#! /usr/bin/env python3

"""
Description:
    This ROS 2 node subscribes to "Hello World" messages on a topic.
    It demonstrates basic ROS concepts such as node creation and subscribing.
-------
Publishing Topics:
    None
-------
Subscription Topics:
    The channel containing the "Hello World" messages
    /py_example_topic - std_msgs/String
-------
Author: Addison Sears-Collins
Date: November 5, 2024
"""

import rclpy  # Import the ROS 2 client library for Python
from rclpy.node import Node  # Import the Node class for creating ROS 2 nodes

from std_msgs.msg import String  # Import the String message type


class MinimalPySubscriber(Node):
    """Create Minimal Subscriber node.

    """

    def __init__(self):
        """ Create a custom node class for subscribing

        """

        # Initialize the node with a name
        super().__init__('minimal_py_subscriber')

        # Creates a subscriber
        self.subscriber_1 = self.create_subscription(
            String,
            '/py_example_topic',
            self.listener_callback,
            10)

    def listener_callback(self, msg):
        """Call this function every time a new message is published on
            the topic.

        """
        # Log a message indicating that the message has been published
        self.get_logger().info(f'I heard: "{msg.data}"')


def main(args=None):
    """Main function to start the ROS 2 node.

    Args:
        args (List, optional): Command-line arguments. Defaults to None.
    """

    # Initialize ROS 2 communication
    rclpy.init(args=args)

    # Create an instance of the MinimalPySubscriber node
    minimal_py_subscriber = MinimalPySubscriber()

    # Keep the node running and processing events.
    rclpy.spin(minimal_py_subscriber)

    # Destroy the node explicitly
    # (optional - otherwise it will be done automatically
    # when the garbage collector destroys the node object)
    minimal_py_subscriber.destroy_node()

    # Shutdown ROS 2 communication
    rclpy.shutdown()


if __name__ == '__main__':
    # Execute the main function if the script is run directly
    main()

cmake_minimum_required(VERSION 3.8)
project(ros2_fundamentals_examples)

# Check if the compiler being used is GNU's C++ compiler (g++) or Clang.
# Add compiler flags for all targets that will be defined later in the
# CMakeLists file. These flags enable extra warnings to help catch
# potential issues in the code.
# Add options to the compilation process
if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
  add_compile_options(-Wall -Wextra -Wpedantic)
endif()

# Locate and configure packages required by the project.
find_package(ament_cmake REQUIRED)
find_package(ament_cmake_python REQUIRED)
find_package(rclcpp REQUIRED)
find_package(rclpy REQUIRED)
find_package(std_msgs REQUIRED)

# Define a CMake variable named dependencies that lists all
# ROS 2 packages and other dependencies the project requires.
set(dependencies
  rclcpp
  std_msgs
)

# Add the specified directories to the list of paths that the compiler
# uses to search for header files. This is important for C++
# projects where you have custom header files that are not located
# in the standard system include paths.
include_directories(
  include
)

# Tells CMake to create an executable target named cpp_minimal_publisher
# from the source file src/cpp_minimal_publisher.cpp. Also make sure CMake
# knows about the program's dependencies.
add_executable(cpp_minimal_publisher src/cpp_minimal_publisher.cpp)
ament_target_dependencies(cpp_minimal_publisher ${dependencies})

#add_executable(cpp_minimal_subscriber src/cpp_minimal_subscriber.cpp)
#ament_target_dependencies(cpp_minimal_subscriber ${dependencies})

# Copy necessary files to designated locations in the project
install (
  DIRECTORY ros2_fundamentals_examples
  DESTINATION share/${PROJECT_NAME}
)

install(
  DIRECTORY include/
  DESTINATION include
)

# Install cpp executables
install(
  TARGETS
  cpp_minimal_publisher
#  cpp_minimal_subscriber
  DESTINATION lib/${PROJECT_NAME}
)

# Install Python modules for import
ament_python_install_package(${PROJECT_NAME})

# Add this section to install Python scripts
install(
  PROGRAMS
  ros2_fundamentals_examples/py_minimal_publisher.py
  ros2_fundamentals_examples/py_minimal_subscriber.py
  DESTINATION lib/${PROJECT_NAME}
)

# Automates the process of setting up linting for the package, which
# is the process of running tools that analyze the code for potential
# errors, style issues, and other discrepancies that do not adhere to
# specified coding standards or best practices.
if(BUILD_TESTING)
  find_package(ament_lint_auto REQUIRED)
  # the following line skips the linter which checks for copyrights
  # comment the line when a copyright and license is added to all source files
  set(ament_cmake_copyright_FOUND TRUE)
  # the following line skips cpplint (only works in a git repo)
  # comment the line when this package is in a git repo and when
  # a copyright and license is added to all source files
  set(ament_cmake_cpplint_FOUND TRUE)
  ament_lint_auto_find_test_dependencies()
endif()

# Used to export include directories of a package so that they can be easily
# included by other packages that depend on this package.
ament_export_include_directories(include)

# Generate and install all the necessary CMake and environment hooks that
# allow other packages to find and use this package.
ament_package()

#!/bin/bash
# Launch publisher and subscriber nodes with cleanup handling

cleanup() {
    echo "Restarting ROS 2 daemon to cleanup before shutting down all processes..."
    ros2 daemon stop
    sleep 1
    ros2 daemon start
    echo "Terminating all ROS 2-related processes..."
    kill 0
    exit
}

trap 'cleanup' SIGINT

# Launch the publisher node
ros2 run ros2_fundamentals_examples py_minimal_publisher.py &
sleep 2

# Launch the subscriber node
ros2 run ros2_fundamentals_examples py_minimal_subscriber.py

# Copy necessary files to designated locations in the project
install (
  DIRECTORY ros2_fundamentals_examples 
  DESTINATION share/${PROJECT_NAME}
)

# Copy necessary files to designated locations in the project
install (
  DIRECTORY ros2_fundamentals_examples scripts
  DESTINATION share/${PROJECT_NAME}
)