Coverage for src / bluetooth_sig / gatt / characteristics / electric_current_specification.py: 90%

1"""Electric Current Specification characteristic implementation.""" 

2 

3from __future__ import annotations 

4 

5import msgspec 

6 

7from ..constants import UINT16_MAX 

8from ..context import CharacteristicContext 

9from .base import BaseCharacteristic 

10from .utils import DataParser 

11 

12 

13class ElectricCurrentSpecificationData(msgspec.Struct, frozen=True, kw_only=True): # pylint: disable=too-few-public-methods 

14 """Data class for electric current specification.""" 

15 

16 minimum: float # Minimum current in Amperes 

17 maximum: float # Maximum current in Amperes 

18 

19 def __post_init__(self) -> None: 

20 """Validate current specification data.""" 

21 if self.minimum > self.maximum: 

22 raise ValueError(f"Minimum current {self.minimum} A cannot be greater than maximum {self.maximum} A") 

23 

24 # Validate range for uint16 with 0.01 A resolution (0 to 655.35 A) 

25 max_current_value = UINT16_MAX * 0.01 

26 if not 0.0 <= self.minimum <= max_current_value: 

27 raise ValueError(f"Minimum current {self.minimum} A is outside valid range (0.0 to {max_current_value} A)") 

28 if not 0.0 <= self.maximum <= max_current_value: 

29 raise ValueError(f"Maximum current {self.maximum} A is outside valid range (0.0 to {max_current_value} A)") 

30 

31 

32class ElectricCurrentSpecificationCharacteristic(BaseCharacteristic[ElectricCurrentSpecificationData]): 

33 """Electric Current Specification characteristic (0x2AF0). 

34 

35 org.bluetooth.characteristic.electric_current_specification 

36 

37 Electric Current Specification characteristic. 

38 

39 Specifies minimum and maximum current values for electrical 

40 specifications. 

41 """ 

42 

43 # Validation attributes 

44 expected_length: int = 4 # 2x uint16 

45 min_length: int = 4 

46 

47 def _decode_value( 

48 self, data: bytearray, _ctx: CharacteristicContext | None = None, *, validate: bool = True 

49 ) -> ElectricCurrentSpecificationData: 

50 """Parse current specification data (2x uint16 in units of 0.01 A). 

51 

52 Args: 

53 data: Raw bytes from the characteristic read 

54 validate: Whether to validate ranges (default True) 

55 

56 Returns: 

57 ElectricCurrentSpecificationData with 'minimum' and 'maximum' current specification values in Amperes 

58 

59 Raises: 

60 ValueError: If data is insufficient 

61 

62 """ 

63 # Convert 2x uint16 (little endian) to current specification in Amperes 

64 min_current_raw = DataParser.parse_int16(data, 0, signed=False) 

65 max_current_raw = DataParser.parse_int16(data, 2, signed=False) 

66 

67 return ElectricCurrentSpecificationData(minimum=min_current_raw * 0.01, maximum=max_current_raw * 0.01) 

68 

69 def _encode_value(self, data: ElectricCurrentSpecificationData) -> bytearray: 

70 """Encode electric current specification value back to bytes. 

71 

72 Args: 

73 data: ElectricCurrentSpecificationData instance 

74 

75 Returns: 

76 Encoded bytes representing the current specification (2x uint16, 0.01 A resolution) 

77 

78 """ 

79 # Convert Amperes to raw values (multiply by 100 for 0.01 A resolution) 

80 min_current_raw = round(data.minimum * 100) 

81 max_current_raw = round(data.maximum * 100) 

82 

83 # Encode as 2 uint16 values (little endian) 

84 result = bytearray() 

85 result.extend(DataParser.encode_int16(min_current_raw, signed=False)) 

86 result.extend(DataParser.encode_int16(max_current_raw, signed=False)) 

87 

88 return result