class ProfileValidator < ActiveModel::Validator
  SUMMARY_ATTRIBUTE = "summary".freeze
  MAX_SUMMARY_LENGTH = 200

  MAX_TEXT_AREA_LENGTH = 200
  MAX_TEXT_FIELD_LENGTH = 100

  HEX_COLOR_REGEXP = /^#?(?:\h{6}|\h{3})$/.freeze

  ERRORS = {
    color_field: "is not a valid hex color",
    text_area: "is too long (maximum: #{MAX_TEXT_AREA_LENGTH})",
    text_field: "is too long (maximum: #{MAX_TEXT_FIELD_LENGTH})"
  }.with_indifferent_access.freeze

  def validate(record)
    # NOTE: @citizen428 The summary is a base profile field, which we add to all
    # new Forem instances, so it should be safe to validate. The method itself
    # also guards against the field's absence.
    record.errors.add(:summary, "is too long") if summary_too_long?(record)

    ProfileField.all.each do |field|
      attribute = field.attribute_name
      next if attribute == SUMMARY_ATTRIBUTE # validated above
      next unless record.respond_to?(attribute) # avoid caching issues
      next if __send__("#{field.input_type}_valid?", record, attribute)

      record.errors.add(attribute, ERRORS[field.input_type])
    end
  end

  private

  def summary_too_long?(record)
    # Calling the summary attribute method on record during onboarding
    # throws a NoMethodError
    return unless record.respond_to?(SUMMARY_ATTRIBUTE)

    return unless ProfileField.exists?(attribute_name: SUMMARY_ATTRIBUTE)
    return if record.summary.blank?

    # Grandfather in people who had a too long summary before
    previous_summary = record.data_was[SUMMARY_ATTRIBUTE]
    return if previous_summary && previous_summary.size > MAX_SUMMARY_LENGTH

    record.summary.size > MAX_SUMMARY_LENGTH
  end

  def check_box_valid?(_record, _attribute)
    true # checkboxes are always valid
  end

  def color_field_valid?(record, attribute)
    hex_value = record.public_send(attribute)
    hex_value.nil? || hex_value.match?(HEX_COLOR_REGEXP)
  end

  def text_area_valid?(record, attribute)
    text = record.public_send(attribute)
    text.nil? || text.size <= MAX_TEXT_AREA_LENGTH
  end

  def text_field_valid?(record, attribute)
    text = record.public_send(attribute)
    text.nil? || text.size <= MAX_TEXT_FIELD_LENGTH
  end
end