// Import types
import { StudentGroupAssignment, EventStateData } from 'dce-live-grouper';

/**
 * Helper for extracting a list of pre-assignments from a previous event.
 * @author Benedikt Arnarsson
 * @param eventStateData the events data, containing the `allGroup: GroupStateMap`.
 * @returns a list of `StudentGroupAssignments` for pre-assignment use.
 */
const allGroupsToGroupAssignment = (eventStateData: EventStateData): StudentGroupAssignment[] => {
  return Object.entries(eventStateData.allGroups)
    .flatMap(([groupId, groupState]) => {
      const groupNum = Number.parseInt(groupId, 10);
      return groupState.studentIds.map((studentId) => {
        return {
          studentId,
          groupNum,
        };
      });
    });
};

export default allGroupsToGroupAssignment;