/* Populations */

/*
 *Initial Population
 */

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 HIV status of partner or contact */

/*
@dataElement: HIV.H.DE35 - Already knew positive
@activity: HIV.B6 Capture or update client history
@description: The partner or contact of the index case already knew they are HIV-positive
*/

define "Already knew positive":
  [Observation: Concepts."HIV status of partner or contact"] O 
    where O.status in { 'final', 'amended', 'corrected' }
    and exists(O.category OC where OC ~ ConceptsCustom."social-history")
    and O.code ~ Concepts."Already knew positive"

/* End of Inconclusive G.DE73 */

/*
@dataElement: HIV.H.DE35 - Already knew positive
@activity: HIV.B6 Capture or update client history
@description: The partner or contact of the index case already knew they are HIV-positive
*/

define "Already knew positive":
  exists(Elements."Already knew positive" O where O.issued during "Measurement Period")

/* End of Already knew positive */

/*
@dataElement: HIV.H.DE36 - Newly diagnosed
@activity: HIV.B6 Capture or update client history
@description: The partner or contact of the index case is newly diagnosed as HIV-positive
*/

define "Newly diagnosed":
  [Observation: Concepts."HIV status of partner or contact"] O 
    where O.status in { 'final', 'amended', 'corrected' }
    and exists(O.category OC where OC ~ ConceptsCustom."social-history")
    and O.code ~ Concepts."Newly diagnosed"

/* End of Already knew positive */

/*
@dataElement: HIV.H.DE36 - Newly diagnosed
@activity: HIV.B6 Capture or update client history
@description: The partner or contact of the index case is newly diagnosed as HIV-positive
*/

define "Newly diagnosed":
  exists(Elements."Newly diagnosed" O where O.issued during "Measurement Period")

/* End of Newly diagnosed */

/*
@dataElement: HIV.H.DE37 - Negative
@activity: HIV.B6 Capture or update client history
@description: The partner or contact of the index case is newly diagnosed is HIV-negative
*/

define "Negative H.DE37":
  [Observation: Concepts."HIV status of partner or contact"] O 
    where O.status in { 'final', 'amended', 'corrected' }
    and exists(O.category OC where OC ~ ConceptsCustom."social-history")
    and O.code ~ Concepts."Negative - HIV.H.DE37"

/* End of Newly diagnosed */

/*
@dataElement: HIV.H.DE37 - Negative
@activity: HIV.B6 Capture or update client history
@description: The partner or contact of the index case is newly diagnosed is HIV-negative
*/

define "Negative H.DE37":
  exists(Elements."Negative H.DE37" O where O.issued during "Measurement Period")

define "HIV status of partner or contact":
  case 
      when "Already knew positive" then Concepts."Already knew positive"
      when "Newly diagnosed" then Concepts."Newly diagnosed"
      when "Negative H.DE37" then Concepts."Negative - HIV.H.DE37"
      else null
  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")

/*
 * By Age Stratifiers
 * Age (0–4, 5–9, 10–14, 15–19, 20–24, 25–49, 50+ years)
 * 
 */
define "By Age Stratifier 2":
  case 
      when "Age In Years" <= 4 then '0-4'
      when "Age In Years" <= 9 then '5-9'
      when "Age In Years" <= 14 then '10–14'
      when "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, ':')

define "Stratification":
 HIE."By Administrative Gender Stratifier".code 
 + ':' + HIE."HIV status of partner or contact".code
  + ':' + HIE."By Age Stratifier 2"
+ ':' + HIE."By Geographic Region Stratifier"
+ Combine(HIE.patientGroups, ':')

/* End of Referred through partner services */

/*
@dataElement: HIV.B.DE6 - Partner or contact of an index case
@activity: HIV.B1 Determine reason for visit
@description: The client is a contact or partner of a person diagnosed with HIV (an index case)
*/

define "Partner or contact of an index case":
    [Observation: Concepts."Referred through partner services"] O 
    where O.status in { 'final', 'amended', 'corrected' }
    and exists(O.category OC where OC ~ ConceptsCustom."social-history")
    and O.code ~ Concepts."Partner or contact of an index case"

define "Drug-injecting partner":
  [Observation: Concepts."Type of contact or partner for partner services"] O 
  where O.status in { 'final', 'amended', 'corrected' }
  and exists(O.category OC where OC ~ ConceptsCustom."social-history")
  and O.code ~ Concepts."Drug-injecting partner - HIV.B.DE10"

/* End of Date informed of HIV-positive diagnosis */

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

/* End of People living in prisons and other closed settings */

/*
@dataElement: HIV.B.DE60 - Date HIV test results returned
@activity: HIV.B6 Capture or update client history
@description: Date HIV test result returned to client
*/
define "HIV test results returned in measurement period":
  Elements."HIV test" O
   where O.issued during "Measurement Period"

define "Sexual partner":
  [Observation: Concepts."Type of contact or partner for partner services"] O 
  where O.status in { 'final', 'amended', 'corrected' }
  and exists(O.category OC where OC ~ ConceptsCustom."social-history")
  and O.code ~ Concepts."Sexual partner - HIV.B.DE11"

/**
 * Measure Population
 *
 * Definition: For the general population: Number of elicited partners and other contacts* of people diagnosed with HIV who received HTS |  | Additional cascade data collected: | • Number of people diagnosed with HIV (index cases) offered partner services | • Number of people diagnosed with HIV (index cases) accepting partner services | • Number of contacts/partners of people living with HIV whose information is elicited from people diagnosed with HIV (index cases) |  | For key populations: Number of elicited contacts1 of members of key populations who received HTS. | Additional cascade data collected: | • Number of key population members offered social network-based/partner services | • Number of key population members accepting social network-based/partner services | • Number of contacts of key population members elicited
 * Calculation: For the general population: Number of elicited partners and other contacts* of people diagnosed with HIV who received HTS |  | Additional cascade data collected: | • Number of people diagnosed with HIV (index cases) offered partner services | • Number of people diagnosed with HIV (index cases) accepting partner services | • Number of contacts/partners of people living with HIV whose information is elicited from people diagnosed with HIV (index cases) |  | For key populations: Number of elicited contacts1 of members of key populations who received HTS. | Additional cascade data collected: | • Number of key population members offered social network-based/partner services | • Number of key population members accepting social network-based/partner services | • Number of contacts of key population members elicited
 */
                                                       
define "Measure Population":
    exists(HE."Partner or contact of an index case" IC
    with HE."Drug-injecting partner" DIP
      such that IC.hasMember.references(DIP)
    with HIE."HIV test results returned in measurement period" HIV
      such that IC.hasMember.references(HIV)
      and HIV.issued.toInterval() during "Measurement Period")
    or 
    exists(HE."Partner or contact of an index case" IC
    with HE."Sexual partner" SP
      such that IC.hasMember.references(SP)
      with HIE."HIV test results returned in measurement period" HIV
      such that IC.hasMember.references(HIV)
      and HIV.issued.toInterval() during "Measurement Period")

define function ToString(value AdministrativeGender): 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

define function ToString(value string): value.value

define function ToString(value AddressUse): 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, '/'))

/*
From FHIRCommon 4.1.0:
*/

/*
@description: Normalizes a value that is a choice of timing-valued types to an equivalent interval
@comment: Normalizes a choice type of FHIR.dateTime, FHIR.Period, FHIR.Timing, FHIR.instance, FHIR.string, FHIR.Age, or FHIR.Range types
to an equivalent interval. This selection of choice types is a superset of the majority of choice types that are used as possible
representations for timing-valued elements in FHIR, allowing this function to be used across any resource.

The input can be provided as a dateTime, Period, Timing, instant, string, Age, or Range.
The intent of this function is to provide a clear and concise mechanism to treat single
elements that have multiple possible representations as intervals so that logic doesn't have to account
for the variability. More complex calculations (such as medication request period or dispense period
calculation) need specific guidance and consideration. That guidance may make use of this function, but
the focus of this function is on single element calculations where the semantics are unambiguous.
If the input is a dateTime, the result a DateTime Interval beginning and ending on that dateTime.
If the input is a Period, the result is a DateTime Interval.
If the input is a Timing, an error is raised indicating a single interval cannot be computed from a Timing.
If the input is an instant, the result is a DateTime Interval beginning and ending on that instant.
If the input is a string, an error is raised indicating a single interval cannot be computed from a string.
If the input is an Age, the result is a DateTime Interval beginning when the patient was the given Age,
and ending immediately prior to when the patient was the given Age plus one year.
If the input is a Range, the result is a DateTime Interval beginning when the patient was the Age given
by the low end of the Range, and ending immediately prior to when the patient was the Age given by the
high end of the Range plus one year.

NOTE: Due to the
complexity of determining a single interval from a Timing or String type, this function will throw a run-time exception if it is used
with a Timing or String.
*/
define fluent function toInterval(choice Choice<FHIR.dateTime, FHIR.Period, FHIR.Timing, FHIR.instant, FHIR.string, FHIR.Age, FHIR.Range>):
  case
    when choice is FHIR.dateTime then
      Interval[FHIRHelpers.ToDateTime(choice as FHIR.dateTime), FHIRHelpers.ToDateTime(choice as FHIR.dateTime)]
    when choice is FHIR.Period then
      FHIRHelpers.ToInterval(choice as FHIR.Period)
    when choice is FHIR.instant then
      Interval[FHIRHelpers.ToDateTime(choice as FHIR.instant), FHIRHelpers.ToDateTime(choice as FHIR.instant)]
    when choice is FHIR.Age then
      Interval[FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity(choice as FHIR.Age),
        FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity(choice as FHIR.Age) + 1 year)
    when choice is FHIR.Range then
      Interval[FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity((choice as FHIR.Range).low),
        FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity((choice as FHIR.Range).high) + 1 year)
    when choice is FHIR.Timing then
      Message(null as Interval<DateTime>, true, 'NOT_IMPLEMENTED', 'Error', 'Calculation of an interval from a Timing value is not supported')
    when choice is FHIR.string then
      Message(null as Interval<DateTime>, true, 'NOT_IMPLEMENTED', 'Error', 'Calculation of an interval from a String value is not supported')
    else
      null as Interval<DateTime>
  end

define function ToDateTime(value dateTime): 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 ToDate(value date): value.value

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

/**
 * Measure Observation
 * Definition: For the general population: Number of elicited partners and other contacts* of people diagnosed with HIV who received HTS |  | Additional cascade data collected: | • Number of people diagnosed with HIV (index cases) offered partner services | • Number of people diagnosed with HIV (index cases) accepting partner services | • Number of contacts/partners of people living with HIV whose information is elicited from people diagnosed with HIV (index cases) |  | For key populations: Number of elicited contacts1 of members of key populations who received HTS. | Additional cascade data collected: | • Number of key population members offered social network-based/partner services | • Number of key population members accepting social network-based/partner services | • Number of contacts of key population members elicited
 * Calculation: For the general population: Number of elicited partners and other contacts* of people diagnosed with HIV who received HTS |  | Additional cascade data collected: | • Number of people diagnosed with HIV (index cases) offered partner services | • Number of people diagnosed with HIV (index cases) accepting partner services | • Number of contacts/partners of people living with HIV whose information is elicited from people diagnosed with HIV (index cases) |  | For key populations: Number of elicited contacts1 of members of key populations who received HTS. | Additional cascade data collected: | • Number of key population members offered social network-based/partner services | • Number of key population members accepting social network-based/partner services | • Number of contacts of key population members elicited                                                      
 */     

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