# C++ Implementation Status

## Current State: Infrastructure Only

The C++ DBAL implementation is currently in the **planning phase**. The following infrastructure has been set up:

### ✅ Available
- **Build System**: CMakeLists.txt with Conan + Ninja support
- **Build Assistant**: `dbal/tools/cpp-build-assistant.js` for build automation
- **CI/CD**: GitHub Actions workflow (`cpp-build.yml`) with conditional execution
- **Project Structure**: Directory layout and header files
- **Documentation**: Comprehensive README.md with architecture plans

### ❌ Not Yet Implemented
- **Source Files**: No `.cpp` implementation files exist yet
- **Core Library**: Client, error handling, capabilities
- **Query Engine**: AST, query builder, normalizer
- **Database Adapters**: SQLite, MongoDB adapters
- **Daemon**: Server, security implementation
- **Tests**: Unit, integration, and conformance tests
- **Utilities**: UUID generation, backoff strategies

## Why CI is Skipped

The GitHub Actions workflow includes a **check-implementation** job that:
1. Checks if `dbal/cpp/src/` directory exists
2. Verifies at least one `.cpp` file is present
3. Sets `has_sources=false` if implementation is missing
4. Skips all build/test jobs when sources don't exist

This prevents CI failures while the C++ codebase is under development.

## Implementation Roadmap

### Phase 1: Core Types & Errors (Not Started)
- [ ] `src/errors.cpp` - Error handling and Result type
- [ ] `src/types.cpp` - Basic type system
- [ ] `src/capabilities.cpp` - Capability detection

### Phase 2: Query Builder (Not Started)
- [ ] `src/query/ast.cpp` - Abstract syntax tree
- [ ] `src/query/builder.cpp` - Query construction
- [ ] `src/query/normalize.cpp` - Query normalization

### Phase 3: Client (Not Started)
- [ ] `src/client.cpp` - Main client interface
- [ ] `src/util/uuid.cpp` - UUID generation
- [ ] `src/util/backoff.cpp` - Retry logic

### Phase 4: Adapters (Not Started)
- [ ] `src/adapters/sqlite/sqlite_adapter.cpp`
- [ ] `src/adapters/sqlite/sqlite_pool.cpp`

### Phase 5: Daemon (Not Started)
- [ ] `src/daemon/main.cpp` - Entry point
- [ ] `src/daemon/server.cpp` - Server implementation
- [ ] `src/daemon/security.cpp` - Security/ACL

### Phase 6: Testing (Not Started)
- [ ] `tests/unit/` - Unit tests
- [ ] `tests/integration/` - Integration tests
- [ ] `tests/conformance/` - Conformance tests

## How to Start Implementation

When you're ready to implement the C++ codebase:

1. **Create the src directory**:
   ```bash
   mkdir -p dbal/cpp/src/{query,util,adapters/sqlite,daemon}
   ```

2. **Create a minimal main.cpp to test the build**:
   ```bash
   cat > dbal/cpp/src/daemon/main.cpp << 'EOF'
#include <iostream>
int main() {
    std::cout << "DBAL Daemon v0.1.0" << std::endl;
    return 0;
}
EOF
   ```

3. **Add stub implementations** for files referenced in CMakeLists.txt

4. **Test the build locally**:
   ```bash
   npm run cpp:check
   npm run cpp:full
   ```

5. **Commit and push** - CI will now detect sources and run builds

## Why This Approach?

**Benefits of conditional CI**:
- ✅ No false-negative CI failures during development
- ✅ Infrastructure is tested and ready when implementation begins
- ✅ Clear signal when implementation starts (CI will activate)
- ✅ Documentation and plans can be refined without CI noise

**Alternative approaches considered**:
- ❌ Disable workflow entirely - hides important infrastructure
- ❌ Create stub implementations - creates technical debt
- ❌ Mark as `continue-on-error` - hides real build failures

## Questions?

If you're working on the C++ implementation:
- Check `dbal/cpp/README.md` for architecture details
- Review `dbal/cpp/CMakeLists.txt` for build configuration
- Use `dbal/tools/cpp-build-assistant.js` for build commands
- See `.github/workflows/cpp-build.yml` for CI details

---

**Last Updated**: 2025-12-24  
**Status**: Infrastructure Ready, Implementation Pending
