feat(OpenSRP): Deduplicator (#5677)

**Story card:**
[sc-16598](https://app.shortcut.com/simpledotorg/story/16598/fix-import-api-duplications)

## Because

The Import API wrongly duplicated records.

## This addresses

Implemeting our [deduplication
strategy](https://docs.google.com/document/d/15AYeR_qnYcT17Xbis_UaepVQJmgTtY5VWGhZp9x8b2w/edit?tab=t.0)

## Test instructions

suite tests

Author: igbanam

app/services/one_off/opensrp/deduplicator.rb

@@ -0,0 +1,63 @@
+# frozen_string_literals: true
+
+module OneOff
+  module Opensrp
+    class ImportedDuplicatesQuery
+      def self.call
+        new.call
+      end
+
+      def call
+        query.map { |patient| [patient.id, patient.patient_id] }
+      end
+
+      private
+
+      def query
+        Patient
+          .joins("inner join patient_business_identifiers on patient_business_identifiers.identifier = patients.id::text")
+          .select("patients.id, patient_business_identifiers.patient_id")
+      end
+    end
+
+    class Deduplicator
+      AFFECTED_ENTITIES = %w[
+        Appointment
+        BloodPressure
+        BloodSugar
+        MedicalHistory
+        PrescriptionDrug
+        Patient
+      ].freeze
+      # The order is important here. Patient must be last.
+
+      def self.call!
+        new.call!
+      end
+
+      def initialize
+        @duplicates = ImportedDuplicatesQuery.call
+      end
+
+      def call!
+        @duplicates.each do |old_id, new_id|
+          AFFECTED_ENTITIES.each do |entity|
+            deduplicator = [
+              Module.nesting[1],
+              "Deduplicators",
+              "For#{entity}"
+            ].join("::").constantize
+            deduplicator.call! old_id, new_id
+          end
+        end
+
+        deprecate_old_patients
+      end
+
+      def deprecate_old_patients
+        @old_patients = @duplicates.map(&:first)
+        Patient.where(id: @old_patients).discard!
+      end
+    end
+  end
+end

app/services/one_off/opensrp/deduplicators/for_appointment.rb

@@ -0,0 +1,11 @@
+module OneOff
+  module Opensrp
+    module Deduplicators
+      class ForAppointment < ForImmutableEntity
+        def initialize old_id, new_id
+          super old_id, new_id, :appointments
+        end
+      end
+    end
+  end
+end

app/services/one_off/opensrp/deduplicators/for_blood_pressure.rb

@@ -0,0 +1,11 @@
+module OneOff
+  module Opensrp
+    module Deduplicators
+      class ForBloodPressure < ForImmutableEntity
+        def initialize old_id, new_id
+          super old_id, new_id, :blood_pressures
+        end
+      end
+    end
+  end
+end

app/services/one_off/opensrp/deduplicators/for_blood_sugar.rb

@@ -0,0 +1,11 @@
+module OneOff
+  module Opensrp
+    module Deduplicators
+      class ForBloodSugar < ForImmutableEntity
+        def initialize old_id, new_id
+          super old_id, new_id, :blood_sugars
+        end
+      end
+    end
+  end
+end

app/services/one_off/opensrp/deduplicators/for_entity.rb

@@ -0,0 +1,32 @@
+module OneOff
+  module Opensrp
+    module Deduplicators
+      class ForEntity
+        def self.call! old_id, new_id
+          new(old_id, new_id).call
+        end
+
+        def initialize old_id, new_id
+          @old_id = old_id
+          @new_id = new_id
+        end
+
+        def new_patient
+          @new_patient ||= Patient.find(@new_id)
+        end
+
+        def old_patient
+          @old_patient ||= Patient.find(@old_id)
+        end
+
+        def call!
+          merge.save!
+        end
+
+        def merge
+          raise "Unimplemented"
+        end
+      end
+    end
+  end
+end

app/services/one_off/opensrp/deduplicators/for_immutable_entity.rb

@@ -0,0 +1,23 @@
+module OneOff
+  module Opensrp
+    module Deduplicators
+      class ForImmutableEntity < ForEntity
+        def initialize old_id, new_id, assoc = nil
+          super(old_id, new_id)
+
+          @association = assoc
+        end
+
+        def merge
+          old_patient.send(assoc).each do |associated|
+            associated.patient = new_patient
+            associated.save!
+          end
+
+          # return the old patient object for the chain
+          old_patient
+        end
+      end
+    end
+  end
+end

app/services/one_off/opensrp/deduplicators/for_medical_history.rb

@@ -0,0 +1,34 @@
+module OneOff
+  module Opensrp
+    module Deduplicators
+      class ForMedicalHistory < ForMutableEntity
+        CHOOSING_NEW = %i[
+          device_updated_at
+          updated_at
+          prior_heart_attack
+          prior_stroke
+          chronic_kidney_disease
+          receiving_treatment_for_hypertension
+          diabetes
+          diagnosed_with_hypertension
+          diagnosed_with_hypertension_boolean
+          hypertension
+          receiving_treatment_for_diabetes
+          deleted_at
+        ].freeze
+
+        CHOOSING_OLD = %i[
+          created_at
+          device_created_at
+        ].freeze
+
+        def merge
+          new_patient.medical_history.tap do |new_medical_history|
+            merge_old(new_medical_history, old_patient.medical_history, CHOOSING_OLD)
+            merge_new(new_medical_history, old_patient.medical_history, CHOOSING_NEW)
+          end
+        end
+      end
+    end
+  end
+end

app/services/one_off/opensrp/deduplicators/for_mutable_entity.rb

@@ -0,0 +1,32 @@
+module OneOff
+  module Opensrp
+    module Deduplicators
+      class ForMutableEntity < ForEntity
+        def merge
+          raise "Unimplemented"
+        end
+
+        def merge_non_null(entity, old_entity, attributes)
+          attributes.each do |attr|
+            val = [entity, old_entity].map { |p| p.send(attr) }.compact
+            if val.size > 1
+              @needs_manual_merge << attr
+              next
+            end
+            entity.send("#{attr}=", val.first)
+          end
+        end
+
+        def merge_new(entity, old_patient, attributes)
+          # no-op; since entity == new_entity
+        end
+
+        def merge_old(entity, old_entity, attributes)
+          attributes.each do |attr|
+            entity.send("#{attr}=", old_entity.send(attr))
+          end
+        end
+      end
+    end
+  end
+end

app/services/one_off/opensrp/deduplicators/for_patient.rb

@@ -0,0 +1,75 @@
+module OneOff
+  module Opensrp
+    module Deduplicators
+      class ForPatient < ForMutableEntity
+        # With these, we don't need to do anything because we are merging
+        # forward. Since some of the attributes here are required from the API
+        # spec, it is guaranteed to be present during the merge
+        CHOOSING_NEW = %i[
+          full_name
+          updated_at
+          gender
+          status
+          date_of_birth
+        ].freeze
+
+        # These are information we believe should be kept the same as the old
+        # record for dsahboard purposes.
+        CHOOSING_OLD = %i[
+          assigned_facility_id
+          created_at
+          eligible_for_reassignment
+          recorded_at
+          registration_facility_id
+          registration_user_id
+          reminder_consent
+        ]
+
+        # These are the information which do not have real bearing on numbers,
+        # but we need to merge them together to get a holistic patient story
+        CHOOSING_NON_NULL = %i[
+          address_id
+          contacted_by_counsellor
+          could_not_contact_reason
+          deleted_at
+          deleted_by_user_id
+          deleted_reason
+        ]
+
+        def initialize old_id, new_id
+          super(old_id, new_id)
+          @needs_manual_merge = []
+        end
+
+        def merge
+          new_patient.tap do |patient|
+            merge_old(patient, old_patient, CHOOSING_OLD)
+            merge_non_null(patient, old_patient, CHOOSING_NON_NULL)
+
+            # For all which could not be merged automatically during the
+            # non-null merge... perfer the newer value. — which is a no-op effectively
+            merge_new(patient, old_patient, @needs_manual_merge)
+
+            # Merge age as a special case
+            merge_age(patient)
+          end
+        end
+
+        private
+
+        def merge_age(patient)
+          # Age consists of three columns: age, date_of_birth, and age_updated_at
+          # For date_of_birth...
+          #   this is required from the API, so this prefers the new
+          # For age
+          #   calculate this from the new date_of_birth
+          # For age_updated_at
+          #   set this to now()
+
+          patient.age = Date.today.year - patient.date_of_birth.year
+          patient.age_updated_at = Time.now
+        end
+      end
+    end
+  end
+end

app/services/one_off/opensrp/deduplicators/for_prescription_drug.rb

@@ -0,0 +1,11 @@
+module OneOff
+  module Opensrp
+    module Deduplicators
+      class ForPrescriptionDrug < ForImmutableEntity
+        def initialize old_id, new_id
+          super old_id, new_id, :prescription_drugs
+        end
+      end
+    end
+  end
+end