/* End of Age of infant */

/*
@dataElement: HIV.E.DE112 - HIV-exposed infant or child
@activity: HIV.F6 Check whether infant/child had HIV exposure
@description: Whether the infant or child was determined to have had HIV exposure
*/
define "HIV-exposed infant or child E.DE112":

  [Observation: Concepts."HIV-exposed infant or child - HIV.E.DE112"] O
    where O.status in { 'final', 'amended', 'corrected' }

define "HIV-exposed infant or child E.DE112":
  Elements."HIV-exposed infant or child E.DE112" O
    where O.effective.toInterval() during "Measurement Period"

/* End of HIV test conducted */

/*
@dataElement: HIV.B.DE81 - HIV test type
@activity: HIV.B7 Test for HIV using testing algorithm
@description: Type of HIV test
*/
define "HIV test type B.DE81":
  [Observation: Concepts."HIV test type - HIV.B.DE81"] O
    where O.status in { 'final', 'amended', 'corrected' }

/* End of Enzyme immunoassay for HIV B.DE83 */

/*
@dataElement: HIV.B.DE84 - Nucleic acid test for HIV
@activity: HIV.B7 Test for HIV using testing algorithm
@description: Virological test, which includes testing for early infant diagnosis
*/
define "Nucleic acid test for HIV B.DE84":
  "HIV test type B.DE81" O
      where O.value ~ Concepts."Nucleic acid test for HIV - HIV.B.DE84"

/**
 * Numerator
 * 
 * Definition: Number of HIV-exposed infants born during the reporting period who received a virological HIV test within two months (and 12 months) of birth
 * Calculation: COUNT of infants who are an "HIV-exposed infant or child" with "Infant date of birth" within the reporting period AND with "Date of viral load sample collection" LESS THAN 2 months AFTER "Infant date of birth" AND "HIV test type"='Nucleic acid test for HIV'
 */


define "Numerator":
  exists(HIE."HIV-exposed infant or child E.DE112" O
  with [Patient] P
      such that O.subject.references(P) and P.birthDate during "Measurement Period")
   and exists(
    HE."Nucleic acid test for HIV B.DE84" O 
    with [Patient] Pt
    such that O.subject.references(Pt) 
    and months between start of O.effective.toInterval() and FHIRHelpers.ToDate(Pt.birthDate) < 2 months)

/**
 * Denominator - THiS SHOULDN'T BE PROPORTION
 *
 * Definition: Estimated number of HIV-positive women who delivered during the reporting period.   |  | Note: The denominator is a proxy measure for the number of infants born to HIV-infected women.
 * Calculation: *Estimated number of HIV-positive women who delivered during the reporting period
 */

define "Denominator":
  true

/* Populations */

/*
 *Initial Population
 */

define "Initial Population":
  true

// Geographic Region
define "By Geographic Region Stratifier":
    First(Patient.address A where A.use in { 'home' }).state

define "Geographic Region Stratifier":
	HIE."By Geographic Region Stratifier"

define function ToString(value ObservationStatus): value.value

/*
@description: Returns true if the given reference is to the given resource
@comment: Returns true if the `id` element of the given resource exactly equals the tail of the given reference.
NOTE: This function assumes resources from the same source server.
*/
define fluent function references(reference FHIR.Reference, resource FHIR.Resource):
  resource.id = Last(Split(reference.reference, '/'))

define function ToString(value string): value.value

define function ToDate(value date): value.value

define function ToConcept(concept FHIR.CodeableConcept):
    if concept is null then
        null
    else
        System.Concept {
            codes: concept.coding C return ToCode(C),
            display: concept.text.value
        }

define function ToCode(coding FHIR.Coding):
    if coding is null then
        null
    else
        System.Code {
          code: coding.code.value,
          system: coding.system.value,
          version: coding.version.value,
          display: coding.display.value
        }

define function ToString(value AddressUse): value.value