/* End of HBsAg test date D.DE161 */


/*
@dataElement: HIV.D.DE162 - HBsAg test result
@activity: HIV.D12 Determine recommended screenings and tests
@description: Hepatitis B virus test result (HBsAg)
*/

define "HBsAg test result D.DE162":
  [Observation: Concepts."HBsAg test result - HIV.D.DE162"] O
    where O.status in { 'final', 'amended', 'corrected' }

/* End of HBsAg test result D.DE162 */

/*
@dataElement: HIV.D.DE163 - Positive
@activity: HIV.D12 Determine recommended screenings and tests
@description: HBsAg test result was positive
*/

define "Positive D.DE163":
  "HBsAg test result D.DE162" O
  where O.value ~ Concepts."Positive - HIV.D.DE163"

/* End of STI testing and treatment D.DE160 */

/*
@dataElement: HIV.D.DE161 - HBsAg test date
@activity: HIV.D12 Determine recommended screenings and tests
@description: Date client was tested for hepatitis B virus (HBV)
*/

define "HBsAg test date D.DE161":
  [Procedure] P
  where P.status = 'completed'
  and P.code ~ ConceptsCustom."HBsAg test"

define "PrEP service date":
  [MedicationStatement] MS
    where exists(MS.reasonCode C where C ~ Concepts."PrEP for HIV prevention")
    return start of MS.effective.toInterval()

define "STI services date":
  [Procedure] P
  where P.status = 'completed'
  and P.code ~ Concepts."STI testing and treatment services"
  return start of P.performed.toInterval()

/* End of STI services */

/*
@dataElement: HIV.PRV.DE7 - VMMC
@activity: HIV.B6 Capture or update client history
@description: Client accessed voluntary medical male circumcision (VMMC) services
*/
// define "VMMC_done":
// [Procedure] P
//   where P.status = 'completed'
//   and P.code ~ Concepts."Voluntary medical male circumcision VMMC"


define "VMMC":
  [Procedure] P
  where P.status = 'completed'
  and P.code ~ Concepts."VMMC procedure"

define "VMMC date":
  "VMMC" P
  return start of P.performed.toInterval()

define "Other PRV.DE8 date":
  [Observation] O
    where O.status in {'final', 'amended'}
    and O.code ~ Concepts."HIV prevention intervention"
    and O.value ~ Concepts."Other - HIV.PRV.DE8"
  return start of O.effective.toInterval()

define "OAMT status date":
  [EpisodeOfCare] EOC
    where exists(EOC.type T where T ~ Concepts."OAMT")
    return start of EOC.period

/* End of Other PRV.DE8 */

/*
@dataElement: HIV.PRV.DE10 - Date accessed HIV prevention intervention
@activity: HIV.B6 Capture or update client history
@description: Date the client accessed HIV prevention intervention
*/
// TODO: NSP date requires fix to DeviceUseStatement support
define "Date accessed HIV prevention intervention": 
  flatten{"PrEP service date", /*"NSP date",*/ "STI services date", "VMMC date", "Other PRV.DE8 date","OAMT status date"}

/**
 * Numerator
 * 
 * Definition: Number of people attending HIV prevention services who tested positive for HBsAg during the reporting period
 * Calculation: COUNT of clients with "HBsAg test date" on a "Date accessed HIV prevention intervention" in the reporting period AND "HBsAg test result"='HBsAg positive'
 */

define "Numerator":
  exists(HE."Positive D.DE163" G
  with HE."HBsAg test date D.DE161" P
  such that G.partOf.references(P) and P.performed.toInterval() during "Measurement Period"
  and exists (HE."Date accessed HIV prevention intervention" t where t = start of P.performed.toInterval()))

/**
 * Denominator
 *
 * Definition: Number of people attending HIV prevention services who were tested for HBsAg during the reporting period
 * Calculation: COUNT of clients with "HBsAg test date" on a "Date accessed HIV prevention intervention" in the reporting period
 */

define "Denominator":
  exists(HE."HBsAg test date D.DE161" P
    where P.performed.toInterval() during "Measurement Period" 
  and exists (HE."Date accessed HIV prevention intervention" t where t = start of P.performed.toInterval()))

/* Populations */

/*
 *Initial Population
 */

define "Initial Population":
  true

define function ToString(value ObservationStatus): 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 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 ToInterval(period FHIR.Period):
    if period is null then
        null
    else
        if period."start" is null then
            Interval(period."start".value, period."end".value]
        else
            Interval[period."start".value, period."end".value]