/// url = 'https://fhir.slade360.co.ke/fhir/StructureMap/ExtractInpatientDischargeNote'
/// name = 'ExtractInpatientDischargeNote'
/// title = 'Inpatient Discharge Note Extraction'
/// status = 'active'
/// description = 'Turns a response to the inpatient discharge note into a discharge-summary Composition and a ServiceRequest for the follow-up. Medication on discharge is referenced, never copied: those MedicationRequests already exist on the server -- the form picks them from it -- so they become section entries rather than new resources. The follow-up is intent `plan` rather than an Appointment because the form captures it as free text with no date to book against; give the item a date and an Appointment becomes the truer target. The Encounter is deliberately untouched: closing the stay -- Encounter.status and the discharge disposition -- belongs to the EMR\'s discharge workflow, which knows about bed release, billing and the actual moment the patient left. Writing a note is not the same event as being discharged, and a map that conflated them would close stays early.'

uses "http://hl7.org/fhir/StructureDefinition/QuestionnaireResponse" alias QR as source
uses "http://hl7.org/fhir/StructureDefinition/Bundle" alias Bundle as target
uses "http://hl7.org/fhir/StructureDefinition/Composition" alias Composition as target
uses "http://hl7.org/fhir/StructureDefinition/ServiceRequest" alias ServiceRequest as target

group ExtractInpatientDischargeNote(source qr : QR, target bundle : Bundle) {
  qr -> bundle.type = 'transaction' "setBundleType";
  qr ->  bundle.entry as entry,  entry.resource = create('Composition') as comp then {
    qr ->  comp,  entry then BuildNoteBase(qr, comp, entry) "noteBase";
    qr -> comp.name = 'InpatientDischargeNote' "noteName";
    qr -> comp.title = 'Discharge note' "noteTitle";
    qr -> comp.type as ty then {
      qr -> ty.coding as sghi then {
        qr -> sghi.system = 'https://fhir.slade360.co.ke/fhir/CodeSystem/inpatient-document-type-codesystem' "sghiSystem";
        qr -> sghi.code = 'discharge-note' "sghiCode";
        qr -> sghi.display = 'Discharge note' "sghiDisplay";
      } "sghiCoding";
      qr -> ty.coding as loinc then {
        qr -> loinc.system = 'http://loinc.org' "loincSystem";
        qr -> loinc.code = '18842-5' "loincCode";
        qr -> loinc.display = 'Discharge summary' "loincDisplay";
      } "loincCoding";
      qr -> ty.text = 'Discharge summary' "typeText";
    } "noteType";
    qr.item as it where ((linkId = 'summary') and answer.value.exists()) -> comp.section as sec then {
      it -> sec.title = 'Admission summary' "summaryTitle";
      it -> sec then AddSectionText(it, sec) "summaryText";
    } "summaryRule";
    // One section, one entry per medication. No MedicationRequest is created:
    // the form picked these off the server, and minting copies would double the
    // patient's prescription list.
    qr.item as itM where ((linkId = 'medsOnDischarge') and answer.value.exists()) -> comp.section as secM then {
      itM -> secM.title = 'Medication on discharge' "medsTitle";
      itM.answer as aM then {
        aM.value as mv -> secM.entry = mv "medsEntry";
      } "medsAnswers";
    } "medsRule";
    qr.item as it where ((linkId = 'followUp') and answer.value.exists()) -> comp.section as sec then {
      it -> sec.title = 'Follow-up' "followUpTitle";
      it -> sec then AddSectionText(it, sec) "followUpText";
    } "followUpSectionRule";
    qr.item as it where ((linkId = 'adviceGiven') and answer.value.exists()) -> comp.section as sec then {
      it -> sec.title = 'Advice given' "adviceTitle";
      it -> sec then AddSectionText(it, sec) "adviceText";
    } "adviceRule";
  } "composition";
  // The follow-up also leaves the document, so it can be worked rather than read.
  qr.item as itF where ((linkId = 'followUp') and answer.value.exists()) then {
    itF.answer first as aF then {
      aF ->  bundle.entry as entryS,  entryS.resource = create('ServiceRequest') as sr then {
        qr -> sr.id = uuid() then SetServiceRequestFullUrl(sr, entryS) "idAndFullUrl";
        qr -> entryS.request as request then {
          qr -> request.method = 'POST' "requestMethod";
          qr -> request.url = 'ServiceRequest' "requestUrl";
        } "entryRequest";
        qr -> sr.status = 'active' "status";
        qr -> sr.intent = 'plan' "intent";
        qr -> sr.priority = 'routine' "priority";
        // R5 ServiceRequest.code is a CodeableReference, so the concept sits one
        // level down.
        aF.value as v -> sr.code as codeRef then {
          aF -> codeRef.concept as concept then {
            aF -> concept.coding as coding then {
              aF -> coding.system = 'https://fhir.slade360.co.ke/fhir/CodeSystem/inpatient-clinical-concept-codesystem' "codeSystem";
              aF -> coding.code = 'discharge-follow-up' "codeCode";
              aF -> coding.display = 'Follow-up arranged on discharge' "codeDisplay";
            } "codeCoding";
            v -> concept.text = v "codeText";
          } "codeConcept";
        } "serviceRequestCode";
        qr.subject as s -> sr.subject = s;
        qr.encounter as e -> sr.encounter = e;
        qr.authored as t -> sr.authoredOn = t "authoredOn";
        qr.author as a -> sr.requester = a "requesterFromAuthor";
        qr where (author.exists().not()) then {
          qr.source as src -> sr.requester = src "requesterFromSource";
        } "requesterFallback";
        qr -> sr.supportingInfo as si then {
          qr -> si.reference = create('Reference') as ref then {
            qr.id as qid -> ref.reference = qid "supportingInfoRef";
          } "supportingInfoTarget";
        } "linkQuestionnaireResponse";
      } "serviceRequest";
    } "followUpAnswer";
  } "followUpRequestRule";
}

// ─────────────────────────────────────────────────────────────────────────────
// Shared note scaffolding. Repeated in each note map rather than imported: the
// transform engine resolves `imports` against whatever StructureMaps happen to
// be on the server, and a note that stops extracting because a shared map was
// not uploaded is a worse failure than a duplicated group.
// ─────────────────────────────────────────────────────────────────────────────
// Two notes on what the publisher's StructureMap validator says about this file.
// Source parameters below are left untyped on purpose. Writing `: Element` makes
// the validator compare QuestionnaireResponse.item against the literal 'Element'
// and report them as incompatible with each other, which is noise, not a finding.
// Untyped, it says only that it cannot check the paths.
// `evaluate(context, expression)` is flagged as "takes 1 parameter but 2 were
// found". Leave it. The FML parser in the same jar refuses the one-argument form
// outright -- it wants a parameter, a comma, then the FHIRPath -- so the publisher
// is objecting to what its own compiler emits. Two arguments is the only form that
// compiles, and it is what the R5 transform engine executes.
group BuildNoteBase(source qr : QR, target comp : Composition, target entry) {
  qr -> comp.id = uuid() then SetCompositionFullUrl(comp, entry) "idAndFullUrl";
  qr -> entry.request as request then {
    qr -> request.method = 'POST' "requestMethod";
    qr -> request.url = 'Composition' "requestUrl";
  } "entryRequest";
  qr -> comp.status = 'final' "status";
  qr.subject as s -> comp.subject = s;
  qr.encounter as e -> comp.encounter = e;
  // Composition.date is 1..1. `authored` is only 0..1 on the response, so when a
  // client sends none the extraction time stands in. It is a poor substitute for
  // when the note was written, but a document with no date at all is worse, and
  // extraction happens moments after submission in practice.
  qr.authored as t -> comp.date = t "date";
  qr where (authored.exists().not()) then {
    qr -> comp.date = evaluate(qr, now()) "dateFromExtractionTime";
  } "dateFallback";
  // Composition.author is 1..1 minimum. R5 QuestionnaireResponse carries both
  // `author` (who recorded the answers) and `source` (who supplied them); the
  // author is the one who wrote the note, so it wins, and `source` only stands
  // in when the client did not send an author. If the response carries neither,
  // the note comes out unauthored -- there is nothing on a QuestionnaireResponse
  // to invent one from, and guessing at who wrote a clinical note is not a thing
  // a map should do.
  qr.author as a -> comp.author = a "authorFromAuthor";
  qr where (author.exists().not()) then {
    qr.source as src -> comp.author = src "authorFromSource";
  } "authorFallback";
  qr -> comp.relatesTo as rel then {
    qr -> rel.type = 'derived-from' "relatesToType";
    qr -> rel.resourceReference = create('Reference') as ref then {
      qr.id as qid -> ref.reference = qid "relatesToRef";
    } "relatesToTarget";
  } "linkQuestionnaireResponse";
}

group AddSectionText(source it, target sec) {
  it.answer first as a then {
    a.value as v -> sec.text as narrative then {
      v -> narrative.status = 'generated' "narrativeStatus";
      v -> narrative.div = create('xhtml') as xhtml then {
        v -> xhtml.value = evaluate(a, '<div xmlns="http://www.w3.org/1999/xhtml"><p>' + value.toString().escape('html') + '</p></div>') "narrativeDiv";
      } "narrativeXhtml";
    } "sectionText";
  } "sectionAnswer";
}

group SetCompositionFullUrl(source comp : Composition, target entry) {
  comp.id as id -> entry.fullUrl = append('https://fhir.slade360.co.ke/fhir/Composition/', id) "assignFullUrl";
}

group SetServiceRequestFullUrl(source sr : ServiceRequest, target entry) {
  sr.id as id -> entry.fullUrl = append('https://fhir.slade360.co.ke/fhir/ServiceRequest/', id) "assignFullUrl";
}