using AcDream.App.Streaming;
using AcDream.Core.World;
using DatReaderWriter.DBObjs;

namespace AcDream.App.Tests.Streaming;

/// <summary>
/// C4 route 4b-1: focused tests for the graphical host's
/// <see cref="GraphicalRemotePlacementServiceWindow"/> — the App-side
/// implementation of <c>IRuntimeRemotePlacementServiceWindow</c> that did not
/// exist before this route. Verifies the predicate matches
/// <see cref="GpuWorldState.IsNearTier"/> exactly (not
/// <see cref="GpuWorldState.IsNearTierOrPending"/>, which is also true for a
/// merely-queued landblock — see the class's own doc comment) and
/// canonicalizes a full ACE cell id to the landblock the tier map keys on.
/// </summary>
public sealed class GraphicalRemotePlacementServiceWindowTests
{
    // GpuWorldState's tier map is keyed by the CANONICAL 0xFFFF-ending form
    // (LoadedLandblock.LandblockId/AddLandblock require callers to already
    // pass it that way — see StreamingControllerReadinessTests' own
    // 0x1236FFFFu convention). The window itself is exercised with a full
    // ACE outdoor-cell id (landblock high word + a real cell low word),
    // matching CreateObject.ServerPosition.LandblockId's actual shape, to
    // prove IsWithinServiceWindow canonicalizes it the same way
    // GpuWorldState's own writers do.
    private const uint LandblockHighWord = 0x0A0B0000u;
    private const uint CanonicalLandblock = LandblockHighWord | 0xFFFFu;
    private const uint OutdoorCell = LandblockHighWord | 0x0001u;

    [Fact]
    public void True_WhenTheLandblockIsNearTier()
    {
        var state = new GpuWorldState();
        state.AddLandblock(new LoadedLandblock(
            CanonicalLandblock,
            new LandBlock(),
            Array.Empty<AcDream.Core.World.WorldEntity>()));
        var window = new GraphicalRemotePlacementServiceWindow(state);

        Assert.True(window.IsWithinServiceWindow(OutdoorCell));
    }

    [Fact]
    public void False_WhenTheLandblockWasNeverPublished()
    {
        var state = new GpuWorldState();
        var window = new GraphicalRemotePlacementServiceWindow(state);

        Assert.False(window.IsWithinServiceWindow(OutdoorCell));
    }

    [Fact]
    public void False_WhenTheLandblockIsOnlyPendingNotYetCollisionPublished()
    {
        var state = new GpuWorldState();
        // A live projection arriving before its landblock loads parks as
        // "pending near tier" — GpuWorldState.IsNearTierOrPending reads true
        // for this, but collision has NOT been published yet.
        Assert.False(
            state.AddEntitiesToExistingLandblock(
                LandblockHighWord, Array.Empty<AcDream.Core.World.WorldEntity>()));
        Assert.True(state.IsNearTierOrPending(CanonicalLandblock));
        var window = new GraphicalRemotePlacementServiceWindow(state);

        Assert.False(window.IsWithinServiceWindow(OutdoorCell));
    }

    [Fact]
    public void False_AfterTheLandblockRetiresViaDetachNearLayer()
    {
        var state = new GpuWorldState();
        state.AddLandblock(new LoadedLandblock(
            CanonicalLandblock,
            new LandBlock(),
            Array.Empty<AcDream.Core.World.WorldEntity>()));
        var window = new GraphicalRemotePlacementServiceWindow(state);
        Assert.True(window.IsWithinServiceWindow(OutdoorCell));

        _ = state.DetachNearLayer(LandblockHighWord);

        Assert.False(window.IsWithinServiceWindow(OutdoorCell));
    }
}