# Author: Phillip Jones
# Date: 08/19/2022, updated 05/25/2023, updated 07/13/2023
# Description: Simple client for sending/recieveing information using a UART interface, or Network Socket
#              to either a mock CyBot server, or the actual CyBot

# General Python tutorials (W3schools):  https://www.w3schools.com/python/

# Serial library:  https://pyserial.readthedocs.io/en/latest/shortintro.html 
import serial
import time # Time library   
# Socket library:  https://realpython.com/python-sockets/  
# See: Background, Socket API Overview, and TCP Sockets  
import socket   

# Choose to create either a UART or TCP port socket to communicate with Cybot (Not both!!: I.e, comment out the one not being used)
# UART BEGIN
#cybot = serial.Serial('COM100', 115200)  # UART (Make sure you are using the correct COM port and Baud rate!!)
# UART END

# TCP Socket BEGIN (See Echo Client example): https://realpython.com/python-sockets/#echo-client-and-server
HOST = "127.0.0.1"  # The server's hostname or IP address
PORT = 65432        # The port used by the server
cybot_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  # Create a socket object
cybot_socket.connect((HOST, PORT))   # Connect to the socket  (Note: Server must first be running)
                      
cybot = cybot_socket.makefile("rbw", buffering=0)  # makefile creates a file object out of a socket:  https://pythontic.com/modules/socket/makefile
# TCP Socket END

# Send some text: Either 1) Choose "Hello" or 2) have the user enter text to send
send_message = "Hello\n"                            # 1) Hard code message to "Hello", or
# send_message = input("Enter a message:") + '\n'   # 2) Have user enter text

cybot.write(send_message.encode()) # Convert String to bytes (i.e., encode), and send data to the server

print("Sent to server: " + send_message) 

# Send messges to server until user sends "quit"
while send_message != 'quit\n':
        print("wait for server reply\n")
        rx_message = cybot.readline()      # Wait for a message, readline expects message to end with "\n"
        print("Got a message from server: " + rx_message.decode() + "\n") # Convert message from bytes to String (i.e., decode)
        send_message = input("Enter a message (enter quit to exit):") + '\n' # Enter next message to send to server
        cybot.write(send_message.encode()) # Convert String to bytes (i.e., encode), and send data to the server
        
print("Client exiting, and closing file descriptor, and/or network socket\n")
time.sleep(2) # Sleep for 2 seconds
cybot.close()         # Close file object associated with the socket or UART
cybot_socket.close()  # Close the socket (NOTE: comment out if using UART interface, only use for network socket option)