/*
 * As defined by Member States
 */
define "Initial Population":
  true

/*
@dataElement: HIV.A.DE18 - Gender
@activity: HIV.A6.1 Review sociodemographic data with client | HIV.A5 Create new client record
@description: Gender of the client
*/

/*
 * By Administrative Gender of Patient Stratifier
 * Need to expand codes
 */

define "By Administrative Gender Stratifier":
  case 
      when Patient.gender = 'male' then Concepts."Male"
      when Patient.gender = 'female' then Concepts."Female"
      when Patient.gender = 'transgender female' then Concepts."Transgender female"
      when Patient.gender = 'transgender male' then Concepts."Transgender male"
      else Concepts."Other - HIV.A.DE23"
  end

/* 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

/* End of Key population member B.DE49 */

/*
@dataElement: HIV.B.DE50 - Key population member type
@activity: HIV.B6 Capture or update client history
@description: The type of key population that the client is included in
*/
define "Key population member type Observation":
  [Observation: Concepts."Key population member - HIV.B.DE49"] O
    where O.status in { 'final', 'amended', 'corrected' }
    and exists(O.category OC where OC ~ ConceptsCustom."social-history")

define "Key population member type Observation":
  Elements."Key population member type Observation" O
    where O.effective.toInterval() before end of "Measurement Period"
    or O.issued before end of "Measurement Period"

// Stratifier
define patientGroups:
  "Key population member type Observation" O
  return Combine(O.code.coding.code, ':')

/**
 * HIV Elements
 */

/* General Data Elements */

// From Common

define "Community_testing":
  exists([Observation] O
    with [Encounter] E
      such that O.encounter.references(E) and exists(E.location.physicalType PT where PT ~  Concepts."Community-level testing") 
  where (O.status in { 'final', 'amended' }
  and O.code ~ Concepts."Rapid diagnostic test for HIV - HIV.B.DE82"
  and O.issued after start of "Measurement Period"
  and O.issued before end of "Measurement Period"))

/*@triggeredBy Encounter with location = facility level testing*/
define "Facility_testing":
  exists([Observation] O
    with [Encounter] E
      such that O.encounter.references(E) and exists(E.location.physicalType PT where PT ~  Concepts."Facility-level testing")
  where (O.status in { 'final', 'amended' }
  and O.code ~ Concepts."Rapid diagnostic test for HIV - HIV.B.DE82"
  and O.issued after start of "Measurement Period"
  and O.issued before end of "Measurement Period")
  )

define setting:
  case
    when Community_testing then Concepts."Community-level testing"
    when Facility_testing then Concepts."Facility-level testing"
    else null
  end

/* End of Date/time of suspected exposure to HIV C.DE9 */

/*
@dataElement: HIV.C.DE10 - Currently on PrEP
@activity: HIV.C3 Capture or update client history
@description: The client is currently taking PrEP. Oral pre-exposure prophylaxis (PrEP) of HIV is the use of ARV drugs by people who are not infected with HIV to block the acquisition of HIV.
*/

/*@triggeredBy Encounter with location = community level testing*/

define "Currently on PrEP":
  [MedicationStatement] MS
    where MS.status = 'completed'
    and exists(MS.reasonCode C where C ~ Concepts."Currently on PrEP")
    and MS.medication ~ Concepts."PrEP for HIV prevention"

/* End of Current PrEP regimen */

/*
@dataElement: HIV.C.DE18 - TDF + FTC
@activity: HIV.C3 Capture or update client history
@description: Treated with tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) pre-exposure prophylaxis (PrEP) regimen (oral PrEP)
*/

define "TDF + FTC C.DE18":
  "Currently on PrEP" MS
  where MS.medication ~ Concepts."TDF + FTC - HIV.C.DE18"

/* End of Other PrEP dosing type */

/*
@dataElement: HIV.C.DE18 - TDF + FTC
@activity: HIV.C3 Capture or update client history
@description: Treated with tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) pre-exposure prophylaxis (PrEP) regimen (oral PrEP)
*/

define "TDF + FTC C.DE18":
  exists (Elements."TDF + FTC C.DE18" MS
  where MS.status = 'completed' and MS.effective.toInterval() during "Measurement Period")

/* End of TDF + FTC C.DE18 */

/*
@dataElement: HIV.C.DE19 - TDF
@activity: HIV.C3 Capture or update client history
@description: Treated with single-agent tenofovir disoproxil fumarate (TDF) pre-exposure prophylaxis (PrEP) regimen (oral PrEP)
*/

define "TDF C.DE19":
  "Currently on PrEP" MS
  where MS.medication ~ Concepts."TDF - HIV.C.DE19"

/* End of TDF + FTC C.DE18 */

/*
@dataElement: HIV.C.DE19 - TDF
@activity: HIV.C3 Capture or update client history
@description: Treated with single-agent tenofovir disoproxil fumarate (TDF) pre-exposure prophylaxis (PrEP) regimen (oral PrEP)
*/

define "TDF C.DE19":
  exists (Elements."TDF C.DE19" MS
  where MS.status = 'completed' and MS.effective.toInterval() during "Measurement Period")

/* End of TDF C.DE19 */

/*
@dataElement: HIV.C.DE20 - TDF + 3TC
@activity: HIV.C3 Capture or update client history
@description: Treated with tenofovir disoproxil fumarate (TDF) and lamivudine (3TC) pre-exposure prophylaxis (PrEP) regimen (oral PrEP)
*/

define "TDF + 3TC C.DE20":
  "Currently on PrEP" MS
  where MS.medication ~ Concepts."TDF + 3TC - HIV.C.DE20"

/* End of TDF C.DE19 */

/*
@dataElement: HIV.C.DE20 - TDF + 3TC
@activity: HIV.C3 Capture or update client history
@description: Treated with tenofovir disoproxil fumarate (TDF) and lamivudine (3TC) pre-exposure prophylaxis (PrEP) regimen (oral PrEP)
*/

define "TDF + 3TC C.DE20":
  exists (Elements."TDF + 3TC C.DE20" MS
  where MS.status = 'completed' and MS.effective.toInterval() during "Measurement Period")

/* End of TDF + 3TC C.DE20 */

/*
@dataElement: HIV.C.DE21 - Other TDF-based regimen
@activity: HIV.C3 Capture or update client history
@description: Treated with other tenofovir disoproxil fumarate (TDF)-based regimen (oral PrEP)
*/

define "Other TDF-based regimen":
  "Currently on PrEP" MS
  where MS.medication ~ Concepts."Other TDF-based regimen"

/* End of TDF + 3TC C.DE20 */

/*
@dataElement: HIV.C.DE21 - Other TDF-based regimen
@activity: HIV.C3 Capture or update client history
@description: Treated with other tenofovir disoproxil fumarate (TDF)-based regimen (oral PrEP)
*/

define "Other TDF-based regimen":
  exists (Elements."Other TDF-based regimen" MS
  where MS.status = 'completed' and MS.effective.toInterval() during "Measurement Period")

/* End of Other TDF-based regimen */

/*
@dataElement: HIV.C.DE22 - Dapivirine vaginal ring DVR
@activity: HIV.C3 Capture or update client history
@description: Dapivirine vaginal ring (DVR) for HIV prevention
*/

define "Dapivirine vaginal ring DVR C.DE22":
  "Currently on PrEP" MS
  where MS.medication ~ Concepts."Dapivirine vaginal ring DVR - HIV.C.DE22"

/* End of Other TDF-based regimen */

/*
@dataElement: HIV.C.DE22 - Dapivirine vaginal ring DVR
@activity: HIV.C3 Capture or update client history
@description: Dapivirine vaginal ring (DVR) for HIV prevention
*/

define "Dapivirine vaginal ring DVR C.DE22":
  exists (Elements."Dapivirine vaginal ring DVR C.DE22" MS
  where MS.status = 'completed' and MS.effective.toInterval() during "Measurement Period")

/*
@dataElement: HIV.C.DE23 - CAB-LA
@activity: HIV.C3 Capture or update client history
@description: Long-acting injectable cabotegravir
*/

define "CAB-LA C.DE23":
  "Currently on PrEP" MS
  where MS.medication ~ Concepts."CAB-LA - HIV.C.DE23"

/*
@dataElement: HIV.C.DE23 - CAB-LA
@activity: HIV.C3 Capture or update client history
@description: Long-acting injectable cabotegravir
*/

define "CAB-LA C.DE23":
  exists (Elements."CAB-LA C.DE23" MS
  where MS.status = 'completed' and MS.effective.toInterval() during "Measurement Period")

define prep_product:
  List<String>{
    if "TDF + FTC C.DE18" or "TDF C.DE19" or "TDF + 3TC C.DE20" or "Other TDF-based regimen" then 'PREP Product Oral' else null,
    if "Dapivirine vaginal ring DVR C.DE22" then 'PREP Product long-acting device' else null,
    if "CAB-LA C.DE23" then 'PREP Product long-acting injectable' else null
  }

/**
 * HIV Elements
 */

/* General Element Definitions */

// From Common

// Exposure to HIV
define Exposure_Occupational:
  exists (
    [Observation: Concepts."HIV exposure type"] O
    where O.status in { 'final', 'amended', 'corrected' }
    and exists(O.category OC where OC ~ ConceptsCustom."social-history")
    and O.value ~ Concepts."Occupational"
  )

define Exposure_Non_Occupational_violent:
  exists (
    [Observation: Concepts."HIV exposure type"] O
    where O.status in { 'final', 'amended', 'corrected' }
    and exists(O.category OC where OC ~ ConceptsCustom."social-history")
    and O.value ~ Concepts."Non-occupational violent"
  )

define Exposure_Non_Occupational_consensual_sex:
  exists (
    [Observation: Concepts."HIV exposure type"] O
    where O.status in { 'final', 'amended', 'corrected' }
    and exists(O.category OC where OC ~ ConceptsCustom."social-history")
    and O.value ~ Concepts."Non-occupational consensual sex"
  )

/*
 * Other Stratifiers
 */
define hiv_exposure_type:
  List<String>{
    if Elements.Exposure_Occupational then 'Occupational' else null,
    if Elements.Exposure_Non_Occupational_violent then 'Non-occupational violent' else null,
    if Elements.Exposure_Non_Occupational_consensual_sex then 'Non-occupational consensual sex' else null
  }

//provider type not provided?

define "Stratification":
 HIE."By Administrative Gender Stratifier".code 
  + ':' + HIE."By Age Stratifier 3"
+ ':' + HIE."By Geographic Region Stratifier"
+ Combine(HIE.patientGroups, ':')
 + ':' + HIE."setting".code
+ Combine(HIE.prep_product, ':')
+ Combine(HIE."hiv_exposure_type", ':')

/* End of PrEP for HIV prevention */

/*
@dataElement: HIV.C.DE77 - PEP for HIV prevention
@activity: HIV.C23 Prescribe or administer PrEP or PEP
@description: Client was prescribed post-exposure prophylaxis (PEP) for HIV prevention
*/

define "PEP for HIV prevention":
  [MedicationRequest] MR
      where MR.status = 'completed'
      and MR.intent = 'order'
      and MR.medication ~ Concepts."PEP for HIV prevention"

/* End of PrEP for HIV prevention */

/*
@dataElement: HIV.C.DE77 - PEP for HIV prevention
@activity: HIV.C23 Prescribe or administer PrEP or PEP
@description: Client was prescribed post-exposure prophylaxis (PEP) for HIV prevention
*/

define "PEP for HIV prevention":
  exists(Elements."PEP for HIV prevention" MR
    where MR.MedicationRequestPeriod() during "Measurement Period")

define "Measure Population":
  HIE."PEP for HIV prevention"

define function ToString(value AdministrativeGender): value.value

define function ToString(value string): value.value

define function ToString(value AddressUse): value.value

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 ToDateTime(value instant): 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 MedicationStatementStatus): value.value

define function ToString(value MedicationRequestStatus): value.value

define function ToString(value MedicationRequestIntent): value.value

define fluent function MedicationRequestPeriod(Request MedicationRequest):
  Request R
    let
      dosage: singleton from R.dosageInstruction,
      doseAndRate: singleton from dosage.doseAndRate,
      doseRange: doseAndRate.dose as Range,
      doseQuantity: doseAndRate.dose as SimpleQuantity,
      dose: Coalesce(end of doseRange, doseQuantity),
      timing: dosage.timing,
      frequency: Coalesce(timing.repeat.frequencyMax, timing.repeat.frequency),
      period: System.Quantity { value: timing.repeat.period, unit: timing.repeat.periodUnit.value },
      dosesPerDay: Coalesce(ToDaily(FHIRHelpers.ToInteger(frequency), period), Count(timing.repeat.timeOfDay), 1.0),
      boundsPeriod: timing.repeat.bounds as Period,
      daysSupply: R.dispenseRequest.expectedSupplyDuration,
      quantity: R.dispenseRequest.quantity,
      refills: Coalesce(R.dispenseRequest.numberOfRepeatsAllowed, 0),
      startDate:
        Coalesce(
          start of boundsPeriod,
          start of R.dispenseRequest.validityPeriod,
          R.authoredOn
        )
    return
      if HasEnd(boundsPeriod) then
        Interval[startDate, end of boundsPeriod]
      else
        (
          Coalesce(daysSupply, quantity / (dose * dosesPerDay))
            * (1 + refills)
        ) durationInDays
          return Interval[startDate, startDate + durationInDays]

define function ToInterval(range FHIR.Range):
    if range is null then
        null
    else
        Interval[ToQuantity(range.low), ToQuantity(range.high)]

define function ToQuantity(quantity FHIR.Quantity):
    case
        when quantity is null then null
        when quantity.value is null then null
        when quantity.comparator is not null then
            Message(null, true, 'FHIRHelpers.ToQuantity.ComparatorQuantityNotSupported', 'Error', 'FHIR Quantity value has a comparator and cannot be converted to a System.Quantity value.')
        when quantity.system is null or quantity.system.value = 'http://unitsofmeasure.org'
              or quantity.system.value = 'http://hl7.org/fhirpath/CodeSystem/calendar-units' then
            System.Quantity { value: quantity.value.value, unit: ToCalendarUnit(Coalesce(quantity.code.value, quantity.unit.value, '1')) }
        else
            Message(null, true, 'FHIRHelpers.ToQuantity.InvalidFHIRQuantity', 'Error', 'Invalid FHIR Quantity code: ' & quantity.unit.value & ' (' & quantity.system.value & '|' & quantity.code.value & ')')
    end

define function ToCalendarUnit(unit System.String):
    case unit
        when 'ms' then 'millisecond'
        when 's' then 'second'
        when 'min' then 'minute'
        when 'h' then 'hour'
        when 'd' then 'day'
        when 'wk' then 'week'
        when 'mo' then 'month'
        when 'a' then 'year'
        else unit
    end

define function ToDecimal(value decimal): value.value

//System.Integer
define function ToDaily(frequency System.Integer, period System.Quantity):
  case period.unit
    when 'h' then frequency * (24.0 / period.value)
    when 'min' then frequency * (24.0 / period.value) * 60
    when 's' then frequency * (24.0 / period.value) * 60 * 60
    when 'd' then frequency * (24.0 / period.value) / 24
    when 'wk' then frequency * (24.0 / period.value) / (24 * 7)
    when 'mo' then frequency * (24.0 / period.value) / (24 * 30) /* assuming 30 days in month */
    when 'a' then frequency * (24.0 / period.value) / (24 * 365) /* assuming 365 days in year */
    when 'hour' then frequency * (24.0 / period.value)
    when 'minute' then frequency * (24.0 / period.value) * 60
    when 'second' then frequency * (24.0 / period.value) * 60 * 60
    when 'day' then frequency * (24.0 / period.value) / 24
    when 'week' then frequency * (24.0 / period.value) / (24 * 7)
    when 'month' then frequency * (24.0 / period.value) / (24 * 30) /* assuming 30 days in month */
    when 'year' then frequency * (24.0 / period.value) / (24 * 365) /* assuming 365 days in year */
    when 'hours' then frequency * (24.0 / period.value)
    when 'minutes' then frequency * (24.0 / period.value) * 60
    when 'seconds' then frequency * (24.0 / period.value) * 60 * 60
    when 'days' then frequency * (24.0 / period.value) / 24
    when 'weeks' then frequency * (24.0 / period.value) / (24 * 7)
    when 'months' then frequency * (24.0 / period.value) / (24 * 30) /* assuming 30 days in month */
    when 'years' then frequency * (24.0 / period.value) / (24 * 365) /* assuming 365 days in year */
    else null
  end

define function ToInteger(value integer): 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]

define function ToDateTime(value dateTime): value.value

define function "HasEnd"(period Interval<DateTime> ):
  not (end of period is null
    or end of period = maximum DateTime
)

/*
 * NOTE: Modeled as a Continuous Variable measure because this is an estimated denominator proportion measure
 */

define function "Measure Observation"(Patient "Patient"):
  1