#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;
using System.Collections.Generic;

#if UNITTEST

using NUnit.Framework;

namespace Nuclex.Support.Collections {

  /// <summary>Unit Test for the read only list wrapper</summary>
  [TestFixture]
  internal class ReadOnlyListTest {

    /// <summary>
    ///   Verifies that the copy constructor of the read only list works
    /// </summary>
    [Test]
    public void TestCopyConstructor() {
      int[] integers = new int[] { 12, 34, 56, 78 };
      ReadOnlyList<int> testList = new ReadOnlyList<int>(integers);

      CollectionAssert.AreEqual(integers, testList);
    }

    /// <summary>Verifies that the IsReadOnly property returns true</summary>
    [Test]
    public void TestIsReadOnly() {
      ReadOnlyList<int> testList = new ReadOnlyList<int>(new int[0]);

      Assert.IsTrue(testList.IsReadOnly);
    }

    /// <summary>
    ///   Verifies that the CopyTo() of the read only list works
    /// </summary>
    [Test]
    public void TestCopyToArray() {
      int[] inputIntegers = new int[] { 12, 34, 56, 78 };
      ReadOnlyList<int> testList = new ReadOnlyList<int>(inputIntegers);

      int[] outputIntegers = new int[testList.Count];
      testList.CopyTo(outputIntegers, 0);

      CollectionAssert.AreEqual(inputIntegers, outputIntegers);
    }

    /// <summary>
    ///   Checks whether the Contains() method of the read only list is able to
    ///   determine if the list contains an item
    /// </summary>
    [Test]
    public void TestContains() {
      int[] integers = new int[] { 1234, 6789 };
      ReadOnlyList<int> testList = new ReadOnlyList<int>(integers);

      Assert.IsTrue(testList.Contains(1234));
      Assert.IsFalse(testList.Contains(4321));
    }

    /// <summary>
    ///   Checks whether the IndexOf() method of the read only list is able to
    ///   determine if the index of an item in the list
    /// </summary>
    [Test]
    public void TestIndexOf() {
      int[] integers = new int[] { 12, 34, 67, 89 };
      ReadOnlyList<int> testList = new ReadOnlyList<int>(integers);

      Assert.AreEqual(0, testList.IndexOf(12));
      Assert.AreEqual(1, testList.IndexOf(34));
      Assert.AreEqual(2, testList.IndexOf(67));
      Assert.AreEqual(3, testList.IndexOf(89));
    }

    /// <summary>
    ///   Checks whether the indexer method of the read only list is able to
    ///   retrieve items from the list
    /// </summary>
    [Test]
    public void TestRetrieveByIndexer() {
      int[] integers = new int[] { 12, 34, 67, 89 };
      ReadOnlyList<int> testList = new ReadOnlyList<int>(integers);

      Assert.AreEqual(12, testList[0]);
      Assert.AreEqual(34, testList[1]);
      Assert.AreEqual(67, testList[2]);
      Assert.AreEqual(89, testList[3]);
    }

    /// <summary>
    ///   Checks whether the read only list will throw an exception if its Insert() method
    ///   is called via the generic IList&lt;&gt; interface
    /// </summary>
    [Test]
    public void TestThrowOnInsertViaGenericIList() {
      ReadOnlyList<int> testList = new ReadOnlyList<int>(new int[0]);
      Assert.Throws<NotSupportedException>(
        delegate() { (testList as IList<int>).Insert(0, 12345); }
      );
    }

    /// <summary>
    ///   Checks whether the read only list will throw an exception if its RemoveAt() method
    ///   is called via the generic IList&lt;&gt; interface
    /// </summary>
    [Test]
    public void TestThrowOnRemoveViaGenericIList() {
      ReadOnlyList<int> testList = new ReadOnlyList<int>(new int[1]);
      Assert.Throws<NotSupportedException>(
        delegate() { (testList as IList<int>).RemoveAt(0); }
      );
    }

    /// <summary>
    ///   Checks whether the indexer method of the read only list will throw an exception
    ///   if it is attempted to be used for replacing an item
    /// </summary>
    [Test]
    public void TestRetrieveByIndexerViaGenericIList() {
      int[] integers = new int[] { 12, 34, 67, 89 };
      ReadOnlyList<int> testList = new ReadOnlyList<int>(integers);

      Assert.AreEqual(12, (testList as IList<int>)[0]);
      Assert.AreEqual(34, (testList as IList<int>)[1]);
      Assert.AreEqual(67, (testList as IList<int>)[2]);
      Assert.AreEqual(89, (testList as IList<int>)[3]);
    }

    /// <summary>
    ///   Checks whether the indexer method of the read only list will throw an exception
    ///   if it is attempted to be used for replacing an item
    /// </summary>
    [Test]
    public void TestThrowOnReplaceByIndexerViaGenericIList() {
      ReadOnlyList<int> testList = new ReadOnlyList<int>(new int[1]);

      Assert.Throws<NotSupportedException>(
        delegate() { (testList as IList<int>)[0] = 12345; }
      );
    }

    /// <summary>
    ///   Checks whether the read only list will throw an exception if its Add() method
    ///   is called via the generic ICollection&lt;&gt; interface
    /// </summary>
    [Test]
    public void TestThrowOnAddViaGenericICollection() {
      ReadOnlyList<int> testList = new ReadOnlyList<int>(new int[0]);
      Assert.Throws<NotSupportedException>(
        delegate() { (testList as ICollection<int>).Add(12345); }
      );
    }

    /// <summary>
    ///   Checks whether the read only list will throw an exception if its Clear() method
    ///   is called via the generic ICollection&lt;&gt; interface
    /// </summary>
    [Test]
    public void TestThrowOnClearViaGenericICollection() {
      ReadOnlyList<int> testList = new ReadOnlyList<int>(new int[1]);
      Assert.Throws<NotSupportedException>(
        delegate() { (testList as ICollection<int>).Clear(); }
      );
    }

    /// <summary>
    ///   Checks whether the read only list will throw an exception if its Remove() method
    ///   is called via the generic ICollection&lt;&gt; interface
    /// </summary>
    [Test]
    public void TestThrowOnRemoveViaGenericICollection() {
      int[] integers = new int[] { 12, 34, 67, 89 };
      ReadOnlyList<int> testList = new ReadOnlyList<int>(integers);

      Assert.Throws<NotSupportedException>(
        delegate() { (testList as ICollection<int>).Remove(89); }
      );
    }

    /// <summary>
    ///   Tests whether the typesafe enumerator of the read only list is working
    /// </summary>
    [Test]
    public void TestTypesafeEnumerator() {
      int[] inputIntegers = new int[] { 12, 34, 56, 78 };
      ReadOnlyList<int> testList = new ReadOnlyList<int>(inputIntegers);

      List<int> outputIntegers = new List<int>();
      foreach(int value in testList) {
        outputIntegers.Add(value);
      }

      CollectionAssert.AreEqual(inputIntegers, outputIntegers);
    }

    /// <summary>
    ///   Checks whether the read only list will throw an exception if its Clear() method
    ///   is called via the IList interface
    /// </summary>
    [Test]
    public void TestThrowOnClearViaIList() {
      ReadOnlyList<int> testList = new ReadOnlyList<int>(new int[1]);
      Assert.Throws<NotSupportedException>(
        delegate() { (testList as IList).Clear(); }
      );
    }

    /// <summary>
    ///   Checks whether the read only list will throw an exception if its Add() method
    ///   is called via the IList interface
    /// </summary>
    [Test]
    public void TestThrowOnAddViaIList() {
      ReadOnlyList<int> testList = new ReadOnlyList<int>(new int[0]);
      Assert.Throws<NotSupportedException>(
        delegate() { (testList as IList).Add(12345); }
      );
    }

    /// <summary>
    ///   Checks whether the Contains() method of the read only list is able to
    ///   determine if the list contains an item
    /// </summary>
    [Test]
    public void TestContainsViaIList() {
      int[] integers = new int[] { 1234, 6789 };
      ReadOnlyList<int> testList = new ReadOnlyList<int>(integers);

      Assert.IsTrue((testList as IList).Contains(1234));
      Assert.IsFalse((testList as IList).Contains(4321));
    }

    /// <summary>
    ///   Checks whether the IndexOf() method of the read only list is able to
    ///   determine if the index of an item in the list
    /// </summary>
    [Test]
    public void TestIndexOfViaIList() {
      int[] integers = new int[] { 12, 34, 67, 89 };
      ReadOnlyList<int> testList = new ReadOnlyList<int>(integers);

      Assert.AreEqual(0, (testList as IList).IndexOf(12));
      Assert.AreEqual(1, (testList as IList).IndexOf(34));
      Assert.AreEqual(2, (testList as IList).IndexOf(67));
      Assert.AreEqual(3, (testList as IList).IndexOf(89));
    }

    /// <summary>
    ///   Checks whether the read only list will throw an exception if its Insert() method
    ///   is called via the IList interface
    /// </summary>
    [Test]
    public void TestThrowOnInsertViaIList() {
      ReadOnlyList<int> testList = new ReadOnlyList<int>(new int[0]);
      Assert.Throws<NotSupportedException>(
        delegate() { (testList as IList).Insert(0, 12345); }
      );
    }

    /// <summary>
    ///   Checks whether the IsFixedSize property of the read only list returns the
    ///   expected result for a read only list based on a fixed array
    /// </summary>
    [Test]
    public void TestIsFixedSizeViaIList() {
      int[] integers = new int[] { 12, 34, 67, 89 };
      ReadOnlyList<int> testList = new ReadOnlyList<int>(integers);

      Assert.IsTrue((testList as IList).IsFixedSize);
    }

    /// <summary>
    ///   Checks whether the read only list will throw an exception if its Remove() method
    ///   is called via the IList interface
    /// </summary>
    [Test]
    public void TestThrowOnRemoveViaIList() {
      int[] integers = new int[] { 1234, 6789 };
      ReadOnlyList<int> testList = new ReadOnlyList<int>(integers);

      Assert.Throws<NotSupportedException>(
        delegate() { (testList as IList).Remove(6789); }
      );
    }

    /// <summary>
    ///   Checks whether the read only list will throw an exception if its Remove() method
    ///   is called via the IList interface
    /// </summary>
    [Test]
    public void TestThrowOnRemoveAtViaIList() {
      ReadOnlyList<int> testList = new ReadOnlyList<int>(new int[1]);

      Assert.Throws<NotSupportedException>(
        delegate() { (testList as IList).RemoveAt(0); }
      );
    }

    /// <summary>
    ///   Checks whether the indexer method of the read only list will throw an exception
    ///   if it is attempted to be used for replacing an item
    /// </summary>
    [Test]
    public void TestRetrieveByIndexerViaIList() {
      int[] integers = new int[] { 12, 34, 67, 89 };
      ReadOnlyList<int> testList = new ReadOnlyList<int>(integers);

      Assert.AreEqual(12, (testList as IList)[0]);
      Assert.AreEqual(34, (testList as IList)[1]);
      Assert.AreEqual(67, (testList as IList)[2]);
      Assert.AreEqual(89, (testList as IList)[3]);
    }

    /// <summary>
    ///   Checks whether the indexer method of the read only list will throw an exception
    ///   if it is attempted to be used for replacing an item
    /// </summary>
    [Test]
    public void TestThrowOnReplaceByIndexerViaIList() {
      ReadOnlyList<int> testList = new ReadOnlyList<int>(new int[1]);

      Assert.Throws<NotSupportedException>(
        delegate() { (testList as IList)[0] = 12345; }
      );
    }

    /// <summary>
    ///   Verifies that the CopyTo() of the read only list works if invoked via
    ///   the ICollection interface
    /// </summary>
    [Test]
    public void TestCopyToArrayViaICollection() {
      int[] inputIntegers = new int[] { 12, 34, 56, 78 };
      ReadOnlyList<int> testList = new ReadOnlyList<int>(inputIntegers);

      int[] outputIntegers = new int[testList.Count];
      (testList as ICollection).CopyTo(outputIntegers, 0);

      CollectionAssert.AreEqual(inputIntegers, outputIntegers);
    }

    /// <summary>
    ///   Verifies that the IsSynchronized property and the SyncRoot property are working
    /// </summary>
    [Test]
    public void TestSynchronization() {
      ReadOnlyList<int> testList = new ReadOnlyList<int>(new int[0]);

      if(!(testList as ICollection).IsSynchronized) {
        lock((testList as ICollection).SyncRoot) {
          Assert.AreEqual(0, testList.Count);
        }
      }
    }

  }

} // namespace Nuclex.Support.Collections

#endif // UNITTEST