feat(fhir): add FHIR medication interface implementation plan script

[Copilot]

Scripts-only implementation plan for the FHIR-based medication interface described in docs/mdr/interface/genpres_interface_specification.md, demonstrating how FHIR R4 scenarios map to GenPRES orders via the OrderContext lookup mechanism and vice versa.

Author checklist

• The described changes have already been described in an issue: #
• This PR documents the plan in a markdown file in ./docs/implementation-plans/.
• I have used the implementation plan template.
• The plan has enough detail: any suggestions that a reveiewer adds to a PR that implements the plan are likely to be relatively quick to implement (intentionally vague to leave room for flexibility!).

Reviewer checklist

• The chosen approach is a good choice.
• The sequence of steps is complete and sensible.
• I have documented resources that may help with implementation.

---

What's in the scripts

src/Informedica.FHIR.Lib/Scripts/load.fsx — standard bootstrap for FSI; references GenUNITS, GenCORE, GenSOLVER, GenFORM, ZIndex, GenORDER DLLs.

src/Informedica.FHIR.Lib/Scripts/ImplementationPlan.fsx — walks all 8 steps of the issue, covering spec scenarios 6.1–6.11:

Step	What it does
1	Typed F# records (FhirScenario, ScenarioProduct, AdministrationSchema) for all spec scenarios 6.1–6.11, including reconstitution (6.8, 6.9), TPN (6.10), and enteral feeding (6.11). AdministrationSchema uses RateFormUnit (numerator) and RateTimeUnit (denominator). Each FhirScenario contains only what a FHIR resource directly provides: patient context, indication, route, shape, dose type, component orderable quantities, dose rate, and schedule frequency.
2	ZIndex.GenericProduct.get [] filtered by generic name; notes that spec GPK codes are placeholders. Concentrations and dose limits are derived from ZIndex results, not hardcoded.
3	ValueUnit construction for the four directly-available FHIR data categories: component orderable quantities, orderable dose quantity, orderable dose rate, and schedule frequency.
4	Reconstructs an OrderScenario from FHIR context via OrderContext: builds a Patient from scenario patient data, sets Filter with indication/route/shape/dose type, calls OrderContext.create + getScenarios. Concentrations and dose limits come from ZIndex/GenFORM lookup — not hardcoded.
5–6	Runs Order.solveMinMax on the retrieved scenario; prints order table.
7	Pass/fail summary across all 11 scenarios.
8	Full FHIR R4 bidirectional translation investigation with official documentation references, F# types mirroring the FHIR R4 data model, and concrete translation function sketches (fromFhirMedicationRequest and toFhirMedicationRequest).

Informedica.FHIR.Lib.fsproj updated to surface both scripts as <None> items.

Key design principle

A FHIR scenario provides only four categories of data that feed directly into the order:

1. Component Orderable Quantities — from the FHIR products block
2. Orderable Dose Quantity — from the FHIR administration block
3. Orderable Dose Rate — from the FHIR schema rate (RateFormUnit/RateTimeUnit)
4. Schedule Frequency — from the FHIR schema pattern

Everything else (concentrations, dose limits, product structure) is derived by ZIndex/GenFORM lookup via OrderContext.getScenarios, using the filter inputs: patient data, indication, route, shape, and dose type.

FHIR R4 bidirectional translation (Step 8)

Step 8 is a full investigation of the official FHIR R4 resource structure:

• F# types mirroring FhirMedicationRequest, FhirMedication, FhirDosage, FhirTiming, FhirTimingRepeat, FhirQuantity, FhirRatio, FhirCodeableConcept
• FhirSystems module: G-Standard OIDs — GPK (urn:oid:2.16.840.1.113883.2.4.4.7), route thesaurus 9, form thesaurus 10, UCUM
• RouteMapping: G-Standard route code ↔ GenPRES route name
• PeriodUnitMapping: FHIR h/d/wk ↔ GenPRES uur/dag/week
• inferDoseType: infers Once/OnceTimed/Discontinuous/Timed/Continuous from the FHIR timing/rate structure
• fromFhirMedicationRequest: FHIR MedicationRequest → FhirScenario (drives OrderContext filter + getScenarios to look up ZIndex rules)
• toFhirMedicationRequest: FhirScenario → FHIR MedicationRequest with GPK coding, G-Standard route, doseAndRate.rateRatio (using RateFormUnit/RateTimeUnit), timing.repeat, and contained Medication with ingredients
• Round-trip demonstration for all 11 scenarios verifying that Route, DoseType, and Indication survive the round-trip

Official FHIR R4 documentation references included:

• MedicationRequest: https://hl7.org/fhir/R4/medicationrequest.html
• Medication: https://hl7.org/fhir/R4/medication.html
• Dosage: https://hl7.org/fhir/R4/dosage.html
• Timing: https://hl7.org/fhir/R4/datatypes.html#Timing

Original prompt

---

This section details on the original issue you should resolve

<issue_title>First implementation plan for a FHIR based medication interface</issue_title>
<issue_description>Is your feature request related to a problem? Please describe.
GenPRES needs to provide an interface to communicate medication orders.

The requirements and how an interface should work to import and export medication orders is described at: docs/mdr/interface/genpres_interface_specification.md. Specifically the document describes a number of scenarios.

The architecture document: docs/roadmap/genpres-architecture-and-timeline.md, shows where this should fit in. This should be implemented in the project stub: src/Informedica.FHIR.Lib

This should be implemented using the
There should be a script based implementation plan with the following steps:

1. Create a src/Informedica.FHIR.Lib/Scripts/ImplementationPlan.fsx
2. Use the provided scenarios as examples.
3. Lookup the product information provided by the product codes in the examples
4. Parse the quantitative variables to ValueUnits
5. Translate each scenario to the medication string representation: src/Informedica.GenORDER.Lib/Medication.fs
6. Try to run the scenario by the Medication.fromString as an order
7. Print out the results.
8. Try to translate this process to a FHIR based solution
   </issue_description>

<agent_instructions>See issue</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes First implementation plan for a FHIR based medication interface #214

---

⌨️ Start Copilot coding agent tasks without leaving your editor — available in VS Code, Visual Studio, JetBrains IDEs and Eclipse.

[halcwb]

Rename:

• RateUnit1 to RateFormUnit
• RateUnit2 to RateTimeUnit

Note: try to match names with the existing naming policy in the code base and data structures.

The current implementation assumes knowledge about dosing but that is not in the scenarios. Only the following can be provided:

1. Component Orderable Quantities
2. Ordererable Dose Quantity and/or
3. Orderable Dose Rate and/or
4. Schedule Frequency

Everything else is derived by lookup or calculation.

For the reconstruction of the OrderScenario type the following is provided:

• Patient data
• Indication
• Route
• Shape
• Dose type

The code should reflect this.

[Copilot]

Rename:

• RateUnit1 to RateFormUnit
• RateUnit2 to RateTimeUnit...

Done in b2ad01b.

• Renamed RateUnit1 → RateFormUnit and RateUnit2 → RateTimeUnit throughout AdministrationSchema and all scenario definitions.
• Restructured the script to reflect the correct data model: FhirScenario now contains only what a FHIR resource actually provides (patient data, indication, route, shape, dose type, component orderable quantities, dose rate, and schedule frequency).
• Removed all hardcoded concentrations and dose limits from the old scenarioToMedicationText function entirely.
• Step 4 now shows the correct approach: build a Patient from scenario patient data, set the Filter with indication/route/shape/dose type from the FHIR scenario, and call OrderContext.create + getScenarios to retrieve concentrations and dose limits from ZIndex/GenFORM by lookup.

[halcwb]

Investigate how GenPRES can translate the FIHR data from and to a scenario and how a scenario then can be translated to a medication and order scenario and vice versa. Look at the official FHIR documentation.

[Copilot]

Investigate how GenPRES can translate the FIHR data from and to a scenario and how a scenario then can be translated to a medication and order scenario and vice versa. Look at the official FHIR docume...

Done in 1665770. Step 8 is now a full FHIR R4 investigation:

F# types mirroring the official FHIR R4 resources (with documentation links):

• FhirMedicationRequest, FhirMedication, FhirDosage, FhirDosageAndRate, FhirTiming/FhirTimingRepeat, FhirQuantity, FhirRatio, FhirCodeableConcept, FhirCoding, FhirMedicationIngredient

G-Standard/FHIR constants and mappings:

• FhirSystems module: GPK OID urn:oid:2.16.840.1.113883.2.4.4.7, route thesaurus 9, form thesaurus 10, UCUM
• RouteMapping: G-Standard route code ↔ GenPRES route name (INTRAVENEUS, RECTAAL, ORAAL, …)
• PeriodUnitMapping: FHIR h/d/wk ↔ GenPRES uur/dag/week

Bidirectional translation:

• inferDoseType: infers Once/OnceTimed/Discontinuous/Timed/Continuous from the FHIR timing/rate structure
• fromFhirMedicationRequest: FHIR MedicationRequest → FhirScenario (which then drives OrderContext filter + getScenarios to look up ZIndex rules)
• toFhirMedicationRequest: FhirScenario → FHIR MedicationRequest with GPK coding, G-Standard route, doseAndRate.rateRatio (using RateFormUnit/RateTimeUnit), and timing.repeat

All 11 spec scenarios (6.1–6.11 including reconstitution, TPN, enteral feeding) are now defined and run through the round-trip demonstration.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• build.fhir.org
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (dns block)
• hl7.org
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (dns block)
• www.hl7.org
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

[greptile-apps]

Greptile Summary

This PR adds a script-only implementation plan (ImplementationPlan.fsx + load.fsx) for the FHIR-based medication interface described in the GenPRES specification, together with a minimal .fsproj update to surface the scripts in the IDE.

• The .fsproj change is correct and non-invasive: the two scripts are registered as <None> items, so they are included in the solution explorer but never compiled into the production assembly.
• Per project policy, the .fsx script files are excluded from this code review.
• No production source files (Library.fs or any .fs file) were modified.

Confidence Score: 5/5

• Safe to merge — only non-compiled script files and a trivial .fsproj update are included.
• The sole production file change is a two-line addition of <None> items to the .fsproj, which has no effect on compilation or runtime behaviour. The .fsx scripts are excluded from review per project policy and do not affect the built assembly.
• No files require special attention.

Important Files Changed

Filename	Overview
src/Informedica.FHIR.Lib/Informedica.FHIR.Lib.fsproj	Adds <None Include="..."> entries for the two new .fsx script files so they appear in the IDE solution explorer; no production compilation is affected.
src/Informedica.FHIR.Lib/Scripts/load.fsx	Standard FSI bootstrap script; excluded from code review per project policy on .fsx files.
src/Informedica.FHIR.Lib/Scripts/ImplementationPlan.fsx	1794-line script-based implementation plan for FHIR medication interface; excluded from code review per project policy on .fsx files.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[FHIR MedicationRequest\nR4 Resource] -->|fromFhirMedicationRequest| B[FhirScenario\nPatient / Route / Shape / DoseType\nProducts / AdminQty / Schema]
    B -->|Build Patient| C[Patient record\nweight / height / age / gender]
    B -->|Build Filter| D[Filter\nIndication / Route / Shape / DoseType]
    C --> E[OrderContext.create\n+ getScenarios]
    D --> E
    E -->|ZIndex / GenFORM lookup| F[OrderScenario\nConcentrations & Dose Limits]
    B -->|Apply orderable quantities\n& schedule from FHIR| F
    F -->|Order.solveMinMax| G[Solved Order]
    G -->|toFhirMedicationRequest| H[FHIR MedicationRequest\nR4 Resource]
    H -->|Round-trip check| A

Loading

_{Reviews (1): Last reviewed commit: "Merge branch 'master' into copilot/add-f..." | Re-trigger Greptile}