import time
import paho.mqtt.client as mqtt
import serial

# Configuration
SERIAL_PORT = '/dev/ttyAMA0'  # Adjust for your system (e.g., 'COM3' on Windows)
BAUD_RATE = 9600
MQTT_BROKER = "localhost"  # Public test broker
MQTT_PORT = 1883
MQTT_TOPIC = "python/mqtt/test"

def main():
    # 1. Initialize Serial Connection
    try:
        ser = serial.Serial(
            port=SERIAL_PORT,
            baudrate=BAUD_RATE,
            parity=serial.PARITY_NONE,
            stopbits=serial.STOPBITS_ONE,
            bytesize=serial.EIGHTBITS,
            timeout=1
        )
    except serial.SerialException as e:
        print(f"Could not open serial port: {e}")
        return

    # 2. Initialize MQTT Client
    client = mqtt.Client()
    
    # Optional: Add callbacks for connection status
    def on_connect(client, userdata, flags, reason_code, properties):
        if reason_code == 0:
            print("Connected to MQTT Broker")
        else:
            print(f"Failed to connect, return code {reason_code}")

    client.on_connect = on_connect
    client.connect(MQTT_BROKER, MQTT_PORT, 60)

    # 3. Read Serial and Publish to MQTT
    print("Reading from serial port and publishing to MQTT...")
    try:
        for i in range(10):  # Read 10 messages as an example
            if ser.in_waiting > 0:
                # Read line from serial port
                data = ser.readline().decode('utf-8').strip()
                if data:
                    # Publish to MQTT topic
                    client.publish(MQTT_TOPIC, data)
                    print(f"Published: {data}")
                else:
                    print("No data available on serial port")
            time.sleep(1) # Wait 1 second between reads
    except KeyboardInterrupt:
        print("Interrupted by user")
    finally:
        # Cleanup
        ser.close()
        client.disconnect()
        client.loop_stop()
        print("Disconnected and closed serial port.")

if __name__ == "__main__":
    main()