draffensperger/type_tracer

# frozen_string_literal: true

module TypeTracer
  module ArgSendTypeCheck
    class Runner
      def initialize(files)
        @files = files
      end

      def bad_arg_sends
        @files.flat_map do |file|
          ast = TypeTracer.parse_file(file)
          AstChecker.new(ast: ast, types: filtered_types).bad_arg_sends
        end
      end

      private

      def changed_files
        @changed_files ||=
          `git diff --name-only #{fetched_types[:git_commit]}`.split("\n")
      end

      def fetched_types
        @fetched_types ||= TypeFetcher.fetch_sampled_types
      end

      def filtered_types
        @filtered_types ||= filter_types
      end

      def filter_types
        type_info = fetched_types[:type_info]
        type_info.each do |klass_sym, method_types|
          method_types.each do |method_sym, method_type_info|
            # All the callers of this method have at least one file changed, so
            # assume that this method type signature may no longer be valid.
            if all_have_changed_file(method_type_info[:callers])
              # Remove it from the type list
              type_info[klass_sym].delete(method_sym)
            end
          end
        end
      end

      def all_have_changed_file(call_stacks)
        call_stacks.all? do |call_stack|
          stack_files = call_stack.map { |frame| frame.split(':')[0] }
          !(stack_files & changed_files).empty?
        end
      end
    end
  end
end