dut_process finishes with code 0
        launch_testing.asserts.assertExitCodes(proc_info, process=dut_process)