syntax = "proto3";

// ---------------------------------------------------------------------------
// TorChat User Identity & Reputation Spec  (v0.1)
// ---------------------------------------------------------------------------
//  * A user is a long-term Ed25519 key-pair.
//  * Profile fields are optional and fully signed.
//  * Multi-device keys are supported via DeviceKey.
//  * Third-party attestations ("signatures") build a web-of-trust layer.
// ---------------------------------------------------------------------------

package torchat.identity;

option go_package   = "github.com/torchat/proto/identity";
option java_package = "org.torchat.identity";
option java_multiple_files = true;

// -------------------------------------------------
// Primitive types
// -------------------------------------------------
message PublicKey   { bytes value = 1; }   // Ed25519 32-byte
message Signature   { bytes value = 1; }   // Ed25519 64-byte on SHA-256 hash
message Sha256Hash  { bytes value = 1; }   // 32-byte hash

// -------------------------------------------------
// User Profile (self-signed)
// -------------------------------------------------
message UserProfile {
  PublicKey  pubkey       = 1;        // unique master key
  string     nickname     = 2;        // optional alias
  string     bio          = 3;        // optional free-text
  string     avatar_url   = 4;        // optional (ipfs:// or https://)
  int64      created_at   = 5;        // epoch millis
  uint32     version      = 6;        // profile schema version
}

// -------------------------------------------------
// Device key (per-device subkey, signed by master)
// -------------------------------------------------
message DeviceKey {
  string      device_id    = 1;       // random UUID / human name
  PublicKey   device_pk    = 2;       // Ed25519 key for this device
  int64       created_at   = 3;
  Signature   master_sig   = 4;       // master key sig over hash(device)
}

// -------------------------------------------------
// Third-party attestation (web-of-trust)
// -------------------------------------------------
message Attestation {
  enum Purpose {
    GENERIC_TRUST  = 0;   // default "I trust this user"
    MODERATOR_ROLE = 1;
    NOTARY_ROLE    = 2;   // can co-sign trades, escrow etc.
  }

  PublicKey signer_pk = 1;            // who signs (must be known peer)
  bytes     subject_pk = 2;           // user being attested
  Purpose   purpose    = 3;
  string    memo       = 4;           // free text or JSON
  int64     timestamp  = 5;
  Signature signature  = 6;           // sig(signer) over hash(all above fields)
}

// -------------------------------------------------
// Full signed user record
// -------------------------------------------------
message SignedUser {
  UserProfile             profile       = 1;  // MUST contain self-sig
  Signature               self_sig      = 2;  // sig(master) over hash(profile)
  repeated DeviceKey      devices       = 3;  // 0+ devices
  repeated Attestation    attestations  = 4;  // 0+ third-party sigs
}

// -------------------------------------------------
// gRPC Identity Service
// -------------------------------------------------
service IdentityService {
  // Register or update your profile. Must include self_sig.
  rpc RegisterUser    (SignedUser) returns (Ack);

  // Add or revoke a device key (master-signed).
  rpc UpsertDeviceKey (DeviceKey)  returns (Ack);

  // Add a third-party attestation.
  rpc AddAttestation  (Attestation) returns (Ack);

  // Get full user record.
  rpc GetUser         (PublicKey)  returns (SignedUser);

  // Stream attestations about a user.
  rpc StreamAttestations(PublicKey) returns (stream Attestation);
}

// Generic acknowledge wrapper
message Ack {
  enum Status { OK = 0; ERROR = 1; }
  Status  status  = 1;
  string  message = 2; // optional error / info
}