/// url = 'https://fhir.slade360.co.ke/fhir/StructureMap/ExtractImagingRequest'
/// name = 'ExtractImagingRequest'
/// title = 'Imaging Request Extraction'
/// status = 'active'
/// description = 'The X-ray and ultrasound request forms out as ServiceRequests: one per scan type ticked on an ultrasound request, or a single one carrying the region and view for an X-ray. The clinical question rides as a supporting Observation the request points at, because the SGHI ServiceRequest profile binds `reason` required to LOINC and the form takes free text -- so the indication cannot go in `reason` without inventing a code for it.'

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/ServiceRequest" alias ServiceRequest as target
uses "http://hl7.org/fhir/StructureDefinition/Observation" alias Observation as target

group ExtractImagingRequest(source qr : QR, target bundle : Bundle) {
  qr -> bundle.type = 'transaction' "setBundleType";
  // ── The indication, as a supporting Observation ─────────────────────────
  // Built first so the ServiceRequests below can point at it. It carries the
  // indication, the clinical summary and the provisional diagnosis: everything
  // the radiographer needs in order to tailor the study, which is the whole
  // reason the form asks for them.
  qr where (item.where(linkId = 'indication').answer.value.exists()) ->  bundle.entry as entry,  entry.resource = create('Observation') as obs then {
    qr ->  obs,  entry then BuildObsBase(qr, obs, entry) "base";
    qr -> obs then SetSurveyCategory(qr, obs) "category";
    qr -> obs.code as cc then {
      qr -> cc.coding as cg then {
        qr -> cg.system = 'https://fhir.slade360.co.ke/fhir/CodeSystem/concept-codesystem' "sys";
        qr -> cg.code = 'imaging-indication' "cd";
        qr -> cg.display = 'Indication for imaging' "dsp";
      } "coding";
    } "code";
    qr.item as it where (linkId = 'indication') then {
      it.answer first as a then {
        a.value as txt ->  obs.note as n,  n.text = txt "text";
      };
    } "note";
    qr.item as it where (linkId = 'clinical-summary') then {
      it.answer first as a then {
        a.value as txt ->  obs.note as n,  n.text = txt "text";
      };
    } "note2";
    qr.item as it where (linkId = 'provisional-diagnosis') then {
      it.answer first as a then {
        a.value as txt ->  obs.note as n,  n.text = txt "text";
      };
    } "note3";
  } "indicationObservation";
  // ── Last menstrual period ───────────────────────────────────────────────
  // Extracted as its own Observation. The X-ray form asks for it so a woman of
  // childbearing age is not irradiated unknowingly in early pregnancy; that is
  // a safety check, and a safety check buried in a request's free text is not
  // one anybody can audit.
  qr.item as it where ((linkId = 'last-menstrual-period') and answer.value.exists()) ->  bundle.entry as entry,  entry.resource = create('Observation') as obs then {
    qr ->  obs,  entry then BuildObsBase(qr, obs, entry) "base";
    qr -> obs then SetSurveyCategory(qr, obs) "category";
    it -> obs.code as cc then {
      it -> cc.coding as cg then {
        it -> cg.system = 'http://loinc.org' "sys";
        it -> cg.code = '8665-2' "cd";
        it -> cg.display = 'Last menstrual period start date' "dsp";
      } "coding";
    } "code";
    it.answer first as a then {
      a.value as v -> obs.value = cast(v, 'dateTime') "set";
    };
  } "measure_8665_2";
  // ── The ultrasound requests, one per scan ticked ─────────────────────────
  // The scan type answer's own coding travels, so a request for a lower limb
  // venous Doppler is coded as exactly that rather than as "ultrasound".
  qr.item as it where (linkId = 'scan-type') then {
    it.answer as a ->  bundle.entry as entry,  entry.resource = create('ServiceRequest') as sr then {
      qr ->  sr,  entry then BuildServiceRequestBase(qr, sr, entry) "base";
      a -> sr.status = 'active' "status";
      a -> sr.intent = 'order' "intent";
      a -> sr.category as cat then {
        a -> cat.coding as cg then {
          a -> cg.system = 'http://snomed.info/sct' "sys";
          a -> cg.code = '363679005' "cd";
          a -> cg.display = 'Imaging' "dsp";
        } "coding";
      } "category";
      a.value as cv ->  sr.code as cr,  cr.concept as cc then {
        cv -> cc.coding = cv "coding";
        cv.display as d -> cc.text = d "text";
      } "codeFromAnswer";
      qr -> sr then SetImagingRequestCommon(qr, sr) "common";
    } "createUltrasoundRequest";
  } "scanTypeGroup";
  // ── The X-ray request ───────────────────────────────────────────────────
  // One request, coded by its free text. Guarded on the modality being X-ray so
  // an ultrasound request does not also produce a second, uncoded request for
  // whatever was typed in the investigation line.
  qr where (item.where(linkId = 'request').item.where(linkId = 'request/modality').answer.value.ofType(Coding).code = 'modality-x-ray') then {
    qr.item as it where ((linkId = 'investigation-requested') and answer.value.exists()) ->  bundle.entry as entry,  entry.resource = create('ServiceRequest') as sr then {
      qr ->  sr,  entry then BuildServiceRequestBase(qr, sr, entry) "base";
      it -> sr.status = 'active' "status";
      it -> sr.intent = 'order' "intent";
      it -> sr.category as cat then {
        it -> cat.coding as cg then {
          it -> cg.system = 'http://snomed.info/sct' "sys";
          it -> cg.code = '363679005' "cd";
          it -> cg.display = 'Imaging' "dsp";
        } "coding";
      } "category";
      it.answer first as a then {
        a.value as txt ->  sr.code as cr,  cr.concept as cc,  cc.text = txt "codeText";
      };
      qr -> sr then SetImagingRequestCommon(qr, sr) "common";
    } "createXrayRequest";
  } "xrayGroup";
}

// Everything both request shapes share: who asked, when, how urgently, from
// which department, and the clinical summary as a note. Factored into a group
// because it is identical for an X-ray and an ultrasound and drifting copies is
// how one of them silently loses its priority.
group SetImagingRequestCommon(source qr : QR, target sr : ServiceRequest) {
  qr.authored as t -> sr.authoredOn = t "authoredOn";
  qr.encounter as e -> sr.encounter = e;
  qr.item as g where (linkId = 'request') then {
    g.item as rq where ((linkId = 'request/requester') and answer.value.exists()) then {
      rq.answer first as a then {
        a.value as ref -> sr.requester = ref "requester";
      };
    } "requesterRule";
    // Priority is a code on ServiceRequest, not a Coding: it takes the code
    // alone and has nowhere to record the system it came from.
    g.item as pr where ((linkId = 'request/priority') and answer.value.exists()) then {
      pr.answer first as a then {
        a.value as cv then {
          cv.code as c -> sr.priority = c "priorityCode";
        } "coding";
      };
    } "priorityRule";
    g.item as dp where ((linkId = 'request/department') and answer.value.exists()) then {
      dp.answer first as a then {
        a.value as txt ->  sr.note as n,  n.text = txt "departmentNote";
      };
    } "departmentRule";
  } "requestGroup";
  qr.item as ind where (linkId = 'indication') then {
    ind.answer first as a then {
      a.value as txt ->  sr.note as n,  n.text = txt "indicationNote";
    };
  } "indicationRule";
  qr.item as cs where (linkId = 'clinical-summary') then {
    cs.answer first as a then {
      a.value as txt ->  sr.note as n,  n.text = txt "clinicalSummaryNote";
    };
  } "clinicalSummaryRule";
}

// ─────────────────────────────────────────────────────────────────────────────
// Shared scaffolding. Repeated in each map rather than imported: the transform
// engine resolves `imports` against whatever StructureMaps happen to be on the
// server, and a form 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.
// `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 BuildObsBase(source qr : QR, target obs : Observation, target entry) {
  qr -> obs then SetResponseProvenance(qr, obs) "responseProvenance";
  qr -> obs.id = uuid() then SetObservationFullUrl(obs, entry) "idAndFullUrl";
  qr -> entry.request as request then {
    qr -> request.method = 'POST' "requestMethod";
    qr -> request.url = 'Observation' "requestUrl";
  } "entryRequest";
  qr -> obs.status = 'final' "status";
  qr.subject as s -> obs.subject = s;
  qr.encounter as e -> obs.encounter = e;
  qr.authored as t -> obs.effective = t "effective";
  qr.source as src -> obs.performer = src "performerFromSource";
  qr where (source.exists().not()) then {
    qr.author as a -> obs.performer = a "performerFromAuthor";
  } "performerFallback";
  // A stored response's id already reads "QuestionnaireResponse/<id>", so it is
  // a relative reference as it stands. The hasValue() guard is what stops an
  // unsaved response -- one posted straight to $extract rather than saved first
  // -- from writing "QuestionnaireResponse/null" into the record.
  qr.id as qid where ($this.hasValue()) ->  obs.derivedFrom = create('Reference') as ref,  ref.reference = qid "linkQuestionnaireResponse";
}

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

// The two answer shapes a component can carry. Both read the answer through the
// untyped `.value` accessor: reading `valueCoding` or `valueQuantity` by its
// typed property name fails at transform time on HAPI R5 with "Attempt to read
// invalid property ... on QuestionnaireResponse.item.answer".
group SetComponentCodedValue(source it, target comp) {
  it.answer first as a then {
    a.value as cv -> comp.value = create('CodeableConcept') as cc then {
      cv -> cc.coding = cv "valueCoding";
      cv.display as d -> cc.text = d "valueText";
    } "codedValue";
  } "componentAnswer";
}

group SetComponentValue(source it, target comp) {
  it.answer first as a then {
    a.value as v -> comp.value = v "plainValue";
  } "componentAnswer";
}

group SetSurveyCategory(source qr : QR, target obs : Observation) {
  qr -> obs.category as cat then {
    qr -> cat.coding as coding then {
      qr -> coding.system = 'http://terminology.hl7.org/CodeSystem/observation-category' "categorySystem";
      qr -> coding.code = 'survey' "categoryCode";
      qr -> coding.display = 'Survey' "categoryDisplay";
    } "categoryCoding";
  } "category";
}

group SetVitalSignsCategory(source qr : QR, target obs : Observation) {
  qr -> obs.category as cat then {
    qr -> cat.coding as coding then {
      qr -> coding.system = 'http://terminology.hl7.org/CodeSystem/observation-category' "categorySystem";
      qr -> coding.code = 'vital-signs' "categoryCode";
      qr -> coding.display = 'Vital Signs' "categoryDisplay";
    } "categoryCoding";
  } "category";
}

group BuildServiceRequestBase(source qr : QR, target r : ServiceRequest, target entry) {
  qr -> r then SetResponseProvenance(qr, r) "responseProvenance";
  qr -> r.id = uuid() then SetServiceRequestFullUrl(r, entry) "idAndFullUrl";
  qr -> entry.request as request then {
    qr -> request.method = 'POST' "requestMethod";
    qr -> request.url = 'ServiceRequest' "requestUrl";
  } "entryRequest";
  qr.subject as s -> r.subject = s;
}

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

// ── Provenance and tenancy ───────────────────────────────────────────────────
// Two tags on everything this map creates. The first says which questionnaire
// produced it, so a form that reopens mid-admission recalls its own earlier
// entries and not another form's. The second copies the tenant tags off the
// response, because nothing else on the path puts them there.
// The code is the form's document type, not the questionnaire's id: every
// environment mints its own ids, and there is only one set of maps, so an id
// here would tie the tag to whichever environment stamped it.
// ── Provenance and tenancy ───────────────────────────────────────────────────
group SetResponseProvenance(source qr : QR, target r) {
  qr -> r.meta as m then {
    qr -> m.tag as t then {
      qr -> t.system = 'http://slade360edi.com/questionnaire-provenance' "provenanceSystem";
      qr -> t.code = 'imaging-request' "provenanceCode";
      qr -> t.display = 'Imaging request' "provenanceDisplay";
    } "provenanceTag";
  } "provenanceMeta";
  // Every tag the response carries, onto the resource. `meta` is 0..1, so this
  // lands on the same meta the rule above created rather than a second one.
  qr.meta as qm then {
    qm.tag as qt ->  r.meta as m,  m.tag = qt "copyTag";
  } "tenantTags";
}