# Pre-Flight Checklist — Before Implementation

## Decisions needed before writing code

- [ ] **YAML or JSON config?**
  - YAML = 1 external dep (`gopkg.in/yaml.v3`), more human-readable
  - JSON = zero external deps (`encoding/json`), `config.json` instead of `config.yaml`
  - **Recommendation**: JSON for true stdlib-only. YAML is fine if 1 dep is ok.

- [ ] **Patient API availability during dev**
  - The patient-data API doesn't exist yet (only spec in `docs/patient-api-spec.md`)
  - Option A: Build a thin PHP stub first (copy the reference impl from the spec)
  - Option B: Make patient API call optional with graceful degradation in Stage 1
  - **Recommendation**: B for Stage 1 (multi-accession ISO falls back to accession-list filename if API unavailable). Build the real API before Stage 2.

- [ ] **`send_rimage_multiple.php` single vs multi routing**
  - The HIS JS calls `send_rimage_multiple.php?accession_number=X` for single AND `send_rimage_multiple.php?accession_number=X,Y,Z` for multi
  - The Go API has TWO endpoints: `/api/iso/print` (single) and `/api/iso/print-multiple` (multi)
  - **Problem**: nginx can't distinguish them — same PHP file, same query param name
  - **Fix**: Merge into one Go endpoint that auto-detects commas:
    - `GET /api/iso/print?accession_number=X` → single
    - `GET /api/iso/print?accession_number=X,Y,Z` → comma → multi
  - Then nginx maps `send_rimage_multiple.php` → `/api/iso/print` only

- [ ] **0-file edge case in DICOM fetch**
  - What if PACS returns success but 0 files? (valid accession, no images)
  - Current plan doesn't explicitly handle this
  - **Fix**: After FetchDICOM, check `filesCount > 0`. If 0, return `404 {"error":"no DICOM data"}` before attempting ISO creation.

- [ ] **microdicom viewer files path**
  - Config: `iso.microdicom_path: "/var/www/html/microdicom"`
  - These files are in `raw/microdicom/` in this project
  - Must exist on the PACS server at the configured path
  - If missing, ISO will still work (just no embedded viewer)

- [ ] **CD Publisher reachability**
  - Config: `cd_publisher.host: "172.16.0.120"`, port 104
  - May not be reachable from dev environment
  - storescu will fail with connection refused — handle gracefully

- [ ] **Config path**
  - Hardcode: `config.yaml` in working directory
  - Or env: `MKISO_CONFIG=/etc/mkiso/config.yaml`
  - **Recommendation**: env var with fallback to `./config.yaml`

## Files that need to be created (not just spec'd)

| File | Status |
|------|--------|
| `go.mod` | Create with `module mkiso-server` |
| `config.example.yaml` | Template from design doc § config.yaml |
| `main.go` | Entrypoint |
| `internal/config/config.go` | Config loading |
| `internal/route/route.go` | Route wiring |
| `internal/middleware/auth.go` | API key middleware (Stage 2) |
| `internal/handler/health.go` | Health check |
| `internal/handler/iso.go` | ISO download handlers |
| `internal/handler/print.go` | Print/relay handlers |
| `internal/service/dicom.go` | DICOM orchestration |
| `internal/service/iso.go` | ISO creation |
| `internal/service/relay.go` | CD Publisher relay |
| `internal/repo/patient.go` | Patient API client |
| `pkg/dicom/command.go` | DICOM binary runner |

## Implementation order (respects dependencies)

```
1. config.go          (no deps)
2. pkg/dicom/command.go (no deps)
3. repo/patient.go    (depends on config)
4. service/dicom.go   (depends on #2)
5. service/iso.go     (depends on #3, #4)
6. service/relay.go   (depends on #3, #4)
7. handler/health.go  (no deps)
8. handler/iso.go     (depends on #5)
9. handler/print.go   (depends on #6)
10. route/route.go    (depends on #7, #8, #9)
11. middleware/auth.go (depends on config) — Stage 2
12. main.go           (depends on #10)
```

## Known gaps in the plan (addressed above)

| Gap | Resolution |
|-----|------------|
| Nginx regex mapping bug (old `$1` didn't map to Go paths) | Fixed — explicit `location =` blocks with correct `proxy_pass` targets |
| `print` vs `print-multiple` routing conflict | Merge into single endpoint with comma detection. Update handler accordingly. |
| 0-files from PACS not handled | Check `filesCount > 0` after FetchDICOM, return 404 if empty |
| Patient API doesn't exist yet | Graceful degradation in Stage 1 (skip patient name for filename) |