# Copyright (c) 2020 Contrast Security, Inc. See https://www.contrastsecurity.com/enduser-terms-0317a for more details.
# frozen_string_literal: true

cs__scoped_require 'contrast/utils/object_share'
cs__scoped_require 'contrast/agent/patching/policy/patch_status'
cs__scoped_require 'contrast/agent/module_data'
cs__scoped_require 'contrast/agent/rewriter'
cs__scoped_require 'contrast/components/interface'

module Contrast
  module Agent
    module Assess
      module Policy
        # This is our interface from the Patcher to the Rewriter
        # functionality
        #
        # TODO: RUBY-714 remove w/ EOL of 2.5
        # @deprecated Changes to this class are discouraged as this approach is
        #   being phased out with support for those language versions.
        module RewriterPatch
          include Contrast::Components::Interface
          access_component :agent, :analysis, :logging

          class << self
            def rewrite_interpolations
              return unless ASSESS.enabled?
              return unless AGENT.rewrite_interpolation?

              logger.debug_with_time("\t\tRunning Assess interpolation rewrite") do
                ObjectSpace.each_object(Module) do |mod|
                  rewrite_interpolation(mod)
                end
              end
            end

            # Rails is being a jerk, again. It passes in a class before it is
            # done being defined. There is a state where the files have been
            # loaded, but the class definition is not complete, so the
            # methods of the class are not defined despite the class existing
            #
            # To get around this, we have those methods tell us the class
            # isn't ready
            def mid_defining? mod
              mod.instance_variable_defined?(:@cs__defining_class) &&
                  mod.instance_variable_get(:@cs__defining_class)
            end

            def rewrite_interpolation mod, redo_rewrite = false
              return unless ASSESS.enabled?
              return unless AGENT.rewrite_interpolation?
              return unless AGENT.interpolation_enabled?
              return if AGENT.skip_instrumentation? mod.cs__name
              return if mod.cs__frozen?
              return if mod.singleton_class?
              return if mid_defining?(mod)

              status = Contrast::Agent::Patching::Policy::PatchStatus.get_status(mod)
              return if (status&.rewritten? || status&.rewriting?) && !redo_rewrite

              module_name = mod.cs__name
              return unless module_name

              if module_name.start_with?(Contrast::Utils::ObjectShare::CONTRAST_MODULE_START, Contrast::Utils::ObjectShare::ANONYMOUS_CLASS_MARKER)
                status.no_rewrite!
                return

              end
              module_data = Contrast::Agent::ModuleData.new(mod, module_name)
              logger.debug_with_time("\t\t\tRewriting #{ module_name }") do
                Contrast::Agent::Rewriter.rewrite_class(module_data, redo_rewrite)
              end
            rescue StandardError => e
              logger.error(
                  e,
                  "Unable to patch assess into the module #{ mod }")
            end
          end
        end
      end
    end
  end
end