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 Not detected D.DE181 */

/*
@dataElement: HIV.D.DE182 - HCV medicine type
@activity: HIV.D12 Determine recommended screenings and tests
@description: Type of medicine client is prescribed
*/

define "HCV medicine type":
[MedicationStatement] MS
    where exists(MS.reasonCode C where C ~ Concepts."Positive - HIV.D.DE171")

/* End of HCV treatment start date */

/*
@dataElement: HIV.D.DE176 - HCV treatment completion date
@activity: HIV.D12 Determine recommended screenings and tests
@description: Date when client completed treatment for hepatitis C virus (HCV)
*/

define "HCV treatment completion date":
  exists Elements."HCV medicine type" MS where end of MS.effective.toInterval() during "Measurement Period"

/* End of HCV viral load test date D.DE178 */

/*
@dataElement: HIV.D.DE179 - HCV viral load test result
@activity: HIV.D12 Determine recommended screenings and tests
@description: Hepatitis C viral load test result (qualitative)
*/

define "HCV viral load test result D.DE179":
  [Observation: Concepts."HCV test result - HIV.D.DE170"] O
    where O.status in { 'final', 'amended', 'corrected' }

/* End of Detected D.DE180 */

/*
@dataElement: HIV.D.DE181 - Not detected
@activity: HIV.D12 Determine recommended screenings and tests
@description: HCV was not detected
*/

define "Not detected D.DE181":
  "HCV viral load test result D.DE179" O where O.value ~ Concepts."Not detected - HIV.D.DE181"

/* End of HCV treatment completion date */

/*
@dataElement: HIV.D.DE178 - HCV viral load test date
@activity: HIV.D12 Determine recommended screenings and tests
@description: Hepatitis C viral load test date
*/

define "HCV viral load test date D.DE178":
  [Procedure] P
  where P.status = 'completed'
  and P.code ~ ConceptsCustom."HCV viral load"

/* End of HCV treatment start date */

/*
@dataElement: HIV.D.DE176 - HCV treatment completion date
@activity: HIV.D12 Determine recommended screenings and tests
@description: Date when client completed treatment for hepatitis C virus (HCV)
*/

define "HCV treatment completion date":
  "HCV medicine type" MS
  sort by end of effective.toInterval()

/**
 * Numerator
 * 
 * Definition: Number of people living with HIV diagnosed with HCV infection who have completed HCV treatment and had a sustained virological response (SVR). SVR is assessed by a viral load measurement 12–24 weeks after the end of treatment.
 * Calculation: COUNT of clients with "HIV status"='HIV-positive' with "HCV treatment completion date" in the reporting period AND with "HCV viral load test date" is BETWEEN '12, 24' weeks after "HCV treatment completion date" AND "HCV viral load test result"='Not detected'
 */

define "Numerator":
  HIE."Has HIV-positive Status" and
  HIE."HCV treatment completion date" and
  exists(
    HE."Not detected D.DE181" O 
    with HE."HCV viral load test date D.DE178" P
    such that O.partOf.references(P) and (weeks between end of P.performed.toInterval() and date from end of Last(HE."HCV treatment completion date").effective.toInterval()> 12 weeks) and 
    (weeks between end of P.performed.toInterval() and date from end of Last(HE."HCV treatment completion date").effective.toInterval()< 24 weeks)
  )

/**
 * Denominator
 *
 * Definition: Number of people living with HIV and co-infected with HCV who completed HCV treatment and were assessed for sustained virological response
 * Calculation: COUNT of clients with "HIV status"='HIV-positive' with "HCV treatment completion date" in the reporting period AND with "HCV viral load test date" is BETWEEN '12, 24' weeks after "HCV treatment completion date"
 */

define "Denominator":
  HIE."Has HIV-positive Status" and
  HIE."HCV treatment completion date" and
  exists(HE."HCV viral load test date D.DE178" P
    where (weeks between end of P.performed.toInterval() and date from end of Last(HE."HCV treatment completion date").effective.toInterval()> 12 weeks) and 
    (weeks between end of P.performed.toInterval() and date from end of Last(HE."HCV treatment completion date").effective.toInterval()< 24 weeks)
  )

/* Populations */

/*
 *Initial Population
 */

define "Initial Population":
  true

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