syntax = "proto3";

package cast.v2;

import "google/protobuf/empty.proto";
import "cast/cast_core/api/bindings/api_bindings.proto";
import "cast/cast_core/api/common/application_config.proto";
import "cast/cast_core/api/common/service_info.proto";
import "cast/cast_core/api/v2/cast_message.proto";
import "cast/cast_core/api/v2/url_rewrite.proto";
import "cast/cast_core/api/web/message_channel.proto";

option optimize_for = LITE_RUNTIME;

// This service is implemented by the CastCore and used by Cast application in
// Runtime to report status and request additional application information. This
// service is scoped per application.
service CoreApplicationService {
  // Returns application config. Idempotent call. Errors are signaled through
  // the gRPC status code.
  rpc GetConfig(GetConfigRequest) returns (GetConfigResponse);

  // Send a Cast V2 message to core application.
  rpc SendCastMessage(CastMessage) returns (CastMessageResponse);

  // Notifies Cast Core on the application state changes. The callback must be
  // called by the Runtime whenever the internal state of the application
  // changes. Cast Core may discard any resources associated with the
  // application upon failures.
  rpc OnApplicationStatus(ApplicationStatus) returns (google.protobuf.Empty);

  // Posts messages between MessagePorts. MessagePorts are connected using other
  // services (e.g. ApiBindings), then registered with the
  // MessageConnectorService to communicate over IPC.
  rpc PostMessage(cast.web.Message) returns (cast.web.MessagePortStatus);

  // Gets the list of bindings to early-inject into javascript at page load.
  rpc GetAll(google.protobuf.Empty) returns (cast.bindings.GetAllResponse);

  // Connects to a binding returned by GetAll.
  rpc Connect(cast.bindings.ConnectRequest) returns (google.protobuf.Empty);
}

message GetConfigRequest {
  // Cast session ID.
  string cast_session_id = 1;
  // RuntimeApplication service info.
  cast.common.ServiceInfo runtime_application_service_info = 2;
}

message GetConfigResponse {
  // Cast application config.
  cast.common.ApplicationConfig application_config = 1;
  // Initial rules to rewrite URL headers.
  UrlRequestRewriteRules url_rewrite_rules = 2;
  // CastMedia service info for this application in CastCore.
  cast.common.ServiceInfo cast_media_service_info = 3;
}

// Contains information about an application status in the runtime.
message ApplicationStatus {
  // The Cast session ID whose application status changed.
  string cast_session_id = 1;

  // Application state.
  enum State {
    STATE_UNDEFINED = 0;  // Added to avoid empty |state| value.
    STARTED = 1;          // Notifies that application has successfully started.
    STOPPED = 2;          // Notified that application has stopped or failed to
                          // start. The |stop_reason| will be populated.
  }
  State state = 2;

  // Reason why the application was stopped. Only valid when |state| is STOPPED.
  enum StopReason {
    REASON_UNDEFINED = 0;     // Added to avoid empty |stop_reason| value.
    APPLICATION_REQUEST = 1;  // Receiver application stopped itself.
    IDLE_TIMEOUT = 2;         // Runtime stopped an idle application.
    USER_REQUEST = 3;         // User closed the application, e.g.
                              // via remote control or system UI. (Normally this
                              // is handled by Cast Core).
    HTTP_ERROR = 4;           // HTTP error while loading the Application. The
                              // |http_response_code| will be populated.
    RUNTIME_ERROR = 5;        // Unrecoverable error in the runtime.
  }
  StopReason stop_reason = 3;

  // HTTP response code if Application URL failed to load. Only valid when
  // |stop_reason| is HTTP_ERROR.
  int32 http_response_code = 4;
}