# 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/components/interface'

module Kernel # :nodoc:
  include Contrast::Components::Interface

  access_component :scope

  alias_method :cs__catch, :catch

  # In the event of a `throw`, we need to override `catch`
  # to save & restore scope state:
  #
  #   scope_level == 0
  #
  #   catch(:abc) do
  #     with_contrast_scope do
  #       throw :abc # will leak
  #     end
  #   end
  #
  #   scope_level == 1
  #
  # While this will fix /all/ scope leaks, not just ones caused by `throw`,
  # it shouldn't be relied upon as a catch-all (lmao) solution.

  private

  def catch *args, &block
    # Save current scope level
    scope_level = SCOPE.scope_for_current_ec.instance_variable_get(:@contrast_scope)

    # Run original catch with block.
    retval = cs__catch(*args, &block)

    # Restore scope.
    SCOPE.scope_for_current_ec.instance_variable_set(:@contrast_scope, scope_level)

    retval
  end
end

# ScopeUtil should probably be merged into Scope component.
module Contrast
  module Utils
    module ScopeUtil # :nodoc:
      include Contrast::Components::Interface

      access_component :analysis, :scope

      # @return [Boolean]
      def skip_contrast_analysis?
        return true if in_contrast_scope?
        return true unless Contrast::Agent::REQUEST_TRACKER.current&.analyze_request?

        false
      end

      # Skip if we should skip_contrast_analysis?, sampling says to ignore this
      # request, or assess has been disabled.
      #
      # @return [Boolean]
      def skip_assess_analysis?
        return true if skip_contrast_analysis?

        current_context = Contrast::Agent::REQUEST_TRACKER.current
        return true unless current_context.analyze_request?

        !ASSESS.enabled?
      end

      def cs__enter_scope
        enter_contrast_scope!
      end

      def cs__leave_scope
        exit_contrast_scope!
      end

      def cs__enter_assess_scope
        # If we shouldn't be doing assess things, don't propagate or whatever
        disable_contrast = skip_assess_analysis?
        return nil if disable_contrast

        enter_contrast_scope!
      end

      def cs__enter_scope_contrast_patch
        # If we're already in Contrast scope, don't propagate or whatever
        disable_contrast = skip_contrast_analysis?
        return nil if disable_contrast

        enter_contrast_scope!
      end
    end
  end
end