using System.Linq;
using AcDream.Core.Physics;
using AcDream.Core.Tests.Conformance;
using DatReaderWriter;
using DatReaderWriter.DBObjs;
using DatReaderWriter.Options;
using Xunit;

namespace AcDream.Core.Tests.Physics;

/// <summary>
/// Real-DAT availability tests for the L.1b dual command catalog. A command
/// only actually ANIMATES if the entity's <c>MotionTable</c> has a
/// <c>Links</c> or <c>Modifiers</c> entry for the full 32-bit value — an
/// enum/table value alone proves nothing about whether the local DATs will
/// ever play it.
///
/// <para>
/// Reproduces the scan from
/// <c>docs/research/2026-06-26-ace-vs-2013-motion-command-gap.md</c> as
/// pinned assertions: a command "exists" for a MotionTable when its full
/// 32-bit value appears as either (a) an outer <c>Links</c> key's low 16
/// bits (the from-state -&gt; command transition key), (b) an inner
/// <c>Links[...].MotionData</c> key (the actual animation-bearing target),
/// or (c) a <c>Modifiers</c> key. This three-way check is what reproduces
/// the gap doc's hit counts exactly (verified against a live scan of the
/// local <c>client_portal.dat</c>: LifestoneRecall/ACE=19,
/// MarketplaceRecall/ACE=19, AllegianceHometownRecall/ACE=19,
/// OffhandSlashHigh/ACE=31, HouseRecall/ACE=24 tables; all four
/// 2013-numbered equivalents=0 tables; HouseRecall/2013=42 tables, i.e.
/// "both exist" for HouseRecall specifically).
/// </para>
///
/// <para>
/// Gated the same way as the existing DAT-backed conformance suite — see
/// <see cref="ConformanceDats.ResolveDatDir"/> (also mirrored by
/// <c>DoorBugTrajectoryReplayTests.ResolveDatDir</c>): resolve
/// <c>ACDREAM_DAT_DIR</c> or the default <c>Documents\Asheron's Call</c>
/// path, and skip cleanly (<c>return</c>, no failure) when the dats aren't
/// present (CI has no local AC install).
/// </para>
/// </summary>
public class MotionCommandCatalogDatTests
{
    /// <summary>
    /// True if any local MotionTable can actually animate
    /// <paramref name="fullCommand"/> — the from-state transition key
    /// (Links outer, low 16 bits), the animation-bearing inner key
    /// (Links[...].MotionData), or a Modifiers entry.
    /// </summary>
    private static bool ExistsInAnyMotionTable(DatCollection dats, uint fullCommand)
    {
        ushort low16 = (ushort)(fullCommand & 0xFFFFu);
        int fullAsInt = unchecked((int)fullCommand);

        foreach (var id in dats.GetAllIdsOfType<MotionTable>())
        {
            var mt = dats.Get<MotionTable>(id);
            if (mt is null) continue;

            bool outerLow = mt.Links.Keys.Any(k => (k & 0xFFFF) == low16);
            if (outerLow) return true;

            bool innerFull = mt.Links.Values.Any(md => md.MotionData.ContainsKey(fullAsInt));
            if (innerFull) return true;

            if (mt.Modifiers.ContainsKey(fullAsInt)) return true;
        }

        return false;
    }

    [Fact]
    public void AceShiftedRecallCommands_ExistInLocalMotionTables()
    {
        var datDir = ConformanceDats.ResolveDatDir();
        if (datDir is null) return;

        using var dats = new DatCollection(datDir, DatAccessType.Read);

        Assert.True(ExistsInAnyMotionTable(dats, 0x10000153u), "LifestoneRecall (ACE 0x10000153) must exist in local DAT MotionTables");
        Assert.True(ExistsInAnyMotionTable(dats, 0x1000013Au), "HouseRecall (ACE 0x1000013A) must exist in local DAT MotionTables");
    }

    [Fact]
    public void TwoThousandThirteenLifestoneAndHouseRecall_AlsoExist()
    {
        var datDir = ConformanceDats.ResolveDatDir();
        if (datDir is null) return;

        using var dats = new DatCollection(datDir, DatAccessType.Read);

        // LifestoneRecall's 2013 numbering (0x10000150) does NOT exist locally —
        // only the ACE-shifted value animates. HouseRecall's 2013 numbering
        // (0x10000137) DOES exist (the gap doc: "both exist; the old value is
        // very common").
        Assert.False(ExistsInAnyMotionTable(dats, 0x10000150u), "LifestoneRecall (2013 0x10000150) unexpectedly found");
        Assert.True(ExistsInAnyMotionTable(dats, 0x10000137u), "HouseRecall (2013 0x10000137) must also exist in local DAT MotionTables");
    }

    [Theory]
    [InlineData(0x10000166u)] // MarketplaceRecall (ACE)
    [InlineData(0x10000171u)] // AllegianceHometownRecall (ACE)
    [InlineData(0x10000173u)] // OffhandSlashHigh (ACE)
    public void AceOnlyCommands_ExistOnlyUnderShiftedIds(uint aceFullCommand)
    {
        var datDir = ConformanceDats.ResolveDatDir();
        if (datDir is null) return;

        using var dats = new DatCollection(datDir, DatAccessType.Read);

        Assert.True(ExistsInAnyMotionTable(dats, aceFullCommand),
            $"ACE value 0x{aceFullCommand:X8} must exist in local DAT MotionTables");
    }

    [Theory]
    [InlineData(0x10000163u)] // MarketplaceRecall (2013)
    [InlineData(0x1000016Eu)] // AllegianceHometownRecall (2013)
    [InlineData(0x10000170u)] // OffhandSlashHigh (2013)
    public void TwoThousandThirteenOnlyValues_HaveZeroLinkHits(uint retail2013FullCommand)
    {
        var datDir = ConformanceDats.ResolveDatDir();
        if (datDir is null) return;

        using var dats = new DatCollection(datDir, DatAccessType.Read);

        Assert.False(ExistsInAnyMotionTable(dats, retail2013FullCommand),
            $"2013 value 0x{retail2013FullCommand:X8} unexpectedly found in local DAT MotionTables");
    }
}