thread-client.py

import socket
import sys

# Constants
ADDR = "localhost"
PORT = 50009

# Enable print logging for debugging
_LOGGING = False


def printLog(message: str) -> None:
    """Print the message if logging is enabled

    :param message: The message to print
    :type message: str
    """
    if _LOGGING:
        print(message)


def handle_query(clientSocket: socket.socket) -> bool:
    while True:
        query = input("Input query: ")

        if query == "quit":
            # Exit the connection by sending 201 status code
            clientSocket.send("201:Client Disconnecting:END".encode())
            printLog("Closing connection with server")
            return False

        try:
            # Status code 200 indicates a query
            encodedQuery = f"200:{query}:END".encode()
            break
        except UnicodeEncodeError:
            print("Data is not in unicode format")
            # Collect input until the data is in unicode format
            continue

    clientSocket.send(encodedQuery)
    printLog(f"Query sent: {query}")

    encodedData = b""
    while True:
        # Receive data in chunks of 1024 bytes
        encodedDataChunk = clientSocket.recv(1024)
        if not encodedDataChunk:
            break
        encodedData += encodedDataChunk

        # Check if the data received is incomplete
        if len(encodedDataChunk) < 1024 and encodedDataChunk[-3:] != b"END":
            print("Data received is incomplete, exiting...")
            # Return False, do not recover from this error
            return False

        # Data send is complete once the END tag is received
        if encodedDataChunk[-3:] == b"END":
            break

    try:
        data = encodedData.decode()
    except UnicodeDecodeError:
        print("Data received is not in unicode format, exiting...")
        # Do not recover from this error
        return False

    # Check if the server sent an error message (status code 4##)
    if data.startswith("4"):
        print(f"Server Response {data.split(":")[0]}: {data.split(':')[1]}")
        # Return True, continue connection even after this error (expected error)
        return True

    # Check if the server sent an unexpected response (successful is status code 1##)
    elif not data.startswith("1"):
        print(f"Unexpected response: {data}")
        # Do not recover from this error
        return False

    # Extract the response from in between the Status Code and END tags
    wordsList = data.split(":")[2]
    wordCount = data.split(":")[1]

    try:
        wordCount = int(wordCount)
    except ValueError:
        print("Response is not in the expected format, exiting...")
        # Do not recover from this error
        return False

    if not wordCount:
        print("No matching words found")
        # Continue Connection
        return True

    # Extract the words from the response (comma-separated)
    words = wordsList.split(",")

    # Print the matching words, add an 's' to "word" if there is more than one word
    print(f"Found {wordCount} matching word{'s' if wordCount > 1 else ''}:")
    for word in words:
        print(word)

    # Continue Connection
    return True


def run_client():
    printLog(f"Attempting connection to {ADDR} on port {PORT}")

    try:
        clientSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        clientSocket.connect((ADDR, PORT))
    except socket.error as e:
        print(f"Socket Error: {e}")
        return

    printLog(f"Successfully connected to {ADDR} on port {PORT}")

    while handle_query(clientSocket):
        continue

    clientSocket.close()
    return


if __name__ == "__main__":
    if len(sys.argv) > 1 and sys.argv[1] == "-debug":
        _LOGGING = True
    run_client()