/*
 * Copyright (C) 2008 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 com.google.common.testing.SerializableTester;

import junit.framework.TestCase;

import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Random;

/**
 * Unit test for {@link Shorts}.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible(emulated = true)
@SuppressWarnings("cast") // redundant casts are intentional and harmless
public class ShortsTest extends TestCase {
  private static final short[] EMPTY = {};
  private static final short[] ARRAY1 = {(short) 1};
  private static final short[] ARRAY234
      = {(short) 2, (short) 3, (short) 4};

  private static final short LEAST = Short.MIN_VALUE;
  private static final short GREATEST = Short.MAX_VALUE;

  private static final short[] VALUES =
      { LEAST, (short) -1, (short) 0, (short) 1, GREATEST };

  public void testHashCode() {
    for (short value : VALUES) {
      assertEquals(((Short) value).hashCode(), Shorts.hashCode(value));
    }
  }

  public void testCheckedCast() {
    for (short value : VALUES) {
      assertEquals(value, Shorts.checkedCast((long) value));
    }
    assertCastFails(GREATEST + 1L);
    assertCastFails(LEAST - 1L);
    assertCastFails(Long.MAX_VALUE);
    assertCastFails(Long.MIN_VALUE);
  }

  public void testSaturatedCast() {
    for (short value : VALUES) {
      assertEquals(value, Shorts.saturatedCast((long) value));
    }
    assertEquals(GREATEST, Shorts.saturatedCast(GREATEST + 1L));
    assertEquals(LEAST, Shorts.saturatedCast(LEAST - 1L));
    assertEquals(GREATEST, Shorts.saturatedCast(Long.MAX_VALUE));
    assertEquals(LEAST, Shorts.saturatedCast(Long.MIN_VALUE));
  }

  private void assertCastFails(long value) {
    try {
      Shorts.checkedCast(value);
      fail("Cast to short should have failed: " + value);
    } catch (IllegalArgumentException ex) {
      assertTrue(value + " not found in exception text: " + ex.getMessage(),
          ex.getMessage().contains(String.valueOf(value)));
    }
  }

  public void testCompare() {
    for (short x : VALUES) {
      for (short y : VALUES) {
        // Only compare the sign of the result of compareTo().
        int expected = Short.valueOf(x).compareTo(y);
        int actual = Shorts.compare(x, y);
        if (expected == 0) {
          assertEquals(x + ", " + y, expected, actual);
        } else if (expected < 0) {
          assertTrue(x + ", " + y + " (expected: " + expected + ", actual" + actual + ")",
              actual < 0);
        } else {
          assertTrue(x + ", " + y + " (expected: " + expected + ", actual" + actual + ")",
              actual > 0);
        }
      }
    }
  }

  public void testContains() {
    assertFalse(Shorts.contains(EMPTY, (short) 1));
    assertFalse(Shorts.contains(ARRAY1, (short) 2));
    assertFalse(Shorts.contains(ARRAY234, (short) 1));
    assertTrue(Shorts.contains(new short[] {(short) -1}, (short) -1));
    assertTrue(Shorts.contains(ARRAY234, (short) 2));
    assertTrue(Shorts.contains(ARRAY234, (short) 3));
    assertTrue(Shorts.contains(ARRAY234, (short) 4));
  }

  public void testIndexOf() {
    assertEquals(-1, Shorts.indexOf(EMPTY, (short) 1));
    assertEquals(-1, Shorts.indexOf(ARRAY1, (short) 2));
    assertEquals(-1, Shorts.indexOf(ARRAY234, (short) 1));
    assertEquals(0, Shorts.indexOf(
        new short[] {(short) -1}, (short) -1));
    assertEquals(0, Shorts.indexOf(ARRAY234, (short) 2));
    assertEquals(1, Shorts.indexOf(ARRAY234, (short) 3));
    assertEquals(2, Shorts.indexOf(ARRAY234, (short) 4));
    assertEquals(1, Shorts.indexOf(
        new short[] { (short) 2, (short) 3, (short) 2, (short) 3 },
        (short) 3));
  }

  public void testIndexOf_arrayTarget() {
    assertEquals(0, Shorts.indexOf(EMPTY, EMPTY));
    assertEquals(0, Shorts.indexOf(ARRAY234, EMPTY));
    assertEquals(-1, Shorts.indexOf(EMPTY, ARRAY234));
    assertEquals(-1, Shorts.indexOf(ARRAY234, ARRAY1));
    assertEquals(-1, Shorts.indexOf(ARRAY1, ARRAY234));
    assertEquals(0, Shorts.indexOf(ARRAY1, ARRAY1));
    assertEquals(0, Shorts.indexOf(ARRAY234, ARRAY234));
    assertEquals(0, Shorts.indexOf(
        ARRAY234, new short[] { (short) 2, (short) 3 }));
    assertEquals(1, Shorts.indexOf(
        ARRAY234, new short[] { (short) 3, (short) 4 }));
    assertEquals(1, Shorts.indexOf(ARRAY234, new short[] { (short) 3 }));
    assertEquals(2, Shorts.indexOf(ARRAY234, new short[] { (short) 4 }));
    assertEquals(1, Shorts.indexOf(new short[] { (short) 2, (short) 3,
        (short) 3, (short) 3, (short) 3 },
        new short[] { (short) 3 }
    ));
    assertEquals(2, Shorts.indexOf(
        new short[] { (short) 2, (short) 3, (short) 2,
            (short) 3, (short) 4, (short) 2, (short) 3},
        new short[] { (short) 2, (short) 3, (short) 4}
    ));
    assertEquals(1, Shorts.indexOf(
        new short[] { (short) 2, (short) 2, (short) 3,
            (short) 4, (short) 2, (short) 3, (short) 4},
        new short[] { (short) 2, (short) 3, (short) 4}
    ));
    assertEquals(-1, Shorts.indexOf(
        new short[] { (short) 4, (short) 3, (short) 2},
        new short[] { (short) 2, (short) 3, (short) 4}
    ));
  }

  public void testLastIndexOf() {
    assertEquals(-1, Shorts.lastIndexOf(EMPTY, (short) 1));
    assertEquals(-1, Shorts.lastIndexOf(ARRAY1, (short) 2));
    assertEquals(-1, Shorts.lastIndexOf(ARRAY234, (short) 1));
    assertEquals(0, Shorts.lastIndexOf(
        new short[] {(short) -1}, (short) -1));
    assertEquals(0, Shorts.lastIndexOf(ARRAY234, (short) 2));
    assertEquals(1, Shorts.lastIndexOf(ARRAY234, (short) 3));
    assertEquals(2, Shorts.lastIndexOf(ARRAY234, (short) 4));
    assertEquals(3, Shorts.lastIndexOf(
        new short[] { (short) 2, (short) 3, (short) 2, (short) 3 },
        (short) 3));
  }

  public void testMax_noArgs() {
    try {
      Shorts.max();
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  public void testMax() {
    assertEquals(LEAST, Shorts.max(LEAST));
    assertEquals(GREATEST, Shorts.max(GREATEST));
    assertEquals((short) 9, Shorts.max(
        (short) 8, (short) 6, (short) 7,
        (short) 5, (short) 3, (short) 0, (short) 9));
  }

  public void testMin_noArgs() {
    try {
      Shorts.min();
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  public void testMin() {
    assertEquals(LEAST, Shorts.min(LEAST));
    assertEquals(GREATEST, Shorts.min(GREATEST));
    assertEquals((short) 0, Shorts.min(
        (short) 8, (short) 6, (short) 7,
        (short) 5, (short) 3, (short) 0, (short) 9));
  }

  public void testConcat() {
    assertTrue(Arrays.equals(EMPTY, Shorts.concat()));
    assertTrue(Arrays.equals(EMPTY, Shorts.concat(EMPTY)));
    assertTrue(Arrays.equals(EMPTY, Shorts.concat(EMPTY, EMPTY, EMPTY)));
    assertTrue(Arrays.equals(ARRAY1, Shorts.concat(ARRAY1)));
    assertNotSame(ARRAY1, Shorts.concat(ARRAY1));
    assertTrue(Arrays.equals(ARRAY1, Shorts.concat(EMPTY, ARRAY1, EMPTY)));
    assertTrue(Arrays.equals(
        new short[] {(short) 1, (short) 1, (short) 1},
        Shorts.concat(ARRAY1, ARRAY1, ARRAY1)));
    assertTrue(Arrays.equals(
        new short[] {(short) 1, (short) 2, (short) 3, (short) 4},
        Shorts.concat(ARRAY1, ARRAY234)));
  }

  @GwtIncompatible("Shorts.toByteArray")
  public void testToByteArray() {
    assertTrue(Arrays.equals(
        new byte[] {0x23, 0x45}, Shorts.toByteArray((short) 0x2345)));
    assertTrue(Arrays.equals(
        new byte[] {(byte) 0xFE, (byte) 0xDC},
        Shorts.toByteArray((short) 0xFEDC)));
  }

  @GwtIncompatible("Shorts.fromByteArray")
  public void testFromByteArray() {
    assertEquals((short) 0x2345,
        Shorts.fromByteArray(new byte[] {0x23, 0x45}));
    assertEquals((short) 0xFEDC, Shorts.fromByteArray(
        new byte[] {(byte) 0xFE, (byte) 0xDC}));

    try {
      Shorts.fromByteArray(new byte[] {0x01});
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  @GwtIncompatible("Shorts.fromBytes")
  public void testFromBytes() {
    assertEquals((short) 0x2345, Shorts.fromBytes((byte) 0x23, (byte) 0x45));
    assertEquals((short) 0xFEDC, Shorts.fromBytes((byte) 0xFE, (byte) 0xDC));
  }

  @GwtIncompatible("Shorts.fromByteArray, Shorts.toByteArray")
  public void testByteArrayRoundTrips() {
    Random r = new Random(5);
    byte[] b = new byte[Shorts.BYTES];

    // total overkill, but, it takes 0.1 sec so why not...
    for (int i = 0; i < 10000; i++) {
      short num = (short) r.nextInt();
      assertEquals(num, Shorts.fromByteArray(Shorts.toByteArray(num)));

      r.nextBytes(b);
      assertTrue(Arrays.equals(b,
          Shorts.toByteArray(Shorts.fromByteArray(b))));
    }
  }

  public void testEnsureCapacity() {
    assertSame(EMPTY, Shorts.ensureCapacity(EMPTY, 0, 1));
    assertSame(ARRAY1, Shorts.ensureCapacity(ARRAY1, 0, 1));
    assertSame(ARRAY1, Shorts.ensureCapacity(ARRAY1, 1, 1));
    assertTrue(Arrays.equals(
        new short[] {(short) 1, (short) 0, (short) 0},
        Shorts.ensureCapacity(ARRAY1, 2, 1)));
  }

  public void testEnsureCapacity_fail() {
    try {
      Shorts.ensureCapacity(ARRAY1, -1, 1);
      fail();
    } catch (IllegalArgumentException expected) {
    }
    try {
      // notice that this should even fail when no growth was needed
      Shorts.ensureCapacity(ARRAY1, 1, -1);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  public void testJoin() {
    assertEquals("", Shorts.join(",", EMPTY));
    assertEquals("1", Shorts.join(",", ARRAY1));
    assertEquals("1,2", Shorts.join(",", (short) 1, (short) 2));
    assertEquals("123",
        Shorts.join("", (short) 1, (short) 2, (short) 3));
  }

  public void testLexicographicalComparator() {
    List<short[]> ordered = Arrays.asList(
        new short[] {},
        new short[] {LEAST},
        new short[] {LEAST, LEAST},
        new short[] {LEAST, (short) 1},
        new short[] {(short) 1},
        new short[] {(short) 1, LEAST},
        new short[] {GREATEST, GREATEST - (short) 1},
        new short[] {GREATEST, GREATEST},
        new short[] {GREATEST, GREATEST, GREATEST});

    Comparator<short[]> comparator = Shorts.lexicographicalComparator();
    Helpers.testComparator(comparator, ordered);
  }

  @GwtIncompatible("SerializableTester")
  public void testLexicographicalComparatorSerializable() {
    Comparator<short[]> comparator = Shorts.lexicographicalComparator();
    assertSame(comparator, SerializableTester.reserialize(comparator));
  }

  public void testToArray() {
    // need explicit type parameter to avoid javac warning!?
    List<Short> none = Arrays.<Short>asList();
    assertTrue(Arrays.equals(EMPTY, Shorts.toArray(none)));

    List<Short> one = Arrays.asList((short) 1);
    assertTrue(Arrays.equals(ARRAY1, Shorts.toArray(one)));

    short[] array = {(short) 0, (short) 1, (short) 3};

    List<Short> three = Arrays.asList((short) 0, (short) 1, (short) 3);
    assertTrue(Arrays.equals(array, Shorts.toArray(three)));

    assertTrue(Arrays.equals(array, Shorts.toArray(Shorts.asList(array))));
  }

  public void testToArray_threadSafe() {
    for (int delta : new int[] { +1, 0, -1 }) {
      for (int i = 0; i < VALUES.length; i++) {
        List<Short> list = Shorts.asList(VALUES).subList(0, i);
        Collection<Short> misleadingSize =
            Helpers.misleadingSizeCollection(delta);
        misleadingSize.addAll(list);
        short[] arr = Shorts.toArray(misleadingSize);
        assertEquals(i, arr.length);
        for (int j = 0; j < i; j++) {
          assertEquals(VALUES[j], arr[j]);
        }
      }
    }
  }

  public void testToArray_withNull() {
    List<Short> list = Arrays.asList((short) 0, (short) 1, null);
    try {
      Shorts.toArray(list);
      fail();
    } catch (NullPointerException expected) {
    }
  }

  public void testAsList_isAView() {
    short[] array = {(short) 0, (short) 1};
    List<Short> list = Shorts.asList(array);
    list.set(0, (short) 2);
    assertTrue(Arrays.equals(new short[] {(short) 2, (short) 1}, array));
    array[1] = (short) 3;
    assertEquals(Arrays.asList((short) 2, (short) 3), list);
  }

  public void testAsList_toArray_roundTrip() {
    short[] array = { (short) 0, (short) 1, (short) 2 };
    List<Short> list = Shorts.asList(array);
    short[] newArray = Shorts.toArray(list);

    // Make sure it returned a copy
    list.set(0, (short) 4);
    assertTrue(Arrays.equals(
        new short[] { (short) 0, (short) 1, (short) 2 }, newArray));
    newArray[1] = (short) 5;
    assertEquals((short) 1, (short) list.get(1));
  }

  // This test stems from a real bug found by andrewk
  public void testAsList_subList_toArray_roundTrip() {
    short[] array = { (short) 0, (short) 1, (short) 2, (short) 3 };
    List<Short> list = Shorts.asList(array);
    assertTrue(Arrays.equals(new short[] { (short) 1, (short) 2 },
        Shorts.toArray(list.subList(1, 3))));
    assertTrue(Arrays.equals(new short[] {},
        Shorts.toArray(list.subList(2, 2))));
  }

  public void testAsListEmpty() {
    assertSame(Collections.emptyList(), Shorts.asList(EMPTY));
  }

  @GwtIncompatible("NullPointerTester")
  public void testNulls() throws Exception {
    NullPointerTester tester = new NullPointerTester();
    tester.setDefault(short[].class, new short[0]);
    tester.testAllPublicStaticMethods(Shorts.class);
  }
}