Chaining Promises And Recursive Functions

example.ts

var loopData = [
    // Array of Objects
]

EventRepo.GetEventById(req.body.event_id.toString())
        .then(function (data: { rows: {}[] }) {

            if (data.rows.length === 0)
                throw new EventRepoError('Event with id:\'' + req.body.event_id + '\' does not exist');

            return loopData;

        }).map(function (rowData: { id: string }) {
            return EventRepo.GetDataById(req.body.event_id, rowData.id);
        }).map(function (data: { rows: { id: string, status: number, name: string, rowData_type: string, parent_id: string }[] }) {
        
            if (data.rows.length === 0) {
                // return Promise of Database call
            } else {
                // return Promise of Database call
            }

        }).then(function (data) {
            return res.status(200).json({ 'status': 'success', message: 'Import has completed successfully'});
        })
        .catch(EventRepoError, function (e) {
            return res.status(400).json({ message: e.message });
        }).catch(function (err) {
            return res.status(500).json({ message: 'Error', error: err.message });
        });