import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;

public class SimpleTest {

    public static TruckLoader loader;

    @BeforeClass
    public static void init() {
        loader = new MyTruckLoader();
    }

    @Test
    public void test1() {
        List<Integer> input = Collections.unmodifiableList(Arrays.asList(12, 12, 12));
        List<Fleet.Truck> antw = loader.pack(input, () -> new TestTruck(12));
        checkInput(input, antw);
        Assert.assertEquals("Probeer het gebruikte aantal vrachtwagens te reduceren.", antw.size(), 3);
    }

    @Test
    public void test2() {
        List<Integer> input = Collections.unmodifiableList(Arrays.asList(4, 3, 4, 6, 2, 4, 5, 1, 1, 2, 2, 2, 4));
        List<Fleet.Truck> antw = loader.pack(input, () -> new TestTruck(10));
        checkInput(input, antw);
        Assert.assertEquals("Probeer het gebruikte aantal vrachtwagens te reduceren.", antw.size(), 4);
    }

    @Test
    public void test3() {
        List<Integer> input = Collections.unmodifiableList(Arrays.asList(1, 1, 1, 1, 8, 7, 6, 6));
        List<Fleet.Truck> antw = loader.pack(input, () -> new TestTruck(9));
        checkInput(input, antw);
        Assert.assertTrue("Probeer het gebruikte aantal vrachtwagens in jouw antwoord (" + antw.size() + ") te reduceren tot maximaal 5.", antw.size() <= 5);
    }

    @Test
    public void test4() {
        List<Integer> input = Collections.unmodifiableList(Arrays.asList(7, 2, 2, 2, 2, 2, 3));
        List<Fleet.Truck> antw = loader.pack(input, () -> new TestTruck(10));
        checkInput(input, antw);
        Assert.assertTrue("Probeer het gebruikte aantal vrachtwagens in jouw antwoord (" + antw.size() + ") te reduceren tot maximaal 3.", antw.size() <= 3);
    }

    private void checkInput(List<Integer> input, List<Fleet.Truck> antw) {
        List<Integer> antwItems = antw.stream().flatMap((truck)->truck.getItems().stream()).collect(Collectors.toList());
        List<Integer> inputKopie = new ArrayList<>(input);
        Collections.sort(inputKopie);
        Collections.sort(antwItems);
        Assert.assertEquals("Items in vrachtwagens komen niet overeen met de gegeven objecten.", inputKopie, antwItems);
    }

    // Private klasse TestTruck, implementatie van Fleet.Truck. item stelt een vrachtwagen voor.
    // Nieuwe vrachtwagen aanmaken via "fleet.createTruck()".
    private class TestTruck implements Fleet.Truck {

        private List<Integer> items;
        private int remainingCapacity;

        private TestTruck(int capacity) {
            remainingCapacity = capacity;
            items = new ArrayList<>();
        }

        public void add(int item) {
            if (!canAdd(item)) {
                throw new Fleet.OverloadException();
            }
            remainingCapacity -= item;
            items.add(item);
        }

        public int getRemainingCapacity() {
            return remainingCapacity;
        }

        public boolean canAdd(int item) {
            return item <= remainingCapacity;
        }

        public List<Integer> getItems() {
            return Collections.unmodifiableList(items);
        }

        @Override
        public String toString() {
            return items.toString();
        }
    }

}