class ProcedureRevisionPreloader
  def initialize(revisions)
    @revisions = revisions
  end

  def all
    revisions = @revisions.to_a
    load_revisions(revisions)
  end

  def self.load_one(revision)
    ProcedureRevisionPreloader.new([revision]).all.first
  end

  private

  def load_revisions(revisions)
    load_procedure_revision_types_de_champ(revisions)
  end

  def load_procedure_revision_types_de_champ(revisions)
    revisions_by_id = revisions.index_by(&:id)
    coordinates_by_revision_id = ProcedureRevisionTypeDeChamp
      .where(revisions:)
      .includes(type_de_champ: { notice_explicative_attachment: :blob, piece_justificative_template_attachment: :blob })
      .order(:position, :id)
      .to_a
      .group_by(&:revision_id)

    coordinates_by_revision_id.each_pair do |revision_id, coordinates|
      revision = revisions_by_id[revision_id]

      coordinates.each do |coordinate|
        coordinate.association(:revision).target = revision
        coordinate.association(:procedure).target = revision.procedure
      end
    end

    assign_revision_type_de_champ(revisions_by_id, coordinates_by_revision_id)
    assign_revision_type_de_champ_public(revisions_by_id, coordinates_by_revision_id)
    assign_revision_type_de_champ_private(revisions_by_id, coordinates_by_revision_id)
  end

  def assign_revision_type_de_champ(revisions_by_id, coordinates_by_revision_id)
    revisions_by_id.each_pair do |revision_id, revision|
      revision.association(:revision_types_de_champ).target = coordinates_by_revision_id[revision_id] || []
      revision.association(:types_de_champ).target = revision.revision_types_de_champ.map(&:type_de_champ)
    end
  end

  def assign_revision_type_de_champ_private(revisions_by_id, coordinates_by_revision_id)
    revisions_by_id.each_pair do |revision_id, revision|
      revision.association(:revision_types_de_champ_private).target = (coordinates_by_revision_id[revision_id] || []).filter do
        _1.parent_id.nil? && _1.type_de_champ.private?
      end
      revision.association(:types_de_champ_private).target = revision.revision_types_de_champ_private.map(&:type_de_champ)
    end
  end

  def assign_revision_type_de_champ_public(revisions_by_id, coordinates_by_revision_id)
    revisions_by_id.each_pair do |revision_id, revision|
      revision.association(:revision_types_de_champ_public).target = (coordinates_by_revision_id[revision_id] || []).filter do
        _1.parent_id.nil? && _1.type_de_champ.public?
      end
      revision.association(:types_de_champ_public).target = revision.revision_types_de_champ_public.map(&:type_de_champ)
    end
  end
end