syntax = "proto3";

package notify.v1;

import "notify/v1/send_notification.proto";

service NotifyService {
  // SendNotification sends notification data to Zen Server.
  //
  // Returns notification_id that can be used to send attachments.
  //
  // notification_id is long lived and can be given attachments even on the far future.
  //
  // If you want to send attachments, use SendAttachment rpc.
  //
  // `notification_id` respond can be used to send attachments via SendAttachment rpc.
  // `upload_url` can be used to upload attachments via http protocol (fetch, axios, http post, etc).
  rpc SendNotification(SendNotificationRequest) returns (SendNotificationResponse);

  // SendAttachment sends attachment data to Zen Server.
  //
  // SendAttachment rpc is not supported by Browser Javascript.
  //
  // If implementing logic for SendAttachment rpc is difficult, consider using `upload_url`
  // to upload attachments via http protocol.
  //
  // SendAttachment requires notification_id that was returned by SendNotification
  // so that Zen server can associate attachment with notification.
  //
  // One Stream One Attachment. To send multiple attachments, spawn multiple streams by calling
  // SendAttachment multiple times with the same notification_id and send chunks of data in order.
  //
  // PSEUDOCODE:
  //
  //   response = client.SendNotification({
  //      payload: {...},
  //      resource: {...},
  //   })
  //
  //   notification_id = response.notification_id
  //
  //   for attachment in attachments {
  //     stream = client.SendAttachment()
  //     // thread.spawn is a pseudo code for creating a new thread or background worker/task.
  //     thread.spawn ({
  //        for chunk in attachment.chunks {
  //            stream.Send({
  //                notification_id: notification_id,
  //                name: attachment.name,
  //                content_type: attachment.content_type,
  //                chunk: chunk,
  //            })
  //        }
  //        stream.Close()
  //     })
  //   }
  rpc SendAttachment(stream SendAttachmentRequest) returns (SendAttachmentResponse);
}

message SendAttachmentRequest {
  string notification_id = 1;
  string name = 2;
  string content_type = 3;
  bytes chunk = 4;
}

message SendAttachmentResponse {}