{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://hypercortex.org/schemas/dht_protocol.json",
  "title": "DHT Protocol Schema",
  "description": "Schema for DISCOVERY and PEER_EXCHANGE messages in the HyperCortex Mesh DHT layer.",
  "schema_version": "4.2",
  "type": "object",

  "oneOf": [
    { "$ref": "#/definitions/discovery" },
    { "$ref": "#/definitions/peerExchangeRequest" },
    { "$ref": "#/definitions/peerExchangeResponse" }
  ],

  "definitions": {
    "interface": {
      "type": "object",
      "required": ["addr", "nonce", "pow_hash", "difficulty", "datetime", "type"],
      "properties": {
        "addr": {
          "type": "string",
          "pattern": "^(tcp|udp)://.+",
          "description": "Full address of the peer (transport://host:port)."
        },
        "nonce": {
          "type": "integer",
          "minimum": 0,
          "description": "Proof-of-Work nonce."
        },
        "pow_hash": {
          "type": "string",
          "description": "Proof-of-Work SHA256 hash result."
        },
        "difficulty": {
          "type": "integer",
          "minimum": 1,
          "description": "Difficulty level of the Proof-of-Work."
        },
        "datetime": {
          "type": "string",
          "format": "date-time",
          "description": "Timestamp of when the address was last validated."
        },
        "type": {
          "type": "string",
          "description": "Interface type: internet, localhost, or private network.",
          "pattern": "^(localhost|internet|yggdrasil|i2p|lan:[0-9]{1,3}(\\.[0-9]{1,3}){3})$"
        }
      },
      "additionalProperties": false
    },

    "peer": {
      "type": "object",
      "required": ["id", "name", "pubkey", "addresses", "signature", "sig_algo", "version"],
      "properties": {
        "version": {
          "type": "string",
          "description": "Version of this peer record format.",
          "default": "1.0"
        },
        "id": {
          "type": "string",
          "description": "Peer's decentralized identifier (DID)."
        },
        "name": {
          "type": "string",
          "description": "Human-readable name of the peer."
        },
        "pubkey": {
          "type": "string",
          "description": "Base58-encoded Ed25519 public key."
        },
        "addresses": {
          "type": "array",
          "items": { "$ref": "#/definitions/interface" },
          "description": "List of network interfaces associated with this peer."
        },
        "signature": {
          "type": "string",
          "description": "Base64URL-encoded Ed25519 signature of this record."
        },
        "sig_algo": {
          "type": "string",
          "enum": ["ed25519"],
          "description": "Signature algorithm used for signing the record."
        }
      },
      "additionalProperties": false
    },

    "discovery": {
      "type": "object",
      "required": ["type", "version", "id", "name", "pubkey", "addresses", "signature", "sig_algo"],
      "properties": {
        "type": { "const": "DISCOVERY" },
        "version": {
          "type": "string",
          "description": "Version of the DISCOVERY message format.",
          "default": "1.0"
        },
        "id": { "type": "string" },
        "name": { "type": "string" },
        "pubkey": { "type": "string" },
        "addresses": {
          "type": "array",
          "items": { "$ref": "#/definitions/interface" }
        },
        "signature": { "type": "string" },
        "sig_algo": { "type": "string", "enum": ["ed25519"] }
      },
      "additionalProperties": false
    },

    "peerExchangeRequest": {
      "type": "object",
      "required": ["type", "version", "id", "name", "addresses", "signature", "sig_algo"],
      "properties": {
        "type": { "const": "PEER_EXCHANGE_REQUEST" },
        "version": {
          "type": "string",
          "description": "Version of the PEER_EXCHANGE_REQUEST format.",
          "default": "1.0"
        },
        "id": { "type": "string" },
        "name": { "type": "string" },
        "addresses": {
          "type": "array",
          "items": { "$ref": "#/definitions/interface" }
        },
        "signature": { "type": "string" },
        "sig_algo": { "type": "string", "enum": ["ed25519"] }
      },
      "additionalProperties": false
    },

    "peerExchangeResponse": {
      "type": "array",
      "items": { "$ref": "#/definitions/peer" },
      "description": "List of peers known to the responding agent."
    }
  }
}