ActionsForUser.java

public class UserHistory_CreateUpdateFromUser  {

    static final String NEWUSERLIST = 'newUserList';
    static final String LOBCHANNELLIST = 'lOBChannelList';
    static final String ISACTIVELIST = 'isActiveList';
    static final String UMANAGERLIST = 'uManagerList';


    public static void findUser(List<User> newUsers, Map<Id,User> oldUsers, Boolean isInsert){

        List<User> uList = new List<User>(); //Store user Ids matches logic 
        List<User> newUserList = new List<User>(); 
        List<User> lOBChannelList = new List<User>();
        List<User> isActiveList = new List<User>(); 
        List<User> uManagerList = new List<User>();
        Map<String, List<User>> reasonForUpdatingUser = new Map<String, List<User>>();


           for(User u : newUsers){
               if(isInsert && !String.isBlank(u.Channel__c)){
                       newUserList.add(u); 
                   }
                   else if(!isInsert && (u.Channel__c != oldUsers.get(u.Id).Channel__c || u.LOB_Focus__c != oldUsers.get(u.Id).LOB_Focus__c)) {
                       lOBChannelList.add(u); 
                   }
                   else if(!isInsert && u.IsActive != oldUsers.get(u.Id).IsActive){
                       isActiveList.add(u); 
                   }
                   else if(!isInsert && u.ManagerId != oldUsers.get(u.Id).ManagerId){
                       uManagerList.add(u); 
                   }
           }

           if(newUserList.size()>0){
              reasonForUpdatingUser.put(NEWUSERLIST, newUserList)); 
           }

           if(lOBChannelList.size()>0){
              reasonForUpdatingUser.put(LOBCHANNELLIST, lOBChannelList); 
           }

           if(isActiveList.size()>0){
              reasonForUpdatingUser.put(ISACTIVELIST, isActiveList); 
           }

           if(uManagerList.size()>0){
              reasonForUpdatingUser.put(UMANAGERLIST, uManagerList);
           }

    }