# sender/client.py — TCP socket client, connects to receiver and sends data

import socket
import time
import logging
import sys
import os
import argparse

from config import HOST, PORT, SEND_INTERVAL, ACK_BYTE, RECONNECT_DELAY, BUFFER_SIZE
from generator import generate_data


parser = argparse.ArgumentParser()
parser.add_argument("--id", required=True, help="Device ID")
args = parser.parse_args()

DEVICE_ID = args.id


logging.basicConfig(
    level=logging.INFO,
    format="[SENDER] %(asctime)s — %(message)s",
    datefmt="%H:%M:%S"
)
log = logging.getLogger(__name__)


def connect_to_server() -> socket.socket:
    """Keep trying to connect until server is available."""
    while True:
        try:
            client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            client.connect((HOST, PORT))
            log.info(f"Connected to server at {HOST}:{PORT}")
            return client
        except ConnectionRefusedError:
            log.warning(f"Server not available. Retrying in {RECONNECT_DELAY}s...")
            time.sleep(RECONNECT_DELAY)


def run():
    log.info(f"Sender starting with DEVICE_ID={DEVICE_ID}...")

    while True:
        client = connect_to_server()

        try:
            while True:
                # 1. Generate data string with unique ID
                data = generate_data(DEVICE_ID)
                display = data.replace('\0', '\\0')
                log.info(f"Sending → {display}")

                # 2. Send encoded bytes
                client.sendall(data.encode('utf-8'))

                # 3. Wait for ACK
                try:
                    client.settimeout(5.0)
                    ack = client.recv(BUFFER_SIZE)
                    if ack == ACK_BYTE:
                        log.info("ACK received")
                    else:
                        log.warning(f"Unexpected response: {ack}")
                except socket.timeout:
                    log.error("ACK timeout — server may be down")
                    break

                # 4. Wait before next send
                time.sleep(SEND_INTERVAL)

        except (ConnectionResetError, BrokenPipeError, OSError) as e:
            log.error(f"Connection lost: {e}. Reconnecting...")
        finally:
            client.close()


if __name__ == "__main__":
    run()