Coverage for src/bluetooth_sig/gatt/descriptors/cccd.py: 86%

1"""Client Characteristic Configuration Descriptor implementation.""" 

2 

3from __future__ import annotations 

4 

5from enum import IntFlag 

6 

7import msgspec 

8 

9from ..characteristics.utils import DataParser 

10from .base import BaseDescriptor 

11 

12 

13class CCCDFlags(IntFlag): 

14 """CCCD (Client Characteristic Configuration Descriptor) flags.""" 

15 

16 NOTIFICATIONS_ENABLED = 0x0001 

17 INDICATIONS_ENABLED = 0x0002 

18 

19 

20class CCCDData(msgspec.Struct, frozen=True, kw_only=True): 

21 """CCCD (Client Characteristic Configuration Descriptor) data.""" 

22 

23 notifications_enabled: bool 

24 indications_enabled: bool 

25 

26 

27class CCCDDescriptor(BaseDescriptor): 

28 """Client Characteristic Configuration Descriptor (0x2902). 

29 

30 Controls notification and indication settings for a characteristic. 

31 Critical for enabling BLE notifications and indications. 

32 """ 

33 

34 _descriptor_name = "Client Characteristic Configuration" 

35 

36 def _has_structured_data(self) -> bool: 

37 return True 

38 

39 def _get_data_format(self) -> str: 

40 return "uint16" 

41 

42 def _parse_descriptor_value(self, data: bytes) -> CCCDData: 

43 """Parse CCCD value into notification/indication flags. 

44 

45 Args: 

46 data: Raw bytes (should be 2 bytes for uint16) 

47 

48 Returns: 

49 CCCDData with notification/indication flags 

50 

51 Raises: 

52 ValueError: If data is not exactly 2 bytes 

53 """ 

54 if len(data) != 2: 

55 raise ValueError(f"CCCD data must be exactly 2 bytes, got {len(data)}") 

56 

57 # Parse as little-endian uint16 

58 value = DataParser.parse_int16(data, endian="little") 

59 

60 return CCCDData( 

61 notifications_enabled=bool(value & CCCDFlags.NOTIFICATIONS_ENABLED), 

62 indications_enabled=bool(value & CCCDFlags.INDICATIONS_ENABLED), 

63 ) 

64 

65 @staticmethod 

66 def create_enable_notifications_value() -> bytes: 

67 """Create value to enable notifications.""" 

68 return CCCDFlags.NOTIFICATIONS_ENABLED.to_bytes(2, "little") 

69 

70 @staticmethod 

71 def create_enable_indications_value() -> bytes: 

72 """Create value to enable indications.""" 

73 return CCCDFlags.INDICATIONS_ENABLED.to_bytes(2, "little") 

74 

75 @staticmethod 

76 def create_enable_both_value() -> bytes: 

77 """Create value to enable both notifications and indications.""" 

78 return (CCCDFlags.NOTIFICATIONS_ENABLED | CCCDFlags.INDICATIONS_ENABLED).to_bytes(2, "little") 

79 

80 @staticmethod 

81 def create_disable_value() -> bytes: 

82 """Create value to disable notifications/indications.""" 

83 return (0).to_bytes(2, "little") 

84 

85 def is_notifications_enabled(self, data: bytes) -> bool: 

86 """Check if notifications are enabled.""" 

87 parsed = self._parse_descriptor_value(data) 

88 return parsed.notifications_enabled 

89 

90 def is_indications_enabled(self, data: bytes) -> bool: 

91 """Check if indications are enabled.""" 

92 parsed = self._parse_descriptor_value(data) 

93 return parsed.indications_enabled 

94 

95 def is_any_enabled(self, data: bytes) -> bool: 

96 """Check if either notifications or indications are enabled.""" 

97 parsed = self._parse_descriptor_value(data) 

98 return parsed.notifications_enabled or parsed.indications_enabled