using System;
using System.Linq;
using NUnit.Framework;
using Developpez.Dotnet;

namespace Developpez.Dotnet.Tests
{
    [TestFixture]
    public class DateExtensionsTests
    {

        private DateTime y2k = new DateTime(2000, 1, 1);
        private long y2kAsUnix = 946684800;

        [Test]
        public void Check_that_20_minutes_from_is_correct()
        {
            Assert.AreEqual(20.Minutes().From(y2k), y2k.AddMinutes(20));
        }

        [Test]
        public void Check_that_20_minutes_fromnow_is_correct()
        {
            Assert.AreEqual(20.Minutes().FromNow(), DateTime.Now.AddMinutes(20));
        }

        [Test]
        public void Check_that_20_minutes_before_is_correct()
        {
            Assert.AreEqual(20.Minutes().Before(y2k), y2k.AddMinutes(-20));
        }

        [Test]
        public void Check_that_20_minutes_ago_is_correct()
        {
            Assert.AreEqual(20.Minutes().Ago(), DateTime.Now.AddMinutes(-20));
        }

        [Test]
        public void Check_that_20_hours_is_correct()
        {
            Assert.AreEqual(20.Hours(), TimeSpan.FromHours(20));
        }

        [Test]
        public void Check_that_20_seconds_is_correct()
        {
            Assert.AreEqual(20.Seconds(), TimeSpan.FromSeconds(20));
        }

        [Test]
        public void Check_that_20_days_is_correct()
        {
            Assert.AreEqual(20.Days(), TimeSpan.FromDays(20));
        }

        [Test]
        public void Check_that_ToUnixTimestamp_Returns_y2kasUnix_timestamp_when_given_y2k()
        {
            Assert.AreEqual(y2k.ToUnixTimestamp(), y2kAsUnix);
        }

        [Test]
        public void Check_that_ToDateTime_Returns_y2k_timestamp_when_given_y2kAsUnix()
        {
            Assert.AreEqual(y2kAsUnix.ToDateTime(), y2k);
        }

        [Test]
        public void Check_next_previous_DayOfWeek()
        {
            DateTime date = new DateTime(1981, 9, 10);
            DateTime nextSaturday = date.Next(DayOfWeek.Saturday);
            Assert.AreEqual(new DateTime(1981, 9, 12), nextSaturday);
            DateTime lastMonday = date.Previous(DayOfWeek.Monday);
            Assert.AreEqual(new DateTime(1981, 9, 7), lastMonday);
        }

        [Test]
        public void Check_AddWorkingDays()
        {
            var actual =
                // Monday 7 to Sunday 13 March 2011
                from i in Enumerable.Range(7, 7).ToArray()
                let date = new DateTime(2011, 3, i)
                // Add -8 to 8 working days
                from days in Enumerable.Range(-8, 17)
                select date.AddWorkingDays(days).Day;

            var expected = new int[]
                {
                    23, 24, 25, 28, 1, 2, 3, 4,         // from Monday 7 (days < 0)
                    7, 8, 9, 10, 11, 14, 15, 16, 17,    // from Monday 7 (days >= 0)
                    24, 25, 28, 1, 2, 3, 4, 7,          // from Tuesday 8 (days < 0)
                    8, 9, 10, 11, 14, 15, 16, 17, 18,   // from Tuesday 8 (days >= 0)
                    25, 28, 1, 2, 3, 4, 7, 8,           // from Wednesday 9 (days < 0)
                    9, 10, 11, 14, 15, 16, 17, 18, 21,  // from Wednesday 9 (days >= 0)
                    28, 1, 2, 3, 4, 7, 8, 9,            // from Thursday 10 (days < 0)
                    10, 11, 14, 15, 16, 17, 18, 21, 22, // from Thursday 10 (days >= 0)
                    1, 2, 3, 4, 7, 8, 9, 10,            // from Friday 11 (days < 0)
                    11, 14, 15, 16, 17, 18, 21, 22, 23, // from Friday 12 (days >= 0)
                    2, 3, 4, 7, 8, 9, 10, 11,           // from Saturday 12 (days < 0)
                    12, 14, 15, 16, 17, 18, 21, 22, 23, // from Saturday 12 (days >= 0)
                    2, 3, 4, 7, 8, 9, 10, 11,           // from Sunday 13 (days < 0)
                    13, 14, 15, 16, 17, 18, 21, 22, 23, // from Sunday 13 (days >= 0)
                };

            Assert2.AreSequenceEqual(expected, actual);

        }

        [Test]
        public void Check_IsWorkingDays()
        {
            DateTime monday = new DateTime(2011, 3, 7);
            DateTime tuesday = monday.AddDays(1);
            DateTime wednesday = monday.AddDays(2);
            DateTime thursday = monday.AddDays(3);
            DateTime friday = monday.AddDays(4);
            DateTime saturday = monday.AddDays(5);
            DateTime sunday = monday.AddDays(6);

            Assert.IsTrue(monday.IsWorkingDay());
            Assert.IsTrue(tuesday.IsWorkingDay());
            Assert.IsTrue(wednesday.IsWorkingDay());
            Assert.IsTrue(thursday.IsWorkingDay());
            Assert.IsTrue(friday.IsWorkingDay());
            Assert.IsFalse(saturday.IsWorkingDay());
            Assert.IsFalse(sunday.IsWorkingDay());
        }
    }
}