syntax = "proto3";

package corestate.v2.backup;

option java_package = "com.corestate.v2.proto.backup";
option java_multiple_files = true;

// Represents a single chunk of a file
message DataChunk {
  string chunk_id = 1; // Blake3 hash of the content
  bytes data = 2;
}

// Metadata for a single file in a backup
message FileMetadata {
  string path = 1;
  int64 size = 2;
  int64 modified_time = 3;
  string checksum = 4; // Blake3 checksum of the full file
  repeated string chunk_ids = 5;
}

// A complete backup manifest
message BackupManifest {
  string backup_id = 1;
  int64 timestamp = 2;
  enum BackupType {
    FULL = 0;
    INCREMENTAL = 1;
    SYNTHETIC_FULL = 2;
  }
  BackupType type = 3;
  repeated FileMetadata files = 4;
}

service BackupService {
  rpc StartBackup(StartBackupRequest) returns (StartBackupResponse);
  rpc UploadChunk(stream DataChunk) returns (UploadChunkResponse);
  rpc FinishBackup(FinishBackupRequest) returns (FinishBackupResponse);
}

message StartBackupRequest {
  BackupManifest.BackupType type = 1;
  string device_id = 2;
}

message StartBackupResponse {
  string backup_id = 1;
  string upload_token = 2;
}

message UploadChunkResponse {
  string chunk_id = 1;
  bool success = 2;
}

message FinishBackupRequest {
  string backup_id = 1;
  BackupManifest manifest = 2;
}

message FinishBackupResponse {
  bool success = 1;
}