/*
 * 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.flink.streaming.api.functions.windowing.delta.extractor;

import static org.junit.Assert.assertEquals;

import org.apache.flink.streaming.api.functions.windowing.delta.extractor.FieldsFromArray;
import org.junit.Test;

public class FieldsFromArrayTest {

	String[] testStringArray = { "0", "1", "2", "3", "4" };
	Integer[] testIntegerArray = { 10, 11, 12, 13, 14 };
	int[] testIntArray = { 20, 21, 22, 23, 24 };

	@Test
	public void testStringArray() {
		// check single field extraction
		for (int i = 0; i < testStringArray.length; i++) {
			String[] tmp = { testStringArray[i] };
			arrayEqualityCheck(tmp,
					new FieldsFromArray<String>(String.class, i).extract(testStringArray));
		}

		// check reverse order
		String[] reverseOrder = new String[testStringArray.length];
		for (int i = 0; i < testStringArray.length; i++) {
			reverseOrder[i] = testStringArray[testStringArray.length - i - 1];
		}
		arrayEqualityCheck(reverseOrder,
				new FieldsFromArray<String>(String.class, 4, 3, 2, 1, 0).extract(testStringArray));

		// check picking fields and reorder
		String[] crazyOrder = { testStringArray[4], testStringArray[1], testStringArray[2] };
		arrayEqualityCheck(crazyOrder,
				new FieldsFromArray<String>(String.class, 4, 1, 2).extract(testStringArray));
	}

	@Test
	public void testIntegerArray() {
		// check single field extraction
		for (int i = 0; i < testIntegerArray.length; i++) {
			Integer[] tmp = { testIntegerArray[i] };
			arrayEqualityCheck(tmp,
					new FieldsFromArray<Integer>(Integer.class, i).extract(testIntegerArray));
		}

		// check reverse order
		Integer[] reverseOrder = new Integer[testIntegerArray.length];
		for (int i = 0; i < testIntegerArray.length; i++) {
			reverseOrder[i] = testIntegerArray[testIntegerArray.length - i - 1];
		}
		arrayEqualityCheck(reverseOrder,
				new FieldsFromArray<Integer>(Integer.class, 4, 3, 2, 1, 0)
						.extract(testIntegerArray));

		// check picking fields and reorder
		Integer[] crazyOrder = { testIntegerArray[4], testIntegerArray[1], testIntegerArray[2] };
		arrayEqualityCheck(crazyOrder,
				new FieldsFromArray<Integer>(Integer.class, 4, 1, 2).extract(testIntegerArray));

	}

	@Test
	public void testIntArray() {
		for (int i = 0; i < testIntArray.length; i++) {
			Integer[] tmp = { testIntArray[i] };
			arrayEqualityCheck(tmp,
					new FieldsFromArray<Integer>(Integer.class, i).extract(testIntArray));
		}

		// check reverse order
		Integer[] reverseOrder = new Integer[testIntArray.length];
		for (int i = 0; i < testIntArray.length; i++) {
			reverseOrder[i] = testIntArray[testIntArray.length - i - 1];
		}
		arrayEqualityCheck(reverseOrder,
				new FieldsFromArray<Integer>(Integer.class, 4, 3, 2, 1, 0).extract(testIntArray));

		// check picking fields and reorder
		Integer[] crazyOrder = { testIntArray[4], testIntArray[1], testIntArray[2] };
		arrayEqualityCheck(crazyOrder,
				new FieldsFromArray<Integer>(Integer.class, 4, 1, 2).extract(testIntArray));

	}

	private void arrayEqualityCheck(Object[] array1, Object[] array2) {
		assertEquals("The result arrays must have the same length", array1.length, array2.length);
		for (int i = 0; i < array1.length; i++) {
			assertEquals("Unequal fields at position " + i, array1[i], array2[i]);
		}
	}
}