using AcDream.Core.Items;
using AcDream.Runtime.Gameplay;

namespace AcDream.Runtime.Tests.Gameplay;

/// <summary>
/// Slice 6.1 — <see cref="VendorShopItemMaterializer"/> in isolation: the
/// diff/materialize/retire logic against a bare <see cref="VendorState"/> +
/// <see cref="ClientObjectTable"/> pair, independent of the wire parse
/// (<see cref="RuntimeVendorLifecycleTests"/> covers the end-to-end
/// ApproachVendor path).
/// </summary>
public sealed class VendorShopItemMaterializerTests
{
    private const uint VendorGuid = 0x40001000u;
    private const uint OtherVendorGuid = 0x40002000u;
    private const uint ItemA = 0x50002000u;
    private const uint ItemB = 0x50002001u;

    private static VendorShopItem Item(uint guid, string name = "Item", int? descStackSize = null) =>
        new(guid, StackSize: -1, WeenieClassId: 1u, Name: name, ItemType: (uint)ItemType.Misc,
            IconId: 0x1234u, Value: 10, DescStackSize: descStackSize);

    [Fact]
    public void Apply_MaterializesEachShopItemWithVendorAsContainer()
    {
        var vendor = new VendorState();
        var objects = new ClientObjectTable();
        using var materializer = new VendorShopItemMaterializer(vendor, objects);

        vendor.Apply(VendorGuid, default, new[] { Item(ItemA, "Iron Sword"), Item(ItemB, "Bread") });

        ClientObject? a = objects.Get(ItemA);
        ClientObject? b = objects.Get(ItemB);
        Assert.NotNull(a);
        Assert.NotNull(b);
        Assert.Equal(VendorGuid, a!.ContainerId);
        Assert.Equal(VendorGuid, b!.ContainerId);
        Assert.Equal("Iron Sword", a.Name);
        Assert.Equal(2, materializer.OwnedCount);
        Assert.True(materializer.Owns(ItemA));
        Assert.True(materializer.Owns(ItemB));
    }

    [Fact]
    public void Close_RemovesEveryMaterializedItem()
    {
        var vendor = new VendorState();
        var objects = new ClientObjectTable();
        using var materializer = new VendorShopItemMaterializer(vendor, objects);
        vendor.Apply(VendorGuid, default, new[] { Item(ItemA), Item(ItemB) });

        vendor.Close();

        Assert.Null(objects.Get(ItemA));
        Assert.Null(objects.Get(ItemB));
        Assert.Equal(0, materializer.OwnedCount);
    }

    [Fact]
    public void Reset_RemovesEveryMaterializedItem()
    {
        var vendor = new VendorState();
        var objects = new ClientObjectTable();
        using var materializer = new VendorShopItemMaterializer(vendor, objects);
        vendor.Apply(VendorGuid, default, new[] { Item(ItemA) });

        vendor.Reset();

        Assert.Null(objects.Get(ItemA));
        Assert.Equal(0, materializer.OwnedCount);
    }

    [Fact]
    public void DifferentVendorSupersedes_RemovesPriorVendorsItemsBeforeMaterializingTheNewOnes()
    {
        var vendor = new VendorState();
        var objects = new ClientObjectTable();
        using var materializer = new VendorShopItemMaterializer(vendor, objects);
        vendor.Apply(VendorGuid, default, new[] { Item(ItemA, "First Vendor Item") });
        Assert.NotNull(objects.Get(ItemA));

        const uint NewItem = 0x50003000u;
        vendor.Apply(OtherVendorGuid, default, new[] { Item(NewItem, "Second Vendor Item") });

        Assert.Null(objects.Get(ItemA));
        ClientObject? replacement = objects.Get(NewItem);
        Assert.NotNull(replacement);
        Assert.Equal(OtherVendorGuid, replacement!.ContainerId);
        Assert.Equal(1, materializer.OwnedCount);
    }

    [Fact]
    public void Refreshed_SameVendor_DoesNotFireObjectRemovedForStillListedItems()
    {
        // A same-vendor re-approach (post-buy refresh) must not remove+
        // re-add a guid that's still in stock -- see the class doc's "diff,
        // not blanket remove-then-reinsert" rationale. A UI panel holding
        // the guid (an open appraisal window) would see a false "it's gone"
        // notice if this regressed to blanket removal.
        var vendor = new VendorState();
        var objects = new ClientObjectTable();
        using var materializer = new VendorShopItemMaterializer(vendor, objects);
        vendor.Apply(VendorGuid, default, new[] { Item(ItemA, "Chainmail") });

        var removed = new List<uint>();
        objects.ObjectRemoved += o => removed.Add(o.ObjectId);

        // Same vendor id re-approaches with the SAME item guid still listed
        // (e.g. a post-buy refresh where this item wasn't the one bought)
        // but with a refreshed field value.
        vendor.Apply(VendorGuid, default, new[] { Item(ItemA, "Chainmail", descStackSize: 5) });

        Assert.Empty(removed);
        Assert.Equal(1, materializer.OwnedCount);
        Assert.Equal(5, objects.Get(ItemA)!.StackSize);
    }

    [Fact]
    public void Refreshed_ItemNoLongerListed_IsRemoved()
    {
        // An item drops out of the vendor's own list WITHOUT ever being
        // re-containered elsewhere (e.g. admin-removed stock, a delisted
        // line item) -- its live ContainerId is still the vendor's own
        // guid, so the retire pass's F1 ownership re-check finds a match
        // and removes it. This is deliberately NOT "I bought it" -- see
        // Refreshed_ItemPurchased_ReparentedIntoBuyerPack_Survives for that
        // case, where the SAME "missing from the new snapshot" trigger must
        // NOT delete the item because a real purchase already moved it into
        // the buyer's own pack before this refresh arrived.
        var vendor = new VendorState();
        var objects = new ClientObjectTable();
        using var materializer = new VendorShopItemMaterializer(vendor, objects);
        vendor.Apply(VendorGuid, default, new[] { Item(ItemA), Item(ItemB) });

        vendor.Apply(VendorGuid, default, new[] { Item(ItemB) });

        Assert.Null(objects.Get(ItemA));
        Assert.NotNull(objects.Get(ItemB));
        Assert.Equal(1, materializer.OwnedCount);
    }

    [Fact]
    public void Refreshed_ItemPurchased_ReparentedIntoBuyerPack_Survives()
    {
        // F1: buying a UNIQUE vendor item does not merely drop it from the
        // next ApproachVendor snapshot -- ACE first re-containers the SAME
        // guid into the BUYER's own pack via CreateObject
        // (Player_Commerce.cs:86-108) and only THEN sends the full-replace
        // refresh that no longer lists it. The retire pass must re-check
        // live ownership (ContainerId) before deleting, or it strips the
        // just-purchased item straight back out of the buyer's inventory.
        var vendor = new VendorState();
        var objects = new ClientObjectTable();
        using var materializer = new VendorShopItemMaterializer(vendor, objects);
        vendor.Apply(VendorGuid, default, new[] { Item(ItemA, "Unique Sword"), Item(ItemB) });
        Assert.Equal(VendorGuid, objects.Get(ItemA)!.ContainerId);

        const uint BuyerGuid = 0x50009000u;
        // Simulate the purchase's CreateObject: ACE re-containers the SAME
        // guid into the buyer's pack BEFORE the post-buy ApproachVendor
        // refresh arrives.
        objects.Ingest(new WeenieData(
            Guid: ItemA,
            Name: null,
            Type: null,
            WeenieClassId: 0,
            IconId: 0,
            IconOverlayId: 0,
            IconUnderlayId: 0,
            Effects: 0,
            Value: null,
            StackSize: null,
            StackSizeMax: null,
            Burden: null,
            ContainerId: BuyerGuid,
            WielderId: null,
            ValidLocations: null,
            CurrentWieldedLocation: null,
            Priority: null,
            ItemsCapacity: null,
            ContainersCapacity: null,
            Structure: null,
            MaxStructure: null,
            Workmanship: null));
        Assert.Equal(BuyerGuid, objects.Get(ItemA)!.ContainerId);

        // Post-buy ApproachVendor refresh: the purchased item is gone from
        // the shop's own list.
        vendor.Apply(VendorGuid, default, new[] { Item(ItemB) });

        ClientObject? survivor = objects.Get(ItemA);
        Assert.NotNull(survivor);
        Assert.Equal(BuyerGuid, survivor!.ContainerId);
        Assert.False(materializer.Owns(ItemA));
        Assert.Equal(1, materializer.OwnedCount);
    }

    [Fact]
    public void CollidingGuid_AlreadyOwnedBySomethingElse_IsNeverClobbered()
    {
        // The Slice 6.1 collision policy: ACE's UniqueItemsForSale can list
        // the EXACT guid a player last held (e.g. a sold-off item, or --
        // worst case -- any other collision). If that guid is already in
        // ClientObjectTable for a reason this materializer did not itself
        // create, it must be left completely untouched, not silently
        // reparented into the vendor's container.
        var vendor = new VendorState();
        var objects = new ClientObjectTable();
        // Simulate a pre-existing, non-vendor-owned object at this guid --
        // e.g. a live entity, or an item still sitting in someone's
        // inventory/equipment.
        const uint LiveOwner = 0x60000001u;
        objects.AddOrUpdate(new ClientObject
        {
            ObjectId = ItemA,
            Name = "Definitely Not A Shop Item",
            ContainerId = LiveOwner,
        });
        using var materializer = new VendorShopItemMaterializer(vendor, objects);

        vendor.Apply(VendorGuid, default, new[] { Item(ItemA, "Shop Listing With A Colliding Guid") });

        ClientObject? survivor = objects.Get(ItemA);
        Assert.NotNull(survivor);
        Assert.Equal("Definitely Not A Shop Item", survivor!.Name);
        Assert.Equal(LiveOwner, survivor.ContainerId);
        Assert.False(materializer.Owns(ItemA));
        Assert.Equal(0, materializer.OwnedCount);

        // The collision guid must also survive session close -- since this
        // materializer never claimed it, it must never remove it either.
        vendor.Close();
        Assert.NotNull(objects.Get(ItemA));
    }

    [Fact]
    public void Dispose_UnsubscribesFromVendorChanged()
    {
        var vendor = new VendorState();
        var objects = new ClientObjectTable();
        var materializer = new VendorShopItemMaterializer(vendor, objects);
        vendor.Apply(VendorGuid, default, new[] { Item(ItemA) });
        Assert.NotNull(objects.Get(ItemA));

        materializer.Dispose();

        // No further reaction once disposed -- a Close() after disposal
        // must not throw and must not touch the table (nothing left
        // subscribed to react).
        vendor.Close();
        Assert.NotNull(objects.Get(ItemA));
    }

    [Fact]
    public void Retire_ThrowingObjectRemovedObserver_StillRetiresRemainingGuidsAndConverges()
    {
        // F5: ClientObjectTable.Remove fires ObjectRemoved with NO
        // per-listener isolation (unlike VendorState's own Changed
        // dispatch). One throwing observer must not abort the retire loop
        // partway through and strand _ownedGuids -- every owned guid still
        // retires, and OwnedCount still converges to zero.
        var vendor = new VendorState();
        var objects = new ClientObjectTable();
        using var materializer = new VendorShopItemMaterializer(vendor, objects);
        vendor.Apply(VendorGuid, default, new[] { Item(ItemA), Item(ItemB) });
        Assert.Equal(2, materializer.OwnedCount);

        // A throwing ObjectRemoved observer fires on EVERY Remove() call
        // (both ItemA's and ItemB's) -- multicast delegate invocation has
        // no per-listener isolation, so each Remove() call itself throws.
        objects.ObjectRemoved += _ => throw new InvalidOperationException("boom");

        vendor.Close();

        // Both guids are gone from the table -- the throwing first observer
        // did not stop the second guid's Remove() call from happening.
        Assert.Null(objects.Get(ItemA));
        Assert.Null(objects.Get(ItemB));
        Assert.Equal(0, materializer.OwnedCount);
        Assert.False(materializer.Owns(ItemA));
        Assert.False(materializer.Owns(ItemB));

        // Dispose still converges cleanly afterward.
        materializer.Dispose();
        Assert.Equal(0, materializer.OwnedCount);
    }
}