package shopping_cart;

import javax.swing.JOptionPane;
import java.util.HashMap;
import java.util.Map;

/**
 *
 * @author Diogo
 */
public class shopping_cart {

    public Map<String, Double> list_item;
    public Map<String, Rule> rules;

    public static void main(String[] args) {

        Rule rules[] = {
            new Rule("A", (double) 50.0, new Discount(3, (float) (double) 130.0)),
            new Rule("B", (double) 30.0, new Discount(2, (float) (double) 45.0)),
            new Rule("C", (double) 20.0, null),
            new Rule("D", (double) 15.0, null)
        };
        shopping_cart shopping = new shopping_cart(rules);
        shopping.validate("A");
        shopping.validate("B");
        shopping.validate("B");
        shopping.validate("A");
        shopping.validate("A");
        JOptionPane.showMessageDialog(null, "Valor total de mercadorias, R$: " + " " + shopping.total());

    }

    public shopping_cart(Rule rules[]) {
        this.rules = new HashMap<>();
        for (Rule rule : rules) {
            this.rules.put(rule.getProduct(), rule);
        }

        this.list_item = new HashMap<>();
    }

    public boolean validate(String product) {
        Rule rule = rules.get(product);
        if (rule != null) {
            Double quantity = list_item.get(product);
            if (quantity == null) {
                quantity = 0.0;
            } else {
                list_item.remove(product);
            }
            list_item.put(product, quantity + 1 );
            return true;
        }
        return false;
    }

    public Double total() {
        Double total = 0.0;
        total = list_item.entrySet().stream().map((implementation) -> {
            Double quantity = implementation.getValue();
            Double total_of_item = 0.0;
            Rule rule = rules.get(implementation.getKey());

            Discount discount = rule.getDiscount();
            if (discount != null && quantity > discount.getQuantity()) {
                total_of_item += (quantity / discount.getQuantity()) * discount.getValue();
                quantity = quantity % discount.getQuantity();
            }


            total_of_item += rule.getValue() * quantity;

            return total_of_item;
        }).map((total_of_item) -> total_of_item).reduce(total, (accumulator, _item) -> accumulator + _item);
        return total;
    }
}