/*
    * Copyright (C) 2011 The Guava Authors
    *
    * Licensed 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 com.google.common.primitives;
  
  import static java.math.BigInteger.ONE;
  
  import com.google.common.annotations.GwtCompatible;
  import com.google.common.annotations.GwtIncompatible;
  import com.google.common.collect.testing.Helpers;
  import com.google.common.testing.NullPointerTester;
  
  import junit.framework.TestCase;
  
  import java.math.BigInteger;
  import java.util.Arrays;
  import java.util.Comparator;
  import java.util.List;
  import java.util.Random;
  
  /**
   * Tests for UnsignedLongs
   *
   * @author Brian Milch
   * @author Louis Wasserman
   */
  @GwtCompatible(emulated = true)
  public class UnsignedLongsTest extends TestCase {
    private static final long LEAST = 0L;
    private static final long GREATEST = 0xffffffffffffffffL;
    
    public void testCompare() {
      // max value
      assertTrue(UnsignedLongs.compare(0, 0xffffffffffffffffL) < 0);
      assertTrue(UnsignedLongs.compare(0xffffffffffffffffL, 0) > 0);
  
      // both with high bit set
      assertTrue(UnsignedLongs.compare(0xff1a618b7f65ea12L, 0xffffffffffffffffL) < 0);
      assertTrue(UnsignedLongs.compare(0xffffffffffffffffL, 0xff1a618b7f65ea12L) > 0);
  
      // one with high bit set
      assertTrue(UnsignedLongs.compare(0x5a4316b8c153ac4dL, 0xff1a618b7f65ea12L) < 0);
      assertTrue(UnsignedLongs.compare(0xff1a618b7f65ea12L, 0x5a4316b8c153ac4dL) > 0);
  
      // neither with high bit set
      assertTrue(UnsignedLongs.compare(0x5a4316b8c153ac4dL, 0x6cf78a4b139a4e2aL) < 0);
      assertTrue(UnsignedLongs.compare(0x6cf78a4b139a4e2aL, 0x5a4316b8c153ac4dL) > 0);
  
      // same value
      assertTrue(UnsignedLongs.compare(0xff1a618b7f65ea12L, 0xff1a618b7f65ea12L) == 0);
    }
  
    public void testMax_noArgs() {
      try {
        UnsignedLongs.max();
        fail();
      } catch (IllegalArgumentException expected) {
      }
    }
    
    public void testMax() {
      assertEquals(LEAST, UnsignedLongs.max(LEAST));
      assertEquals(GREATEST, UnsignedLongs.max(GREATEST));
      assertEquals(0xff1a618b7f65ea12L, UnsignedLongs.max(
          0x5a4316b8c153ac4dL, 8L, 100L,
          0L, 0x6cf78a4b139a4e2aL, 0xff1a618b7f65ea12L));
    }
    
    public void testMin_noArgs() {
      try {
        UnsignedLongs.min();
        fail();
      } catch (IllegalArgumentException expected) {
      }
    }
    
    public void testMin() {
      assertEquals(LEAST, UnsignedLongs.min(LEAST));
      assertEquals(GREATEST, UnsignedLongs.min(GREATEST));
      assertEquals(0L, UnsignedLongs.min(
          0x5a4316b8c153ac4dL, 8L, 100L,
          0L, 0x6cf78a4b139a4e2aL, 0xff1a618b7f65ea12L));
    }
    
    public void testLexicographicalComparator() {
      List<long[]> ordered = Arrays.asList(
          new long[] {},
          new long[] {LEAST},
         new long[] {LEAST, LEAST},
         new long[] {LEAST, (long) 1},
         new long[] {(long) 1},
         new long[] {(long) 1, LEAST},
         new long[] {GREATEST, GREATEST - (long) 1},
         new long[] {GREATEST, GREATEST},
         new long[] {GREATEST, GREATEST, GREATEST});
     
     Comparator<long[]> comparator = UnsignedLongs.lexicographicalComparator();
     Helpers.testComparator(comparator, ordered);
   }
 
   public void testDivide() {
     assertEquals(2, UnsignedLongs.divide(14, 5));
     assertEquals(0, UnsignedLongs.divide(0, 50));
     assertEquals(1, UnsignedLongs.divide(0xfffffffffffffffeL, 0xfffffffffffffffdL));
     assertEquals(0, UnsignedLongs.divide(0xfffffffffffffffdL, 0xfffffffffffffffeL));
     assertEquals(281479271743488L, UnsignedLongs.divide(0xfffffffffffffffeL, 65535));
     assertEquals(0x7fffffffffffffffL, UnsignedLongs.divide(0xfffffffffffffffeL, 2));
     assertEquals(3689348814741910322L, UnsignedLongs.divide(0xfffffffffffffffeL, 5));
   }
 
   public void testRemainder() {
     assertEquals(4, UnsignedLongs.remainder(14, 5));
     assertEquals(0, UnsignedLongs.remainder(0, 50));
     assertEquals(1, UnsignedLongs.remainder(0xfffffffffffffffeL, 0xfffffffffffffffdL));
     assertEquals(0xfffffffffffffffdL,
         UnsignedLongs.remainder(0xfffffffffffffffdL, 0xfffffffffffffffeL));
     assertEquals(65534L, UnsignedLongs.remainder(0xfffffffffffffffeL, 65535));
     assertEquals(0, UnsignedLongs.remainder(0xfffffffffffffffeL, 2));
     assertEquals(4, UnsignedLongs.remainder(0xfffffffffffffffeL, 5));
   }
 
   @GwtIncompatible("Too slow in GWT (~3min fully optimized)")
   public void testDivideRemainderEuclideanProperty() {
     // Use a seed so that the test is deterministic:
     Random r = new Random(0L);
     for (int i = 0; i < 1000000; i++) {
       long dividend = r.nextLong();
       long divisor = r.nextLong();
       // Test that the Euclidean property is preserved:
       assertEquals(0,
           dividend - (divisor * UnsignedLongs.divide(dividend, divisor)
           + UnsignedLongs.remainder(dividend, divisor)));
     }
   }
 
   public void testParseLong() {
     assertEquals(0xffffffffffffffffL, UnsignedLongs.parseUnsignedLong("18446744073709551615"));
     assertEquals(0x7fffffffffffffffL, UnsignedLongs.parseUnsignedLong("9223372036854775807"));
     assertEquals(0xff1a618b7f65ea12L, UnsignedLongs.parseUnsignedLong("18382112080831834642"));
     assertEquals(0x5a4316b8c153ac4dL, UnsignedLongs.parseUnsignedLong("6504067269626408013"));
     assertEquals(0x6cf78a4b139a4e2aL, UnsignedLongs.parseUnsignedLong("7851896530399809066"));
 
     try {
       // One more than maximum value
       UnsignedLongs.parseUnsignedLong("18446744073709551616");
       fail();
     } catch (NumberFormatException expected) {
     }
   }
 
   public void testDecodeLong() {
     assertEquals(0xffffffffffffffffL, UnsignedLongs.decode("0xffffffffffffffff"));
     assertEquals(01234567, UnsignedLongs.decode("01234567")); // octal
     assertEquals(0x1234567890abcdefL, UnsignedLongs.decode("#1234567890abcdef"));
     assertEquals(987654321012345678L, UnsignedLongs.decode("987654321012345678"));
     assertEquals(0x135791357913579L, UnsignedLongs.decode("0x135791357913579"));
     assertEquals(0x135791357913579L, UnsignedLongs.decode("0X135791357913579"));
     assertEquals(0L, UnsignedLongs.decode("0"));
   }
 
   public void testDecodeLongFails() {
     try {
       // One more than maximum value
       UnsignedLongs.decode("0xfffffffffffffffff");
       fail();
     } catch (NumberFormatException expected) {
     }
 
     try {
       UnsignedLongs.decode("-5");
       fail();
     } catch (NumberFormatException expected) {
     }
 
     try {
       UnsignedLongs.decode("-0x5");
       fail();
     } catch (NumberFormatException expected) {
     }
 
     try {
       UnsignedLongs.decode("-05");
       fail();
     } catch (NumberFormatException expected) {
     }
   }
 
   public void testParseLongWithRadix() {
     assertEquals(0xffffffffffffffffL, UnsignedLongs.parseUnsignedLong("ffffffffffffffff", 16));
     assertEquals(0x1234567890abcdefL, UnsignedLongs.parseUnsignedLong("1234567890abcdef", 16));
 
     BigInteger max = BigInteger.ZERO.setBit(64).subtract(ONE);
     // loops through all legal radix values.
     for (int radix = Character.MIN_RADIX; radix <= Character.MAX_RADIX; radix++) {
       // tests can successfully parse a number string with this radix.
       String maxAsString = max.toString(radix);
       assertEquals(max.longValue(), UnsignedLongs.parseUnsignedLong(maxAsString, radix));
 
       try {
         // tests that we get exception whre an overflow would occur.
         BigInteger overflow = max.add(ONE);
         String overflowAsString = overflow.toString(radix);
         UnsignedLongs.parseUnsignedLong(overflowAsString, radix);
         fail();
       } catch (NumberFormatException expected) {
       }
     }
 
     try {
       UnsignedLongs.parseUnsignedLong("1234567890abcdef1", 16);
       fail();
     } catch (NumberFormatException expected) {
     }
   }
 
   public void testParseLongThrowsExceptionForInvalidRadix() {
     // Valid radix values are Character.MIN_RADIX to Character.MAX_RADIX, inclusive.
     try {
       UnsignedLongs.parseUnsignedLong("0", Character.MIN_RADIX - 1);
       fail();
     } catch (NumberFormatException expected) {
     }
 
     try {
       UnsignedLongs.parseUnsignedLong("0", Character.MAX_RADIX + 1);
       fail();
     } catch (NumberFormatException expected) {
     }
 
     // The radix is used as an array index, so try a negative value.
     try {
       UnsignedLongs.parseUnsignedLong("0", -1);
       fail();
     } catch (NumberFormatException expected) {
     }
   }
 
   public void testToString() {
     String[] tests = {
         "ffffffffffffffff",
         "7fffffffffffffff",
         "ff1a618b7f65ea12",
         "5a4316b8c153ac4d",
         "6cf78a4b139a4e2a"
     };
     int[] bases = { 2, 5, 7, 8, 10, 16 };
     for (int base : bases) {
       for (String x : tests) {
         BigInteger xValue = new BigInteger(x, 16);
         long xLong = xValue.longValue(); // signed
         assertEquals(xValue.toString(base), UnsignedLongs.toString(xLong, base));
       }
     }
   }
 
   public void testJoin() {
     assertEquals("", UnsignedLongs.join(","));
     assertEquals("1", UnsignedLongs.join(",", 1));
     assertEquals("1,2", UnsignedLongs.join(",", 1, 2));
     assertEquals("18446744073709551615,9223372036854775808",
         UnsignedLongs.join(",", -1, Long.MIN_VALUE));
     assertEquals("123", UnsignedLongs.join("", 1, 2, 3));
     assertEquals("184467440737095516159223372036854775808",
         UnsignedLongs.join("", -1, Long.MIN_VALUE));
   }
 
   @GwtIncompatible("NullPointerTester")
   public void testNulls() {
     new NullPointerTester().testAllPublicStaticMethods(UnsignedLongs.class);
   }
 }