syntax = "proto3";

package keyboard.cdc;

// The AA55 CDC frame still lives outside protobuf:
// [head1][head2][len][type][data][checksum]
// `data` is the serialized protobuf payload for the matching `type`.
// Keep the outer `type` field for fast dispatch and debugging.

enum CdcPacketType {
  CDC_PACKET_TYPE_UNKNOWN = 0;
  CDC_PACKET_TYPE_HELLO_REQ = 1;
  CDC_PACKET_TYPE_HELLO_RSP = 2;
  CDC_PACKET_TYPE_BITMAP = 16;
  CDC_PACKET_TYPE_FUNCTION_KEY_EVENT = 32;
  CDC_PACKET_TYPE_LED_STATE = 33;
  CDC_PACKET_TYPE_TIME_SYNC = 48;
  CDC_PACKET_TYPE_THEME_RGB = 49;
  CDC_PACKET_TYPE_ACK = 126;
  CDC_PACKET_TYPE_ERROR = 127;
}

enum KeyAction {
  KEY_ACTION_RELEASE = 0;
  KEY_ACTION_PRESS = 1;
}

enum ErrorCode {
  ERROR_CODE_NONE = 0;
  ERROR_CODE_UNKNOWN_TYPE = 1;
  ERROR_CODE_INVALID_LENGTH = 2;
  ERROR_CODE_INVALID_PARAM = 3;
  ERROR_CODE_NOT_READY = 4;
}

message HelloReqPayload {
  uint32 protocol_version = 1;
}

message HelloRspPayload {
  uint32 protocol_version = 1;
  uint32 vendor_id = 2;
  uint32 product_id = 3;
  uint32 firmware_major = 4;
  uint32 firmware_minor = 5;
  uint32 capability_flags = 6;
}

message BitmapPayload {
  bytes usage_bitmap = 1;
}

message FunctionKeyEventPayload {
  uint32 usage = 1;
  KeyAction action = 2;
}

message LedStatePayload {
  uint32 led_mask = 1;
}

message TimeSyncPayload {
  uint32 version = 1;
  uint32 flags = 2;
  sint32 timezone_min = 3;
  fixed64 utc_ms = 4;
  fixed32 accuracy_ms = 5;
}

message ThemeRgbPayload {
  uint32 red = 1;
  uint32 green = 2;
  uint32 blue = 3;
}

message AckPayload {
  uint32 acked_type = 1;
}

message ErrorPayload {
  uint32 error_type = 1;
  ErrorCode error_code = 2;
}