#region Apache License 2.0
/*
Nuclex .NET Framework
Copyright (C) 2002-2024 Markus Ewald / Nuclex Development Labs

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.
*/
#endregion // Apache License 2.0

using System;
using System.Collections.Generic;

#if UNITTEST

using NUnit.Framework;

namespace Nuclex.Support.Collections {

  /// <summary>Unit Test for the priority queue class</summary>
  [TestFixture]
  internal class PairPriorityQueueTest {

    /// <summary>Tests to ensure the count property is properly updated</summary>
    [Test]
    public void TestCount() {
      PairPriorityQueue<float, string> testQueue = new PairPriorityQueue<float, string>();

      Assert.AreEqual(0, testQueue.Count);
      testQueue.Enqueue(12.34f, "a");
      Assert.AreEqual(1, testQueue.Count);
      testQueue.Enqueue(56.78f, "b");
      Assert.AreEqual(2, testQueue.Count);
      testQueue.Dequeue();
      Assert.AreEqual(1, testQueue.Count);
      testQueue.Enqueue(9.0f, "c");
      Assert.AreEqual(2, testQueue.Count);
      testQueue.Clear();
      Assert.AreEqual(0, testQueue.Count);
    }

    /// <summary>Tests to ensure that the priority collection actually sorts items</summary>
    [Test]
    public void TestOrdering() {
      PairPriorityQueue<float, string> testQueue = new PairPriorityQueue<float, string>();

      testQueue.Enqueue(1.0f, "a");
      testQueue.Enqueue(9.0f, "i");
      testQueue.Enqueue(2.0f, "b");
      testQueue.Enqueue(8.0f, "h");
      testQueue.Enqueue(3.0f, "c");
      testQueue.Enqueue(7.0f, "g");
      testQueue.Enqueue(4.0f, "d");
      testQueue.Enqueue(6.0f, "f");
      testQueue.Enqueue(5.0f, "e");

      Assert.AreEqual("i", testQueue.Dequeue().Item);
      Assert.AreEqual("h", testQueue.Dequeue().Item);
      Assert.AreEqual("g", testQueue.Dequeue().Item);
      Assert.AreEqual("f", testQueue.Dequeue().Item);
      Assert.AreEqual("e", testQueue.Dequeue().Item);
      Assert.AreEqual("d", testQueue.Dequeue().Item);
      Assert.AreEqual("c", testQueue.Dequeue().Item);
      Assert.AreEqual("b", testQueue.Dequeue().Item);
      Assert.AreEqual("a", testQueue.Dequeue().Item);
    }

    /// <summary>Tests to ensure that the priority collection's Peek() method works</summary>
    [Test]
    public void TestPeek() {
      PairPriorityQueue<float, string> testQueue = new PairPriorityQueue<float, string>();

      testQueue.Enqueue(1.0f, "a");
      testQueue.Enqueue(2.0f, "b");
      testQueue.Enqueue(0.0f, "c");

      Assert.AreEqual("b", testQueue.Peek().Item);
    }

    /// <summary>Tests whether the priority collection can copy itself into an array</summary>
    [Test]
    public void TestCopyTo() {
      PairPriorityQueue<float, string> testQueue = new PairPriorityQueue<float, string>();

      testQueue.Enqueue(1.0f, "a");
      testQueue.Enqueue(9.0f, "i");
      testQueue.Enqueue(2.0f, "b");
      testQueue.Enqueue(8.0f, "h");
      testQueue.Enqueue(3.0f, "c");
      testQueue.Enqueue(7.0f, "g");
      testQueue.Enqueue(4.0f, "d");
      testQueue.Enqueue(6.0f, "f");
      testQueue.Enqueue(5.0f, "e");

      PriorityItemPair<float, string>[] itemArray = new PriorityItemPair<float, string>[9];
      testQueue.CopyTo(itemArray, 0);

      CollectionAssert.AreEquivalent(testQueue, itemArray);
    }

    /// <summary>
    ///   Tests whether the priority collection provides a synchronization root
    /// </summary>
    [Test]
    public void TestSyncRoot() {
      PairPriorityQueue<int, int> testQueue = new PairPriorityQueue<int, int>();

      // If IsSynchronized returns true, SyncRoot is allowed to be null
      if(!testQueue.IsSynchronized) {
        lock(testQueue.SyncRoot) {
          testQueue.Clear();
        }
      }
    }

    /// <summary>
    ///   Tests whether the priority collection provides a working type-safe enumerator
    /// </summary>
    [Test]
    public void TestEnumerator() {
      PairPriorityQueue<float, string> testQueue = new PairPriorityQueue<float, string>();

      testQueue.Enqueue(1.0f, "a");
      testQueue.Enqueue(2.0f, "b");
      testQueue.Enqueue(0.0f, "c");

      List<PriorityItemPair<float, string>> testList =
        new List<PriorityItemPair<float,string>>();

      foreach(PriorityItemPair<float, string> entry in testQueue) {
        testList.Add(entry);
      }    

      CollectionAssert.AreEquivalent(testQueue, testList);
    }

  }

} // namespace Nuclex.Support.Collections

#endif // UNITTEST