/*
    * 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.
   */
  
  package org.apache.commons.compress.archivers.zip;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertNotEquals;
  
  import java.math.BigInteger;
  
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link ZipEightByteInteger}.
   */
  class ZipEightByteIntegerTest {
  
      private byte[] getBytes(final ZipEightByteInteger zl) {
          final byte[] result = zl.getBytes();
          assertEquals(8, result.length, "length getBytes");
          return result;
      }
  
      private byte[] newMaxByteArrayValue() {
          return new byte[] { (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF };
      }
  
      private ZipEightByteInteger newMaxValue() {
          return new ZipEightByteInteger(newMaxByteArrayValue());
      }
  
      /**
       * Tests conversion from bytes.
       */
      @Test
      void testBIFromBytes() {
          final byte[] val = { (byte) 0xFE, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF };
          final ZipEightByteInteger zl = new ZipEightByteInteger(val);
          assertEquals(BigInteger.valueOf(Long.MAX_VALUE).shiftLeft(1), zl.getValue(), "value from bytes");
      }
  
      /**
       * Tests conversion from max value.
       */
      @Test
      void testBIFromMaxValue() {
          // https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT
          // 4.4.1.1 All fields unless otherwise noted are unsigned and stored in Intel low-byte:high-byte, low-word:high-word order.
          final ZipEightByteInteger zipEightByteInteger = newMaxValue();
          assertEquals("18446744073709551615", zipEightByteInteger.getValue().toString());
      }
  
      /**
       * Tests conversion from bytes.
       */
      @Test
      void testBILongFromBytes() {
          final ZipEightByteInteger zl = newMaxValue();
          assertEquals(0XFFFFFFFFFFFFFFFFL, zl.getLongValue(), "longValue from bytes");
      }
  
      /**
       * Tests conversion to bytes.
       */
      @Test
      void testBIToBytes() {
          final byte[] result = getBytes(new ZipEightByteInteger(BigInteger.valueOf(Long.MAX_VALUE).shiftLeft(1)));
          assertEquals((byte) 0xFE, result[0], "first byte getBytes");
          assertEquals((byte) 0xFF, result[1], "second byte getBytes");
          assertEquals((byte) 0xFF, result[2], "third byte getBytes");
          assertEquals((byte) 0xFF, result[3], "fourth byte getBytes");
          assertEquals((byte) 0xFF, result[4], "fifth byte getBytes");
          assertEquals((byte) 0xFF, result[5], "sixth byte getBytes");
          assertEquals((byte) 0xFF, result[6], "seventh byte getBytes");
          assertEquals((byte) 0xFF, result[7], "eighth byte getBytes");
      }
  
      /**
       * Tests the contract of the equals method.
       */
      @Test
      void testEquals() {
          final ZipEightByteInteger zl = new ZipEightByteInteger(0x12345678);
         final ZipEightByteInteger zl2 = new ZipEightByteInteger(0x12345678);
         final ZipEightByteInteger zl3 = new ZipEightByteInteger(0x87654321);
 
         assertEquals(zl, zl, "reflexive");
 
         assertEquals(zl, zl2, "works");
         assertNotEquals(zl, zl3, "works, part two");
 
         assertEquals(zl2, zl, "symmetric");
 
         assertNotEquals(null, zl, "null handling");
         assertNotEquals(zl, Integer.valueOf(0x1234), "non ZipEightByteInteger handling");
     }
 
     /**
      * Tests conversion from bytes.
      */
     @Test
     void testLongFromBytes() {
         final byte[] val = { 0x78, 0x56, 0x34, 0x12, (byte) 0xAB, 0x00, 0x00, 0x00 };
         final ZipEightByteInteger zl = new ZipEightByteInteger(val);
         assertEquals(0xAB12345678L, zl.getLongValue(), "longValue from bytes");
     }
 
     /**
      * Tests conversion to bytes.
      */
     @Test
     void testLongToBytes() {
         final byte[] result = getBytes(new ZipEightByteInteger(0xAB12345678L));
         assertEquals(8, result.length, "length getBytes");
         assertEquals(0x78, result[0], "first byte getBytes");
         assertEquals(0x56, result[1], "second byte getBytes");
         assertEquals(0x34, result[2], "third byte getBytes");
         assertEquals(0x12, result[3], "fourth byte getBytes");
         assertEquals((byte) 0xAB, result[4], "fifth byte getBytes");
         assertEquals(0, result[5], "sixth byte getBytes");
         assertEquals(0, result[6], "seventh byte getBytes");
         assertEquals(0, result[7], "eighth byte getBytes");
     }
 
     /**
      * Tests sign handling.
      */
     @Test
     void testSign() {
         assertEquals(BigInteger.valueOf(Long.MAX_VALUE).shiftLeft(1).setBit(0), newMaxValue().getValue());
     }
 
     /**
      * Tests {@link ZipEightByteInteger#toString()}.
      */
     @Test
     void testToString() {
         assertEquals("0", ZipEightByteInteger.ZERO.toString());
         assertEquals("0", ZipEightByteInteger.getValue(new byte[ZipEightByteInteger.BYTES]).toString());
         assertEquals(Long.toString(Long.MAX_VALUE), new ZipEightByteInteger(BigInteger.valueOf(Long.MAX_VALUE)).toString());
         assertEquals("18446744073709551615", newMaxValue().toString());
     }
 
     /**
      * Tests {@link ZipEightByteInteger#toUnsignedBigInteger(long)}.
      */
     @Test
     void testToUnsignedBigInteger() {
         assertEquals(BigInteger.valueOf(Long.MAX_VALUE), ZipEightByteInteger.toUnsignedBigInteger(Long.MAX_VALUE));
         assertEquals(BigInteger.valueOf(Long.MAX_VALUE).shiftLeft(1), ZipEightByteInteger.toUnsignedBigInteger(0XFFFFFFFFFFFFFFFEL));
     }
 }