from pymodbus.client import ModbusTcpClient
import struct
import sys
from typing import Optional

# === Verbindungseinstellungen ===
MODBUS_IP   = "192.168.1.112"
MODBUS_PORT = 502  # SetApp: 1502; LCD-Menü: 502 -> ggf. anpassen
UNIT_ID     = 1     # Default laut Doku: 1

client = ModbusTcpClient(MODBUS_IP, port=MODBUS_PORT)
if not client.connect():
    print("Verbindung fehlgeschlagen.")
    sys.exit(1)

def read_regs(addr: int, count: int):
    """Hilfsfunktion: liest 'count' Holding-Register ab base-0 'addr'."""
    rr = client.read_holding_registers(address=addr, count=count)
    if rr.isError():
        return None
    return rr.registers

def read_string(addr: int, words: int) -> Optional[str]:
    """
    SunSpec-Strings: ASCII, Big-Endian, 2 Bytes pro Register, 0x00 gepadded.
    """
    regs = read_regs(addr, words)
    if regs is None:
        return None
    b = b"".join(struct.pack(">H", r) for r in regs)
    # SunSpec Strings sind meist mit \x00 und Spaces gepadded:
    s = b.decode("ascii", errors="ignore").rstrip("\x00 ").strip()
    return s or None

def to_int16(u16: int) -> int:
    """unsigned 16 -> signed 16"""
    return struct.unpack(">h", struct.pack(">H", u16))[0]

def apply_sf(raw: int, sf: int) -> float:
    return raw * (10 ** sf)

def read_scaled(value_addr: int, sf_addr: int) -> Optional[float]:
    regs = read_regs(value_addr, 1)
    sf   = read_regs(sf_addr, 1)
    if regs is None or sf is None:
        return None
    raw  = to_int16(regs[0])
    sff  = to_int16(sf[0])
    return apply_sf(raw, sff)

def read_u32_with_sf(value_addr: int, sf_addr: int) -> Optional[float]:
    """
    Liest 32-bit Zähler (acc32, Big-Endian, 2 Register) + SF.
    """
    regs = read_regs(value_addr, 2)
    sf   = read_regs(sf_addr, 1)
    if regs is None or sf is None:
        return None
    # Big-Endian zusammenbauen:
    u32 = (regs[0] << 16) | regs[1]
    sff = to_int16(sf[0])
    return apply_sf(u32, sff)

# ==== Common Block (base-0) ====
manufacturer = read_string(40004, 16)  # C_Manufacturer
model        = read_string(40020, 16)  # C_Model
version      = read_string(40044, 8)   # C_Version
serial       = read_string(40052, 16)  # C_SerialNumber

print(f"Hersteller:     {manufacturer}")
print(f"Modell:         {model}")
print(f"Version:        {version}")
print(f"Seriennummer:   {serial}")

# ==== Inverter Block (base-0) ====
# AC Power + Scale Factor
ac_power = read_scaled(40083, 40084)  # I_AC_Power, I_AC_Power_SF
if ac_power is not None:
    print(f"AC Power:       {ac_power} W")
else:
    print("Fehler beim Lesen von AC Power")

# AC Spannung L-N Durchschnitt (falls 1ph/3ph mit N verfügbar) + SF
ac_voltage = read_scaled(40079, 40082)  # I_AC_VoltageAN, I_AC_Voltage_SF
if ac_voltage is not None:
    print(f"AC Spannung:    {ac_voltage} V")

# AC Frequenz + SF
ac_freq = read_scaled(40085, 40086)  # I_AC_Frequency, _SF
if ac_freq is not None:
    print(f"Frequenz:       {ac_freq} Hz")

# DC Power + SF
dc_power = read_scaled(40100, 40101)  # I_DC_Power, _SF
if dc_power is not None:
    print(f"DC Power:       {dc_power} W")

# Lifetime Energy (AC_Energy_WH, acc32) + SF
lifetime_wh = read_u32_with_sf(40093, 40095)  # I_AC_Energy_WH, _SF
if lifetime_wh is not None:
    print(f"Lifetime Energy: {lifetime_wh} Wh")

# Status
status_regs = read_regs(40107, 2)  # I_Status, I_Status_Vendor
if status_regs:
    i_status        = status_regs[0]
    i_status_vendor = status_regs[1]
    print(f"Status:         {i_status} (Vendor: {i_status_vendor})")

client.close()