/*
 * 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.commons.io.output;

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

import java.io.ByteArrayOutputStream;
import java.io.IOException;

import org.apache.commons.io.IOUtils;
import org.apache.commons.io.input.NullInputStream;
import org.junit.jupiter.api.Test;

/**
 * Tests {@link CountingOutputStream}.
 */
public class CountingOutputStreamTest {

    private void assertByteArrayEquals(final String msg, final byte[] array, final int start, final int end) {
        for (int i = start; i < end; i++) {
            assertEquals(array[i], i-start, msg+": array[" + i + "] mismatch");
        }
    }

    @Test
    public void testCounting() throws IOException {
        final ByteArrayOutputStream baos = new ByteArrayOutputStream();
        try (CountingOutputStream cos = new CountingOutputStream(baos)) {

            for (int i = 0; i < 20; i++) {
                cos.write(i);
            }
            assertByteArrayEquals("CountingOutputStream.write(int)", baos.toByteArray(), 0, 20);
            assertEquals(cos.getCount(), 20, "CountingOutputStream.getCount()");

            final byte[] array = new byte[10];
            for (int i = 20; i < 30; i++) {
                array[i - 20] = (byte) i;
            }
            cos.write(array);
            assertByteArrayEquals("CountingOutputStream.write(byte[])", baos.toByteArray(), 0, 30);
            assertEquals(cos.getCount(), 30, "CountingOutputStream.getCount()");

            for (int i = 25; i < 35; i++) {
                array[i - 25] = (byte) i;
            }
            cos.write(array, 5, 5);
            assertByteArrayEquals("CountingOutputStream.write(byte[], int, int)", baos.toByteArray(), 0, 35);
            assertEquals(cos.getCount(), 35, "CountingOutputStream.getCount()");

            final int count = cos.resetCount();
            assertEquals(count, 35, "CountingOutputStream.resetCount()");

            for (int i = 0; i < 10; i++) {
                cos.write(i);
            }
            assertByteArrayEquals("CountingOutputStream.write(int)", baos.toByteArray(), 35, 45);
            assertEquals(cos.getCount(), 10, "CountingOutputStream.getCount()");
        }
    }

    /*
     * Test for files > 2GB in size - see issue IO-84
     */
    @Test
    public void testLargeFiles_IO84() throws Exception {
        final long size = (long) Integer.MAX_VALUE + (long) 1;

        final NullInputStream mock = new NullInputStream(size);
        final CountingOutputStream cos = new CountingOutputStream(NullOutputStream.INSTANCE);

        // Test integer methods
        IOUtils.copyLarge(mock, cos);
        assertThrows(ArithmeticException.class, () -> cos.getCount());
        assertThrows(ArithmeticException.class, () -> cos.resetCount());

        mock.close();

        // Test long methods
        IOUtils.copyLarge(mock, cos);
        assertEquals(size, cos.getByteCount(), "getByteCount()");
        assertEquals(size, cos.resetByteCount(), "resetByteCount()");
    }

}