Files
hassio-bluetti-bt/custom_components/bluetti_bt/bluetti_bt_lib/utils/struct.py
T

239 lines
7.7 KiB
Python

"""Struct definitions."""
# Copy of https://github.com/warhammerkid/bluetti_mqtt/blob/main/bluetti_mqtt/core/devices/struct.py
from decimal import Decimal
from enum import Enum
from .commands import ReadHoldingRegisters
import struct
from typing import Any, List, Optional, Tuple, Type
def swap_bytes(data: bytes):
"""Swaps the place of every other byte, returning a new byte array"""
arr = bytearray(data)
for i in range(0, len(arr) - 1, 2):
arr[i], arr[i + 1] = arr[i + 1], arr[i]
return arr
class DeviceField:
def __init__(self, name: str, address: int, size: int):
self.name = name
self.address = address
self.size = size
def parse(self, data: bytes) -> Any:
raise NotImplementedError
def in_range(self, val: Any) -> bool:
return True
class UintField(DeviceField):
def __init__(self, name: str, address: int, range: Optional[Tuple[int, int]], multiplier: float):
self.range = range
self.multiplier = multiplier
super().__init__(name, address, 1)
def parse(self, data: bytes) -> int:
val = struct.unpack("!H", data)[0]
return val * self.multiplier
def in_range(self, val: int) -> bool:
if self.range is None:
return True
else:
return val >= self.range[0] and val <= self.range[1]
class IntField(DeviceField):
def __init__(self, name: str, address: int, range: Optional[Tuple[int, int]]):
self.range = range
super().__init__(name, address, 1)
def parse(self, data: bytes) -> int:
return struct.unpack(">h", data)[0]
def in_range(self, val: int) -> bool:
if self.range is None:
return True
else:
return val >= self.range[0] and val <= self.range[1]
class BoolField(DeviceField):
def __init__(self, name: str, address: int):
super().__init__(name, address, 1)
def parse(self, data: bytes) -> bool:
return struct.unpack("!H", data)[0] == 1
class EnumField(DeviceField):
def __init__(self, name: str, address: int, enum: Type[Enum]):
self.enum = enum
super().__init__(name, address, 1)
def parse(self, data: bytes) -> Any:
val = struct.unpack("!H", data)[0]
return self.enum(val)
class DecimalField(DeviceField):
def __init__(
self, name: str, address: int, scale: int, range: Optional[Tuple[int, int]], multiplier: float
):
self.scale = scale
self.range = range
self.multiplier = multiplier
super().__init__(name, address, 1)
def parse(self, data: bytes) -> Decimal:
val = Decimal(struct.unpack("!H", data)[0])
return (val / 10 ** self.scale) * Decimal(self.multiplier)
def in_range(self, val: Decimal) -> bool:
if self.range is None:
return True
else:
return val >= self.range[0] and val <= self.range[1]
class DecimalArrayField(DeviceField):
def __init__(self, name: str, address: int, size: int, scale: int):
self.scale = scale
super().__init__(name, address, size)
def parse(self, data: bytes) -> Decimal:
values = list(struct.unpack(f"!{self.size}H", data))
return [Decimal(v) / 10 ** self.scale for v in values]
class StringField(DeviceField):
"""Fixed-width null-terminated string field"""
def parse(self, data: bytes) -> str:
return data.rstrip(b"\0").decode("ascii")
class SwapStringField(DeviceField):
"""Fixed-width null-terminated string field"""
def parse(self, data: bytes) -> str:
return swap_bytes(data).rstrip(b"\0").decode("ascii")
class VersionField(DeviceField):
def __init__(self, name: str, address: int):
super().__init__(name, address, 2)
def parse(self, data: bytes) -> int:
values = struct.unpack("!2H", data)
return Decimal(values[0] + (values[1] << 16)) / 100
class SerialNumberField(DeviceField):
def __init__(self, name: str, address: int):
super().__init__(name, address, 4)
def parse(self, data: bytes) -> int:
values = struct.unpack("!4H", data)
return values[0] + (values[1] << 16) + (values[2] << 32) + (values[3] << 48)
class DeviceStruct:
fields: List[DeviceField]
def __init__(self):
self.fields = []
def add_uint_field(self, name: str, address: int, range: Tuple[int, int] = None, multiplier: float = 1):
self.fields.append(UintField(name, address, range, multiplier))
def add_int_field(self, name: str, address: int, range: Tuple[int, int] = None):
self.fields.append(IntField(name, address, range))
def add_bool_field(self, name: str, address: int):
self.fields.append(BoolField(name, address))
def add_enum_field(self, name: str, address: int, enum: Type[Enum]):
self.fields.append(EnumField(name, address, enum))
def add_decimal_field(
self, name: str, address: int, scale: int, range: Tuple[int, int] = None, multiplier: float = 1
):
self.fields.append(DecimalField(name, address, scale, range, multiplier))
def add_decimal_array_field(self, name: str, address: int, size: int, scale: int):
self.fields.append(DecimalArrayField(name, address, size, scale))
def add_string_field(self, name: str, address: int, size: int):
self.fields.append(StringField(name, address, size))
def add_swap_string_field(self, name: str, address: int, size: int):
self.fields.append(SwapStringField(name, address, size))
def add_version_field(self, name: str, address: int):
self.fields.append(VersionField(name, address))
def add_sn_field(self, name: str, address: int):
self.fields.append(SerialNumberField(name, address))
def get_read_holding_registers(self, tolerance=20, filter=lambda address: True):
address_set = set()
for field in self.fields:
for address in range(field.address, field.address + field.size):
address_set.add(address)
# Filter out addresses that we specificly
# specified to exclude.
for address in set(address_set):
if not filter(address):
address_set.remove(address)
# Fast path: no addresses -> no commands.
if not address_set:
return []
commands = []
address_list = sorted(address_set)
start = address_list[0]
last = address_list[0]
for address in address_list[1:]:
# Create a new group if there's a gap
# in the addresses.
if address >= last + tolerance:
commands.append(ReadHoldingRegisters(start, last - start + 1))
start = address
last = address
commands.append(ReadHoldingRegisters(start, last - start + 1))
return commands
def parse(self, starting_address: int, data: bytes) -> dict:
# Offsets and size are counted in 2 byte chunks, so for the range we
# need to divide the byte size by 2
data_size = int(len(data) / 2)
# Filter out fields not in range
r = range(starting_address, starting_address + data_size)
fields = [
f for f in self.fields if f.address in r and f.address + f.size - 1 in r
]
# Parse fields
parsed = {}
for f in fields:
data_start = 2 * (f.address - starting_address)
field_data = data[data_start : data_start + 2 * f.size]
val = f.parse(field_data)
# Skip if the value is "out-of-range" - sometimes the sensors
# report weird values
if not f.in_range(val):
continue
parsed[f.name] = val
return parsed