syntax = "proto3";

package chatto.api.v1;

import "buf/validate/validate.proto";

// Browser Web Push subscription commands for the authenticated user.
service PushNotificationService {
  // Stores or updates the caller's browser push subscription.
  //
  // The server must have Web Push configured. Clients normally call this after
  // the browser grants notification permission and returns a PushSubscription.
  rpc Subscribe(SubscribeRequest) returns (SubscribeResponse);

  // Removes the caller's browser push subscription by endpoint.
  //
  // The call is idempotent: removing an unknown endpoint still succeeds.
  rpc Unsubscribe(UnsubscribeRequest) returns (UnsubscribeResponse) {
    option idempotency_level = IDEMPOTENT;
  }

  // Sends a test notification to the caller's registered browser subscriptions.
  // Calls are rate-limited per account. Delivery failures return a generic
  // unavailable error without exposing the push provider's response body.
  rpc SendTestNotification(SendTestNotificationRequest) returns (SendTestNotificationResponse);
}

// Request to store a PushSubscription returned by the browser Push API.
message SubscribeRequest {
  // Absolute HTTPS push service endpoint URL. The server rejects redirects and
  // destinations that resolve to private or other special-use addresses.
  string endpoint = 1 [(buf.validate.field).string = {
    min_len: 1
    max_len: 4096
  }];

  // Client P-256 ECDH public key from PushSubscription.keys.p256dh.
  string p256dh = 2 [(buf.validate.field).string = {
    min_len: 1
    max_len: 256
  }];

  // Authentication secret from PushSubscription.keys.auth.
  string auth = 3 [(buf.validate.field).string = {
    min_len: 1
    max_len: 128
  }];

  // Optional browser user-agent string for device identification.
  optional string user_agent = 4 [(buf.validate.field).string.max_len = 512];

  // URL host of the Chatto server that supplied the installed web app. The
  // sending server combines this with its own hostname to reconstruct the
  // client route. A host can include a port but no scheme, path, or user info.
  string client_host = 5 [(buf.validate.field).string = {
    min_len: 1
    max_len: 255
  }];

  // Random per-save capability generated by the client. A cancelled save can
  // later remove only the record carrying this exact token, even when the same
  // browser PushSubscription has since moved to another account.
  string cleanup_token = 6 [(buf.validate.field).string = {
    min_len: 32
    max_len: 128
  }];
}

// Response from storing a browser push subscription.
message SubscribeResponse {
  reserved 1;
  reserved "subscribed";
}

// Request to remove a browser push subscription.
message UnsubscribeRequest {
  // Push service endpoint URL to remove.
  string endpoint = 1 [(buf.validate.field).string = {
    min_len: 1
    max_len: 4096
  }];
}

// Response from removing a browser push subscription.
message UnsubscribeResponse {
  reserved 1;
  reserved "unsubscribed";
}

// Request to test the current user's registered browser push subscriptions.
message SendTestNotificationRequest {}

// Result of sending a test Web Push notification.
message SendTestNotificationResponse {
  reserved 1;
  reserved "sent";
}