package utils;

import utils.comparator.PlayerAccountComparator;
import edu.neu.ccs.demeterf.TUCombiner;
import edu.neu.ccs.demeterf.demfgen.lib.List;
import classes.*;

/** Class for updating the accounts 
 * @author animesh */
public class AccountUpdater{
    /** Returns a list of new accounts that are updated after a round
     * @param existingAccounts
     * @param trans
     * @return {@link List}
     */
    public static Accounts updateAccounts(Accounts existingAccounts, PlayerTransaction trans) {
        List<Pair<PlayerID, Double>> accountChanges = TUCombiner.traverse(trans, new AccountChangesFinder());
        for(Pair<PlayerID, Double> accountChange: accountChanges){
            Pair<PlayerID, Double>  existingAccount = existingAccounts.accounts.find(new PlayerAccountComparator(accountChange));
            Pair<PlayerID, Double> newAccount = new Pair<PlayerID, Double>(accountChange.a, existingAccount.b+accountChange.b);
            existingAccounts.accounts = existingAccounts.accounts.replace(new PlayerAccountComparator(accountChange), newAccount);
        }
        return existingAccounts;
    }
}

/** Class for traversing
 * @author animesh */
class AccountChangesFinder extends ListTUCombiner<Pair<PlayerID, Double>>{
    TransactionType combine(TransactionType t){ return t; }
    
    List<Pair<PlayerID, Double>> combine(Transaction trans, Buy b) {
        //deduct from account of buyer
        Pair<PlayerID, Double> accountC1 = new Pair<PlayerID, Double>(trans.deriv.optbuyer.inner(), -trans.deriv.price.val);
        //add to the account of seller
        Pair<PlayerID, Double> accountC2 = new Pair<PlayerID, Double>(trans.deriv.seller, trans.deriv.price.val);
        return List.<Pair<PlayerID,Double>>create(accountC1, accountC2);
    }
    List<Pair<PlayerID, Double>> combine(Transaction trans, Finish f) {
        //add to the account of buyer
        Pair<PlayerID, Double> accountC1 = new Pair<PlayerID, Double>(trans.deriv.optbuyer.inner(), trans.deriv.optfinished.inner().quality.val);
        //deduct from the account of seller
        Pair<PlayerID, Double> accountC2 = new Pair<PlayerID, Double>(trans.deriv.seller, -trans.deriv.optfinished.inner().quality.val);
        return List.<Pair<PlayerID,Double>>create(accountC1, accountC2);		
    }

    List<Pair<PlayerID, Double>> combine(Transaction trans, TransactionType b){ return List.create(); }
}