using System;

using NUnit.Framework;

namespace Xamarin.Forms.Core.UnitTests
{
	[TestFixture]
	public class DatePickerUnitTest : BaseTestFixture
	{
		[Test]
		public void TestMinimumDateException ()
		{
			DatePicker picker = new DatePicker ();

			picker.MinimumDate = new DateTime (1950, 1, 1);

			Assert.AreEqual (new DateTime (1950, 1, 1), picker.MinimumDate);

			Assert.That (() => picker.MinimumDate = new DateTime (2200, 1, 1), Throws.ArgumentException);
		}

		[Test]
		public void TestMaximumDateException ()
		{
			DatePicker picker = new DatePicker ();
			
			picker.MaximumDate = new DateTime (2050, 1, 1);
			
			Assert.AreEqual (new DateTime (2050, 1, 1), picker.MaximumDate);

			Assert.That (() => picker.MaximumDate = new DateTime (1800, 1, 1), Throws.ArgumentException);
		}

		[Test]
		public void TestMaximumDateClamping ()
		{
			DatePicker picker = new DatePicker ();

			picker.Date = new DateTime (2050, 1, 1);

			Assert.AreEqual (new DateTime (2050, 1, 1), picker.Date);

			bool dateChanged = false;
			bool maximumDateChanged = false;
			picker.PropertyChanged += (sender, e) => {
				switch (e.PropertyName) {
				case "MaximumDate":
					maximumDateChanged = true;
					break;
				case "Date":
					dateChanged = true;
					Assert.IsFalse (maximumDateChanged);
					break;
				}
			};

			var newDate = new DateTime (2000, 1, 1);
			picker.MaximumDate = newDate;

			Assert.IsTrue (maximumDateChanged);
			Assert.IsTrue (dateChanged);

			Assert.AreEqual (newDate, picker.MaximumDate);
			Assert.AreEqual (newDate, picker.Date);
			Assert.AreEqual (picker.MaximumDate, picker.Date);
		}

		[Test]
		public void TestMinimumDateClamping ()
		{
			DatePicker picker = new DatePicker ();
			
			picker.Date = new DateTime (1950, 1, 1);
			
			Assert.AreEqual (new DateTime (1950, 1, 1), picker.Date);
			
			bool dateChanged = false;
			bool minimumDateChanged = false;
			picker.PropertyChanged += (sender, e) => {
				switch (e.PropertyName) {
				case "MinimumDate":
					minimumDateChanged = true;
					break;
				case "Date":
					dateChanged = true;
					Assert.IsFalse (minimumDateChanged);
					break;
				}
			};
			
			var newDate = new DateTime (2000, 1, 1);
			picker.MinimumDate = newDate;
			
			Assert.IsTrue (minimumDateChanged);
			Assert.IsTrue (dateChanged);
			
			Assert.AreEqual (newDate, picker.MinimumDate);
			Assert.AreEqual (newDate, picker.Date);
			Assert.AreEqual (picker.MinimumDate, picker.Date);
		}

		[Test]
		public void TestDateClamping ()
		{
			DatePicker picker = new DatePicker ();

			picker.Date = new DateTime (1500, 1, 1);

			Assert.AreEqual (picker.MinimumDate, picker.Date);

			picker.Date = new DateTime (2500, 1, 1);

			Assert.AreEqual (picker.MaximumDate, picker.Date);
		}

		[Test]
		public void TestDateSelected ()
		{
			var picker = new DatePicker ();

			bool selected = false;
			picker.DateSelected += (sender, arg) => selected = true;

			// we can be fairly sure it wont ever be 2008 again
			picker.Date = new DateTime (2008, 5, 5);

			Assert.True (selected);
		}

		public static object[] DateTimes = {
			new object[] { new DateTime (2006, 12, 20), new DateTime (2011, 11, 30) },
			new object[] { new DateTime (1900, 1, 1), new DateTime (1999, 01, 15) }, // Minimum Date
			new object[] { new DateTime (2006, 12, 20), new DateTime (2100, 12, 31) } // Maximum Date
		};

		[Test, TestCaseSource("DateTimes")]
		public void DatePickerSelectedEventArgs (DateTime initialDate, DateTime finalDate)
		{
			var datePicker = new DatePicker ();
			datePicker.Date = initialDate;

			DatePicker pickerFromSender = null;
			DateTime oldDate = new DateTime ();
			DateTime newDate = new DateTime ();

			datePicker.DateSelected += (s, e) => {
				pickerFromSender = (DatePicker)s;
				oldDate = e.OldDate;
				newDate = e.NewDate;
			};

			datePicker.Date = finalDate;

			Assert.AreEqual (datePicker, pickerFromSender);
			Assert.AreEqual (initialDate, oldDate);
			Assert.AreEqual (finalDate, newDate);
		}

		[Test]
		//https://bugzilla.xamarin.com/show_bug.cgi?id=32144
		public void SetNullValueDoesNotThrow ()
		{
			var datePicker = new DatePicker ();
			Assert.DoesNotThrow (() => datePicker.SetValue (DatePicker.DateProperty, null));
			Assert.AreEqual (DateTime.Today, datePicker.Date);
		}

		[Test]
		public void SetNullableDateTime ()
		{
			var datePicker = new DatePicker ();
			var dateTime = new DateTime (2015, 7, 21);
			DateTime? nullableDateTime = dateTime;
			datePicker.SetValue (DatePicker.DateProperty, nullableDateTime);
			Assert.AreEqual (dateTime, datePicker.Date);
		}
	}
}