printer_service.py

import socketio
import unicodedata
from pathlib import Path

PRINTER_PATH = "/dev/usb/lp0"

sio = socketio.Server(cors_allowed_origins='*')
app = socketio.WSGIApp(sio)

def remove_accents(text):
    """Remove acentos do texto"""
    nfkd = unicodedata.normalize('NFKD', text)
    return ''.join([c for c in nfkd if not unicodedata.combining(c)])

def is_printer_connected():
    """Verifica se a impressora está conectada"""
    return Path(PRINTER_PATH).exists()

def print_text(text):
    """Envia texto para a impressora"""
    if not is_printer_connected():
        raise Exception("Impressora não conectada")
    text = remove_accents(text)
    with open(PRINTER_PATH, "wb") as f:
        f.write(text.encode("latin1"))
        f.write(b"\n\n")
        f.write(b"\x1D\x56\x00")

@sio.event
def connect(sid, environ=None, auth=None):
    """Handler para conexão do cliente"""
    print(f"Cliente conectado: {sid}")
    sio.emit('connection_established', {'printer_connected': is_printer_connected()}, to=sid)

@sio.event
def disconnect(sid, *args):
    """Handler para desconexão do cliente"""
    print(f"Cliente desconectado: {sid}")

@sio.event
def print_document(sid, data):
    """Handler para imprimir documento"""
    try:
        texto = data.get("texto", "") if isinstance(data, dict) else str(data)
        print_text(texto)
        sio.emit('print_success', {'message': 'Impresso com sucesso'}, to=sid)
    except Exception as e:
        print(f"Erro ao imprimir: {str(e)}")
        sio.emit('print_error', {'message': str(e)}, to=sid)

@sio.event
def get_status(sid, data=None):
    """Handler para verificar status da impressora"""
    sio.emit('status', {'printer_connected': is_printer_connected()}, to=sid)

@sio.event
def ping(sid, data=None):
    """Handler para ping/pong"""
    sio.emit('pong', {'timestamp': data.get('timestamp') if isinstance(data, dict) else None}, to=sid)

if __name__ == "__main__":
    import eventlet
    import eventlet.wsgi
    print("Servidor Socket.IO iniciando em 0.0.0.0:4444")
    eventlet.wsgi.server(eventlet.listen(('0.0.0.0', 4444)), app)