#! /usr/bin/env python3

"""
Description:
    This ROS 2 node periodically publishes "Hello World" messages on a topic.
    It demonstrates basic ROS concepts such as node creation, publishing, and
    timer usage.
-------
Publishing Topics:
    The channel containing the "Hello World" messages
    /topic - std_msgs/String
-------
Subscription Topics:
    None    
-------
Author: Addison Sears-Collins
Date: January 31, 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 for publishing


class MinimalPublisher(Node):
    """Create MinimalPublisher node.

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

        """

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

        # Creates a publisher on the topic "topic" with a queue size of 10 messages
        self.publisher_1 = self.create_publisher(String, '/topic', 10)

        # Create a timer with a period of 0.5 seconds to trigger the callback function
        timer_period = 0.5  # seconds
        self.timer = self.create_timer(timer_period, self.timer_callback)   

        # Initialize a counter variable for message content
        self.i = 0

    def timer_callback(self):
        """Callback function executed periodically by the timer.

        """
        # Create a new String message object
        msg = String()

        # Set the message data with a counter
        msg.data = 'Hello World: %d' % self.i

        # Publish the message on the topic
        self.publisher_1.publish(msg)

        # Log a message indicating that the message has been published
        self.get_logger().info('Publishing: "%s"' % msg.data)

        # Increment the counter for the next message
        self.i = self.i + 1


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 MinimalPublisher node
    minimal_publisher = MinimalPublisher()

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

    # Destroy the node explicitly
    # (optional - otherwise it will be done automatically
    # when the garbage collector destroys the node object)
    minimal_publisher.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(cobot_arm_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 minimal_cpp_publisher
# from the source file src/minimal_cpp_publisher.cpp. Also make sure CMake
# knows about the program's dependencies.
add_executable(minimal_cpp_publisher src/minimal_cpp_publisher.cpp)
ament_target_dependencies(minimal_cpp_publisher ${dependencies})

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

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

install(
  DIRECTORY include/
  DESTINATION include
)

# Install cpp executables
install(
  TARGETS
  minimal_cpp_publisher
  minimal_cpp_subscriber
  DESTINATION lib/${PROJECT_NAME}
)

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

# Install Python executables
install(
  PROGRAMS
  scripts/minimal_py_publisher.py
  scripts/minimal_py_subscriber.py
  #scripts/example3.py
  #scripts/example4.py
  #scripts/example5.py
  #scripts/example6.py
  #scripts/example7.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()