Coverage for src/bluetooth_sig/gatt/descriptors/process_tolerances.py: 83%

1"""Process Tolerances Descriptor implementation.""" 

2 

3from __future__ import annotations 

4 

5import msgspec 

6 

7from ..characteristics.utils import DataParser 

8from .base import BaseDescriptor 

9 

10 

11class ProcessTolerancesData(msgspec.Struct, frozen=True, kw_only=True): 

12 """Process Tolerances descriptor data.""" 

13 

14 tolerance_min: int | float 

15 tolerance_max: int | float 

16 

17 

18class ProcessTolerancesDescriptor(BaseDescriptor): 

19 """Process Tolerances Descriptor (0x2914). 

20 

21 Defines process tolerances for characteristic values. 

22 Contains minimum and maximum tolerance values. 

23 """ 

24 

25 def _has_structured_data(self) -> bool: 

26 return True 

27 

28 def _get_data_format(self) -> str: 

29 return "struct" 

30 

31 def _parse_descriptor_value(self, data: bytes) -> ProcessTolerancesData: 

32 """Parse Process Tolerances descriptor value. 

33 

34 The format depends on the characteristic's value type. 

35 For simplicity, this implementation assumes uint16 tolerance values. 

36 

37 Args: 

38 data: Raw bytes containing tolerance min and max values 

39 

40 Returns: 

41 ProcessTolerancesData with process tolerances 

42 

43 Raises: 

44 ValueError: If data length is incorrect 

45 """ 

46 # Process Tolerances format: tolerance_min + tolerance_max 

47 # For now, assume 4 bytes total (2 bytes each for uint16) 

48 if len(data) != 4: 

49 raise ValueError(f"Process Tolerances data expected 4 bytes, got {len(data)}") 

50 

51 tolerance_min = DataParser.parse_int16(data, offset=0, endian="little") 

52 tolerance_max = DataParser.parse_int16(data, offset=2, endian="little") 

53 

54 return ProcessTolerancesData( 

55 tolerance_min=tolerance_min, 

56 tolerance_max=tolerance_max, 

57 ) 

58 

59 def get_tolerance_min(self, data: bytes) -> int | float: 

60 """Get the minimum process tolerance.""" 

61 parsed = self._parse_descriptor_value(data) 

62 return parsed.tolerance_min 

63 

64 def get_tolerance_max(self, data: bytes) -> int | float: 

65 """Get the maximum process tolerance.""" 

66 parsed = self._parse_descriptor_value(data) 

67 return parsed.tolerance_max