/// url = 'https://fhir.slade360.co.ke/fhir/StructureMap/ExtractSurgicalDressingChart'
/// name = 'ExtractSurgicalDressingChart'
/// title = 'Surgical Dressing Chart Extraction'
/// status = 'active'
/// description = 'A Procedure per dressing change, each with its own timestamp and the nurse who did it, plus an Observation carrying the sheet\'s own grading. The grading answer records the letter that was ticked -- B, M or S -- because the sheet never expands them anywhere on it and putting an invented expansion into the record would be worse than recording the letter.'

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

group ExtractSurgicalDressingChart(source qr : QR, target bundle : Bundle) {
  qr -> bundle.type = 'transaction' "setBundleType";
  qr.item as row where ((linkId = 'dressing') and item.where(linkId = 'dressing/remarks').answer.value.exists()) then {
    row ->  bundle.entry as entry,  entry.resource = create('Procedure') as proc then {
      qr ->  proc,  entry then BuildProcedureBase(qr, proc, entry) "base";
      row -> proc.status = 'completed' "status";
      qr.encounter as e -> proc.encounter = e;
      row -> proc.code as cc then {
        row -> cc.coding as cg then {
          row -> cg.system = 'http://snomed.info/sct' "sys";
          row -> cg.code = '182531007' "cd";
          row -> cg.display = 'Dressing of wound' "dsp";
        } "coding";
      } "code";
      row.item as it where ((linkId = 'dressing/at') and answer.value.exists()) then {
        it.answer first as a then {
          a.value as v -> proc.occurrence = v "occurrence";
        };
      } "atRule";
      row.item as it where ((linkId = 'dressing/done-by') and answer.value.exists()) then {
        it.answer first as a then {
          a.value as ref ->  proc.performer as p,  p.actor = ref "performer";
        };
      } "byRule";
      row.item as it where (linkId = 'dressing/remarks') then {
        it.answer first as a then {
          a.value as txt ->  proc.note as n,  n.text = txt "remarksNote";
        };
      } "remarksRule";
    } "dressingProcedure";
    row.item as it where ((linkId = 'dressing/grade') 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 SetExamCategory(qr, obs) "category";
      it -> obs.code as cc then {
        it -> cc.coding as cg then {
          it -> cg.system = 'https://fhir.slade360.co.ke/fhir/CodeSystem/concept-codesystem' "sys";
          it -> cg.code = 'wound-care-surgical-dressing-grade' "cd";
          it -> cg.display = 'Surgical dressing grade' "dsp";
        } "coding";
      } "code";
      it.answer first as a then {
        a.value as cv -> obs.value = create('CodeableConcept') as vc then {
          cv -> vc.coding = cv "valueCoding";
          cv.display as d -> vc.text = d "valueText";
        } "codedValue";
      };
      it ->  obs.note as n,  n.text = 'The grading letter printed on the surgical dressing sheet. The sheet does not expand the letters.' "gradeNote";
      row -> obs then SetDressingRowTime(row, obs) "rowTime";
    } "dressingGrade";
  } "dressingRows";
}

// The row's own timestamp on everything extracted from that row.
group SetDressingRowTime(source row, target obs : Observation) {
  row.item as it where ((linkId = 'dressing/at') and answer.value.exists()) then {
    it.answer first as a then {
      a.value as v -> obs.effective = v "effective";
    };
  } "rowTimeRule";
  row.item as it where ((linkId = 'dressing/done-by') and answer.value.exists()) then {
    it.answer first as a then {
      a.value as ref -> obs.performer = ref "by";
    };
  } "rowByRule";
}

// ─────────────────────────────────────────────────────────────────────────────
// 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 SetExamCategory(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 = 'exam' "categoryCode";
      qr -> coding.display = 'Exam' "categoryDisplay";
    } "categoryCoding";
  } "category";
}

group BuildProcedureBase(source qr : QR, target r : Procedure, target entry) {
  qr -> r then SetResponseProvenance(qr, r) "responseProvenance";
  qr -> r.id = uuid() then SetProcedureFullUrl(r, entry) "idAndFullUrl";
  qr -> entry.request as request then {
    qr -> request.method = 'POST' "requestMethod";
    qr -> request.url = 'Procedure' "requestUrl";
  } "entryRequest";
  // The response's own time, as a floor, the way BuildObsBase does it. A rule
  // that reads a time off the form overwrites this; without it a procedure whose
  // date column was taken off on review has no time at all, and a procedure with
  // no time cannot be ordered against the rest of the admission.
  qr.authored as t -> r.occurrence = t "occurrenceFallback";
  qr.subject as s -> r.subject = s;
}

group SetProcedureFullUrl(source r : Procedure, target entry) {
  r.id as id -> entry.fullUrl = append('https://fhir.slade360.co.ke/fhir/Procedure/', 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 = 'surgical-dressing-chart' "provenanceCode";
      qr -> t.display = 'Surgical dressing chart' "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";
}