Untitled

package com.epam.rd.autocode.queue;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.Deque;
import java.util.LinkedList;
import java.util.List;

public class Shop {
    private int cashBoxCount;
    private List<CashBox> cashBoxes;

    public Shop(int count) {
        cashBoxes = new ArrayList<>(count);
        for (int i = 0; i < count; i++) {
            cashBoxes.add(new CashBox(i));
        }
        cashBoxCount = count;
    }

    public int getCashBoxCount() {
        return cashBoxCount;
    }

    public void addBuyer(Buyer buyer) {
        CashBox smallestQueueCashBox = findSmallestQueueCashBox();
        smallestQueueCashBox.addLast(buyer);
    }

    private CashBox findSmallestQueueCashBox() {
        CashBox smallestQueueCashBox = null;
        int minSize = Integer.MAX_VALUE;

        for (CashBox cashBox : cashBoxes) {
            if (cashBox.inState(CashBox.State.ENABLED)) {
                int size = cashBox.getQueue().size();
                if (size < minSize) {
                    minSize = size;
                    smallestQueueCashBox = cashBox;
                }
            }
        }

        if (smallestQueueCashBox == null) {
            throw new IllegalStateException("No enabled cash boxes found");
        }

        return smallestQueueCashBox;
    }

    public void tact() {
        // Step 1: Serve one buyer from each non-empty queue
        for (CashBox cashBox : cashBoxes) {
            cashBox.serveBuyer();
        }


        // Step 2: Balance the queues
        balance();

        // Step 3: Update the state of cashboxes that reached the end of their queues
        for (CashBox cashBox : cashBoxes) {
            if (cashBox.inState(CashBox.State.IS_CLOSING) && cashBox.getQueue().isEmpty()) {
                cashBox.setState(CashBox.State.DISABLED);
            }
        }

    }


    public void print() {
        cashBoxes.sort(Comparator.comparingInt(CashBox::getNumber));

        for (CashBox cashBox : cashBoxes) {
            StringBuilder sb = new StringBuilder();
            sb.append("#").append(cashBox.getNumber());

            CashBox.State state = cashBox.getState();
            if (state == CashBox.State.ENABLED) {
                sb.append("[+]");
            } else if (state == CashBox.State.DISABLED) {
                sb.append("[-]");
            } else if (state == CashBox.State.IS_CLOSING) {
                sb.append("[|]");
            }

            Deque<Buyer> queue = cashBox.getQueue();
            for (Buyer buyer : queue) {
                sb.append(buyer.toString());
            }

            System.out.println(sb.toString());
        }
    }


    public CashBox getCashBox(int cashBoxNumber) {
        if (cashBoxNumber >= 0 && cashBoxNumber < cashBoxes.size()) {
            return cashBoxes.get(cashBoxNumber);
        }
        throw new IllegalArgumentException("Invalid cashbox number");
    }

    public void setCashBoxState(int cashBoxNumber, CashBox.State state) {
        CashBox cashBox = getCashBox(cashBoxNumber);
        cashBox.setState(state);
    }

    private void balance() {

        long sum = cashBoxes.stream().mapToInt(cashBox -> cashBox.getQueue().size()).sum();
        long enabled = cashBoxes.stream().filter(cashBox -> cashBox.inState(CashBox.State.ENABLED)).count();
		long closing = cashBoxes.stream().filter(cashBox -> cashBox.inState(CashBox.State.IS_CLOSING)).count();
		long closingQueues = cashBoxes.stream().filter(cashBox -> cashBox.inState(CashBox.State.IS_CLOSING)).mapToInt(e -> e.getQueue().size()).sum();
        long rest = sum % enabled;
        long max = sum / enabled - closingQueues;
        if (rest != 0) {
            max += enabled / rest;
        }
//		long max = sum / enabled + (sum % enabled);
//		long max = sum / enabled + sum / enabled % enabled;
        long min = sum / enabled;
//		Integer max = cashBoxes.stream().filter(cashBox -> cashBox.inState(CashBox.State.ENABLED))
//		Integer max = cashBoxes.stream().map(cashBox -> cashBox.getQueue().size()).max(Integer::compare).get();
//		Integer min = cashBoxes.stream().filter(cashBox -> cashBox.inState(CashBox.State.ENABLED)).map(cashBox -> cashBox.getQueue().size()).min(Integer::compare).get();
//		long sum = cashBoxes.stream().filter(cashBox -> cashBox.inState(CashBox.State.ENABLED)).mapToInt(cashBox -> cashBox.getQueue().size()).sum();

        Deque<Buyer> defectorBuyers = new LinkedList<>();
        for (CashBox cashBox : cashBoxes) {
            long size = cashBox.getQueue().size() - max;
            if (size > 0) {
                for (int i = 0; i < size; i++) {
                    Buyer buyer = cashBox.removeLast();
                    defectorBuyers.add(buyer);
                }
            }
        }

        for (CashBox cashBox : cashBoxes) {
            if (cashBox.inState(CashBox.State.ENABLED)) {
                while (cashBox.getQueue().size() < max && !defectorBuyers.isEmpty()) {
                    cashBox.addLast(defectorBuyers.removeFirst());
                }
            }
        }
    }

    private static int getTotalBuyersCount(List<CashBox> cashBoxes) {
        int totalBuyers = 0;
        for (CashBox cashBox : cashBoxes) {
            totalBuyers += cashBox.getQueue().size();
        }
        return totalBuyers;
    }
}