# Copyright (c) 2022 Contrast Security, Inc. See https://www.contrastsecurity.com/enduser-terms-0317a for more details.
# frozen_string_literal: true

module Contrast
  module Utils
    # used in Contrast::Agent::Response
    module ResponseUtils
      private

      # From the dtm for normalized_response_headers:
      #   Key is UPPERCASE_UNDERSCORE
      #
      #   Example: Content-Type: text/html; charset=utf-8
      #   "CONTENT_TYPE" => Content-Type,["text/html; charset=utf8"]
      def append_pair map, key, value
        return unless key && value
        return if value.is_a?(Hash)

        safe_key = Contrast::Utils::StringUtils.force_utf8(key)
        hash_key = Contrast::Utils::StringUtils.normalized_key(safe_key)
        map[hash_key] ||= Contrast::Api::Dtm::Pair.new
        map[hash_key].key = safe_key
        map[hash_key].values << Contrast::Utils::StringUtils.force_utf8(value)
      end

      HTTP_PREFIX = /^[Hh][Tt][Tt][Pp][_-]/i.cs__freeze

      # Given some holder of the content of the response's body, extract that
      # content and return it as a String
      #
      # @param body [String, Rack::File, Rack::BodyProxy,
      #   ActionDispatch::Response::RackBody, Rack::Response] Something that
      #   holds, wraps, or is the body of the Response
      # @return [nil, String] the content of the body
      def extract_body body
        return unless body
        return if defined?(Rack::File) && body.is_a?(Rack::File)

        return handle_rack_body_proxy(body) if body.is_a?(Rack::BodyProxy)
        return extract_body(body.body) if sub_extractable?(body)
        return enumerable_text_from(body) if Contrast::Utils::DuckUtils.quacks_to?(body, :each)
        # https://stackoverflow.com/questions/15654676/how-to-convert-activesupportsafebuffer-to-string
        return body.to_str if body.is_a?(ActionView::OutputBuffer)

        read_or_string(body)
      end

      def sub_extractable? body
        (defined?(ActionDispatch::Response::RackBody) && body.is_a?(ActionDispatch::Response::RackBody)) ||
            body.is_a?(Rack::Response)
      end

      def enumerable_text_from body
        entries = body.map { |entry| read_or_string(entry) }
        entries.compact!
        entries.join(Contrast::Utils::ObjectShare::NEW_LINE)
      end

      def handle_rack_body_proxy body
        next_body = body.instance_variable_get(:@body)
        case next_body
        when Array
          extract_body(next_body[0])
        else
          extract_body(next_body)
        end
      end

      def read_or_string obj
        return unless obj

        if Contrast::Utils::DuckUtils.quacks_to?(obj, :read)
          tmp = obj.read
          obj.rewind
          tmp
        else
          obj.to_s
        end
      end
    end
  end
end