import time
import pandas as pd
from pymodbus.client import ModbusTcpClient

class PvInverter:
    def __init__(self, device_name: str, ip_address: str, port: int = 502, unit: int = 1):
        self.device_name = device_name
        self.ip = ip_address
        self.port = port
        self.unit = unit
        self.client = None
        self.registers = None

        self.connect_to_modbus()
        self.get_registers()

    def connect_to_modbus(self):
        # Timeout & retries optional, aber hilfreich:
        self.client = ModbusTcpClient(self.ip, port=self.port, timeout=3.0, retries=3)
        if not self.client.connect():
            print("Verbindung zu Wechselrichter fehlgeschlagen.")
            raise SystemExit(1)
        print("Verbindung zu Wechselrichter erfolgreich.")

        # WICHTIG: NICHT hier schließen!
        # finally: self.client.close()  <-- entfernen

    def close(self):
        if self.client:
            self.client.close()
            self.client = None

    def get_registers(self):
        excel_path = "modbus_registers/pv_inverter_registers.xlsx"
        xls = pd.ExcelFile(excel_path)
        df_input_registers = xls.parse()
        df_clean = df_input_registers[['MB Adresse', 'Beschreibung', 'Variabel Typ']].dropna()
        df_clean['MB Adresse'] = df_clean['MB Adresse'].astype(int)

        self.registers = {
            row['MB Adresse']: {
                'desc': row['Beschreibung'],
                'type': 'REAL' if str(row['Variabel Typ']).upper() == 'REAL' else 'INT'
            }
            for _, row in df_clean.iterrows()
        }

    def get_state(self):
        data = {'Zeit': time.strftime('%Y-%m-%d %H:%M:%S')}
        for address, info in self.registers.items():
            reg_type = info['type']
            # Unit-ID mitgeben (wichtig bei pymodbus>=3)
            result = self.client.read_holding_registers(
                address=address,
                count=2 if reg_type == 'REAL' else 1,
                slave=self.unit  # pymodbus 2.x -> 'slave', nicht 'unit'
            )
            if result.isError():
                print(f"Fehler beim Lesen von Adresse {address}: {result}")
                continue

            # Minimal invasiv: wie bei dir – erstes Register verwenden
            value = result.registers[0]
            print(f"Adresse {address} - {info['desc']}: {value}")
            data[f"{address} - {info['desc']}"] = value
        return data