syntax = "proto3";

package cursor;

// handle cursor events and broadcast to all users
service Cursor {
	// send cursor movement to server
	rpc Moved  (CursorEvent)      returns (MovedResponse);
	// attach to a workspace and receive cursor events
	rpc Listen (UserIdentity)     returns (stream CursorEvent);
}

// empty request
message MovedResponse {}

// a tuple indicating row and column
message RowCol {
	int32 row = 1;
	int32 col = 2;
}

// cursor position object
message CursorPosition {
	// path of current buffer this cursor is into
	string buffer = 1;
	// cursor start position
	RowCol start = 2;
	// cursor end position
	RowCol end = 3;
}

// cursor event, with user id and cursor position
message CursorEvent {
	// user moving the cursor
	string user = 1;
	// new cursor position
	CursorPosition position = 2;
}

// payload identifying user for cursor attaching
message UserIdentity {
	// user identifier
	string id = 1;
}