/*
 * 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 static java.lang.Long.MAX_VALUE;
import static java.lang.Long.MIN_VALUE;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Converter;
import com.google.common.collect.testing.Helpers;

import junit.framework.TestCase;

import java.math.BigInteger;
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 Longs}.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible(emulated = true)
@SuppressWarnings("cast") // redundant casts are intentional and harmless
public class LongsTest extends TestCase {
  private static final long[] EMPTY = {};
  private static final long[] ARRAY1 = {(long) 1};
  private static final long[] ARRAY234
      = {(long) 2, (long) 3, (long) 4};

  private static final long[] VALUES =
      { MIN_VALUE, (long) -1, (long) 0, (long) 1, MAX_VALUE };

  public void testCompare() {
    for (long x : VALUES) {
      for (long y : VALUES) {
        // note: spec requires only that the sign is the same
        assertEquals(x + ", " + y,
                     Long.valueOf(x).compareTo(y),
                     Longs.compare(x, y));
      }
    }
  }

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

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

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

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

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

  public void testMax() {
    assertEquals(MIN_VALUE, Longs.max(MIN_VALUE));
    assertEquals(MAX_VALUE, Longs.max(MAX_VALUE));
    assertEquals((long) 9, Longs.max(
        (long) 8, (long) 6, (long) 7,
        (long) 5, (long) 3, (long) 0, (long) 9));
  }

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

  public void testMin() {
    assertEquals(MIN_VALUE, Longs.min(MIN_VALUE));
    assertEquals(MAX_VALUE, Longs.min(MAX_VALUE));
    assertEquals((long) 0, Longs.min(
        (long) 8, (long) 6, (long) 7,
        (long) 5, (long) 3, (long) 0, (long) 9));
  }

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

  private static void assertByteArrayEquals(byte[] expected, byte[] actual) {
    assertTrue(
        "Expected: " + Arrays.toString(expected) + ", but got: " + Arrays.toString(actual),
        Arrays.equals(expected, actual));
  }

  public void testToByteArray() {
    assertByteArrayEquals(
        new byte[] {0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19},
        Longs.toByteArray(0x1213141516171819L));
    assertByteArrayEquals(
        new byte[] {
            (byte) 0xFF, (byte) 0xEE, (byte) 0xDD, (byte) 0xCC,
            (byte) 0xBB, (byte) 0xAA, (byte) 0x99, (byte) 0x88},
        Longs.toByteArray(0xFFEEDDCCBBAA9988L));
  }

  public void testFromByteArray() {
    assertEquals(0x1213141516171819L, Longs.fromByteArray(
        new byte[] {0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x33}));
    assertEquals(0xFFEEDDCCBBAA9988L, Longs.fromByteArray(
        new byte[] {
            (byte) 0xFF, (byte) 0xEE, (byte) 0xDD, (byte) 0xCC,
            (byte) 0xBB, (byte) 0xAA, (byte) 0x99, (byte) 0x88}));

    try {
      Longs.fromByteArray(new byte[Longs.BYTES - 1]);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  public void testFromBytes() {
    assertEquals(0x1213141516171819L, Longs.fromBytes(
        (byte) 0x12, (byte) 0x13, (byte) 0x14, (byte) 0x15,
        (byte) 0x16, (byte) 0x17, (byte) 0x18, (byte) 0x19));
    assertEquals(0xFFEEDDCCBBAA9988L, Longs.fromBytes(
        (byte) 0xFF, (byte) 0xEE, (byte) 0xDD, (byte) 0xCC,
        (byte) 0xBB, (byte) 0xAA, (byte) 0x99, (byte) 0x88));
  }

  public void testByteArrayRoundTrips() {
    Random r = new Random(5);
    byte[] b = new byte[Longs.BYTES];

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

      r.nextBytes(b);
      long value = Longs.fromByteArray(b);
      assertTrue("" + value, Arrays.equals(b, Longs.toByteArray(value)));
    }
  }

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

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

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

  public void testLexicographicalComparator() {
    List<long[]> ordered = Arrays.asList(
        new long[] {},
        new long[] {MIN_VALUE},
        new long[] {MIN_VALUE, MIN_VALUE},
        new long[] {MIN_VALUE, (long) 1},
        new long[] {(long) 1},
        new long[] {(long) 1, MIN_VALUE},
        new long[] {MAX_VALUE, MAX_VALUE - (long) 1},
        new long[] {MAX_VALUE, MAX_VALUE},
        new long[] {MAX_VALUE, MAX_VALUE, MAX_VALUE});

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

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

    List<Long> one = Arrays.asList((long) 1);
    assertTrue(Arrays.equals(ARRAY1, Longs.toArray(one)));

    long[] array = {(long) 0, (long) 1, 0x0FF1C1AL};

    List<Long> three = Arrays.asList((long) 0, (long) 1, 0x0FF1C1AL);
    assertTrue(Arrays.equals(array, Longs.toArray(three)));

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

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

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

  public void testToArray_withConversion() {
    long[] array = {(long) 0, (long) 1, (long) 2};

    List<Byte> bytes = Arrays.asList((byte) 0, (byte) 1, (byte) 2);
    List<Short> shorts = Arrays.asList((short) 0, (short) 1, (short) 2);
    List<Integer> ints = Arrays.asList(0, 1, 2);
    List<Float> floats = Arrays.asList((float) 0, (float) 1, (float) 2);
    List<Long> longs = Arrays.asList((long) 0, (long) 1, (long) 2);
    List<Double> doubles = Arrays.asList((double) 0, (double) 1, (double) 2);

    assertTrue(Arrays.equals(array, Longs.toArray(bytes)));
    assertTrue(Arrays.equals(array, Longs.toArray(shorts)));
    assertTrue(Arrays.equals(array, Longs.toArray(ints)));
    assertTrue(Arrays.equals(array, Longs.toArray(floats)));
    assertTrue(Arrays.equals(array, Longs.toArray(longs)));
    assertTrue(Arrays.equals(array, Longs.toArray(doubles)));
  }

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

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

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

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

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

  public void testStringConverter_convert() {
    Converter<String, Long> converter = Longs.stringConverter();
    assertEquals((Long) 1L, converter.convert("1"));
    assertEquals((Long) 0L, converter.convert("0"));
    assertEquals((Long) (-1L), converter.convert("-1"));
    assertEquals((Long) 255L, converter.convert("0xff"));
    assertEquals((Long) 255L, converter.convert("0xFF"));
    assertEquals((Long) (-255L), converter.convert("-0xFF"));
    assertEquals((Long) 255L, converter.convert("#0000FF"));
    assertEquals((Long) 438L, converter.convert("0666"));
  }

  public void testStringConverter_convertError() {
    try {
      Longs.stringConverter().convert("notanumber");
      fail();
    } catch (NumberFormatException expected) {
    }
  }

  public void testStringConverter_nullConversions() {
    assertNull(Longs.stringConverter().convert(null));
    assertNull(Longs.stringConverter().reverse().convert(null));
  }

  public void testStringConverter_reverse() {
    Converter<String, Long> converter = Longs.stringConverter();
    assertEquals("1", converter.reverse().convert(1L));
    assertEquals("0", converter.reverse().convert(0L));
    assertEquals("-1", converter.reverse().convert(-1L));
    assertEquals("255", converter.reverse().convert(0xffL));
    assertEquals("255", converter.reverse().convert(0xFFL));
    assertEquals("-255", converter.reverse().convert(-0xFFL));
    assertEquals("438", converter.reverse().convert(0666L));
  }

  public void testTryParse() {
    tryParseAndAssertEquals(0L, "0");
    tryParseAndAssertEquals(0L, "-0");
    tryParseAndAssertEquals(1L, "1");
    tryParseAndAssertEquals(-1L, "-1");
    tryParseAndAssertEquals(8900L, "8900");
    tryParseAndAssertEquals(-8900L, "-8900");
    tryParseAndAssertEquals(MAX_VALUE, Long.toString(MAX_VALUE));
    tryParseAndAssertEquals(MIN_VALUE, Long.toString(MIN_VALUE));
    assertNull(Longs.tryParse(""));
    assertNull(Longs.tryParse("-"));
    assertNull(Longs.tryParse("+1"));
    assertNull(Longs.tryParse("999999999999999999999999"));
    assertNull("Max long + 1",
        Longs.tryParse(BigInteger.valueOf(MAX_VALUE).add(BigInteger.ONE).toString()));
    assertNull("Max long * 10",
        Longs.tryParse(BigInteger.valueOf(MAX_VALUE).multiply(BigInteger.TEN).toString()));
    assertNull("Min long - 1",
        Longs.tryParse(BigInteger.valueOf(MIN_VALUE).subtract(BigInteger.ONE).toString()));
    assertNull("Min long * 10",
        Longs.tryParse(BigInteger.valueOf(MIN_VALUE).multiply(BigInteger.TEN).toString()));
    assertNull(Longs.tryParse("\u0662\u06f3"));
  }

  /**
   * Applies {@link Longs#tryParse(String)} to the given string and asserts that
   * the result is as expected.
   */
  private static void tryParseAndAssertEquals(Long expected, String value) {
    assertEquals(expected, Longs.tryParse(value));
  }
}

