# Step 23: HDF5 Writer Modules

## 담당 역할과 필수 스킬

- 담당 역할: `implementation-agent`
- 필수 스킬: `harness`, `fesa-cpp-msvc-tdd`
- 이 Step만 `RED -> observed failure -> minimal GREEN -> focused/full VERIFY`로 수행한다.

## 읽어야 할 파일

- `/AGENTS.md`
- `/docs/CODINGSTYLE.md`
- `/docs/ARCHITECTURE.md`
- `/docs/ADR.md`
- `/docs/linear-static-3d-euler-beam/io.md`
- `/docs/linear-static-mitc4-shell/io.md`
- `/docs/cpp-object-oriented-modular-refactoring/implementation-plan.md`
- Step 22 recovery candidate/result records
- `/include/fesa/io/hdf5/hdf5_results_writer.h`
- `/src/fesa/io/hdf5/hdf5_results_writer.cpp`
- `/include/fesa/results/results_writer.h`
- `/tests/unit/io/hdf5/hdf5_results_writer_test.cpp`
- `/src/fesa/CMakeLists.txt`, `/tests/CMakeLists.txt`
- `/phases/cpp-object-oriented-modular-refactoring/index.json`
- `/phases/cpp-object-oriented-modular-refactoring/step23.md`

## 작업

Requirement `R-MODULE-001`의 HDF5 split을 구현한다.

1. `/tests/unit/io/hdf5/hdf5_writer_components_test.cpp`를 먼저 추가한다.
   `C-MODULE-003` tests backend-neutral dataset plans, finite inventory validation, self-check
   failure and atomic final-file preservation through private component seams.
2. Missing component headers/symbols provides RED.
3. Keep `Hdf5ResultsWriter` as the only public facade and keep all HDF5 ids/types private.
   Candidate modules:

```text
hdf5_raii.h                    move-only private HDF5 handle wrappers
hdf5_primitives.h/.cpp         scalar/string/array/group/attribute operations
hdf5_model_writer.h/.cpp       exact model/source identity datasets
hdf5_result_writer.h/.cpp      exact mandatory beam/shell/global result datasets
hdf5_self_check.h/.cpp         reopen, shape, attribute and finite inventory checks
hdf5_atomic_file.h/.cpp        candidate path, preservation and final replacement
```

4. Testable backend-neutral plan records may be private to `src/fesa/io/hdf5`; tests may receive a
   PRIVATE include directory. Do not expose `hid_t`, HDF5 headers or storage handles in
   `/include/fesa/`.
5. Preserve every schema-v0 path, shape, attribute, units, row order, mandatory-output behavior,
   warning dataset, reopen self-check and existing-final preservation.
6. Reduce `hdf5_results_writer.cpp` to facade orchestration.

## Acceptance Criteria

```powershell
cmake --build .harness/build --config Debug --target fesa_unit_tests
ctest --test-dir .harness/build -C Debug `
  -R "Hdf5ResultsWriter|Hdf5WriterComponents|ResultsWriter" --output-on-failure
$componentFiles = @(
  "src/fesa/io/hdf5/hdf5_raii.h",
  "src/fesa/io/hdf5/hdf5_primitives.cpp",
  "src/fesa/io/hdf5/hdf5_model_writer.cpp",
  "src/fesa/io/hdf5/hdf5_result_writer.cpp",
  "src/fesa/io/hdf5/hdf5_self_check.cpp",
  "src/fesa/io/hdf5/hdf5_atomic_file.cpp"
)
foreach ($componentFile in $componentFiles) {
  if (-not (Test-Path -LiteralPath $componentFile -PathType Leaf)) {
    throw "Missing HDF5 component: $componentFile"
  }
}
rg -n "WriteModel|WriteResults|SelfCheck|Atomic" `
  src/fesa/io/hdf5/hdf5_results_writer.cpp
$vendorLeaks = @(rg -n "hid_t|hdf5\.h|H5[A-Z]" include/fesa)
if ($vendorLeaks.Count -ne 0) { $vendorLeaks; throw "HDF5 type leaked into public headers" }
& "C:/Program Files/LLVM/bin/clang-format.exe" --dry-run --Werror `
  (rg --files src/fesa/io/hdf5 -g "*.h" -g "*.cpp") `
  tests/unit/io/hdf5/hdf5_results_writer_test.cpp `
  tests/unit/io/hdf5/hdf5_writer_components_test.cpp
cmake --build .harness/build --config Debug
ctest --test-dir .harness/build -C Debug --show-only=json-v1
ctest --test-dir .harness/build -C Debug --output-on-failure
```

## 검증 및 상태 갱신

- RED missing components, schema/atomicity focused suite, facade/vendor scans and full CTest를 summary에 기록한다.
- Schema, required output or preservation regression is `error`; never edit I/O docs to pass.
- 성공 시 현재 Step만 `completed`로 갱신한다.
- timestamp, retry, commit, advancement는 Executor 소유다.

## 금지사항

- HDF5 schema version, dataset paths/shapes/attributes를 변경하지 마라.
- HDF5 types/lifetime을 public solver core에 노출하지 마라.
- Invalid candidate로 existing final file을 replace하지 마라.
- 직접 commit하거나 hook script를 수동 실행하지 마라.