import socket
import os, sys
from time import sleep

def transfer_progress(percent_done):
    if percent_done==100:
        output_text = f"\rTransfer Complete!   (100% done)                  "
    else:
        output_text = f"\rTransfer in progress:  {percent_done:.2f} %"
    sys.stdout.write(output_text)
    sys.stdout.flush()
    #sleep(0.15)

def main(file_name, host, port):
    # Connect to the server
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect((host, port))

    print(f"Begin transfer of '{file_name}' to {host} : {port}")

    try:
        f = open(file_name, 'rb')
    except:
        raise Exception('Error reading the specified file!')

    size = os.path.getsize(file_name)   # Get size of the file to be sent first.
    sock.send(file_name.encode())       # Send the name of the file to the server.

    response = int(sock.recv(1).decode())    # Get integer bit 0 or 1 as acknowledgement/response
    if response:
        total = 0
        percent = total / size
        # Initialise progress bar
        transfer_progress(percent)
        data = f.read(1024)
        # Send data
        while data:
            sock.send(data)
            total += 1024
            percent = total / size
            if percent > 1:
                percent = 1
            transfer_progress(percent * 100)
            data = f.read(1024)
    else:
        print("Error: Sending {} failed!".format(file_name))
    sock.close()


if __name__ == "__main__":
    args = sys.argv

    if len(args) != 4:
        print('Argument Error: Program expects exactly 3 arguments: -file_name -hostname -portnumber')
    else:
        main(args[1], args[2], int(args[3]))