import snap7
import json
import socket
import time
import logging
from datetime import datetime
from typing import Dict, Any
import struct

class PLCDataStreamer:
    def __init__(self, plc_ip: str, plc_rack: int = 0, plc_slot: int = 2, 
                 udp_host: str = "127.0.0.1", udp_port: int = 9870):
        """
        Inicializa el streamer de datos del PLC
        
        Args:
            plc_ip: IP del PLC S7-315
            plc_rack: Rack del PLC (típicamente 0)
            plc_slot: Slot del PLC (típicamente 2)
            udp_host: IP para el servidor UDP
            udp_port: Puerto UDP para PlotJuggler
        """
        self.plc_ip = plc_ip
        self.plc_rack = plc_rack
        self.plc_slot = plc_slot
        self.udp_host = udp_host
        self.udp_port = udp_port
        
        # Inicializar cliente PLC
        self.plc = snap7.client.Client()
        
        # Inicializar socket UDP
        self.udp_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        
        # Configurar logging
        logging.basicConfig(
            level=logging.INFO,
            format='%(asctime)s - %(levelname)s - %(message)s',
            handlers=[
                logging.FileHandler('plc_data.log'),
                logging.StreamHandler()
            ]
        )
        self.logger = logging.getLogger(__name__)
        
        # Variables a leer del PLC (personalizar según tu aplicación)
        self.data_blocks = {
            'DB1': {
                'address': 1,
                'size': 100,
                'variables': {
                    'temperatura': {'offset': 0, 'type': 'real'},
                    'presion': {'offset': 4, 'type': 'real'},
                    'nivel': {'offset': 8, 'type': 'real'},
                    'estado_bomba': {'offset': 12, 'type': 'bool'},
                    'contador': {'offset': 14, 'type': 'int'}
                }
            }
        }
        
        self.running = False

    def connect_plc(self) -> bool:
        """Conecta al PLC S7-315"""
        try:
            self.plc.connect(self.plc_ip, self.plc_rack, self.plc_slot)
            self.logger.info(f"Conectado al PLC {self.plc_ip}")
            return True
        except Exception as e:
            self.logger.error(f"Error conectando al PLC: {e}")
            return False

    def disconnect_plc(self):
        """Desconecta del PLC"""
        try:
            self.plc.disconnect()
            self.logger.info("Desconectado del PLC")
        except Exception as e:
            self.logger.error(f"Error desconectando del PLC: {e}")

    def read_data_block(self, db_name: str) -> Dict[str, Any]:
        """Lee un bloque de datos del PLC"""
        db_config = self.data_blocks[db_name]
        
        try:
            # Leer el bloque completo
            raw_data = self.plc.db_read(db_config['address'], 0, db_config['size'])
            
            parsed_data = {}
            
            # Parsear cada variable según su tipo
            for var_name, var_config in db_config['variables'].items():
                offset = var_config['offset']
                var_type = var_config['type']
                
                if var_type == 'real':
                    # REAL de Siemens (32-bit IEEE 754, big endian)
                    value = struct.unpack('>f', raw_data[offset:offset+4])[0]
                elif var_type == 'int':
                    # INT de Siemens (16-bit signed, big endian)
                    value = struct.unpack('>h', raw_data[offset:offset+2])[0]
                elif var_type == 'bool':
                    # BOOL - primer bit del byte
                    value = bool(raw_data[offset] & 0x01)
                else:
                    continue
                
                parsed_data[var_name] = value
            
            return parsed_data
            
        except Exception as e:
            self.logger.error(f"Error leyendo {db_name}: {e}")
            return {}

    def send_to_plotjuggler(self, data: Dict[str, Any]):
        """Envía datos a PlotJuggler vía UDP JSON"""
        try:
            # Agregar timestamp
            message = {
                'timestamp': time.time(),
                'data': data
            }
            
            # Convertir a JSON y enviar
            json_message = json.dumps(message)
            self.udp_socket.sendto(
                json_message.encode('utf-8'), 
                (self.udp_host, self.udp_port)
            )
            
        except Exception as e:
            self.logger.error(f"Error enviando datos a PlotJuggler: {e}")

    def log_data(self, data: Dict[str, Any]):
        """Registra datos en el log"""
        timestamp = datetime.now().strftime('%Y-%m-%d %H:%M:%S.%f')[:-3]
        self.logger.info(f"[{timestamp}] {data}")

    def run(self, sampling_interval: float = 0.1):
        """Ejecuta el bucle principal de lectura y streaming"""
        if not self.connect_plc():
            return
        
        self.running = True
        self.logger.info(f"Iniciando streaming con intervalo de {sampling_interval}s")
        
        try:
            while self.running:
                start_time = time.time()
                
                # Leer todos los bloques de datos configurados
                all_data = {}
                for db_name in self.data_blocks:
                    db_data = self.read_data_block(db_name)
                    all_data.update(db_data)
                
                if all_data:
                    # Enviar a PlotJuggler
                    self.send_to_plotjuggler(all_data)
                    
                    # Registrar en log
                    self.log_data(all_data)
                
                # Mantener intervalo de muestreo
                elapsed = time.time() - start_time
                sleep_time = max(0, sampling_interval - elapsed)
                time.sleep(sleep_time)
                
        except KeyboardInterrupt:
            self.logger.info("Deteniendo por interrupción del usuario")
        except Exception as e:
            self.logger.error(f"Error en el bucle principal: {e}")
        finally:
            self.stop()

    def stop(self):
        """Detiene el streaming y limpia recursos"""
        self.running = False
        self.disconnect_plc()
        self.udp_socket.close()
        self.logger.info("Streaming detenido")

def main():
    # Configuración
    PLC_IP = "192.168.1.100"  # Cambiar por la IP de tu PLC
    SAMPLING_INTERVAL = 0.1   # 10 Hz
    
    # Crear y ejecutar el streamer
    streamer = PLCDataStreamer(plc_ip=PLC_IP)
    
    try:
        streamer.run(sampling_interval=SAMPLING_INTERVAL)
    except Exception as e:
        print(f"Error: {e}")
    finally:
        streamer.stop()

if __name__ == "__main__":
    main()