data-collector-debugtool/app/services/s7_codec.py

from __future__ import annotations

import struct
from typing import Any


def byte_size_for_type(point_type: str) -> int:
    if point_type in {"bool", "byte", "int8"}:
        return 1
    if point_type in {"int16", "uint16"}:
        return 2
    if point_type in {"int64", "uint64", "float64"}:
        return 8
    return 4


def bytes_to_hex(data: bytes | bytearray) -> str:
    return " ".join(f"{value:02X}" for value in data)


def convert_s7_value(data: bytes | bytearray, point_type: str, bit: int | None) -> Any:
    payload = bytes(data)

    if point_type == "bool":
        value = payload[0]
        if bit is None:
            return value != 0
        return ((value >> bit) & 1) == 1
    if point_type == "byte":
        return payload[0]
    if point_type == "int8":
        return int.from_bytes(payload, byteorder="big", signed=True)
    if point_type == "int16":
        return int.from_bytes(payload, byteorder="big", signed=True)
    if point_type == "uint16":
        return int.from_bytes(payload, byteorder="big", signed=False)
    if point_type == "int32":
        return int.from_bytes(payload, byteorder="big", signed=True)
    if point_type == "uint32":
        return int.from_bytes(payload, byteorder="big", signed=False)
    if point_type == "int64":
        return int.from_bytes(payload, byteorder="big", signed=True)
    if point_type == "uint64":
        return int.from_bytes(payload, byteorder="big", signed=False)
    if point_type == "float32":
        return struct.unpack(">f", payload)[0]
    if point_type == "float64":
        return struct.unpack(">d", payload)[0]

    raise ValueError(f"unsupported point type: {point_type}")