using System;
using System.Collections.Generic;
using AcDream.App.UI;
using AcDream.App.UI.Layout;
using AcDream.Core.Combat;
using AcDream.Core.Items;
using AcDream.Core.Net.Messages;
using Xunit;

namespace AcDream.App.Tests.UI.Layout;

public class ToolbarControllerTests
{
    private static readonly uint[] Row1 =
        { 0x100001A7,0x100001A8,0x100001A9,0x100001AA,0x100001AB,0x100001AC,0x100001AD,0x100001AE,0x100001AF };
    private static readonly uint[] Row2 =
        { 0x100006B7,0x100006B8,0x100006B9,0x100006BA,0x100006BB,0x100006BC,0x100006BD,0x100006BE,0x100006BF };

    // The four mutually-exclusive combat-mode indicator element ids (must match ToolbarController's list).
    private static readonly uint[] CombatIds = { 0x10000192u, 0x10000193u, 0x10000194u, 0x10000195u };

    private static (ImportedLayout layout, Dictionary<uint, UiItemList> slots,
                    Dictionary<uint, UiElement> indicators) FakeToolbar()
    {
        var dict = new Dictionary<uint, UiElement>();
        var slots = new Dictionary<uint, UiItemList>();
        var indicators = new Dictionary<uint, UiElement>();
        var root = new UiPanel();
        foreach (var id in Row1) AddSlot(id);
        foreach (var id in Row2) AddSlot(id);
        // Add combat indicator elements as plain UiPanels keyed by id.
        foreach (var id in CombatIds)
        {
            var e = new UiPanel { Visible = true };
            dict[id] = e; indicators[id] = e; root.AddChild(e);
        }
        return (new ImportedLayout(root, dict), slots, indicators);

        void AddSlot(uint id)
        {
            var list = new UiItemList(_ => (0u, 0, 0)) { Width = 32, Height = 32 };
            dict[id] = list; slots[id] = list; root.AddChild(list);
        }
    }

    [Fact]
    public void Populate_bindsShortcutToCorrectSlot()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable();
        repo.AddOrUpdate(new ClientObject { ObjectId = 0x5001u, WeenieClassId = 1u, IconId = 0x06001234u });
        var shortcuts = new List<PlayerDescriptionParser.ShortcutEntry>
        { new(Index: 0, ObjectGuid: 0x5001u, SpellId: 0, Layer: 0) };

        ToolbarController.Bind(layout, repo, () => shortcuts,
            iconIds: (_,_,_,_,_) => 0x77u, useItem: _ => { });

        Assert.Equal(0x5001u, slots[Row1[0]].Cell.ItemId);
        Assert.Equal(0x77u,   slots[Row1[0]].Cell.IconTexture);
        Assert.Equal(0u,      slots[Row1[1]].Cell.ItemId); // others empty
    }

    [Fact]
    public void DeferredRebind_whenItemArrivesLate()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable(); // item NOT present yet
        var shortcuts = new List<PlayerDescriptionParser.ShortcutEntry>
        { new(Index: 2, ObjectGuid: 0x5002u, SpellId: 0, Layer: 0) };

        ToolbarController.Bind(layout, repo, () => shortcuts,
            iconIds: (_,_,_,_,_) => 0x88u, useItem: _ => { });
        Assert.Equal(0u, slots[Row1[2]].Cell.ItemId); // not bound yet

        repo.AddOrUpdate(new ClientObject { ObjectId = 0x5002u, WeenieClassId = 1u, IconId = 0x06005678u });

        Assert.Equal(0x5002u, slots[Row1[2]].Cell.ItemId); // rebound on ItemAdded
    }

    [Fact]
    public void Click_emitsUseForBoundItem()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable();
        repo.AddOrUpdate(new ClientObject { ObjectId = 0x5001u, WeenieClassId = 1u, IconId = 0x06001234u });
        var shortcuts = new List<PlayerDescriptionParser.ShortcutEntry>
        { new(Index: 0, ObjectGuid: 0x5001u, SpellId: 0, Layer: 0) };
        uint used = 0;

        ToolbarController.Bind(layout, repo, () => shortcuts,
            iconIds: (_,_,_,_,_) => 0x77u, useItem: g => used = g);
        // Use now fires on Click (mouse-up), not MouseDown — drag/click disambiguation.
        slots[Row1[0]].Cell.OnEvent(new UiEvent(0u, null, UiEventType.Click));

        Assert.Equal(0x5001u, used);
    }

    // ── C1: combat-mode indicator tests ─────────────────────────────────────

    /// <summary>
    /// At bind time (default NonCombat), only the peace indicator (0x10000192) is visible;
    /// the melee/missile/magic indicators (0x10000193/4/5) are hidden.
    /// Port of gmToolbarUI::RecvNotice_SetCombatMode (acclient_2013_pseudo_c.txt:196632-196669).
    /// </summary>
    [Fact]
    public void CombatIndicator_defaultNonCombat_onlyPeaceVisible()
    {
        var (layout, _, indicators) = FakeToolbar();
        var repo = new ClientObjectTable();

        ToolbarController.Bind(layout, repo,
            () => Array.Empty<PlayerDescriptionParser.ShortcutEntry>(),
            iconIds: (_,_,_,_,_) =>0u, useItem: _ => { });

        // Only peace indicator (index 0 = 0x10000192) is visible.
        Assert.True (indicators[0x10000192u].Visible, "peace indicator should be visible after bind");
        Assert.False(indicators[0x10000193u].Visible, "melee indicator should be hidden after bind");
        Assert.False(indicators[0x10000194u].Visible, "missile indicator should be hidden after bind");
        Assert.False(indicators[0x10000195u].Visible, "magic indicator should be hidden after bind");
    }

    /// <summary>
    /// SetCombatMode(Melee) hides peace/missile/magic and shows only the melee indicator.
    /// </summary>
    [Fact]
    public void CombatIndicator_setCombatModeMelee_onlyMeleeVisible()
    {
        var (layout, _, indicators) = FakeToolbar();
        var repo = new ClientObjectTable();

        var ctrl = ToolbarController.Bind(layout, repo,
            () => Array.Empty<PlayerDescriptionParser.ShortcutEntry>(),
            iconIds: (_,_,_,_,_) =>0u, useItem: _ => { });

        ctrl.SetCombatMode(CombatMode.Melee);

        Assert.False(indicators[0x10000192u].Visible, "peace indicator should be hidden in melee mode");
        Assert.True (indicators[0x10000193u].Visible, "melee indicator should be visible in melee mode");
        Assert.False(indicators[0x10000194u].Visible, "missile indicator should be hidden in melee mode");
        Assert.False(indicators[0x10000195u].Visible, "magic indicator should be hidden in melee mode");
    }

    /// <summary>
    /// CombatModeChanged event on CombatState automatically updates the indicator.
    /// </summary>
    [Fact]
    public void CombatIndicator_liveSignal_updatesWhenCombatStateChanges()
    {
        var (layout, _, indicators) = FakeToolbar();
        var repo = new ClientObjectTable();
        var combat = new CombatState();

        ToolbarController.Bind(layout, repo,
            () => Array.Empty<PlayerDescriptionParser.ShortcutEntry>(),
            iconIds: (_,_,_,_,_) =>0u, useItem: _ => { },
            combatState: combat);

        // Initially NonCombat after bind.
        Assert.True(indicators[0x10000192u].Visible, "peace should be visible initially");

        // Server fires CombatModeChanged → Magic.
        combat.SetCombatMode(CombatMode.Magic);

        Assert.False(indicators[0x10000192u].Visible, "peace should be hidden in magic mode");
        Assert.False(indicators[0x10000193u].Visible, "melee should be hidden in magic mode");
        Assert.False(indicators[0x10000194u].Visible, "missile should be hidden in magic mode");
        Assert.True (indicators[0x10000195u].Visible, "magic indicator should be visible");
    }

    // ── D1: Shortcut number (slot label) tests ───────────────────────────────
    // Port of UIElement_UIItem::SetShortcutNum (acclient_2013_pseudo_c.txt:229465);
    // gmToolbarUI::RecvNotice_SetCombatMode (196610-196621).

    // Fake digit arrays: 9 peace entries (0x10..0x18), 9 war entries (0x20..0x28),
    // 9 empty (background) entries (0x30..0x38).
    private static readonly uint[] FakePeace = { 0x10u,0x11u,0x12u,0x13u,0x14u,0x15u,0x16u,0x17u,0x18u };
    private static readonly uint[] FakeWar   = { 0x20u,0x21u,0x22u,0x23u,0x24u,0x25u,0x26u,0x27u,0x28u };
    private static readonly uint[] FakeEmpty = { 0x30u,0x31u,0x32u,0x33u,0x34u,0x35u,0x36u,0x37u,0x38u };

    /// <summary>
    /// After Bind with peace/war digit arrays, top-row cells (indices 0–8) have
    /// ShortcutNum == i (the slot position) and ShortcutPeace == true (default NonCombat).
    /// Bottom-row cells (indices 9–17) have ShortcutNum == -1 (no label).
    /// Retail: numbers are slot LABELS — shown on ALL top-row slots including empty ones.
    /// </summary>
    [Fact]
    public void ShortcutNumbers_afterBind_topRowHasNumbers_bottomRowEmpty()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable();

        ToolbarController.Bind(layout, repo,
            () => Array.Empty<PlayerDescriptionParser.ShortcutEntry>(),
            iconIds: (_,_,_,_,_) => 0u, useItem: _ => { },
            peaceDigits: FakePeace, warDigits: FakeWar);

        // Top row: ShortcutNum == slot index, peace == true.
        for (int i = 0; i < Row1.Length; i++)
        {
            var cell = slots[Row1[i]].Cell;
            Assert.Equal(i,    cell.ShortcutNum);
            Assert.True(cell.ShortcutPeace, $"top-row slot {i} should be peace at NonCombat");
        }
        // Bottom row: no shortcut number.
        foreach (var id in Row2)
            Assert.Equal(-1, slots[id].Cell.ShortcutNum);
    }

    /// <summary>
    /// After SetCombatMode(Melee), top-row cells switch to ShortcutPeace == false (war).
    /// </summary>
    [Fact]
    public void ShortcutNumbers_setCombatModeWar_topRowUsesWarDigits()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable();
        var ctrl = ToolbarController.Bind(layout, repo,
            () => Array.Empty<PlayerDescriptionParser.ShortcutEntry>(),
            iconIds: (_,_,_,_,_) => 0u, useItem: _ => { },
            peaceDigits: FakePeace, warDigits: FakeWar);

        ctrl.SetCombatMode(CombatMode.Melee);

        // Top row: still ShortcutNum == i, but now peace == false.
        for (int i = 0; i < Row1.Length; i++)
        {
            var cell = slots[Row1[i]].Cell;
            Assert.Equal(i,     cell.ShortcutNum);
            Assert.False(cell.ShortcutPeace, $"top-row slot {i} should be war after Melee");
        }
        // Bottom row still has no number.
        foreach (var id in Row2)
            Assert.Equal(-1, slots[id].Cell.ShortcutNum);
    }

    /// <summary>
    /// After SetCombatMode back to NonCombat, top-row switches back to peace (ShortcutPeace == true).
    /// </summary>
    [Fact]
    public void ShortcutNumbers_backToNonCombat_restoresPeaceDigits()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable();
        var ctrl = ToolbarController.Bind(layout, repo,
            () => Array.Empty<PlayerDescriptionParser.ShortcutEntry>(),
            iconIds: (_,_,_,_,_) => 0u, useItem: _ => { },
            peaceDigits: FakePeace, warDigits: FakeWar);

        ctrl.SetCombatMode(CombatMode.Melee);
        ctrl.SetCombatMode(CombatMode.NonCombat);

        for (int i = 0; i < Row1.Length; i++)
            Assert.True(slots[Row1[i]].Cell.ShortcutPeace,
                $"top-row slot {i} should be peace after returning to NonCombat");
    }

    /// <summary>
    /// Digit arrays are correctly injected into each cell (PeaceDigits + WarDigits references).
    /// </summary>
    [Fact]
    public void ShortcutNumbers_digitArraysInjected()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable();

        ToolbarController.Bind(layout, repo,
            () => Array.Empty<PlayerDescriptionParser.ShortcutEntry>(),
            iconIds: (_,_,_,_,_) => 0u, useItem: _ => { },
            peaceDigits: FakePeace, warDigits: FakeWar);

        foreach (var id in Row1)
        {
            Assert.Same(FakePeace, slots[id].Cell.PeaceDigits);
            Assert.Same(FakeWar,   slots[id].Cell.WarDigits);
        }
    }

    /// <summary>
    /// EmptyDigits (0x1000005e background digit) is injected into every slot cell.
    /// Retail ref: UIElement_UIItem::SetShortcutNum (decomp 229481) — empty-slot branch.
    /// </summary>
    [Fact]
    public void ShortcutNumbers_emptyDigitArrayInjected()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable();

        ToolbarController.Bind(layout, repo,
            () => Array.Empty<PlayerDescriptionParser.ShortcutEntry>(),
            iconIds: (_,_,_,_,_) => 0u, useItem: _ => { },
            peaceDigits: FakePeace, warDigits: FakeWar, emptyDigits: FakeEmpty);

        foreach (var id in Row1)
            Assert.Same(FakeEmpty, slots[id].Cell.EmptyDigits);
        foreach (var id in Row2)
            Assert.Same(FakeEmpty, slots[id].Cell.EmptyDigits);
    }

    /// <summary>
    /// When emptyDigits is null, cells have EmptyDigits == null (no digit on empty slots).
    /// This is the safe fallback when the dat property 0x1000005e is absent.
    /// </summary>
    [Fact]
    public void ShortcutNumbers_nullEmptyDigits_cellsHaveNullEmptyDigits()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable();

        ToolbarController.Bind(layout, repo,
            () => Array.Empty<PlayerDescriptionParser.ShortcutEntry>(),
            iconIds: (_,_,_,_,_) => 0u, useItem: _ => { },
            peaceDigits: FakePeace, warDigits: FakeWar, emptyDigits: null);

        foreach (var id in Row1)
            Assert.Null(slots[id].Cell.EmptyDigits);
    }

    // ── E1: Guid filter + ObjectRemoved tests (D.5.4) ───────────────────────

    /// <summary>
    /// ObjectAdded for a guid NOT in the shortcut list does NOT call iconIds again
    /// (no spurious Populate on creature/NPC spawns in a busy zone).
    /// D.5.4: ToolbarController filters to shortcut guids only.
    /// The iconIds spy lets us count how many times Populate actually ran.
    /// </summary>
    [Fact]
    public void ObjectAdded_nonShortcutGuid_doesNotCallIconIds()
    {
        var (layout, _, _) = FakeToolbar();
        var repo = new ClientObjectTable();
        repo.AddOrUpdate(new ClientObject { ObjectId = 0x5001u, WeenieClassId = 1u, IconId = 0x06001234u });
        var shortcuts = new List<PlayerDescriptionParser.ShortcutEntry>
        { new(Index: 0, ObjectGuid: 0x5001u, SpellId: 0, Layer: 0) };

        int iconCallCount = 0;
        ToolbarController.Bind(layout, repo, () => shortcuts,
            iconIds: (_,_,_,_,_) => { iconCallCount++; return 0x77u; }, useItem: _ => { });

        int callsAfterBind = iconCallCount; // 1 call from initial Populate

        // Fire ObjectAdded with a completely unrelated guid (a creature, NOT a shortcut).
        repo.AddOrUpdate(new ClientObject { ObjectId = 0xDEADBEEFu, WeenieClassId = 42u, IconId = 0u });

        // iconIds must NOT have been called again — the filter blocked Populate.
        Assert.Equal(callsAfterBind, iconCallCount);
    }

    /// <summary>
    /// ObjectAdded for a guid that IS in the shortcut list calls iconIds again (deferred bind).
    /// This is the filtered-path counterpart of DeferredRebind_whenItemArrivesLate.
    /// </summary>
    [Fact]
    public void ObjectAdded_shortcutGuid_callsIconIds()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable(); // item NOT present yet
        var shortcuts = new List<PlayerDescriptionParser.ShortcutEntry>
        { new(Index: 1, ObjectGuid: 0x5003u, SpellId: 0, Layer: 0) };

        int iconCallCount = 0;
        ToolbarController.Bind(layout, repo, () => shortcuts,
            iconIds: (_,_,_,_,_) => { iconCallCount++; return 0x99u; }, useItem: _ => { });

        Assert.Equal(0, iconCallCount); // not called — item absent during initial Populate
        Assert.Equal(0u, slots[Row1[1]].Cell.ItemId);

        // Now the shortcut item arrives — filter must PASS and Populate re-run.
        repo.AddOrUpdate(new ClientObject { ObjectId = 0x5003u, WeenieClassId = 1u, IconId = 0x06005678u });

        Assert.Equal(1, iconCallCount);              // iconIds called exactly once for the deferred bind
        Assert.Equal(0x5003u, slots[Row1[1]].Cell.ItemId);
    }

    /// <summary>
    /// ObjectRemoved for a guid that IS in the shortcut list clears the slot.
    /// D.5.4: subscribes to ObjectRemoved so a removed item evicts its icon.
    /// </summary>
    [Fact]
    public void ObjectRemoved_shortcutGuid_clearsSlot()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable();
        repo.AddOrUpdate(new ClientObject { ObjectId = 0x5004u, WeenieClassId = 1u, IconId = 0x06001234u });
        var shortcuts = new List<PlayerDescriptionParser.ShortcutEntry>
        { new(Index: 3, ObjectGuid: 0x5004u, SpellId: 0, Layer: 0) };

        ToolbarController.Bind(layout, repo, () => shortcuts,
            iconIds: (_,_,_,_,_) => 0xAAu, useItem: _ => { });

        Assert.Equal(0x5004u, slots[Row1[3]].Cell.ItemId); // bound

        // Remove the item from the session (server despawn / trade away).
        // Populate re-runs: item is gone from repo → slot clears.
        repo.Remove(0x5004u);

        Assert.Equal(0u, slots[Row1[3]].Cell.ItemId);
    }

    /// <summary>
    /// ObjectRemoved for a guid NOT in the shortcut list does NOT call iconIds again.
    /// D.5.4: the ObjectRemoved subscription also filters to shortcut guids.
    /// </summary>
    [Fact]
    public void ObjectRemoved_nonShortcutGuid_doesNotCallIconIds()
    {
        var (layout, _, _) = FakeToolbar();
        var repo = new ClientObjectTable();
        repo.AddOrUpdate(new ClientObject { ObjectId = 0x5005u, WeenieClassId = 1u, IconId = 0x06001234u });
        repo.AddOrUpdate(new ClientObject { ObjectId = 0xCAFEBABEu, WeenieClassId = 99u, IconId = 0u });
        var shortcuts = new List<PlayerDescriptionParser.ShortcutEntry>
        { new(Index: 4, ObjectGuid: 0x5005u, SpellId: 0, Layer: 0) };

        int iconCallCount = 0;
        ToolbarController.Bind(layout, repo, () => shortcuts,
            iconIds: (_,_,_,_,_) => { iconCallCount++; return 0xBBu; }, useItem: _ => { });

        int callsAfterBind = iconCallCount; // 1 call for the shortcut item

        // Remove an unrelated object — filter must block Populate.
        repo.Remove(0xCAFEBABEu);

        Assert.Equal(callsAfterBind, iconCallCount); // unchanged
    }

    // ── B.1: drag-drop spine wiring ──────────────────────────────────────────

    /// <summary>Bind registers the controller as each slot list's drag handler and
    /// stamps every cell's SlotIndex + SourceKind=ShortcutBar.</summary>
    [Fact]
    public void Bind_registersDragHandler_andStampsSlots()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable();

        var ctrl = ToolbarController.Bind(layout, repo,
            () => Array.Empty<PlayerDescriptionParser.ShortcutEntry>(),
            iconIds: (_,_,_,_,_) => 0u, useItem: _ => { });

        for (int i = 0; i < Row1.Length; i++)
        {
            Assert.Same(ctrl, slots[Row1[i]].DragHandler);
            Assert.Equal(i, slots[Row1[i]].Cell.SlotIndex);
            Assert.Equal(ItemDragSource.ShortcutBar, slots[Row1[i]].Cell.SourceKind);
        }
        // Bottom row slots are indices 9..17; same handler + source kind as the top row.
        for (int j = 0; j < Row2.Length; j++)
        {
            Assert.Same(ctrl, slots[Row2[j]].DragHandler);
            Assert.Equal(9 + j, slots[Row2[j]].Cell.SlotIndex);
            Assert.Equal(ItemDragSource.ShortcutBar, slots[Row2[j]].Cell.SourceKind);
        }
    }

    /// <summary>OnDragOver accepts a real item (ObjId != 0). Eligibility (IsShortcutEligible)
    /// is Stream B.2; the stub accepts any non-empty payload.</summary>
    [Fact]
    public void OnDragOver_acceptsRealItem()
    {
        var (layout, slots, _) = FakeToolbar();
        var ctrl = ToolbarController.Bind(layout, new ClientObjectTable(),
            () => Array.Empty<PlayerDescriptionParser.ShortcutEntry>(),
            iconIds: (_,_,_,_,_) => 0u, useItem: _ => { });

        var list = slots[Row1[0]];
        var payload = new ItemDragPayload(0x5001u, ItemDragSource.Inventory, 0, new UiItemSlot());
        Assert.True(ctrl.OnDragOver(list, list.Cell, payload));
    }

    /// <summary>OnDragOver rejects a ghost payload with ObjId 0 (the guard against an
    /// empty cell that somehow produced a payload). Complements OnDragOver_acceptsRealItem.</summary>
    [Fact]
    public void OnDragOver_rejectsZeroObjId()
    {
        var (layout, slots, _) = FakeToolbar();
        var ctrl = ToolbarController.Bind(layout, new ClientObjectTable(),
            () => Array.Empty<PlayerDescriptionParser.ShortcutEntry>(),
            iconIds: (_,_,_,_,_) => 0u, useItem: _ => { });
        var list = slots[Row1[0]];
        var payload = new ItemDragPayload(0u, ItemDragSource.Inventory, 0, new UiItemSlot());
        Assert.False(ctrl.OnDragOver(list, list.Cell, payload));
    }

    // ── B.2: live drag handler (store + reorder/remove + wire) ───────────────
    private static (System.Collections.Generic.List<(uint i,uint g)> adds,
                    System.Collections.Generic.List<uint> removes) NewSpies(out System.Action<uint,uint> add, out System.Action<uint> rem)
    {
        var adds = new System.Collections.Generic.List<(uint,uint)>();
        var removes = new System.Collections.Generic.List<uint>();
        add = (i, g) => adds.Add((i, g));
        rem = i => removes.Add(i);
        return (adds, removes);
    }

    [Fact]
    public void OnDragLift_removesSourceSlot_sendsRemove_emptiesCell()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable();
        repo.AddOrUpdate(new ClientObject { ObjectId = 0x5001u, WeenieClassId = 1u, IconId = 0x06001234u });
        var shortcuts = new System.Collections.Generic.List<PlayerDescriptionParser.ShortcutEntry>
        { new(Index: 3, ObjectGuid: 0x5001u, SpellId: 0, Layer: 0) };
        var (adds, removes) = NewSpies(out var add, out var rem);

        var ctrl = ToolbarController.Bind(layout, repo, () => shortcuts,
            iconIds: (_,_,_,_,_) => 0x77u, useItem: _ => { },
            sendAddShortcut: add, sendRemoveShortcut: rem);
        Assert.Equal(0x5001u, slots[Row1[3]].Cell.ItemId);

        var payload = new ItemDragPayload(0x5001u, ItemDragSource.ShortcutBar, 3, slots[Row1[3]].Cell);
        ctrl.OnDragLift(slots[Row1[3]], slots[Row1[3]].Cell, payload);

        Assert.Contains(3u, removes);
        Assert.Equal(0u, slots[Row1[3]].Cell.ItemId);
    }

    [Fact]
    public void HandleDropRelease_ontoOccupied_swaps_andSendsRetailSequence()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable();
        repo.AddOrUpdate(new ClientObject { ObjectId = 0x5001u, WeenieClassId = 1u, IconId = 0x06001234u }); // A
        repo.AddOrUpdate(new ClientObject { ObjectId = 0x5002u, WeenieClassId = 1u, IconId = 0x06005678u }); // B
        var shortcuts = new System.Collections.Generic.List<PlayerDescriptionParser.ShortcutEntry>
        { new(Index: 3, ObjectGuid: 0x5001u, SpellId: 0, Layer: 0),
          new(Index: 5, ObjectGuid: 0x5002u, SpellId: 0, Layer: 0) };
        var (adds, removes) = NewSpies(out var add, out var rem);
        var ctrl = ToolbarController.Bind(layout, repo, () => shortcuts,
            iconIds: (_,_,_,_,_) => 0x77u, useItem: _ => { },
            sendAddShortcut: add, sendRemoveShortcut: rem);

        var payload = new ItemDragPayload(0x5001u, ItemDragSource.ShortcutBar, 3, slots[Row1[3]].Cell);
        ctrl.OnDragLift(slots[Row1[3]], slots[Row1[3]].Cell, payload);
        ctrl.HandleDropRelease(slots[Row1[5]], slots[Row1[5]].Cell, payload);

        Assert.Equal(0x5001u, slots[Row1[5]].Cell.ItemId);
        Assert.Equal(0x5002u, slots[Row1[3]].Cell.ItemId);
        Assert.Equal(new[] { 3u, 5u }, removes.ToArray());
        Assert.Contains((5u, 0x5001u), adds);
        Assert.Contains((3u, 0x5002u), adds);
    }

    [Fact]
    public void HandleDropRelease_ontoEmpty_placesOnly_sourceStaysEmpty()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable();
        repo.AddOrUpdate(new ClientObject { ObjectId = 0x5001u, WeenieClassId = 1u, IconId = 0x06001234u });
        var shortcuts = new System.Collections.Generic.List<PlayerDescriptionParser.ShortcutEntry>
        { new(Index: 3, ObjectGuid: 0x5001u, SpellId: 0, Layer: 0) };
        var (adds, removes) = NewSpies(out var add, out var rem);
        var ctrl = ToolbarController.Bind(layout, repo, () => shortcuts,
            iconIds: (_,_,_,_,_) => 0x77u, useItem: _ => { },
            sendAddShortcut: add, sendRemoveShortcut: rem);

        var payload = new ItemDragPayload(0x5001u, ItemDragSource.ShortcutBar, 3, slots[Row1[3]].Cell);
        ctrl.OnDragLift(slots[Row1[3]], slots[Row1[3]].Cell, payload);
        ctrl.HandleDropRelease(slots[Row1[7]], slots[Row1[7]].Cell, payload);

        Assert.Equal(0x5001u, slots[Row1[7]].Cell.ItemId);
        Assert.Equal(0u, slots[Row1[3]].Cell.ItemId);
        Assert.Contains((7u, 0x5001u), adds);
        Assert.DoesNotContain(adds, a => a.i == 3u);
    }

    [Fact]
    public void HandleDropRelease_ontoSelf_reAddsToSource()
    {
        var (layout, slots, _) = FakeToolbar();
        var repo = new ClientObjectTable();
        repo.AddOrUpdate(new ClientObject { ObjectId = 0x5001u, WeenieClassId = 1u, IconId = 0x06001234u });
        var shortcuts = new System.Collections.Generic.List<PlayerDescriptionParser.ShortcutEntry>
        { new(Index: 3, ObjectGuid: 0x5001u, SpellId: 0, Layer: 0) };
        var (adds, removes) = NewSpies(out var add, out var rem);
        var ctrl = ToolbarController.Bind(layout, repo, () => shortcuts,
            iconIds: (_,_,_,_,_) => 0x77u, useItem: _ => { },
            sendAddShortcut: add, sendRemoveShortcut: rem);

        var payload = new ItemDragPayload(0x5001u, ItemDragSource.ShortcutBar, 3, slots[Row1[3]].Cell);
        ctrl.OnDragLift(slots[Row1[3]], slots[Row1[3]].Cell, payload);            // slot 3 emptied
        ctrl.HandleDropRelease(slots[Row1[3]], slots[Row1[3]].Cell, payload);     // drop back on slot 3

        Assert.Equal(0x5001u, slots[Row1[3]].Cell.ItemId);   // re-added to source (net no-op)
        Assert.Contains((3u, 0x5001u), adds);                // AddShortcut(3, A) sent
        Assert.Single(removes);   // exactly RemoveShortcut(3) [from the lift]
        Assert.Single(adds);      // exactly AddShortcut(3, A) [the re-place]
    }

    [Fact]
    public void ToolbarSlots_useGreenCrossAcceptSprite()
    {
        var (layout, slots, _) = FakeToolbar();
        ToolbarController.Bind(layout, new ClientObjectTable(),
            () => System.Array.Empty<PlayerDescriptionParser.ShortcutEntry>(),
            iconIds: (_,_,_,_,_) => 0u, useItem: _ => { });
        Assert.Equal(0x060011FAu, slots[Row1[0]].Cell.DragAcceptSprite);   // green cross, not the ring F9
    }
}