mastodon/app/models/announcement_filter.rb

# frozen_string_literal: true

class AnnouncementFilter
  KEYS = %i(
    published
    unpublished
  ).freeze

  attr_reader :params

  def initialize(params)
    @params = params
  end

  def results
    scope = Announcement.unscoped

    params.each do |key, value|
      next if key.to_s == 'page'

      scope.merge!(scope_for(key, value.to_s.strip)) if value.present?
    end

    scope.chronological
  end

  private

  def scope_for(key, _value)
    case key.to_s
    when 'published'
      Announcement.published
    when 'unpublished'
      Announcement.unpublished
    else
      raise "Unknown filter: #{key}"
    end
  end
end