/// url = 'https://fhir.slade360.co.ke/fhir/StructureMap/ExtractRehabilitationServices'
/// name = 'ExtractRehabilitationServices'
/// title = 'Rehabilitation Services Extraction'
/// status = 'active'
/// description = 'A Procedure per contact carrying the units billed and the devices used, plus a ClinicalImpression per contact for the progress note. Per contact and not per episode, because the question asked of a rehabilitation episode is whether the patient is improving across it -- and that needs each contact to keep its own date.'

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

group ExtractRehabilitationServices(source qr : QR, target bundle : Bundle) {
  qr -> bundle.type = 'transaction' "setBundleType";
  qr.item as row where ((linkId = 'contact') and item.where(linkId = 'contact/note').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 = '91251008' "cd";
          row -> cg.display = 'Physical therapy procedure' "dsp";
        } "coding";
      } "code";
      row.item as it where ((linkId = 'contact/date') and answer.value.exists()) then {
        it.answer first as a then {
          a.value as v -> proc.occurrence = cast(v, 'dateTime') "occurrence";
        };
      } "dateRule";
      row.item as it where ((linkId = 'contact/therapist') and answer.value.exists()) then {
        it.answer first as a then {
          a.value as ref ->  proc.performer as p,  p.actor = ref "performer";
        };
      } "therapistRule";
      row.item as it where ((linkId = 'contact/devices-and-materials') and answer.value.exists()) then {
        it.answer first as a then {
          a.value as txt ->  proc.used as u,  u.concept as uc,  uc.text = txt "usedText";
        };
      } "devicesRule";
      row.item as it where ((linkId = 'contact/units') and answer.value.exists()) then {
        it.answer first as a then {
          a.value as n ->  proc.note as note,  note.text = 'Billable units recorded for this rehabilitation contact' "unitsNote";
        };
      } "unitsRule";
    } "rehabProcedure";
    row ->  bundle.entry as entry,  entry.resource = create('ClinicalImpression') as ci then {
      qr ->  ci,  entry then BuildClinicalImpressionBase(qr, ci, entry) "base";
      row -> ci.status = 'completed' "status";
      qr.encounter as e -> ci.encounter = e;
      row -> ci.description = 'Rehabilitation progress note' "description";
      row.item as it where (linkId = 'contact/note') then {
        it.answer first as a then {
          a.value as txt -> ci.summary = txt "summary";
        };
      } "noteRule";
      row.item as it where ((linkId = 'contact/date') and answer.value.exists()) then {
        it.answer first as a then {
          a.value as v -> ci.effective = cast(v, 'dateTime') "effective";
        };
      } "dateRule";
      row.item as it where ((linkId = 'contact/therapist') and answer.value.exists()) then {
        it.answer first as a then {
          a.value as ref -> ci.performer = ref "performer";
        };
      } "therapistRule";
    } "rehabImpression";
    row.item as it where ((linkId = 'contact/units') 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 = 'https://fhir.slade360.co.ke/fhir/CodeSystem/concept-codesystem' "sys";
          it -> cg.code = 'rehabilitation-units-billed' "cd";
          it -> cg.display = 'Rehabilitation units billed' "dsp";
        } "coding";
      } "code";
      it.answer first as a then {
        a.value as n -> obs.value = n;
      };
      row -> obs then SetRehabRowTime(row, obs) "rowTime";
    } "unitsObservation";
  } "contactRows";
  qr.item as g where (linkId = 'episode') then {
    g.item as it where ((linkId = 'episode/treatment-diagnosis') 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 = 'https://fhir.slade360.co.ke/fhir/CodeSystem/concept-codesystem' "sys";
          it -> cg.code = 'rehabilitation-treatment-diagnosis-for-rehabilitation' "cd";
          it -> cg.display = 'Treatment diagnosis for rehabilitation' "dsp";
        } "coding";
      } "code";
      it.answer first as a then {
        a.value as txt ->  obs.note as n,  n.text = txt "text";
      };
    } "narr_rehabilitation_treatment_diagnosis_for_rehabilitation";
  } "episodeGroup";
}

// The row's own timestamp on everything extracted from that row.
group SetRehabRowTime(source row, target obs : Observation) {
  row.item as it where ((linkId = 'contact/date') and answer.value.exists()) then {
    it.answer first as a then {
      a.value as v -> obs.effective = cast(v, 'dateTime') "effective";
    };
  } "rowTimeRule";
  row.item as it where ((linkId = 'contact/therapist') 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 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 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";
}

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

group SetClinicalImpressionFullUrl(source r : ClinicalImpression, target entry) {
  r.id as id -> entry.fullUrl = append('https://fhir.slade360.co.ke/fhir/ClinicalImpression/', 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 = 'rehabilitation-services' "provenanceCode";
      qr -> t.display = 'Rehabilitation services record' "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";
}