using System;
using FluentAssertions;
using PKHeX.Core;
using Xunit;

namespace PKHeX.Tests.Util
{
    public class DateUtilTests
    {
        [Theory]
        [InlineData(2000, 1, 1)]
        [InlineData(2001, 1, 31)]
        public void RecognizesCorrectDates(int year, int month, int day)
        {
            Assert.True(DateUtil.IsDateValid(year, month, day), $"Failed to recognize {year}/{month}/{day}");
        }

        [Theory]
        [InlineData(2016, 1, 31)]
        [InlineData(2016, 2, 28)]
        [InlineData(2016, 3, 31)]
        [InlineData(2016, 4, 30)]
        [InlineData(2016, 5, 31)]
        [InlineData(2016, 6, 30)]
        [InlineData(2016, 7, 31)]
        [InlineData(2016, 8, 31)]
        [InlineData(2016, 9, 30)]
        [InlineData(2016, 10, 31)]
        [InlineData(2016, 11, 30)]
        [InlineData(2016, 12, 31)]
        public void RecognizesValidMonthBoundaries(int year, int month, int day)
        {
            Assert.True(DateUtil.IsDateValid(year, month, day), $"Incorrect month boundary for {year}/{month}/{day}");
        }

        [Fact]
        public void RecognizeCorrectLeapYear()
        {
            Assert.True(DateUtil.IsDateValid(2004, 2, 29));
        }

        [Theory]
        [InlineData(0, 0, 0, false, "Zero date")]
        [InlineData(2005, 2, 29, false, "Bad leap year")]
        [InlineData(0, 1, 1, false, "Zero year")]
        [InlineData(2000, 0, 1, false, "Zero month")]
        [InlineData(2000, 1, 0, false, "Zero day")]
        [InlineData(10000, 1, 0, false, "Big year")]
        [InlineData(2000, 13, 0, false, "Big month")]
        [InlineData(2000, 1, 32, false, "Big day")]
        [InlineData(2019, 11, 31, false, "Bad date, November doesn't have a 31st")]
        [InlineData(uint.MaxValue, uint.MaxValue, uint.MaxValue, false, "Failed with uint.MaxValue, negative")]
        public void CheckDate(uint year, uint month, uint day, bool cmp, string because)
        {
            var result = DateUtil.IsDateValid(year, month, day);
            result.Should().Be(cmp, because);
        }

        [Theory]
        [InlineData(2000, 12, 1, 2000, 12, 31, 1337)] // +6
        [InlineData(2000, 12, 1, 2000, 12, 31, 35)] // rand->+0
        [InlineData(2000, 12, 1, 2000, 12, 31, 12)] // rand->+30
        public void CheckRandomDate(int y1, int m1, int d1, int y2, int m2, int d2, int seed)
        {
            var start = new DateTime(y1, m1, d1);
            var end = new DateTime(y2, m2, d2);
            (start <= end).Should().BeTrue();

            var r = new Random(seed);
            var rand = DateUtil.GetRandomDateWithin(start, end, r);
            (start <= rand).Should().BeTrue();
            (rand <= end).Should().BeTrue();
        }
    }
}
