/*
    * 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 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.util.Arrays;
  import java.util.Comparator;
  import java.util.List;
  import java.util.Random;
  
  /**
   * Tests for UnsignedInts
   *
   * @author Louis Wasserman
   */
  @GwtCompatible(emulated = true)
  public class UnsignedIntsTest extends TestCase {
    private static final long[] UNSIGNED_INTS = {
        0L,
        1L,
        2L,
        3L,
        0x12345678L,
        0x5a4316b8L,
        0x6cf78a4bL,
        0xff1a618bL,
        0xfffffffdL,
        0xfffffffeL,
        0xffffffffL};
    
    private static final int LEAST = (int) 0L;
    private static final int GREATEST = (int) 0xffffffffL;
  
    public void testToLong() {
      for (long a : UNSIGNED_INTS) {
        assertEquals(a, UnsignedInts.toLong((int) a));
      }
    }
  
    public void testCompare() {
      for (long a : UNSIGNED_INTS) {
        for (long b : UNSIGNED_INTS) {
          int cmpAsLongs = Longs.compare(a, b);
          int cmpAsUInt = UnsignedInts.compare((int) a, (int) b);
          assertEquals(Integer.signum(cmpAsLongs), Integer.signum(cmpAsUInt));
        }
      }
    }
    
    public void testMax_noArgs() {
      try {
        UnsignedInts.max();
        fail();
      } catch (IllegalArgumentException expected) {
      }
    }
    
    public void testMax() {
      assertEquals(LEAST, UnsignedInts.max(LEAST));
      assertEquals(GREATEST, UnsignedInts.max(GREATEST));
      assertEquals((int) 0xff1a618bL, UnsignedInts.max(
          (int) 8L, (int) 6L, (int) 7L,
          (int) 0x12345678L, (int) 0x5a4316b8L,
          (int) 0xff1a618bL, (int) 0L));
    }
    
    public void testMin_noArgs() {
      try {
        UnsignedInts.min();
        fail();
      } catch (IllegalArgumentException expected) {
      }
    }
    
    public void testMin() {
      assertEquals(LEAST, UnsignedInts.min(LEAST));
      assertEquals(GREATEST, UnsignedInts.min(GREATEST));
      assertEquals((int) 0L, UnsignedInts.min(
          (int) 8L, (int) 6L, (int) 7L,
          (int) 0x12345678L, (int) 0x5a4316b8L,
          (int) 0xff1a618bL, (int) 0L));
   }
   
   public void testLexicographicalComparator() {
     List<int[]> ordered = Arrays.asList(
         new int[] {},
         new int[] {LEAST},
         new int[] {LEAST, LEAST},
         new int[] {LEAST, (int) 1L},
         new int[] {(int) 1L},
         new int[] {(int) 1L, LEAST},
         new int[] {GREATEST, (GREATEST - (int) 1L)},
         new int[] {GREATEST, GREATEST},
         new int[] {GREATEST, GREATEST, GREATEST}
         );
 
     Comparator<int[]> comparator = UnsignedInts.lexicographicalComparator();
     Helpers.testComparator(comparator, ordered);
   }
 
   public void testDivide() {
     for (long a : UNSIGNED_INTS) {
       for (long b : UNSIGNED_INTS) {
         try {
           assertEquals((int) (a / b), UnsignedInts.divide((int) a, (int) b));
           assertFalse(b == 0);
         } catch (ArithmeticException e) {
           assertEquals(0, b);
         }
       }
     }
   }
 
   public void testRemainder() {
     for (long a : UNSIGNED_INTS) {
       for (long b : UNSIGNED_INTS) {
         try {
           assertEquals((int) (a % b), UnsignedInts.remainder((int) a, (int) b));
           assertFalse(b == 0);
         } catch (ArithmeticException e) {
           assertEquals(0, b);
         }
       }
     }
   }
 
   @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++) {
       int dividend = r.nextInt();
       int divisor = r.nextInt();
       // Test that the Euclidean property is preserved:
       assertTrue(dividend
           - (divisor * UnsignedInts.divide(dividend, divisor) + UnsignedInts.remainder(dividend,
               divisor)) == 0);
     }
   }
 
   public void testParseInt() {
     try {
       for (long a : UNSIGNED_INTS) {
         assertEquals((int) a, UnsignedInts.parseUnsignedInt(Long.toString(a)));
       }
     } catch (NumberFormatException e) {
       fail(e.getMessage());
     }
 
     try {
       UnsignedInts.parseUnsignedInt(Long.toString(1L << 32));
       fail("Expected NumberFormatException");
     } catch (NumberFormatException expected) {}
   }
 
   public void testParseIntWithRadix() throws NumberFormatException {
     for (long a : UNSIGNED_INTS) {
       for (int radix = Character.MIN_RADIX; radix <= Character.MAX_RADIX; radix++) {
         assertEquals((int) a, UnsignedInts.parseUnsignedInt(Long.toString(a, radix), radix));
       }
     }
 
     // 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 = Long.toString((1L << 32) - 1, radix);
       assertEquals(-1, UnsignedInts.parseUnsignedInt(maxAsString, radix));
 
       try {
         // tests that we get exception whre an overflow would occur.
         long overflow = 1L << 32;
         String overflowAsString = Long.toString(overflow, radix);
         UnsignedInts.parseUnsignedInt(overflowAsString, radix);
         fail();
       } catch (NumberFormatException expected) {}
     }
   }
 
   public void testParseIntThrowsExceptionForInvalidRadix() {
     // Valid radix values are Character.MIN_RADIX to Character.MAX_RADIX,
     // inclusive.
     try {
       UnsignedInts.parseUnsignedInt("0", Character.MIN_RADIX - 1);
       fail();
     } catch (NumberFormatException expected) {}
 
     try {
       UnsignedInts.parseUnsignedInt("0", Character.MAX_RADIX + 1);
       fail();
     } catch (NumberFormatException expected) {}
 
     // The radix is used as an array index, so try a negative value.
     try {
       UnsignedInts.parseUnsignedInt("0", -1);
       fail();
     } catch (NumberFormatException expected) {}
   }
 
   public void testDecodeInt() {
     assertEquals(0xffffffff, UnsignedInts.decode("0xffffffff"));
     assertEquals(01234567, UnsignedInts.decode("01234567")); // octal
     assertEquals(0x12345678, UnsignedInts.decode("#12345678"));
     assertEquals(76543210, UnsignedInts.decode("76543210"));
     assertEquals(0x13579135, UnsignedInts.decode("0x13579135"));
     assertEquals(0x13579135, UnsignedInts.decode("0X13579135"));
     assertEquals(0, UnsignedInts.decode("0"));
   }
 
   public void testDecodeIntFails() {
     try {
       // One more than maximum value
       UnsignedInts.decode("0xfffffffff");
       fail();
     } catch (NumberFormatException expected) {
     }
 
     try {
       UnsignedInts.decode("-5");
       fail();
     } catch (NumberFormatException expected) {
     }
 
     try {
       UnsignedInts.decode("-0x5");
       fail();
     } catch (NumberFormatException expected) {
     }
 
     try {
       UnsignedInts.decode("-05");
       fail();
     } catch (NumberFormatException expected) {
     }
   }
 
   public void testToString() {
     int[] bases = {2, 5, 7, 8, 10, 16};
     for (long a : UNSIGNED_INTS) {
       for (int base : bases) {
         assertEquals(UnsignedInts.toString((int) a, base), Long.toString(a, base));
       }
     }
   }
 
   public void testJoin() {
     assertEquals("", join());
     assertEquals("1", join(1));
     assertEquals("1,2", join(1, 2));
     assertEquals("4294967295,2147483648", join(-1, Integer.MIN_VALUE));
 
     assertEquals("123", UnsignedInts.join("", 1, 2, 3));
   }
 
   private static String join(int... values) {
     return UnsignedInts.join(",", values);
   }
 
   @GwtIncompatible("NullPointerTester")
   public void testNulls() {
     new NullPointerTester().testAllPublicStaticMethods(UnsignedInts.class);
   }
 }