class GraphQL::Language::DocumentFromSchemaDefinition

def build_argument_node(argument)
  if argument.default_value?
    default_value = build_default_value(argument.default_value, argument.type)
  else
    default_value = nil
  end
  argument_node = GraphQL::Language::Nodes::InputValueDefinition.new(
    name: argument.graphql_name,
    comment: argument.comment,
    description: argument.description,
    type: build_type_name_node(argument.type),
    default_value: default_value,
    directives: directives(argument),
  )
  argument_node
end

def build_argument_nodes(arguments)
  if !arguments.empty?
    nodes = arguments.map { |arg| build_argument_node(arg) }
    nodes.sort_by!(&:name)
    nodes
  else
    arguments
  end
end

def build_default_value(default_value, type)
  if default_value.nil?
    return GraphQL::Language::Nodes::NullValue.new(name: "null")
  end
  case type.kind.name
  when "SCALAR"
    type.coerce_isolated_result(default_value)
  when "ENUM"
    GraphQL::Language::Nodes::Enum.new(name: type.coerce_isolated_result(default_value))
  when "INPUT_OBJECT"
    GraphQL::Language::Nodes::InputObject.new(
      arguments: default_value.to_h.map do |arg_name, arg_value|
        args = @types.arguments(type)
        arg = args.find { |a| a.keyword.to_s == arg_name.to_s }
        if arg.nil?
          raise ArgumentError, "No argument definition on #{type.graphql_name} for argument: #{arg_name.inspect} (expected one of: #{args.map(&:keyword)})"
        end
        GraphQL::Language::Nodes::Argument.new(
          name: arg.graphql_name.to_s,
          value: build_default_value(arg_value, arg.type)
        )
      end
    )
  when "NON_NULL"
    build_default_value(default_value, type.of_type)
  when "LIST"
    default_value.to_a.map { |v| build_default_value(v, type.of_type) }
  else
    raise GraphQL::RequiredImplementationMissingError, "Unexpected default value type #{type.inspect}"
  end
end

def build_definition_nodes
  dirs_to_build = @types.directives
  if !include_built_in_directives
    dirs_to_build = dirs_to_build.reject { |directive| directive.default_directive? }
  end
  definitions = build_directive_nodes(dirs_to_build)
  all_types = @types.all_types
  type_nodes = build_type_definition_nodes(all_types)
  if !(ex_t = schema.extra_types).empty?
    dummy_query = Class.new(GraphQL::Schema::Object) do
      graphql_name "DummyQuery"
      (all_types + ex_t).each_with_index do |type, idx|
        if !type.kind.input_object? && !type.introspection?
          field "f#{idx}", type
        end
      end
    end
    extra_types_schema = Class.new(GraphQL::Schema) do
      query(dummy_query)
    end
    extra_types_types = GraphQL::Query.new(extra_types_schema, "{ __typename }", context: @context).types  # rubocop:disable Development/ContextIsPassedCop
    # Temporarily replace `@types` with something from this example schema.
    # It'd be much nicer to pass this in, but that would be a big refactor :S
    prev_types = @types
    @types = extra_types_types
    type_nodes += build_type_definition_nodes(ex_t)
    @types = prev_types
  end
  type_nodes.sort_by!(&:name)
  if @include_one_of
    # This may have been set to true when iterating over all types
    definitions.concat(build_directive_nodes([GraphQL::Schema::Directive::OneOf]))
  end
  definitions.concat(type_nodes)
  if include_schema_node?
    definitions.unshift(build_schema_node)
  end
  definitions
end

def build_directive_location_node(location)
  GraphQL::Language::Nodes::DirectiveLocation.new(
    name: location.to_s
  )
end

def build_directive_location_nodes(locations)
  locations.sort.map { |location| build_directive_location_node(location) }
end

def build_directive_node(directive)
  GraphQL::Language::Nodes::DirectiveDefinition.new(
    name: directive.graphql_name,
    repeatable: directive.repeatable?,
    arguments: build_argument_nodes(@types.arguments(directive)),
    locations: build_directive_location_nodes(directive.locations),
    description: directive.description,
  )
end

def build_directive_nodes(directives)
  directives
    .map { |directive| build_directive_node(directive) }
    .sort_by(&:name)
end

def build_enum_type_node(enum_type)
  GraphQL::Language::Nodes::EnumTypeDefinition.new(
    name: enum_type.graphql_name,
    comment: enum_type.comment,
    values: @types.enum_values(enum_type).sort_by(&:graphql_name).map do |enum_value|
      build_enum_value_node(enum_value)
    end,
    description: enum_type.description,
    directives: directives(enum_type),
  )
end

def build_enum_value_node(enum_value)
  GraphQL::Language::Nodes::EnumValueDefinition.new(
    name: enum_value.graphql_name,
    comment: enum_value.comment,
    description: enum_value.description,
    directives: directives(enum_value),
  )
end

def build_field_node(field)
  GraphQL::Language::Nodes::FieldDefinition.new(
    name: field.graphql_name,
    comment: field.comment,
    arguments: build_argument_nodes(@types.arguments(field)),
    type: build_type_name_node(field.type),
    description: field.description,
    directives: directives(field),
  )
end

def build_field_nodes(fields)
  f_nodes = fields.map { |field| build_field_node(field) }
  f_nodes.sort_by!(&:name)
  f_nodes
end

def build_input_object_node(input_object)
  GraphQL::Language::Nodes::InputObjectTypeDefinition.new(
    name: input_object.graphql_name,
    comment: input_object.comment,
    fields: build_argument_nodes(@types.arguments(input_object)),
    description: input_object.description,
    directives: directives(input_object),
  )
end

def build_interface_type_node(interface_type)
  GraphQL::Language::Nodes::InterfaceTypeDefinition.new(
    name: interface_type.graphql_name,
    comment: interface_type.comment,
    interfaces: @types.interfaces(interface_type).sort_by(&:graphql_name).map { |type| build_type_name_node(type) },
    description: interface_type.description,
    fields: build_field_nodes(@types.fields(interface_type)),
    directives: directives(interface_type),
  )
end

def build_object_type_node(object_type)
  ints = @types.interfaces(object_type)
  if !ints.empty?
    ints.sort_by!(&:graphql_name)
    ints.map! { |iface| build_type_name_node(iface) }
  end
  GraphQL::Language::Nodes::ObjectTypeDefinition.new(
    name: object_type.graphql_name,
    comment: object_type.comment,
    interfaces: ints,
    fields: build_field_nodes(@types.fields(object_type)),
    description: object_type.description,
    directives: directives(object_type),
  )
end

def build_scalar_type_node(scalar_type)
  GraphQL::Language::Nodes::ScalarTypeDefinition.new(
    name: scalar_type.graphql_name,
    comment: scalar_type.comment,
    description: scalar_type.description,
    directives: directives(scalar_type),
  )
end

def build_schema_node
  if !schema_respects_root_name_conventions?(@schema)
    GraphQL::Language::Nodes::SchemaDefinition.new(
      query:  @types.query_root&.graphql_name,
      mutation: @types.mutation_root&.graphql_name,
      subscription: @types.subscription_root&.graphql_name,
      directives: definition_directives(@schema, :schema_directives)
    )
  else
    # A plain `schema ...` _must_ include root type definitions.
    # If the only difference is directives, then you have to use `extend schema`
    GraphQL::Language::Nodes::SchemaExtension.new(directives: definition_directives(@schema, :schema_directives))
  end
end

def build_type_definition_node(type)
  case type.kind.name
  when "OBJECT"
    build_object_type_node(type)
  when "UNION"
    build_union_type_node(type)
  when "INTERFACE"
    build_interface_type_node(type)
  when "SCALAR"
    build_scalar_type_node(type)
  when "ENUM"
    build_enum_type_node(type)
  when "INPUT_OBJECT"
    build_input_object_node(type)
  else
    raise TypeError
  end
end

def build_type_definition_nodes(types)
  if !include_introspection_types
    types = types.reject { |type| type.introspection? }
  end
  if !include_built_in_scalars
    types = types.reject { |type| type.kind.scalar? && type.default_scalar? }
  end
  types.map { |type| build_type_definition_node(type) }
end

def build_type_name_node(type)
  case type.kind.name
  when "LIST"
    GraphQL::Language::Nodes::ListType.new(
      of_type: build_type_name_node(type.of_type)
    )
  when "NON_NULL"
    GraphQL::Language::Nodes::NonNullType.new(
      of_type: build_type_name_node(type.of_type)
    )
  else
    @cached_type_name_nodes ||= {}
    @cached_type_name_nodes[type.graphql_name] ||= GraphQL::Language::Nodes::TypeName.new(name: type.graphql_name)
  end
end

def build_union_type_node(union_type)
  GraphQL::Language::Nodes::UnionTypeDefinition.new(
    name: union_type.graphql_name,
    comment: union_type.comment,
    description: union_type.description,
    types: @types.possible_types(union_type).sort_by(&:graphql_name).map { |type| build_type_name_node(type) },
    directives: directives(union_type),
  )
end

def definition_directives(member, directives_method)
  if !member.respond_to?(directives_method) || member.directives.empty?
    EmptyObjects::EMPTY_ARRAY
  else
    visible_directives = member.public_send(directives_method).select { |dir| @types.directive_exists?(dir.graphql_name) }
    visible_directives.map! do |dir|
      args = []
      dir.arguments.argument_values.each_value do |arg_value| # rubocop:disable Development/ContextIsPassedCop -- directive instance method
        arg_defn = arg_value.definition
        if arg_defn.default_value? && arg_value.value == arg_defn.default_value
          next
        else
          value_node = build_default_value(arg_value.value, arg_value.definition.type)
          args << GraphQL::Language::Nodes::Argument.new(
            name: arg_value.definition.name,
            value: value_node,
          )
        end
      end
      # If this schema uses this built-in directive definition,
      # include it in the print-out since it's not part of the spec yet.
      @include_one_of ||= dir.class == GraphQL::Schema::Directive::OneOf
      GraphQL::Language::Nodes::Directive.new(
        name: dir.class.graphql_name,
        arguments: args
      )
    end
    visible_directives
  end
end

def directives(member)
  definition_directives(member, :directives)
end

def document
  GraphQL::Language::Nodes::Document.new(
    definitions: build_definition_nodes
  )
end

def include_schema_node?
  always_include_schema ||
    !schema_respects_root_name_conventions?(schema) ||
    !schema.schema_directives.empty?
end

def initialize(
  schema, context: nil, include_introspection_types: false,
  include_built_in_directives: false, include_built_in_scalars: false, always_include_schema: false
)
  @schema = schema
  @context = context
  @always_include_schema = always_include_schema
  @include_introspection_types = include_introspection_types
  @include_built_in_scalars = include_built_in_scalars
  @include_built_in_directives = include_built_in_directives
  @include_one_of = false
  dummy_query = @schema.query_class.new(@schema, "{ __typename }", validate: false, context: context)
  @types = dummy_query.types # rubocop:disable Development/ContextIsPassedCop
end

def schema_respects_root_name_conventions?(schema)
  (schema.query.nil? || schema.query.graphql_name == 'Query') &&
  (schema.mutation.nil? || schema.mutation.graphql_name == 'Mutation') &&
  (schema.subscription.nil? || schema.subscription.graphql_name == 'Subscription')
end