class Imports::JoinRecords

# File app/lib/imports/join_records.rb, line 55
  def self.call(...) = new(...).call

  def call
    return [] if records.blank?

    join_table_class.import(
      ["#{records_type.underscore}_id", "#{import_type.underscore}_id"],
      records.map(&:id).product([import.id]).uniq,
      on_duplicate_key_ignore: true
    )
  end

  private

  # Resolve (or generate) the ActiveRecord model representing the join table.
  #
  # @return [Class<ApplicationRecord>] join model class
  def join_table_class
    join_table_name = "#{import_type.pluralize}#{records_type}"
    outer_import_type = @import_type
    outer_records_type = @records_type

    join_table_name.safe_constantize ||
      Class.new(ApplicationRecord) do
        @import_type = outer_import_type
        @records_type = outer_records_type

        self.table_name = "#{@import_type.tableize}_#{@records_type.tableize}"

        def self.model_name
          ActiveModel::Name.new(
            self,
            nil,
            [@import_type, @records_type].sort.join
          )
        end
      end
  end
end

# File app/lib/imports/join_records.rb, line 84
def self.model_name
  ActiveModel::Name.new(
    self,
    nil,
    [@import_type, @records_type].sort.join
  )
end

# File app/lib/imports/join_records.rb, line 38
def initialize(import, records, records_type: nil)
  @import = import
  @records = records

  # e.g. ClassImport, CohortImport, ImmunisationImport
  @import_type = import.class.name

  # We don't do this sooner because it may be useful for debugging to
  # populate what we can in instances where there are no records to actually
  # operate on.
  return if records.blank?

  # e.g. Patient, Parent, ParentRelationship, VaccinationRecord
  @records_type =
    records_type&.classify || records.map(&:class).uniq.sole.name
end

# File app/lib/imports/join_records.rb, line 57
def call
  return [] if records.blank?

  join_table_class.import(
    ["#{records_type.underscore}_id", "#{import_type.underscore}_id"],
    records.map(&:id).product([import.id]).uniq,
    on_duplicate_key_ignore: true
  )
end

# File app/lib/imports/join_records.rb, line 72
def join_table_class
  join_table_name = "#{import_type.pluralize}#{records_type}"
  outer_import_type = @import_type
  outer_records_type = @records_type

  join_table_name.safe_constantize ||
    Class.new(ApplicationRecord) do
      @import_type = outer_import_type
      @records_type = outer_records_type

      self.table_name = "#{@import_type.tableize}_#{@records_type.tableize}"

      def self.model_name
        ActiveModel::Name.new(
          self,
          nil,
          [@import_type, @records_type].sort.join
        )
      end
    end
end