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

namespace AcDream.App.Tests.UI.Layout;

public class PaperdollControllerTests
{
    private const uint Player = 0x50000001u;
    private const uint Pack   = 0x40000005u;
    private const uint HeadSlot   = 0x100005ABu;  // HeadWear 0x1
    private const uint ShieldSlot = 0x100001E1u;  // Shield 0x200000
    private const uint WeaponSlot = 0x100001DFu;  // composite 0x3500000
    private const uint FingerLSlot= 0x100001DCu;  // FingerWearLeft 0x40000

    private sealed class RootElement : UiElement { }

    private static (ImportedLayout layout, Dictionary<uint, UiItemList> lists) BuildLayout()
    {
        var ids = new[] { HeadSlot, ShieldSlot, WeaponSlot, FingerLSlot };
        var lists = new Dictionary<uint, UiItemList>();
        var byId  = new Dictionary<uint, UiElement>();
        var root  = new RootElement { Width = 224, Height = 214 };
        foreach (var id in ids)
        {
            var list = new UiItemList { Width = 32, Height = 32 };
            lists[id] = list; byId[id] = list; root.AddChild(list);
        }
        return (new ImportedLayout(root, byId), lists);
    }

    private static PaperdollController Bind(ImportedLayout layout, ClientObjectTable objects,
        List<(uint item, uint mask)>? wields = null, uint emptySlot = 0u)
        => PaperdollController.Bind(layout, objects, () => Player,
            iconIds: (_, _, _, _, _) => 0x1234u,
            sendWield: wields is null ? null : (i, m) => wields.Add((i, m)),
            emptySlotSprite: emptySlot);

    private static void SeedEquipped(ClientObjectTable t, uint guid, EquipMask loc)
    {
        t.AddOrUpdate(new ClientObject { ObjectId = guid, WielderId = Player });
        t.MoveItem(guid, Player, newSlot: -1, newEquipLocation: loc);
    }

    private static void SeedPackItem(ClientObjectTable t, uint guid, EquipMask validLocations)
    {
        t.AddOrUpdate(new ClientObject { ObjectId = guid, ValidLocations = validLocations });
        t.MoveItem(guid, Pack, newSlot: 0);
    }

    [Fact]
    public void Populate_shows_equipped_item_in_its_slot()
    {
        var (layout, lists) = BuildLayout();
        var objects = new ClientObjectTable();
        SeedEquipped(objects, 0xA01u, EquipMask.HeadWear);
        Bind(layout, objects);
        Assert.Equal(0xA01u, lists[HeadSlot].Cell.ItemId);   // helm in the head slot
        Assert.Equal(0u, lists[ShieldSlot].Cell.ItemId);     // shield slot empty
    }

    [Fact]
    public void Populate_matches_a_weapon_into_the_composite_slot()
    {
        var (layout, lists) = BuildLayout();
        var objects = new ClientObjectTable();
        SeedEquipped(objects, 0xB01u, EquipMask.MeleeWeapon);     // a sword's actual equip loc
        Bind(layout, objects);
        Assert.Equal(0xB01u, lists[WeaponSlot].Cell.ItemId);     // matched via (loc & composite) != 0
    }

    [Fact]
    public void OnDragOver_accepts_only_valid_locations()
    {
        var (layout, lists) = BuildLayout();
        var objects = new ClientObjectTable();
        SeedPackItem(objects, 0xC01u, EquipMask.HeadWear);       // a helm in the pack
        var ctrl = Bind(layout, objects);
        var payload = new ItemDragPayload(0xC01u, ItemDragSource.Inventory, 0, lists[HeadSlot].Cell);
        Assert.True(ctrl.OnDragOver(lists[HeadSlot],   lists[HeadSlot].Cell,   payload)); // helm → head OK
        Assert.False(ctrl.OnDragOver(lists[ShieldSlot], lists[ShieldSlot].Cell, payload)); // helm → shield NO
    }

    [Fact]
    public void HandleDropRelease_wields_optimistically_and_sends_wire()
    {
        var (layout, lists) = BuildLayout();
        var objects = new ClientObjectTable();
        SeedPackItem(objects, 0xD01u, EquipMask.HeadWear);
        var wields = new List<(uint item, uint mask)>();
        var ctrl = Bind(layout, objects, wields);
        var payload = new ItemDragPayload(0xD01u, ItemDragSource.Inventory, 0, lists[HeadSlot].Cell);
        ctrl.HandleDropRelease(lists[HeadSlot], lists[HeadSlot].Cell, payload);
        Assert.Equal(EquipMask.HeadWear, objects.Get(0xD01u)!.CurrentlyEquippedLocation); // equipped instantly
        Assert.Equal(Player, objects.Get(0xD01u)!.ContainerId);     // contained-by-wielder (the optimistic wield is ContainerId-based; it does NOT write WielderId)
        Assert.Single(wields);
        Assert.Equal((0xD01u, (uint)EquipMask.HeadWear), wields[0]);                       // GetAndWieldItem wire
    }

    [Fact]
    public void HandleDropRelease_resolves_the_finger_bit_for_a_dual_finger_ring()
    {
        var (layout, lists) = BuildLayout();
        var objects = new ClientObjectTable();
        SeedPackItem(objects, 0xE01u, EquipMask.FingerWearLeft | EquipMask.FingerWearRight);
        var wields = new List<(uint item, uint mask)>();
        var ctrl = Bind(layout, objects, wields);
        var payload = new ItemDragPayload(0xE01u, ItemDragSource.Inventory, 0, lists[FingerLSlot].Cell);
        ctrl.HandleDropRelease(lists[FingerLSlot], lists[FingerLSlot].Cell, payload);
        Assert.Equal((uint)EquipMask.FingerWearLeft, wields[0].mask);   // ValidLocations & slotMask = left finger only
    }

    [Fact]
    public void Empty_equip_slot_shows_the_configured_frame()  // visible frame so all positions are usable (Slice 1; the doll is Slice 2)
    {
        var (layout, lists) = BuildLayout();
        Bind(layout, new ClientObjectTable(), emptySlot: 0x06004D20u);
        Assert.Equal(0x06004D20u, lists[HeadSlot].Cell.EmptySprite);
    }

    [Fact]
    public void Live_player_wield_repaints_the_slot() // event-driven: ObjectMoved → Concerns → Populate
    {
        var (layout, lists) = BuildLayout();
        var objects = new ClientObjectTable();
        Bind(layout, objects);                                          // slots empty at bind
        SeedPackItem(objects, 0xF01u, EquipMask.HeadWear);              // a helm appears in the pack (not on the doll)
        Assert.Equal(0u, lists[HeadSlot].Cell.ItemId);
        objects.WieldItemOptimistic(0xF01u, Player, EquipMask.HeadWear); // player wields it → ObjectMoved(to=player)
        Assert.Equal(0xF01u, lists[HeadSlot].Cell.ItemId);             // the head slot repainted with the helm
    }

    [Fact]
    public void Live_npc_equip_does_not_appear_on_the_doll() // player-scoped: a remote creature's wielded item never leaks
    {
        var (layout, lists) = BuildLayout();
        var objects = new ClientObjectTable();
        Bind(layout, objects);
        const uint npc = 0x60000001u;
        objects.AddOrUpdate(new ClientObject
        {
            ObjectId = 0xF02u, WielderId = npc, CurrentlyEquippedLocation = EquipMask.HeadWear,
        });
        Assert.Equal(0u, lists[HeadSlot].Cell.ItemId);                 // the NPC's helm is NOT on the player's doll
    }
}