# frozen_string_literal: true

module MalawiHivProgramReports
  module Pepfar
    ##
    # Common utilities for Pepfar reports
    module Utils
      ##
      # An array of all groups as required by Pepfar.
      def pepfar_age_groups
        @pepfar_age_groups ||= [
          'Unknown',
          '<1 year',
          '1-4 years', '5-9 years',
          '10-14 years', '15-19 years',
          '20-24 years',
          '25-29 years', '30-34 years',
          '35-39 years', '40-44 years',
          '45-49 years', '50-54 years',
          '55-59 years', '60-64 years',
          '65-69 years', '70-74 years',
          '75-79 years', '80-84 years',
          '85-89 years',
          '90 plus years'
        ].freeze
      end

      ##
      # Returns the drilldown information for all specified patients (ie patient_ids)
      #
      # Information returned for a patient is as follows:
      #   * patient_id
      #   * arv_number or filing_number
      #   * age_group
      #   * birthdate
      #   * gender
      def pepfar_patient_drilldown_information(patients, current_date)
        raise ::ArgumentError, "current_date can't be nil" unless current_date

        ::Person.joins("LEFT JOIN patient_identifier #{current_partition} ON patient_identifier.patient_id = person.person_id
                          AND patient_identifier.voided = 0
                          AND patient_identifier.identifier_type IN (#{pepfar_patient_identifier_type.to_sql})")
                .where(person_id: patients)
                .select("person.person_id AS patient_id,
                         person.gender,
                         person.birthdate,
                         disaggregated_age_group(person.birthdate, DATE(#{ActiveRecord::Base.connection.quote(current_date)})) AS age_group,
                         patient_identifier.identifier AS arv_number")
      end

      ##
      # Returns the preferred Pepfar identifier type.
      #
      # In some clinics like Lighthouse Filing numbers are used exclusively and in other
      # sites, ARV Numbers are used.
      def pepfar_patient_identifier_type
        name = GlobalProperty.find_by(property: 'use.filing.numbers')&.property_value 
        name = (name.present? && name == 'true') ? 'Filing number' : 'ARV Number'
        ::PatientIdentifierType.where(name:).select(:patient_identifier_type_id)
      end

      FULL_6H_COURSE_PILLS = 146
      FULL_3HP_COURSE_DAYS = 12.days
      # NOTE: Arrived at 12 days above from how 3HP is prescribed. 1st time prescription
      #       A patient takes 3HP once every week. Therefore it is 4 times a months
      #       Multiply that with 3 months we arrive at 12
      #       Hence the patient is taking this drug 12 times to be considered complete on
      #       3HP

      ##
      # Returns whether a patient completed their course of TPT
      def patient_completed_tpt?(patient, tpt)
        if tpt == '3HP'
          # return true if patient['total_days_on_medication'].to_i >= 83 # 3 months
          return true if patient['months_on_tpt'].to_i >= 3

          divider = patient['drug_concepts'].split(',').length > 1 ? 14.0 : 7.0
          days_on_medication = (patient['total_days_on_medication'] / divider).round
          days_on_medication.days >= FULL_3HP_COURSE_DAYS
        else
          patient['total_days_on_medication'].to_i >= FULL_6H_COURSE_PILLS
        end
      end

      # this just gives all clients who are truly external or drug refill
      # rubocop:disable Metrics/MethodLength
      # rubocop:disable Metrics/AbcSize
      def drug_refills_and_external_consultation_list
        to_remove = [0]

        type_of_patient_concept = ::ConceptName.find_by_name('Type of patient').concept_id
        new_patient_concept = ::ConceptName.find_by_name('New patient').concept_id
        drug_refill_concept = ::ConceptName.find_by_name('Drug refill').concept_id
        external_concept = ::ConceptName.find_by_name('External consultation').concept_id
        hiv_clinic_registration_id = ::EncounterType.find_by_name('HIV CLINIC REGISTRATION').encounter_type_id

        res = ActiveRecord::Base.connection.select_all <<~SQL
            SELECT p.person_id patient_id
            FROM person #{current_partition} p
            INNER JOIN patient_program #{current_partition} pp ON pp.patient_id = p.person_id AND pp.program_id = #{::Program.find_by_name('HIV PROGRAM').id} AND pp.voided = 0
            INNER JOIN patient_state #{current_partition} ps ON ps.patient_program_id = pp.patient_program_id AND ps.state = 7 AND ps.start_date IS NOT NULL
            LEFT JOIN encounter #{current_partition} as hiv_registration ON hiv_registration.patient_id = p.person_id AND hiv_registration.encounter_datetime < DATE(#{ActiveRecord::Base.connection.quote(end_date)}) AND hiv_registration.encounter_type = #{hiv_clinic_registration_id} AND hiv_registration.voided = 0
            LEFT JOIN (
              SELECT * FROM obs #{current_partition} WHERE concept_id = #{type_of_patient_concept} AND voided = 0 AND value_coded = #{new_patient_concept} AND obs_datetime < #{interval_manager(date: end_date, value: 1, interval: 'DAY', operator: '+')}
            ) AS new_patient ON p.person_id = new_patient.person_id
            LEFT JOIN (
              SELECT * FROM obs #{current_partition} WHERE concept_id = #{type_of_patient_concept} AND voided = 0 AND value_coded = #{drug_refill_concept} AND obs_datetime < #{interval_manager(date: end_date, value: 1, interval: 'DAY', operator: '+')}
              ) AS refill ON p.person_id = refill.person_id
            LEFT JOIN (
              SELECT * FROM obs #{current_partition} WHERE concept_id = #{type_of_patient_concept} AND voided = 0 AND value_coded = #{external_concept} AND obs_datetime < #{interval_manager(date: end_date, value: 1, interval: 'DAY', operator: '+')}
              ) AS external ON p.person_id = external.person_id
            WHERE (refill.value_coded IS NOT NULL OR external.value_coded IS NOT NULL)
            AND NOT (hiv_registration.encounter_id IS NOT NULL OR new_patient.value_coded IS NOT NULL)
            GROUP BY p.person_id
            ORDER BY hiv_registration.encounter_datetime DESC, refill.obs_datetime DESC, external.obs_datetime DESC
          SQL
        res.each do |record|
          to_remove << record['patient_id'].to_i
        end
        to_remove.join(',')
      end
      # rubocop:enable Metrics/MethodLength
      # rubocop:enable Metrics/AbcSize

      def rifapentine_concept
        @rifapentine_concept ||= ::ConceptName.find_by!(name: 'Rifapentine')
      end

      def isoniazid_rifapentine_concept
        @isoniazid_rifapentine_concept ||= ::ConceptName.find_by!(name: 'Isoniazid/Rifapentine')
      end

      def patient_on_3hp?(patient)
        drug_concepts = patient['drug_concepts'].split(',').collect(&:to_i)
        drug_concepts.intersect?([rifapentine_concept.concept_id, isoniazid_rifapentine_concept&.concept_id])
      end

      def patient_on_tb_treatment?(patient_id)
        ::Observation.where(person_id: patient_id, concept_id: ::ConceptName.find_by_name('TB status').concept_id,
                            value_coded: ::ConceptName.find_by_name('Confirmed TB on treatment').concept_id)
                     .where("obs_datetime < #{interval_manager(date: end_date, value: 1, interval: 'DAY', operator: '+')}").exists?
      end
    end
  end
end