HID report parser for kaitai struct

usb_hid_report.ksy

meta:
  id: usb_hid
  file-extension: usb_hid
  bit-endian: le
  endian: le
seq:
  - id: items
    type: item
    repeat: eos
enums:
  item_type:
    0: main
    1: global
    2: local
types:
  item:
    seq:
      - id: b_size
        type: b2
      - id: b_type
        type: b2
        enum: item_type
      - id: b_tag
        type: b4
      - id: data
        type:
          switch-on: b_tag
          cases:
            0xff: long_item
            _: short_item
  long_item:
    seq:
      - id: b_data_size
        type: u1
      - id: b_long_item_tag
        type: u1
      - id: data
        size: b_data_size
  unknown_short_item:
    seq:
      - id: data
        size: _parent._parent.b_size == 0 ? 0 : (1 << (_parent._parent.b_size - 1))
  short_item:
    seq:
      - id: item
        type:
          switch-on: _parent.b_type
          cases:
            'item_type::main': main_item
            'item_type::local': local_item
            'item_type::global': global_item
            _: unknown_short_item
  main_item:
    seq:
      - id: item
        type:
          switch-on: _parent._parent.b_tag
          cases:
            0x8: field_item
            0x9: field_item
            0xB: field_item
            0xA: collection_item
            0xC: end_collection_item
            
  collection_item:
    seq:
      - id: collection_type
        # type: collection_type
        type: u1
      - id: subitems
        type: item
        # repeat: expr
        # repeat-expr: 10
        repeat: until
        repeat-until: _.b_type == item_type::main and _.b_tag == 0xc
        
  end_collection_item:
    doc: no data
  
  field_attributes:
    seq:
      - id: data
        type: b1
      - type: b7

  field_item:
    seq:
      - id: field
        type: field_attributes
        #size: _parent._parent._parent.b_size == 0 ? 0 : (1 << (_parent._parent._parent.b_size - 1))

  usage_item:
    seq:
      - id: usage
        type: u1

  usage_page_item:
    seq:
      - id: usage
        type: u2

  local_item:
    seq:
      - id: item
        size: _parent._parent.b_size == 0 ? 0 : (1 << (_parent._parent.b_size - 1))
        type:
          switch-on: _parent._parent.b_tag
          cases:
            0x0: usage_item
  
  global_item:
    seq:
      - id: item
        size: _parent._parent.b_size == 0 ? 0 : (1 << (_parent._parent.b_size - 1))
        type:
          switch-on: _parent._parent.b_tag
          cases:
            0x0: usage_page_item