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

require 'contrast/agent/reporting/reporting_events/application_update'
require 'contrast/agent/reporting/reporting_events/application_inventory'
require 'contrast/components/logger'
require 'contrast/extension/module'
require 'contrast/framework/grape/support'
require 'contrast/framework/manager_extend'
require 'contrast/framework/rack/support'
require 'contrast/framework/rails/support'
require 'contrast/framework/sinatra/support'
require 'contrast/utils/class_util'

module Contrast
  module Framework
    # Allows access to framework specific information
    class Manager
      include Contrast::Components::Logger::InstanceMethods
      include Contrast::Framework::ManagerExtend

      # Order here does matter as the first framework listed will be the first one we pull information from Rack will
      # be a special case that may involve updating some logic to handle only applying Rack if Rails/Sinatra do not
      # exist
      SUPPORTED_FRAMEWORKS = [
        Contrast::Framework::Rails::Support, Contrast::Framework::Sinatra::Support,
        Contrast::Framework::Grape::Support, Contrast::Framework::Rack::Support
      ].cs__freeze

      def initialize
        @_frameworks = SUPPORTED_FRAMEWORKS.map do |framework_klass|
          next unless enable_framework_support?(framework_klass.detection_class)

          logger.info('Framework detected. Enabling support.', framework: framework_klass.detection_class)
          framework_klass
        end
        @_frameworks.compact!
      end

      # Patches that have to be applied as early as possible to catch calls that happen prior to the first Request,
      # typically those around configuration.
      def before_load_patches!
        @_before_load_patches ||= begin
          SUPPORTED_FRAMEWORKS.each(&:before_load_patches!)
          true
        end
      end

      # Return all the After Load Patches for all the Frameworks we know, even if that Framework hasn't been detected.
      #
      # @return [Set<Contrast::Agent::Patching::Policy::AfterLoadPatch>] the AfterLoadPatches of each framework
      def find_after_load_patches
        patches = Set.new
        SUPPORTED_FRAMEWORKS.each do |framework|
          framework_patches = framework.after_load_patches
          patches.merge(framework_patches) if framework_patches && !framework_patches.empty?
        end
        patches
      end

      # @return [Array<Contrast::Agent::Reporting::DiscoveredRoute>]
      def find_route_discovery_data
        routes_for_all_frameworks
      end

      def server_type
        first_framework_result(:server_type, 'rack')
      end

      def app_name
        first_framework_result(:application_name, 'root')
      end

      def app_root
        found = first_framework_result(:application_root, nil)
        found || ::Rack::Directory.new('').root
      end

      # Build a request from the provided env, based on the framework(s) we're currently supporting.
      #
      # @param env [Hash] the various variables stored by this and other Middlewares to know the state and values of
      #   this particular Request
      # @return [::Rack::Request] either a rack request or subclass thereof.
      def retrieve_request env
        # If we're mounted on Rails, use Rails.
        if @_frameworks.include?(Contrast::Framework::Rails::Support)
          return Contrast::Framework::Rails::Support.retrieve_request(env)
        end

        # If we know the framework, use it.
        return @_frameworks[0].retrieve_request(env) if @_frameworks.length == 1

        # Fall back on a regular Rack::Request
        ::Rack::Request.new(env)
      rescue StandardError => e
        logger.warn('Unable to retrieve_request', e)
      end

      # @param env [Hash] the various variables stored by this and other Middlewares to know the state and values of
      #   this particular Request
      # @return [Boolean] true if at least one framework is streaming the response; false if none are streaming
      def streaming? env
        result = false
        @_frameworks.each do |framework|
          result = framework.streaming?(env)
          break if result
        end
        result
      end

      # Iterate through current frameworks and return the current request's route. This will be the first non-nil
      # result.
      #
      # @param request [Contrast::Agent::Request] the current request.
      # @return [Contrast::Api::Dtm::RouteCoverage] the current route as a Dtm.
      def get_route_dtm request
        @_frameworks.lazy.map { |framework_support| framework_support.current_route(request) }.
            reject(&:nil?).first # rubocop:disable Style/CollectionCompact
      end

      # Iterate through current frameworks and return the current request's route. This will be the first non-nil
      # result.
      #
      # @param request [Contrast::Agent::Request] the current request.
      # @return [Contrast::Agent::Reporting::RouteCoverage] the current route as a Dtm.
      def get_route_information request
        @_frameworks.lazy.map { |framework_support| framework_support.current_route_coverage(request) }.
            reject(&:nil?).first # rubocop:disable Style/CollectionCompact
      end

      # Sometimes the framework we want to instrument is loaded after our agent code. To catch that case, we'll detect
      # if the loaded_module is the marker class for any of our supported frameworks. If it is, and we don't already
      # have support enabled, we'll enable it now. We'll also need to catch up on any other startup actions that we've
      # missed. Most likely, this is only necessary for those applications which have applications mounted on them.
      #
      # TODO: RUBY-1356
      #
      # @param mod [Module] the module or class that was just loaded
      def register_late_framework mod
        return unless mod

        module_name = mod.cs__name
        # Otherwise, check if the provided module_name requires us to register a new support
        SUPPORTED_FRAMEWORKS.each do |framework|
          next if @_frameworks.include?(framework)
          next unless module_name == framework.detection_class

          @_frameworks << framework
          report = Contrast::Agent::Reporting::ApplicationUpdate.new
          # This convert here is left as it'll be easier to be replaced when the Library is being changed
          report.libraries = Contrast::Agent::Inventory::DependencyAnalysis.instance.library_pb_list
          [report, Contrast::Agent::Reporting::ApplicationInventory.new].each do |e|
            Contrast::Agent.reporter.send_event(e)
          end

          logger.info('Framework detected after initialization. Enabling support.',
                      framework: framework.detection_class,
                      frameworks: @_frameworks)
          break
        end
      rescue StandardError => e
        logger.warn('Unable to register a late framework', e, module: mod.cs__name)
      end
    end
  end
end