//
// EnumerableTest.cs
//
// Author:
//   Jb Evain (jbevain@novell.com)
//
// (C) 2007 Novell, Inc. (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;

using NUnit.Framework;

namespace MonoTests.System.Linq {

	[TestFixture]
	public class EnumerableTest {

		[Test]
		public void TestSimpleExcept ()
		{
			int [] first = {0, 1, 2, 3, 4, 5};
			int [] second = {2, 4, 6};
			int [] result = {0, 1, 3, 5};

			AssertAreSame (result, first.Except (second));
		}

		[Test]
		public void TestSimpleIntersect ()
		{
			int [] first = {0, 1, 2, 3, 4, 5};
			int [] second = {2, 4, 6};
			int [] result = {2, 4};

			AssertAreSame (result, first.Intersect (second));
		}

		[Test]
		public void TestSimpleUnion ()
		{
			int [] first = {0, 1, 2, 3, 4, 5};
			int [] second = {2, 4, 6};
			int [] result = {0, 1, 2, 3, 4, 5, 6};

			AssertAreSame (result, first.Union (second));
		}

		class Foo {}
		class Bar : Foo {}

		[Test]
		public void TestCast ()
		{
			Bar a = new Bar ();
			Bar b = new Bar ();
			Bar c = new Bar ();

			Foo [] foos = new Foo [] {a, b, c};
			Bar [] result = new Bar [] {a, b, c};

			AssertAreSame (result, foos.Cast<Bar> ());
		}

		[Test]
		public void TestLast ()
		{
			int [] data = {1, 2, 3};

			Assert.AreEqual (3, data.Last ());
		}

		[Test]
		public void TestLastOrDefault ()
		{
			int [] data = {};

			Assert.AreEqual (default (int), data.LastOrDefault ());
		}

		[Test]
		public void TestFirst ()
		{
			int [] data = {1, 2, 3};

			Assert.AreEqual (1, data.First ());
		}

		[Test]
		public void TestFirstOrDefault ()
		{
			int [] data = {};

			Assert.AreEqual (default (int), data.FirstOrDefault ());
		}

		[Test]
		public void TestSequenceEqual ()
		{
			int [] first = {0, 1, 2, 3, 4, 5};
			int [] second = {0, 1, 2};
			int [] third = {0, 1, 2, 3, 4, 5};

			Assert.IsFalse (first.SequenceEqual (second));
			Assert.IsTrue (first.SequenceEqual (third));
		}

		[Test]
		public void TestSkip ()
		{
			int [] data = {0, 1, 2, 3, 4, 5};
			int [] result = {3, 4, 5};

			AssertAreSame (result, data.Skip (3));
		}

		[Test]
		public void TestSkipWhile ()
		{
			int [] data = {0, 1, 2, 3, 4, 5};
			int [] result = {3, 4, 5};

			AssertAreSame (result, data.SkipWhile (i => i < 3));
		}

		[Test]
		public void TestTake ()
		{
			int [] data = {0, 1, 2, 3, 4, 5};
			int [] result = {0, 1, 2};

			AssertAreSame (result, data.Take (3));
		}

		[Test]
		public void TestTakeWhile ()
		{
			int [] data = {0, 1, 2, 3, 4, 5};
			int [] result = {0, 1, 2};

			AssertAreSame (result, data.TakeWhile (i => i < 3));
		}

		[Test]
		public void TestSelect ()
		{
			int [] data = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
			int [] result = {1, 3, 5, 7, 9};

			AssertAreSame (result, data.Where (i => i % 2 != 0));
		}

		[Test]
		public void TestReverse ()
		{
			int [] data = {0, 1, 2, 3, 4};
			int [] result = {4, 3, 2, 1, 0};

			AssertAreSame (result, data.Reverse ());
		}

		[Test]
		public void TestSum ()
		{
			int [] data = {1, 2, 3, 4};

			Assert.AreEqual (10, data.Sum ());
		}

		[Test]
		public void TestMax ()
		{
			int [] data = {1, 3, 5, 2};

			Assert.AreEqual (5, data.Max ());
		}

		[Test]
		public void TestMin ()
		{
			int [] data = {3, 5, 2, 6, 1, 7};

			Assert.AreEqual (1, data.Min ());
		}

		[Test]
		public void TestToList ()
		{
			int [] data = {3, 5, 2};

			var list = data.ToList ();

			AssertAreSame (data, list);

			Assert.AreEqual (typeof (List<int>), list.GetType ());
		}

		[Test]
		public void TestToArray ()
		{
			ICollection<int> coll = new List<int> ();
			coll.Add (0);
			coll.Add (1);
			coll.Add (2);

			int [] result = {0, 1, 2};

			var array = coll.ToArray ();

			AssertAreSame (result, array);

			Assert.AreEqual (typeof (int []), array.GetType ());
		}
                
                [Test]
                public void TestOrderBy ()
                {
                        int [] array = { 14, 53, 3, 9, 11, 14, 5, 32, 2 };
                        var q = from i in array
                                orderby i
                                select i;
                        AssertIsOrdered (q);
                }
                
                static void AssertIsOrdered (IEnumerable<int> e)
                {
                        int f = int.MinValue;
                        foreach(int i in e) {
                                Assert.IsTrue (f <= i);
                                f = i;
                        }
                }

		static void AssertAreSame<T> (IEnumerable<T> expected, IEnumerable<T> actual)
		{
			if (expected == null) {
				Assert.IsNull (actual);
				return;
			}

			Assert.IsNotNull (actual);

			IEnumerator<T> ee = expected.GetEnumerator ();
			IEnumerator<T> ea = actual.GetEnumerator ();

			while (ee.MoveNext ()) {
				Assert.IsTrue (ea.MoveNext (), "'" + ee.Current + "' expected.");
				Assert.AreEqual (ee.Current, ea.Current);
			}

			if (ea.MoveNext ())
				Assert.Fail ("Unexpected element: " + ea.Current);
		}
	}
}