List items not getting removed

Question

I want to remove Accounts from List to which user doesn't have access.

Here is my code. However in the debug logs, I can see all the accounts, that is none of them are removed.

query += QUERY_BASE + FROM_BASE + wherClause + criteria + order + limitStr;
returnAccounts= Database.query(query); 

//START: Account sharing check:-Fetch all the records where user has access
Set<Id> setAccIds = new Set<Id>();
for(Account a:returnAccounts){
    setAccIds.add(a.Id);
}

List<AccountShare> lstAccountShares = [Select AccountId from AccountShare where UserOrGroupId=:UserInfo.getUserId()];
System.debug(LoggingLevel.Error,'MVK lstAccountShares--->'+lstAccountShares);
if(lstAccountShares!=null && lstAccountShares.size() > 0){
    Set<Id> setAccountShares = new Set<Id>();
    for(AccountShare ashare:lstAccountShares){
        setAccountShares.add(ashare.AccountId);
    }
    System.debug(LoggingLevel.Error,'MVK setAccountShares--->'+setAccountShares);
    if(setAccIds.size()>0){
        for(Integer i=0;i<returnAccounts.size();i++){
            if(!setAccountShares.contains(returnAccounts.get(i).Id)){
                //System.debug(LoggingLevel.Error,'MVK setAccountShares--->'+returnAccounts.get(i).Id);
                returnAccounts.remove(i);
            }
        }
        system.debug('MVK returnAccounts--->'+returnAccounts);
    }
}
else{
    returnAccounts.clear(); // If user has access to none of the records then return empty
}

Answer 1

It's much easier to create a tiny with sharing helper class and allow the platform to handle visibility calculations for you. It could look something like this:

public with sharing class QueryHelper {
    public static List<sObject> query(String q) {
        return Database.query(q);
    }
}

Then, in your main class, do

query += QUERY_BASE + FROM_BASE + wherClause + criteria + order + limitStr;
returnAccounts = (List<Account>)QueryHelper.query(query);

That obviates all the complexity of manually querying the share table and calculating visibility, something the platform is already very good at doing for you.