import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.JUnitCore;
import org.junit.runner.Result;
import org.junit.runner.notification.Failure;

import java.util.ArrayList;
import java.util.List;

import static org.hamcrest.CoreMatchers.is;


public class SolutionTests {

    public static void main(String[] args) {
        Result result = JUnitCore.runClasses(SolutionTests.class);
        for (Failure failure : result.getFailures()) {
            System.out.println(failure.toString());
        }
    }

    @Test
    public void testThatWeCanAddToMapAndRetrieveFromMap() {
        MyMap<Integer, Integer> myMap = new MyMap<>();

        int value = 2;
        int key = 1;
        myMap.put(key, value);

        Assert.assertThat(myMap.get(key), is(value));

    }


    @Test
    public void testThatWeCanAddMultipleValuesAndRetrieveRightValueFromMap() {
        MyMap<Integer, Integer> myMap = new MyMap<>();

        int[][] setupData = {{1, 2}, {4, 5}};

        for (int[] pair : setupData) {
            Integer key = pair[0];
            Integer value = pair[1];
            myMap.put(key, value);

        }

        Assert.assertThat(myMap.get(1), is(2));
        Assert.assertThat(myMap.get(4), is(5));

    }

    @Test
    public void testThatWeUpdateAMapNewValueForExistingKey() {
        MyMap<Integer, Integer> myMap = new MyMap<>();

        int[][] setupData = {{1, 2}, {1, 5}};

        for (int[] pair : setupData) {
            Integer key = pair[0];
            Integer value = pair[1];
            myMap.put(key, value);

        }

        Assert.assertThat(myMap.get(1), is(6));

    }

    public class MyMap<K, V> {

        private List<MyEntry<K, V>> myEntryList = new ArrayList<>();

        public void put(K key, V value) {
            myEntryList.add(key.hashCode(), new MyEntry<>(key, value));
        }

        public V get(K key) {
            return myEntryList.get(key.hashCode()).getValue();
        }

        public class MyEntry<K, V> {
            private K key;
            private V value;

            public MyEntry(K key, V value) {
                this.key = key;
                this.value = value;
            }

            public K getKey() {
                return key;
            }

            public V getValue() {
                return value;
            }

            @Override
            public String toString() {
                return "MyEntry{" +
                        "key=" + key +
                        ", value=" + value +
                        '}';
            }
        }
    }