/*
 * 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.lucene.facet.taxonomy.writercache;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.nio.ByteBuffer;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CodingErrorAction;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;

import org.apache.lucene.facet.FacetTestCase;

import org.junit.Test;

public class TestCharBlockArray extends FacetTestCase {

  @Test public void testArray() throws Exception {
    CharBlockArray array = new CharBlockArray();
    StringBuilder builder = new StringBuilder();

    final int n = 100 * 1000;

    byte[] buffer = new byte[50];

    for (int i = 0; i < n; i++) {
      random().nextBytes(buffer);
      int size = 1 + random().nextInt(50);
      // This test is turning random bytes into a string,
      // this is asking for trouble.
      CharsetDecoder decoder = StandardCharsets.UTF_8.newDecoder()
          .onUnmappableCharacter(CodingErrorAction.REPLACE)
          .onMalformedInput(CodingErrorAction.REPLACE);
      String s = decoder.decode(ByteBuffer.wrap(buffer, 0, size)).toString();
      array.append(s);
      builder.append(s);
    }

    for (int i = 0; i < n; i++) {
      random().nextBytes(buffer);
      int size = 1 + random().nextInt(50);
      // This test is turning random bytes into a string,
      // this is asking for trouble.
      CharsetDecoder decoder = StandardCharsets.UTF_8.newDecoder()
          .onUnmappableCharacter(CodingErrorAction.REPLACE)
          .onMalformedInput(CodingErrorAction.REPLACE);
      String s = decoder.decode(ByteBuffer.wrap(buffer, 0, size)).toString();
      array.append((CharSequence)s);
      builder.append(s);
    }

    for (int i = 0; i < n; i++) {
      random().nextBytes(buffer);
      int size = 1 + random().nextInt(50);
      // This test is turning random bytes into a string,
      // this is asking for trouble.
      CharsetDecoder decoder = StandardCharsets.UTF_8.newDecoder()
          .onUnmappableCharacter(CodingErrorAction.REPLACE)
          .onMalformedInput(CodingErrorAction.REPLACE);
      String s = decoder.decode(ByteBuffer.wrap(buffer, 0, size)).toString();
      for (int j = 0; j < s.length(); j++) {
        array.append(s.charAt(j));
      }
      builder.append(s);
    }

    assertEqualsInternal("GrowingCharArray<->StringBuilder mismatch.", builder, array);

    Path tempDir = createTempDir("growingchararray");
    Path f = tempDir.resolve("GrowingCharArrayTest.tmp");
    BufferedOutputStream out = new BufferedOutputStream(Files.newOutputStream(f));
    array.flush(out);
    out.flush();
    out.close();

    BufferedInputStream in = new BufferedInputStream(Files.newInputStream(f));
    array = CharBlockArray.open(in);
    assertEqualsInternal("GrowingCharArray<->StringBuilder mismatch after flush/load.", builder, array);
    in.close();
  }

  private static void assertEqualsInternal(String msg, StringBuilder expected, CharBlockArray actual) {
    assertEquals(msg, expected.length(), actual.length());
    for (int i = 0; i < expected.length(); i++) {
      assertEquals(msg, expected.charAt(i), actual.charAt(i));
    }
  }

}