# frozen_string_literal: true
module GraphQL
  module Authorization
    class InaccessibleFieldsError < GraphQL::AnalysisError
      # @return [Array<Schema::Field, GraphQL::Field>] Fields that failed `.accessible?` checks
      attr_reader :fields

      # @return [GraphQL::Query::Context] The current query's context
      attr_reader :context

      # @return [Array<GraphQL::InternalRepresentation::Node>] The visited nodes that failed `.accessible?` checks
      # @see {#fields} for the Field definitions
      attr_reader :irep_nodes

      def initialize(fields:, irep_nodes:, context:)
        @fields = fields
        @irep_nodes = irep_nodes
        @context = context
        super("Some fields in this query are not accessible: #{fields.map(&:graphql_name).join(", ")}")
      end
    end

    # @deprecated authorization at query runtime is generally a better idea.
    module Analyzer
      module_function
      def initial_value(query)
        {
          schema: query.schema,
          context: query.context,
          inaccessible_nodes: [],
        }
      end

      def call(memo, visit_type, irep_node)
        if visit_type == :enter
          field = irep_node.definition
          if field
            schema = memo[:schema]
            ctx = memo[:context]
            next_field_accessible = schema.accessible?(field, ctx)
            if !next_field_accessible
              memo[:inaccessible_nodes] << irep_node
            else
              arg_accessible = true
              irep_node.arguments.argument_values.each do |name, arg_value|
                arg_accessible = schema.accessible?(arg_value.definition, ctx)
                if !arg_accessible
                  memo[:inaccessible_nodes] << irep_node
                  break
                end
              end
              if arg_accessible
                return_type = field.type.unwrap
                next_type_accessible = schema.accessible?(return_type, ctx)
                if !next_type_accessible
                  memo[:inaccessible_nodes] << irep_node
                end
              end
            end
          end
        end
        memo
      end

      def final_value(memo)
        nodes = memo[:inaccessible_nodes]
        if nodes.any?
          fields = nodes.map do |node|
            field_inst = node.definition
            # Get the "source of truth" for this field
            field_inst.metadata[:type_class] || field_inst
          end
          context = memo[:context]
          err = InaccessibleFieldsError.new(fields: fields, irep_nodes: nodes, context: context)
          context.schema.inaccessible_fields(err)
        else
          nil
        end
      end
    end
  end
end