module HTTPX
  class GRPCError < Error
    attr_reader status: Integer
    attr_reader details: String
    attr_reader metadata: headers
  end

  module Plugins
    module GRPC
      type compression_option = bool | String
      type rpc_def = [String, untyped, untyped, Hash[Symbol, untyped]]

      type grpc_message = String | _Each[String]

      type grpc_request = untyped | _Each[untyped]
      type grpc_response = untyped | _Each[untyped]

      type credentials = Proc

      class Call
        attr_writer decoder: _Callable

        def metadata: () -> headers

        def trailing_metadata: () -> headers?

        private

        def initialize: (Response | StreamResponse response) -> untyped

        def grpc_response: () -> grpc_response
      end

      module Message
        def self?.unary: (response) -> grpc_message

        def self?.stream: (StreamResponse) { (String) -> void } -> void
                        | (StreamResponse) -> Enumerable[String]

        def self?.encode: (String bytes, ?deflater: Compression::_Deflater?) -> String

        def self?.decode: (String message, encodings: Array[String], encoders: Compression::encodings_registry) -> String
                        | (String message, encodings: Array[String], encoders: Compression::encodings_registry) { (String) -> void } -> void

        def self?.cancel: (Request) -> void

        def self?.verify_status: (StreamResponse | response) -> void
      end

      interface _GRPCOptions
        def grpc_service: () -> String?

        def grpc_compression: () -> compression_option?

        def grpc_rpcs: () -> Hash[String, rpc_def]?

        def grpc_deadline: () -> Integer?

        def call_credentials: () -> credentials?
      end

      def self.extra_options: (Options) -> (Options & _GRPCOptions)
      def self.load_dependencies: (singleton(Session)) -> void

      module ResponseMethods
        def merge_headers: (headers_input trailers) -> void

        def encoders: () -> Compression::encodings_registry
      end

      module InstanceMethods
        def with_channel_credentials: (String ca_path, ?String? key, ?String? cert, **untyped) -> instance

        def rpc: (_ToS rpc_name, untyped input, untyped output, **untyped) -> instance

        def build_stub: (string origin, ?service: _ToS, ?compression: compression_option) -> instance

        def execute:  (_ToS rpc_method, grpc_message input, ?deadline: Integer, ?metadata: headers_input, **untyped) -> Call

        private

        def rpc_execute: (_ToS rpc_method, grpc_request input, **untyped) -> Call

        def build_grpc_request: (string rpc_method, grpc_message input, ?deadline: Integer, ?metadata?: headers_input, **untyped) -> Request
      end
    end

    type grpcSession = Session & GRPC::InstanceMethods
  end
end