using Jellyfin.Plugin.Vanguard.Seasons;
using Xunit;

namespace Jellyfin.Plugin.Vanguard.Tests;

public class SeasonPolicyTests
{
    private static readonly TimeZoneInfo NY = TimeZoneInfo.FindSystemTimeZoneById("America/New_York");
    private static DateTimeOffset Ny(int y, int mo, int d, int h, int mi, int s = 0)
    {
        var local = new DateTime(y, mo, d, h, mi, s, DateTimeKind.Unspecified);
        return new DateTimeOffset(local, NY.GetUtcOffset(local));
    }

    // "now" = Thursday 2026-10-30 12:00 Eastern (ISO week 44)
    private static readonly DateTimeOffset Now = Ny(2026, 10, 30, 12, 0);

    [Fact]
    public void SameWeek_IsDaySeason()
    {
        var slot = SeasonPolicy.Resolve(Ny(2026, 10, 29, 21, 3, 11), Now, NY, 4);
        Assert.Equal(SeasonKind.Day, slot.Kind);
        Assert.Equal(20261029, slot.SeasonNumber);
        Assert.Equal("Thursday, Oct 29", slot.SeasonName);
        Assert.Equal(1029210311, slot.EpisodeNumber);
    }

    [Fact]
    public void AfterMidnight_BelongsToPreviousBroadcastDay()
    {
        var slot = SeasonPolicy.Resolve(Ny(2026, 10, 30, 1, 15), Now, NY, 4);
        Assert.Equal(new DateOnly(2026, 10, 29), slot.BroadcastDay);
        Assert.Equal(20261029, slot.SeasonNumber);
        Assert.Equal(1030011500, slot.EpisodeNumber);   // episode number keeps the real clock time
    }

    [Fact]
    public void EarlierInMonth_IsWeekSeason()
    {
        var slot = SeasonPolicy.Resolve(Ny(2026, 10, 14, 20, 0), Now, NY, 4);   // ISO week 42
        Assert.Equal(SeasonKind.Week, slot.Kind);
        Assert.Equal(1202642, slot.SeasonNumber);
        Assert.Equal("Week 42", slot.SeasonName);
    }

    [Fact]
    public void EarlierInYear_IsMonthSeason()
    {
        var slot = SeasonPolicy.Resolve(Ny(2026, 7, 4, 20, 0), Now, NY, 4);
        Assert.Equal(SeasonKind.Month, slot.Kind);
        Assert.Equal(202607, slot.SeasonNumber);
        Assert.Equal("July 2026", slot.SeasonName);
    }

    [Fact]
    public void PreviousYear_IsYearSeason()
    {
        var slot = SeasonPolicy.Resolve(Ny(2025, 12, 31, 23, 0), Now, NY, 4);
        Assert.Equal(SeasonKind.Year, slot.Kind);
        Assert.Equal(2025, slot.SeasonNumber);
        Assert.Equal("2025", slot.SeasonName);
    }

    [Fact]
    public void EpisodeNumber_IsStableAcrossRolls()
    {
        var ts = Ny(2026, 10, 29, 21, 3, 11);
        var e1 = SeasonPolicy.Resolve(ts, Now, NY, 4).EpisodeNumber;
        var e2 = SeasonPolicy.Resolve(ts, Ny(2026, 11, 20, 12, 0), NY, 4).EpisodeNumber;   // weeks later: week bucket? no -> month bucket
        var e3 = SeasonPolicy.Resolve(ts, Ny(2027, 3, 1, 12, 0), NY, 4).EpisodeNumber;     // next year -> year bucket
        Assert.Equal(e1, e2);
        Assert.Equal(e1, e3);
        Assert.Equal(202610, SeasonPolicy.Resolve(ts, Ny(2026, 11, 20, 12, 0), NY, 4).SeasonNumber);
        Assert.Equal(2026, SeasonPolicy.Resolve(ts, Ny(2027, 3, 1, 12, 0), NY, 4).SeasonNumber);
    }

    [Fact]
    public void Overrides_ReplaceGeneratedName()
    {
        var over = SeasonPolicy.ParseOverrides("# comment\n202610 = Fall Training Block\nbad line\n");
        var slot = SeasonPolicy.Resolve(Ny(2026, 10, 14, 20, 0), Ny(2026, 12, 1, 12, 0), NY, 4, over);
        Assert.Equal("Fall Training Block", slot.SeasonName);
    }

    [Fact]
    public void DstTransition_UsesCorrectOffset()
    {
        // 2026-11-01 02:30 local does not exist twice in a way that breaks us; 01:30 is ambiguous: must not throw
        var slot = SeasonPolicy.Resolve(Ny(2026, 11, 1, 1, 30), Ny(2026, 11, 2, 12, 0), NY, 4);
        Assert.Equal(new DateOnly(2026, 10, 31), slot.BroadcastDay);
    }

    [Fact]
    public void Describe_RecoversKindAndName()
    {
        Assert.Equal((SeasonKind.Day, "Thursday, Oct 29"), SeasonPolicy.Describe(20261029));
        Assert.Equal((SeasonKind.Week, "Week 42"), SeasonPolicy.Describe(1202642));
        Assert.Equal((SeasonKind.Month, "October 2026"), SeasonPolicy.Describe(202610));
        Assert.Equal((SeasonKind.Year, "2025"), SeasonPolicy.Describe(2025));
        Assert.Null(SeasonPolicy.Describe(7));
        Assert.Equal("Fall Block", SeasonPolicy.Describe(202610, new Dictionary<int, string> { [202610] = "Fall Block" })!.Value.Name);
    }

    [Fact]
    public void Filename_ParsesMediaMtxPattern()
    {
        var ts = ItemTimestamp.TryParseFilename("2026-10-29_21-03-11", NY);
        Assert.NotNull(ts);
        Assert.Equal(Ny(2026, 10, 29, 21, 3, 11), ts!.Value);
        Assert.Null(ItemTimestamp.TryParseFilename("clip-final-v2", NY));
        Assert.Equal(Ny(2026, 10, 29, 21, 3, 11), ItemTimestamp.TryParseFilename("Overwatch 2 2026.10.29 - 21.03.11.05.DVR", NY));
        Assert.Equal(Ny(2026, 10, 29, 21, 3, 11), ItemTimestamp.TryParseFilename("Halo Infinite 2026-10-29 21-03-11", NY));
        Assert.Equal(Ny(2026, 10, 29, 21, 3, 11), ItemTimestamp.TryParseFilename("clip_730_20261029_210311", NY));
    }
}