using JdeScoping.Core.Helpers;
using Shouldly;

namespace JdeScoping.Core.Tests.Unit;

public class JdeDateConverterTests
{
    #region ToDateTime(int jdeDate) Tests

    [Fact]
    public void ToDateTime_WithZero_ReturnsNull()
    {
        // Act
        var result = JdeDateConverter.ToDateTime(0);

        // Assert
        result.ShouldBeNull();
    }

    [Fact]
    public void ToDateTime_WithNegative_ReturnsNull()
    {
        // Act
        var result = JdeDateConverter.ToDateTime(-1);

        // Assert
        result.ShouldBeNull();
    }

    [Fact]
    public void ToDateTime_With1900sDate_ConvertsCorrectly()
    {
        // Arrange - January 1, 1990 = 090001 (C=0, YY=90, DDD=001)
        int jdeDate = 90001;

        // Act
        var result = JdeDateConverter.ToDateTime(jdeDate);

        // Assert
        result.ShouldNotBeNull();
        result.Value.Year.ShouldBe(1990);
        result.Value.Month.ShouldBe(1);
        result.Value.Day.ShouldBe(1);
    }

    [Fact]
    public void ToDateTime_With2000sDate_ConvertsCorrectly()
    {
        // Arrange - January 1, 2024 = 124001 (C=1, YY=24, DDD=001)
        int jdeDate = 124001;

        // Act
        var result = JdeDateConverter.ToDateTime(jdeDate);

        // Assert
        result.ShouldNotBeNull();
        result.Value.Year.ShouldBe(2024);
        result.Value.Month.ShouldBe(1);
        result.Value.Day.ShouldBe(1);
    }

    [Fact]
    public void ToDateTime_WithLeapYearDay366_ConvertsCorrectly()
    {
        // Arrange - December 31, 2024 = 124366 (2024 is a leap year)
        int jdeDate = 124366;

        // Act
        var result = JdeDateConverter.ToDateTime(jdeDate);

        // Assert
        result.ShouldNotBeNull();
        result.Value.Year.ShouldBe(2024);
        result.Value.Month.ShouldBe(12);
        result.Value.Day.ShouldBe(31);
    }

    [Fact]
    public void ToDateTime_WithNonLeapYearDay366_ReturnsNull()
    {
        // Arrange - 2023 is not a leap year, so day 366 is invalid
        int jdeDate = 123366;

        // Act
        var result = JdeDateConverter.ToDateTime(jdeDate);

        // Assert
        result.ShouldBeNull();
    }

    [Fact]
    public void ToDateTime_WithInvalidDayOfYear_Zero_ReturnsNull()
    {
        // Arrange - day 0 is invalid
        int jdeDate = 124000;

        // Act
        var result = JdeDateConverter.ToDateTime(jdeDate);

        // Assert
        result.ShouldBeNull();
    }

    [Fact]
    public void ToDateTime_WithInvalidDayOfYear_TooHigh_ReturnsNull()
    {
        // Arrange - day 400 is invalid
        int jdeDate = 124400;

        // Act
        var result = JdeDateConverter.ToDateTime(jdeDate);

        // Assert
        result.ShouldBeNull();
    }

    [Fact]
    public void ToDateTime_WithMidYearDate_ConvertsCorrectly()
    {
        // Arrange - July 4, 2024 = day 186 of year = 124186
        int jdeDate = 124186;

        // Act
        var result = JdeDateConverter.ToDateTime(jdeDate);

        // Assert
        result.ShouldNotBeNull();
        result.Value.Year.ShouldBe(2024);
        result.Value.Month.ShouldBe(7);
        result.Value.Day.ShouldBe(4);
    }

    #endregion

    #region ToDateTime(int jdeDate, int jdeTime) Tests

    [Fact]
    public void ToDateTime_WithValidTime_ConvertsCorrectly()
    {
        // Arrange - January 1, 2024 at 14:30:45
        int jdeDate = 124001;
        int jdeTime = 143045;

        // Act
        var result = JdeDateConverter.ToDateTime(jdeDate, jdeTime);

        // Assert
        result.ShouldNotBeNull();
        result.Value.Year.ShouldBe(2024);
        result.Value.Month.ShouldBe(1);
        result.Value.Day.ShouldBe(1);
        result.Value.Hour.ShouldBe(14);
        result.Value.Minute.ShouldBe(30);
        result.Value.Second.ShouldBe(45);
    }

    [Fact]
    public void ToDateTime_WithZeroTime_ReturnsDateOnly()
    {
        // Arrange
        int jdeDate = 124001;
        int jdeTime = 0;

        // Act
        var result = JdeDateConverter.ToDateTime(jdeDate, jdeTime);

        // Assert
        result.ShouldNotBeNull();
        result.Value.Hour.ShouldBe(0);
        result.Value.Minute.ShouldBe(0);
        result.Value.Second.ShouldBe(0);
    }

    [Fact]
    public void ToDateTime_WithMidnight_ConvertsCorrectly()
    {
        // Arrange - midnight = 000000
        int jdeDate = 124001;
        int jdeTime = 1; // 00:00:01

        // Act
        var result = JdeDateConverter.ToDateTime(jdeDate, jdeTime);

        // Assert
        result.ShouldNotBeNull();
        result.Value.Hour.ShouldBe(0);
        result.Value.Minute.ShouldBe(0);
        result.Value.Second.ShouldBe(1);
    }

    [Fact]
    public void ToDateTime_WithEndOfDay_ConvertsCorrectly()
    {
        // Arrange - 23:59:59
        int jdeDate = 124001;
        int jdeTime = 235959;

        // Act
        var result = JdeDateConverter.ToDateTime(jdeDate, jdeTime);

        // Assert
        result.ShouldNotBeNull();
        result.Value.Hour.ShouldBe(23);
        result.Value.Minute.ShouldBe(59);
        result.Value.Second.ShouldBe(59);
    }

    [Fact]
    public void ToDateTime_WithInvalidDate_IgnoresTime()
    {
        // Arrange
        int jdeDate = 0;
        int jdeTime = 120000;

        // Act
        var result = JdeDateConverter.ToDateTime(jdeDate, jdeTime);

        // Assert
        result.ShouldBeNull();
    }

    #endregion

    #region ToJdeDate Extension Method Tests

    [Fact]
    public void ToJdeDate_With1900sDate_ConvertsCorrectly()
    {
        // Arrange
        var date = new DateTime(1990, 1, 1);

        // Act
        var result = date.ToJdeDate();

        // Assert
        result.ShouldBe(90001);
    }

    [Fact]
    public void ToJdeDate_With2000sDate_ConvertsCorrectly()
    {
        // Arrange
        var date = new DateTime(2024, 1, 1);

        // Act
        var result = date.ToJdeDate();

        // Assert
        result.ShouldBe(124001);
    }

    [Fact]
    public void ToJdeDate_WithLeapYearLastDay_ConvertsCorrectly()
    {
        // Arrange - December 31, 2024 is day 366
        var date = new DateTime(2024, 12, 31);

        // Act
        var result = date.ToJdeDate();

        // Assert
        result.ShouldBe(124366);
    }

    [Fact]
    public void ToJdeDate_WithMidYearDate_ConvertsCorrectly()
    {
        // Arrange - July 4, 2024 is day 186
        var date = new DateTime(2024, 7, 4);

        // Act
        var result = date.ToJdeDate();

        // Assert
        result.ShouldBe(124186);
    }

    #endregion

    #region ToJdeTime Extension Method Tests

    [Fact]
    public void ToJdeTime_WithMidnight_ReturnsZero()
    {
        // Arrange
        var date = new DateTime(2024, 1, 1, 0, 0, 0);

        // Act
        var result = date.ToJdeTime();

        // Assert
        result.ShouldBe(0);
    }

    [Fact]
    public void ToJdeTime_WithAfternoon_ConvertsCorrectly()
    {
        // Arrange
        var date = new DateTime(2024, 1, 1, 14, 30, 45);

        // Act
        var result = date.ToJdeTime();

        // Assert
        result.ShouldBe(143045);
    }

    [Fact]
    public void ToJdeTime_WithEndOfDay_ConvertsCorrectly()
    {
        // Arrange
        var date = new DateTime(2024, 1, 1, 23, 59, 59);

        // Act
        var result = date.ToJdeTime();

        // Assert
        result.ShouldBe(235959);
    }

    #endregion

    #region Round-Trip Tests

    [Theory]
    [InlineData(1990, 1, 1)]
    [InlineData(1999, 12, 31)]
    [InlineData(2000, 1, 1)]
    [InlineData(2024, 7, 4)]
    [InlineData(2024, 12, 31)]
    public void RoundTrip_DateOnly_PreservesValue(int year, int month, int day)
    {
        // Arrange
        var original = new DateTime(year, month, day);

        // Act
        var jdeDate = original.ToJdeDate();
        var converted = JdeDateConverter.ToDateTime(jdeDate);

        // Assert
        converted.ShouldNotBeNull();
        converted.Value.Date.ShouldBe(original.Date);
    }

    [Theory]
    [InlineData(0, 0, 0)]
    [InlineData(12, 30, 45)]
    [InlineData(23, 59, 59)]
    public void RoundTrip_DateAndTime_PreservesValue(int hour, int minute, int second)
    {
        // Arrange
        var original = new DateTime(2024, 6, 15, hour, minute, second);

        // Act
        var jdeDate = original.ToJdeDate();
        var jdeTime = original.ToJdeTime();
        var converted = JdeDateConverter.ToDateTime(jdeDate, jdeTime);

        // Assert
        converted.ShouldNotBeNull();
        converted.Value.ShouldBe(original);
    }

    #endregion
}