/*
 * 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
 *
 *   https://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.
 *
 *   SPDX-License-Identifier: Apache-2.0
 */

package org.apache.jena.atlas.iterator;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertThrows;

import java.util.Arrays;
import java.util.List;

import org.junit.jupiter.api.Test;

public class TestIteratorWithHistory {
    @Test
    public void iterHistory_01() {
        IteratorWithHistory<String> iter = createHistory(1, "a", "b", "c");
        assertEquals(0, iter.currentSize());
        assertEquals(null, iter.getPrevious(0));
    }

    @Test
    public void iterHistory_02() {
        IteratorWithHistory<String> iter = createHistory(1, "a", "b", "c");
        assertEquals("a", iter.next());
        assertEquals(1, iter.currentSize());
    }

    @Test
    public void iterHistory_03() {
        IteratorWithHistory<String> iter = createHistory(2, "a", "b", "c");
        assertEquals("a", iter.next());
        assertEquals("b", iter.next());
        assertEquals(2, iter.currentSize());
        assertEquals("b", iter.getPrevious(0));
        assertEquals("a", iter.getPrevious(1));
    }

    @Test
    public void iterHistory_04() {
        IteratorWithHistory<String> iter = createHistory(2, "a", "b", "c");
        assertThrows(IndexOutOfBoundsException.class, () -> iter.getPrevious(2));
    }

    @Test
    public void iterHistory_05() {
        IteratorWithHistory<String> iter = createHistory(2, "a", "b", "c");
        assertEquals("a", iter.next());
        assertEquals("a", iter.getPrevious(0));
        assertEquals(1, iter.currentSize());

        assertEquals("b", iter.next());
        assertEquals("b", iter.getPrevious(0));
        assertEquals("a", iter.getPrevious(1));
        assertEquals(2, iter.currentSize());

        assertEquals("c", iter.next());
        assertEquals(2, iter.currentSize());
        assertEquals("c", iter.getPrevious(0));
        assertEquals("b", iter.getPrevious(1));
    }

    private static IteratorWithHistory<String> createHistory(int N, String...strings) {
        List<String> data = Arrays.asList(strings);
        IteratorWithHistory<String> iter = new IteratorWithHistory<>(data.iterator(), N);
        return iter;
    }

}
