Ensures that provided timezones are respected while converting UTC/Unrecognized timezones into zone set by Time.zone

params_sanitizer.rb

module Api::ParamsSanitizer

  def sanitize_param_timezones
    params.merge!(traverse_params(params.to_unsafe_h))
  end

  def traverse_params(params)
    params.map { |k, v| traverser(k, v) }.to_h
  end

  def traverser(key, value)
    new_val = value

    case value.class.name
    when "ActionController::Parameters", "Hash", "ActiveSupport::HashWithIndifferentAccess"
      new_val = traverse_params(value)
    when "Array"
      new_val = value.map { |array_val| traverser(key, array_val)[1] }
    else
      new_val = process_date_parameter(value) if date_parameter_names.include?(key)
    end
    
    [key, new_val]
  end

  # @param value [String] string representation of date or datetime
  # @return [DateTime] DateTime with parsed timezone offset of
  #                    DateTime with PDT (Time.zone) offset
  # @note Respects any timezone parsed from the string except for UTC
  def process_date_parameter(value)
    parsed_with_zone = DateTime.parse(value)
    if parsed_with_zone.utc_offset.zero?
      parsed_with_zone.in_time_zone.to_datetime
    else
      parsed_with_zone
    end
  rescue => _e
    value
  end

  def hash_traversable?(param)
    %w[ActionController::Parameters, Hash].include? param.class
  end

  def date_parameter_names
    @date_parameter_names ||=
      %w[
        start_date end_date finish_date from_date to_date publication_date
        last_opened_date current_school_year_opening_date loan_start loan_expiration
      ]
  end

end