import os

from ament_index_python.packages import get_package_share_directory

from launch import LaunchDescription
from launch.substitutions import LaunchConfiguration
from launch.actions import IncludeLaunchDescription, DeclareLaunchArgument
from launch.launch_description_sources import PythonLaunchDescriptionSource
from launch.conditions import IfCondition
from nav2_common.launch import RewrittenYaml
from launch.actions import ExecuteProcess
from launch_ros.actions import Node


def generate_launch_description():
    # Get the launch directory
    bringup_dir = get_package_share_directory('nav2_bringup')
    launch_dir = os.path.join(bringup_dir, 'launch')
    params_dir = os.path.join(bringup_dir, "params")

    nav2_params = os.path.join(params_dir, "real_truck_nav2_params.yaml")
    configured_params = RewrittenYaml(
        source_file=nav2_params, root_key="", param_rewrites="", convert_types=True
    )

    # Keep truck static by publishing to /cmd_vel in a loop
    keep_truck_static_cmd = ExecuteProcess(
        cmd=['bash', '-c', "while true; do ros2 topic pub /cmd_vel geometry_msgs/msg/Twist '{linear: {x: -0.8, y: 0.0, z: 0.0}, angular: {x: 0.0, y: 0.0, z: 0.0}}' -1; sleep 0.1; done"],
        output='screen'
    )

    use_rviz = LaunchConfiguration('use_rviz')
    use_mapviz = LaunchConfiguration('use_mapviz')

    declare_use_rviz_cmd = DeclareLaunchArgument(
        'use_rviz',
        default_value='False',
        description='Whether to start RVIZ')

    declare_use_mapviz_cmd = DeclareLaunchArgument(
        'use_mapviz',
        default_value='True',
        description='Whether to start mapviz')

    robot_localization_cmd = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            os.path.join(launch_dir, 'real_bot_dual_ekf_navsat.launch.py'))
    )

    navigation2_cmd = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            os.path.join(bringup_dir, "launch", "real_navigation_launch.py")
        ),
        launch_arguments={
            "use_sim_time": "False",
            "params_file": configured_params,
            "autostart": "True",
        }.items(),
    )

    rviz_cmd = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            os.path.join(bringup_dir, "launch", 'rviz_launch.py')),
        condition=IfCondition(use_rviz)
    )

    mapviz_cmd = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            os.path.join(launch_dir, 'mapviz.launch.py')),
        condition=IfCondition(use_mapviz)
    )

    robot_cmd = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            os.path.join(launch_dir, 'real_truck_environment_launch.py'))
    )

    # Node to run broadcast_odom_base_footprint.py
    broadcast_odom_base_footprint_node = Node(
        package='nav2_bringup',
        executable='broadcast_odom_base_footprint.py',
        name='broadcast_odom_base_footprint',
        output='screen'
    )

    # Node to relay GPS from CAN to proper topic
    nmea_to_navsat_converter_node = Node(
        package='nav2_bringup',
        executable='nmea_to_navsat_converter.py',
        name='nmea_to_navsat_converter',
        output='screen'
    )

    # Relay command to publish GPS data to the correct topic
    relay_gps_fix_cmd = ExecuteProcess(
        cmd=['ros2', 'run', 'topic_tools', 'relay', '/real_gps/fix', '/gps/fix'],
        output='screen'
    )

    # Create the launch description and populate
    ld = LaunchDescription()

    # Add launch arguments
    ld.add_action(declare_use_rviz_cmd)
    ld.add_action(declare_use_mapviz_cmd)

    # Add robot launch
    ld.add_action(robot_cmd)

    # Add robot localization launch
    ld.add_action(robot_localization_cmd)

    # Add navigation2 launch
    ld.add_action(navigation2_cmd)

    # Add viz launch
    ld.add_action(rviz_cmd)
    ld.add_action(mapviz_cmd)

    # Add the broadcast_odom_base_footprint node
    ld.add_action(broadcast_odom_base_footprint_node)

    # Add nmea relay
    # ld.add_action(nmea_to_navsat_converter_node)

    # Add the relay GPS fix command
    ld.add_action(relay_gps_fix_cmd)

    # Uncomment when the terrain does not move the truck backwards (plane terrains don't need it)
    # ld.add_action(keep_truck_static_cmd) #FAKE BRAKE

    return ld