# Protocol Buffers (Protobuf) Integration

This project supports optional Protocol Buffers integration via [vcpkg](https://vcpkg.io/).

## Installation

Install protobuf via vcpkg:

```bash
vcpkg install protobuf[zlib] protobuf[zlib]:x64-windows
```

## CMake Configuration

### Option 1: Using vcpkg Toolchain (Recommended)

When configuring CMake, specify the vcpkg toolchain file:

```bash
cmake -S applications -B build --toolchain [path to vcpkg]/scripts/buildsystems/vcpkg.cmake
```

Or set it as an environment variable:

```powershell
$env:CMAKE_TOOLCHAIN_FILE = "[path to vcpkg]/scripts/buildsystems/vcpkg.cmake"
cmake -S applications -B build
```

### Option 2: Disable Protobuf (if not needed)

```bash
cmake -S applications -B build -DENABLE_PROTOBUF=OFF
```

## CMake Options

- `ENABLE_PROTOBUF` (default: `ON`) - Enable or disable Protocol Buffers support

## Usage in Code

When protobuf is enabled, the `ENABLE_PROTOBUF` preprocessor macro is defined:

```cpp
#ifdef ENABLE_PROTOBUF
    #include <google/protobuf/...>
    // Use protobuf APIs
#else
    // Fallback code when protobuf is disabled
#endif
```

## Targets

All executables automatically link to protobuf when available:
- `nodehub`
- `nodehub-console`
- `core_tests`

Protobuf is linked via the `protobuf_interface` interface library, which provides:
- `protobuf::libprotobuf` - Main protobuf library
- `protobuf::libprotoc` - Protocol compiler library
- `ENABLE_PROTOBUF=1` compile definition

## References

- [Protobuf CMake README](https://github.com/protocolbuffers/protobuf/blob/main/cmake/README.md)
- [vcpkg Documentation](https://vcpkg.io/)