define "HIV Status Positive Condition":
  [Condition: Concepts."HIV-positive - HIV.B.DE116"] C
    where C.clinicalStatus ~ ConceptsCustom."active"
      and exists(C.category CC where CC ~ ConceptsCustom."encounter-diagnosis")
    sort by start of onset.toInterval()

define "HIV Status Positive Condition":
  Elements."HIV Status Positive Condition" C
  where C.onset before end of "Measurement Period"

/* End of HIV-inconclusive */

/*
@dataElement: HIV.B.DE115 - HIV status
@activity: HIV.B7 Test for HIV using testing algorithm
@description: HIV status reported after applying the national HIV testing algorithm. No single HIV test can provide an HIV-positive diagnosis.
*/
define "HIV Status Observation":
  [Observation: Concepts."HIV status"] O
    where O.status in { 'final', 'amended', 'corrected' }

define "HIV Status Positive Observation":
"HIV Status Observation" O
    where O.value ~ Concepts."HIV-positive - HIV.B.DE116"
      sort by start of effective.toInterval()

define "HIV Status Positive Observation":
  Elements."HIV Status Positive Observation" O
  where O.issued before end of "Measurement Period"
  or O.effective.toInterval() starts before end of "Measurement Period"

define "Has HIV-positive Status":
  exists "HIV Status Positive Condition"
  or exists "HIV Status Positive Observation"

/* End of Serodiscordant partner D.DE37 */

/*
@dataElement: HIV.D.DE38 - On ART
@activity: HIV.D8 Capture or update client history
@description: Client is currently taking ART
*/

define "On ART D.DE38":
    [MedicationStatement] MS
    where exists(MS.reasonCode C where C ~ Concepts."On ART - HIV.D.DE38")
    sort by start of effective.toInterval()

/* End of Breastfeeding D.DE32 */

/*
@dataElement: HIV.D.DE38 - On ART
@activity: HIV.D8 Capture or update client history
@description: Client is currently taking ART
*/

define "On ART D.DE38":
  exists(Elements."On ART D.DE38" ART
   where ART.effective.toInterval() during "Measurement Period")

/* End of Delivery date */

/*
@dataElement: HIV.E.DE67 - Place of delivery
@activity: HIV.E1 Capture or update mother's history
@description: The type of place where the woman delivered
*/

define "Place of delivery":
  [Observation: Concepts."Place of delivery"] O
    where O.status in { 'final', 'amended', 'corrected' }
    and O.value is not null

/* End of Place of delivery */

/*
@dataElement: HIV.E.DE68 - Health facility
@activity: HIV.E1 Capture or update mother's history
@description: The woman delivered at a health facility
*/

define "Health facility":
  "Place of delivery" O
  with [Location] L
      such that O.value is FHIR.Reference and O.subject.reference = L.id
      and L.physicalType ~ Concepts."Health facility"

/* End of Place of delivery */

/*
@dataElement: HIV.E.DE68 - Health facility
@activity: HIV.E1 Capture or update mother's history
@description: The woman delivered at a health facility
*/
// TODO: Replace placeholder with relevant CQL logic
define "Health facility":
  exists (Elements."Health facility" O
  where O.effective.toInterval() during "Measurement Period")

/* End of Time to start ART */

/*
@dataElement: HIV.D.DE387 - Viral load test result
@activity: HIV.D20 Diagnostics
@description: Result from the viral load test in number of copies/mL
*/

define "Viral load test result D.DE387":
  [Observation: Concepts."Viral load test result - HIV.D.DE387"] O
    where O.status in { 'final', 'amended', 'corrected' }

/* End of Date of baseline CD4 count test D.DE368 */

/*
@dataElement: HIV.D.DE387 - Viral load test result
@activity: HIV.D20 Diagnostics
@description: Result from the viral load test in number of copies/mL
*/

define "Viral load test result D.DE387":
  Elements."Viral load test result D.DE387" O
    where O.effective.toInterval() during "Measurement Period"

define "viral load sample collection":
  [Procedure] P
  where P.status = 'completed'
  and P.code ~ ConceptsCustom."viral load test"

/**
 * Numerator
 * 
 * Definition: Number of HIV-positive pregnant women on ART during pregnancy and delivering at a facility during the reporting period who were virally suppressed (<1000 copies/mL) at delivery
 * Calculation: COUNT of clients with "HIV status"='HIV-positive' AND "Place of delivery" is a 'Health facility' AND "Delivery date" is in the reporting period AND "Date of viral load sample collection" is on "Delivery date" AND "Viral load test result" LESS THAN 1000 copies/mL
 */

//health facility birth
define "First Health facility":
  (First(HE."Health facility"))

define "Numerator":
  HIE."Has HIV-positive Status"
  and HIE."On ART D.DE38"
  and HIE."Health facility"
  and exists(
    HIE."Viral load test result D.DE387" VL
    with HE."viral load sample collection" P 
    such that VL.partOf.references(P) and start of P.performed.toInterval() = start of "First Health facility".effective.toInterval()
    where VL.value < 1000
    )

/**
 * Denominator
 *
 * Definition: Number of HIV-positive pregnant women on ART during pregnancy who deliver at a facility during the reporting period and had a viral load test during delivery, or the estimated total number of pregnant women living with HIV
 * Calculation: COUNT of clients with "HIV status"='HIV-positive' AND "Place of delivery" is a 'Health facility' AND "Delivery date" is in the reporting period AND "Date of viral load sample collection" is on "Delivery date" |  | Alternatively: *Estimated total number of pregnant women living with HIV
 */

define "Denominator":
  HIE."Has HIV-positive Status"
  and HIE."On ART D.DE38"
  and HIE."Health facility"
  and exists(
    HIE."Viral load test result D.DE387" VL
    with HE."viral load sample collection" P 
    such that VL.partOf.references(P) and start of P.performed.toInterval() = start of "First Health facility".effective.toInterval()
    )

/* Populations */

/*
 *Initial Population
 */

define "Initial Population":
  true

/* End of Visit date A.DE3 */

/*
@dataElement: HIV.A.DE17 - Age
@activity: HIV.A6.1 Review sociodemographic data with client | HIV.A5 Create new client record
@description: Calculated age (number of years) of the client based on date of birth
*/
define "Age In Years":
  AgeInYearsAt(start of "Measurement Period")

define "By Age Stratifier 3":
  case 
      when "Age In Years" >= 15 and "Age In Years"<= 19 then '15-19'
      when "Age In Years" <= 24 then '20-24'
      when "Age In Years" <= 49 then '25–49'
      when "Age In Years" >= 50 then '50+'
      else null
  end

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

define "Timing of ART initiation Observation":
  [Observation: Concepts."Timing of ART initiation"] O
    where O.status in { 'final', 'amended', 'corrected' }

/* End of Timing of ART initiation */

/*
@dataElement: HIV.E.DE42 - Already on ART at first antenatal care visit
@activity: HIV.E1 Capture or update mother's history
@description: The pregnant woman was already on antiretroviral therapy (ART) at first antenatal care visit
*/

define "Already on ART at first antenatal care visit":
  "Timing of ART initiation Observation" O
    where O.status in { 'final', 'amended', 'corrected' }
      and O.value ~ Concepts."Already on ART at first antenatal care visit"

/* End of Timing of ART initiation */

/*
@dataElement: HIV.E.DE42 - Already on ART at first antenatal care visit
@activity: HIV.E1 Capture or update mother's history
@description: The pregnant woman was already on antiretroviral therapy (ART) at first antenatal care visit
*/

define "Already on ART at first antenatal care visit":
  exists Elements."Already on ART at first antenatal care visit" O
    where O.effective.toInterval() during "Measurement Period"

/* End of Already on ART at first antenatal care visit */

/*
@dataElement: HIV.E.DE43 - Newly on ART during pregnancy
@activity: HIV.E1 Capture or update mother's history
@description: The pregnant woman started ART during her pregnancy
*/

define "Newly on ART during pregnancy":
  "Timing of ART initiation Observation" O
    where O.status in { 'final', 'amended', 'corrected' }
      and O.value ~ Concepts."Newly on ART during pregnancy"

/* End of Already on ART at first antenatal care visit */

/*
@dataElement: HIV.E.DE43 - Newly on ART during pregnancy
@activity: HIV.E1 Capture or update mother's history
@description: The pregnant woman started ART during her pregnancy
*/

define "Newly on ART during pregnancy":
  exists Elements."Newly on ART during pregnancy" O
    where O.effective.toInterval() during "Measurement Period"

/* End of Newly on ART during pregnancy */

/*
@dataElement: HIV.E.DE44 - Newly on ART during labour and delivery
@activity: HIV.E1 Capture or update mother's history
@description: The woman started ART during labour and delivery
*/

define "Newly on ART during labour and delivery":
  "Timing of ART initiation Observation" O
    where O.status in { 'final', 'amended', 'corrected' }
      and O.value ~ Concepts."Newly on ART during labour and delivery"

/* End of Newly on ART during pregnancy */

/*
@dataElement: HIV.E.DE44 - Newly on ART during labour and delivery
@activity: HIV.E1 Capture or update mother's history
@description: The woman started ART during labour and delivery
*/

define "Newly on ART during labour and delivery":
  exists Elements."Newly on ART during labour and delivery" O
    where O.effective.toInterval() during "Measurement Period"

/* End of Completed */

/*
@dataElement: HIV.E.DE41 - Timing of ART initiation
@activity: HIV.E1 Capture or update mother's history
@description: When the pregnant woman or mother initiated ART, for women living with HIV.
*/

define "Timing of ART initiation":
  case
    when "Already on ART at first antenatal care visit" then Concepts."Already on ART at first antenatal care visit"
    when "Newly on ART during pregnancy" then Concepts."Newly on ART during pregnancy"
    when "Newly on ART during labour and delivery" then Concepts."Newly on ART during labour and delivery"
    else null
  end

define "Stratification":
 HIE."By Age Stratifier 3"
+ ':' + HIE."By Geographic Region Stratifier"
+ HIE."Timing of ART initiation".code

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 ToDateTime(value dateTime): value.value

define function ToString(value ObservationStatus): value.value

define function ToDateTime(value instant): value.value

define function ToString(value ProcedureStatus): value.value

/*
@description: Returns true if any of the given references are to the given resource
@comment: Returns true if the `id` element of the given resource exactly equals the tail of any of the given references.
NOTE: This function assumes resources from the same source server.
*/
define fluent function references(references List<FHIR.Reference>, resource FHIR.Resource):
  exists (references R where R.references(resource))

/*
@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 ToInteger(value integer): value.value

define function ToString(value AddressUse): value.value