{
  "$schema": "../../schema/test-vector.schema.json",
  "name": "Header - Combined Field Encoding",
  "spec_ref": "src/02-header.md",
  "protocol_version": 0,
  "description": "Combinatorial tests of header byte encoding, exercising various combinations of version, payload type, and route type to verify correct bit packing.",
  "vectors": [
    {
      "id": "hdr-000",
      "description": "All-zero header: version=0, request=0, transport_flood=0",
      "type": "encode_decode",
      "structured": {
        "header": {
          "version": 0,
          "payload_type": "request",
          "route_type": "transport_flood"
        },
        "transport_codes": [
          0,
          0
        ],
        "path": {
          "hash_size": 1,
          "hash_count": 0,
          "hashes": []
        },
        "payload": {
          "dest_hash": "00",
          "src_hash": "00",
          "cipher_mac": "0000",
          "ciphertext": "00000000000000000000000000000000"
        }
      },
      "binary": "00 0000 0000 00 0000 0000 00000000000000000000000000000000",
      "notes": "Header: (0<<6)|(0<<2)|0 = 0x00."
    },
    {
      "id": "hdr-001",
      "description": "Version=0, ADVERT, DIRECT route",
      "type": "encode_decode",
      "structured": {
        "header": {
          "version": 0,
          "payload_type": "advert",
          "route_type": "direct"
        },
        "path": {
          "hash_size": 1,
          "hash_count": 2,
          "hashes": [
            "AA",
            "BB"
          ]
        },
        "payload": {
          "data": "FF"
        }
      },
      "binary": "12 02 AABB FF",
      "notes": "Header: (0<<6)|(4<<2)|2 = 0x12. path_len=0x02 (hash_size=1, count=2). Path: AA BB."
    },
    {
      "id": "hdr-002",
      "description": "Version=1, CONTROL, FLOOD route",
      "type": "encode_decode",
      "structured": {
        "header": {
          "version": 1,
          "payload_type": "control",
          "route_type": "flood"
        },
        "path": {
          "hash_size": 1,
          "hash_count": 0,
          "hashes": []
        },
        "payload": {
          "data": "FF"
        }
      },
      "binary": "6D 00 FF",
      "notes": "Header: (1<<6)|(11<<2)|1 = 0x40+0x2C+0x01 = 0x6D."
    },
    {
      "id": "hdr-003",
      "description": "Version=0, RAW_CUSTOM, TRANSPORT_DIRECT with non-trivial transport codes",
      "type": "encode_decode",
      "structured": {
        "header": {
          "version": 0,
          "payload_type": "raw_custom",
          "route_type": "transport_direct"
        },
        "transport_codes": [
          256,
          512
        ],
        "path": {
          "hash_size": 1,
          "hash_count": 1,
          "hashes": [
            "AA"
          ]
        },
        "payload": {
          "data": "CAFEBABE"
        }
      },
      "binary": "3F 0001 0002 01 AA CAFEBABE",
      "notes": "Header: (0<<6)|(15<<2)|3 = 0x3F. Transport codes: 256=0x0100 LE=0001, 512=0x0200 LE=0002."
    },
    {
      "id": "hdr-004",
      "description": "Version=0, TRACE, FLOOD with path",
      "type": "encode_decode",
      "structured": {
        "header": {
          "version": 0,
          "payload_type": "trace",
          "route_type": "flood"
        },
        "path": {
          "hash_size": 1,
          "hash_count": 3,
          "hashes": [
            "AA",
            "BB",
            "CC"
          ]
        },
        "payload": {
          "data": "0102030405060708 09"
        }
      },
      "binary": "25 03 AABBCC 010203040506070809",
      "notes": "Header: (0<<6)|(9<<2)|1 = 0x25. path_len=0x03 (1-byte hashes, 3 hops)."
    },
    {
      "id": "hdr-005",
      "description": "Maximum header value that isn't 0xFF sentinel: version=2, RAW_CUSTOM, TRANSPORT_DIRECT",
      "type": "encode_decode",
      "structured": {
        "header": {
          "version": 2,
          "payload_type": "raw_custom",
          "route_type": "transport_direct"
        },
        "transport_codes": [
          0,
          0
        ],
        "path": {
          "hash_size": 1,
          "hash_count": 0,
          "hashes": []
        },
        "payload": {
          "data": "AA"
        }
      },
      "binary": "BF 0000 0000 00 AA",
      "notes": "Header: (2<<6)|(15<<2)|3 = 0x80+0x3C+0x03 = 0xBF."
    }
  ]
}