define "Initial Population":
  AgeInYearsAt(date from start of "Measurement Period") in Interval[15, 65]
    and exists "Qualifying Encounters"

define "Denominator":
  "Initial Population"

define "Denominator Exclusions":
  exists ( ["Condition": "HIV"] HIV
      where QICoreCommon."ToPrevalenceInterval" ( HIV Indicators ) starts before start of "Measurement Period"
        and HIV.verificationStatus !~ "refuted"
  )

define "Numerator":
  ( "Has HIV Test Performed" )

define "SDE Sex":
  case
      when Patient.gender = 'male' then "M"
      when Patient.gender = 'female' then "F"
      else null
    end

define "SDE Sex":
  SDE."SDE Sex"

define "Has HIV Test Performed":
  exists ( ["Observation": "Human Immunodeficiency Virus (HIV) Laboratory Test Codes (Ab and Ag)"]
    union ["Observation": "HIV 1 and 2 tests - Meaningful Use set"] ) HIVTest
    where AgeInYearsAt(date from start of QICoreCommon."ToInterval"(HIVTest.effective)) in Interval[15, 65]
      and QICoreCommon."ToInterval" ( HIVTest.effective ) starts before end of "Measurement Period"
      and ( HIVTest.status = 'final'
          or HIVTest.status = 'amended'
          or HIVTest.status = 'corrected'
      )

define "Numerator":
  ( "Has HIV Test Performed" )

define "Qualifying Encounters":
  ( ["Encounter": "Preventive Care Services, Initial Office Visit, 0 to 17"]
    union ["Encounter": "Preventive Care Services-Initial Office Visit, 18 and Up"]
    union ["Encounter": "Preventive Care, Established Office Visit, 0 to 17"]
    union ["Encounter": "Preventive Care Services - Established Office Visit, 18 and Up"]
    union ["Encounter": "Office Visit"] ) Encounter
    where Encounter.period during "Measurement Period"
      and Encounter.class ~ "AMB"
      and Encounter.status = 'finished'

define "Initial Population":
  AgeInYearsAt(date from start of "Measurement Period") in Interval[15, 65]
    and exists "Qualifying Encounters"

define "Denominator":
  "Initial Population"

define "SDE Payer":
  [Coverage: type in "Payer Type"] Payer
    return {
      code: Payer.type,
      period: Payer.period
    }

define "SDE Payer":
  SDE."SDE Payer"

define "SDE Ethnicity":
  Patient.ethnicity E
    return Tuple {
      codes: { E.ombCategory } union E.detailed,
      display: E.text
    }

define "SDE Ethnicity":
  SDE."SDE Ethnicity"

define "Denominator Exclusions":
  exists ( ["Condition": "HIV"] HIV
      where QICoreCommon."ToPrevalenceInterval" ( HIV Indicators ) starts before start of "Measurement Period"
        and HIV.verificationStatus !~ "refuted"
  )

define "SDE Race":
  Patient.race R
    return Tuple {
      codes: R.ombCategory union R.detailed,
      display: R.text
    }

define "SDE Race":
  SDE."SDE Race"

/*
@description: Normalizes a value that is a choice of timing-valued types to an equivalent interval
@comment: Normalizes a choice type of DateTime, Quanitty, Interval<DateTime>, or Interval<Quantity> 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 QICore, allowing this function to be used across any resource.
The input can be provided as a DateTime, Quantity, Interval<DateTime> or Interval<Quantity>.
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 Quantity, the quantity is expected to be a calendar-duration interpreted as an Age,
and the result is a DateTime Interval beginning on the Date the patient turned that age and ending immediately before one year later.
If the input is a DateTime Interval, the result is the input.
If the input is a Quantity Interval, the quantities are expected to be calendar-durations interpreted as an Age, and the result
is a DateTime Interval beginning on the date the patient turned the age given as the start of the quantity interval, and ending
immediately before one year later than the date the patient turned the age given as the end of the quantity interval.
Any other input will reslt in a null DateTime Interval
@deprecated: This function is deprecated. Use the fluent function `toInterval()` instead
*/
define function ToInterval(choice Choice<DateTime, Quantity, Interval<DateTime>, Interval<Quantity>>):
  case
	  when choice is DateTime then
    	Interval[choice as DateTime, choice as DateTime]
		when choice is Interval<DateTime> then
  		choice as Interval<DateTime>
		when choice is Quantity then
		  Interval[Patient.birthDate + (choice as Quantity),
			  Patient.birthDate + (choice as Quantity) + 1 year)
		when choice is Interval<Quantity> then
		  Interval[Patient.birthDate + (choice.low as Quantity),
			  Patient.birthDate + (choice.high as Quantity) + 1 year)
		when choice is QICore.Timing then
            null as Interval<DateTime>
		else
			null as Interval<DateTime>
	end

define function ToString(value uri): value.value

/*
@description: Converts the given FHIR [Coding](https://hl7.org/fhir/datatypes.html#Coding) value to a CQL Code.
*/
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
        }

/*
@description: Returns an interval representing the normalized prevalence period of a given Condition.
@comment: Uses the ToInterval and ToAbatementInterval functions to determine the widest potential interval from
onset to abatement as specified in the given Condition. If the condition is active, the resulting interval will have
a closed ending boundary. If the condition is not active, the resulting interval will have an open ending boundary.
@deprecated: This function is deprecated. Use the `prevalenceInterval()` fluent function instead
*/
define function ToPrevalenceInterval(condition Condition):
if condition.clinicalStatus ~ "active"
  or condition.clinicalStatus ~ "recurrence"
  or condition.clinicalStatus ~ "relapse" then
  Interval[start of ToInterval(condition.onset), end of ToAbatementInterval(condition)]
else
  Interval[start of ToInterval(condition.onset), end of ToAbatementInterval(condition))