dicom-iso/todo/pre-flight.md

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)