/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.surefire.api.util.internal;

import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

import org.apache.maven.surefire.api.util.internal.ImmutableMap.Node;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.hasItem;
import static org.hamcrest.Matchers.hasSize;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.Matchers.not;
import static org.hamcrest.Matchers.nullValue;
import static org.junit.jupiter.api.Assertions.assertThrows;

/**
 * @since 2.20
 */
public class ImmutableMapTest {
    private ImmutableMap<String, String> map;

    @BeforeEach
    public void setUp() {
        Map<String, String> backingMap = new LinkedHashMap<>();
        backingMap.put("a", "1");
        backingMap.put("x", null);
        backingMap.put("b", "2");
        backingMap.put("c", "3");
        backingMap.put("", "");
        backingMap.put(null, "1");
        map = new ImmutableMap<>(backingMap);
    }

    @Test
    public void testEntrySet() {
        Set<Entry<String, String>> entries = map.entrySet();
        assertThat(entries, hasSize(6));
        assertThat(entries, hasItem(new Node<>("a", "1")));
        assertThat(entries, hasItem(new Node<>("x", (String) null)));
        assertThat(entries, hasItem(new Node<>("b", "2")));
        assertThat(entries, hasItem(new Node<>("c", "3")));
        assertThat(entries, hasItem(new Node<>("", "")));
        assertThat(entries, hasItem(new Node<>((String) null, "1")));
    }

    @Test
    public void testGetter() {
        assertThat(map.size(), is(6));
        assertThat(map.get("a"), is("1"));
        assertThat(map.get("x"), is((String) null));
        assertThat(map.get("b"), is("2"));
        assertThat(map.get("c"), is("3"));
        assertThat(map.get(""), is(""));
        assertThat(map.get(null), is("1"));
    }

    @Test
    public void shouldNotModifyEntries() {
        assertThrows(UnsupportedOperationException.class, () -> map.entrySet().clear());
    }

    @Test
    public void shouldSafelyEnumerateEntries() {
        Iterator<Entry<String, String>> it = map.entrySet().iterator();

        assertThat(it.hasNext(), is(true));
        Entry<String, String> val = it.next();
        assertThat(val.getKey(), is("a"));
        assertThat(val.getValue(), is("1"));

        assertThat(it.hasNext(), is(true));
        val = it.next();
        assertThat(val.getKey(), is("x"));
        assertThat(val.getValue(), is(nullValue()));

        assertThat(it.hasNext(), is(true));
        val = it.next();
        assertThat(val.getKey(), is("b"));
        assertThat(val.getValue(), is("2"));

        assertThat(it.hasNext(), is(true));
        val = it.next();
        assertThat(val.getKey(), is("c"));
        assertThat(val.getValue(), is("3"));

        assertThat(it.hasNext(), is(true));
        val = it.next();
        assertThat(val.getKey(), is(""));
        assertThat(val.getValue(), is(""));

        assertThat(it.hasNext(), is(true));
        val = it.next();
        assertThat(val.getKey(), is(nullValue()));
        assertThat(val.getValue(), is("1"));

        assertThat(it.hasNext(), is(false));
    }

    @Test
    public void shouldNotSetEntries() {
        assertThrows(
                UnsupportedOperationException.class,
                () -> map.entrySet().iterator().next().setValue(""));
    }

    @Test
    public void shouldNotRemove() {
        assertThrows(UnsupportedOperationException.class, () -> map.remove("a"));
    }

    @Test
    public void shouldNotRemoveNull() {
        assertThrows(UnsupportedOperationException.class, () -> map.remove(null));
    }

    @Test
    public void shouldNotHaveEqualEntry() {
        Map<String, String> map = new ImmutableMap<>(Collections.singletonMap("k", "v"));
        Entry<String, String> e = map.entrySet().iterator().next();
        assertThat(e, is(not((Entry<String, String>) null)));
        assertThat(e, is(not(new Object())));
    }

    @Test
    public void shouldHaveEqualEntry() {
        Map<String, String> map = new ImmutableMap<>(Collections.singletonMap("k", "v"));
        Entry<String, String> e = map.entrySet().iterator().next();
        assertThat(e, is(e));
        assertThat(e, is((Entry<String, String>) new Node<>("k", "v")));
    }
}
