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

namespace AcDream.App.Tests.UI.Layout;

/// <summary>
/// Slice 5.4 — mirrors <see cref="ExternalContainerControllerTests"/>'s
/// harness shape (hand-built <see cref="ImportedLayout"/> over
/// <see cref="RetailWindowFrame.Mount"/>) for the behavioral suite, plus one
/// real-dat-fixture smoke test (mirroring
/// <c>AppraisalUiControllerTests</c>'s use of <see cref="FixtureLoader"/>)
/// that catches drift between the hardcoded ids in
/// <see cref="VendorUiController"/> and the actual LayoutDesc 0x21000012.
/// </summary>
public sealed class VendorUiControllerTests
{
    private const uint VendorGuid = 0x70000010u;
    private const uint ArmorItemGuid = 0x60000101u;
    private const uint FoodItemGuid = 0x60000102u;
    private const uint StackedItemGuid = 0x60000103u;

    private sealed class TestElement : UiElement { }

    [Fact]
    public void Bind_FromRealDatFixture_ResolvesAllRequiredControls()
    {
        ImportedLayout layout = FixtureLoader.LoadVendor();
        var screen = new UiRoot { Width = 1280f, Height = 800f };
        RetailWindowHandle window = RetailWindowFrame.Mount(
            screen,
            layout.Root,
            static _ => (0u, 0, 0),
            new RetailWindowFrame.Options
            {
                WindowName = "vendor-fixture-smoke",
                Chrome = RetailWindowChrome.Imported,
                Visible = false,
            });

        VendorUiController? controller = VendorUiController.Bind(
            layout,
            new VendorState(),
            window,
            static (_, _, _, _, _) => 0u);

        Assert.NotNull(controller);
    }

    private sealed class Harness
    {
        public readonly VendorState State = new();
        public readonly UiRoot Screen = new() { Width = 800f, Height = 600f };
        public readonly UiItemList ItemList = new();
        public readonly UiScrollbar ItemScrollbar = new();
        public readonly UiMenu TypeMenu = new();
        public readonly UiText ItemNameText = new();
        public readonly UiText ItemCostText = new();
        public readonly UiText ItemsTab = new();
        public readonly UiText BuyingTab = new();
        public readonly UiText SellingTab = new();
        public readonly UiElement ItemsPage = new TestElement();
        public readonly UiElement BuyingPage = new TestElement();
        public readonly UiElement SellingPage = new TestElement();
        public readonly UiButton CloseButton;
        public readonly RetailWindowHandle Window;
        public readonly VendorUiController Controller;

        public Harness()
        {
            var root = new TestElement { Width = 800f, Height = 110f };
            CloseButton = new UiButton(
                new ElementInfo { Id = VendorUiController.CloseId, Type = 1 },
                static _ => (0u, 0, 0));

            root.AddChild(CloseButton);
            root.AddChild(ItemsTab);
            root.AddChild(BuyingTab);
            root.AddChild(SellingTab);
            root.AddChild(ItemsPage);
            root.AddChild(BuyingPage);
            root.AddChild(SellingPage);
            ItemsPage.AddChild(ItemList);
            ItemsPage.AddChild(ItemScrollbar);
            ItemsPage.AddChild(TypeMenu);
            ItemsPage.AddChild(ItemNameText);
            ItemsPage.AddChild(ItemCostText);

            var layout = new ImportedLayout(root, new Dictionary<uint, UiElement>
            {
                [VendorUiController.CloseId] = CloseButton,
                [VendorUiController.ItemsTabId] = ItemsTab,
                [VendorUiController.BuyingTabId] = BuyingTab,
                [VendorUiController.SellingTabId] = SellingTab,
                [VendorUiController.ItemsPageId] = ItemsPage,
                [VendorUiController.BuyingPageId] = BuyingPage,
                [VendorUiController.SellingPageId] = SellingPage,
                [VendorUiController.ItemListId] = ItemList,
                [VendorUiController.ItemScrollbarId] = ItemScrollbar,
                [VendorUiController.TypeFilterMenuId] = TypeMenu,
                [VendorUiController.ItemNameTextId] = ItemNameText,
                [VendorUiController.ItemCostTextId] = ItemCostText,
            });

            Window = RetailWindowFrame.Mount(
                Screen,
                root,
                static _ => (0u, 0, 0),
                new RetailWindowFrame.Options
                {
                    WindowName = WindowNames.Vendor,
                    Chrome = RetailWindowChrome.Imported,
                    Visible = false,
                    Draggable = false,
                    Resizable = false,
                });

            Controller = VendorUiController.Bind(
                layout,
                State,
                Window,
                static (_, iconId, _, _, _) => iconId != 0u ? iconId + 1000u : 0u)!;
            Screen.WindowManager.AttachController(WindowNames.Vendor, Controller);
        }
    }

    private static VendorShopProfile Profile(
        float sellRate = 1.5f, uint altCurrency = 0u, string altName = "") =>
        new(0u, 0u, 0u, false, 1.0f, sellRate, altCurrency, 0u, altName);

    private static string GetText(UiText text)
        => string.Concat(text.LinesProvider().Select(line => line.Text));

    [Fact]
    public void Bind_WiresTheScrollbarToTheItemListsScrollModel()
    {
        var h = new Harness();

        Assert.True(h.ItemScrollbar.Horizontal);
        Assert.Same(h.ItemList.Scroll, h.ItemScrollbar.Model);
    }

    [Fact]
    public void Opened_ShowsWindowAndPopulatesFirstPresentCategoryInTableOrder()
    {
        var h = new Harness();
        var items = new[]
        {
            // Food is table entry #5, Armor is #1 — retail's fixed table
            // order, not insertion order, decides the default selection.
            new VendorShopItem(FoodItemGuid, -1, 1u, "Bread", (uint)ItemType.Food, 100u, 5),
            new VendorShopItem(ArmorItemGuid, -1, 2u, "Chainmail", (uint)ItemType.Armor, 200u, 500),
        };

        h.State.Apply(VendorGuid, Profile(), items);

        Assert.True(h.Window.IsVisible);
        Assert.True(h.ItemsPage.Visible);
        Assert.False(h.BuyingPage.Visible);
        Assert.False(h.SellingPage.Visible);
        Assert.Equal(1, h.ItemList.GetNumUIItems());
        Assert.Equal(ArmorItemGuid, h.ItemList.GetItem(0)!.ItemId);
        Assert.Equal("Armor", h.TypeMenu.Items.Single(i => Equals(i.Payload, h.TypeMenu.Selected)).Label);
    }

    [Fact]
    public void Closed_HidesWindowAndClearsListAndText()
    {
        var h = new Harness();
        h.State.Apply(VendorGuid, Profile(), new[]
        {
            new VendorShopItem(ArmorItemGuid, -1, 2u, "Chainmail", (uint)ItemType.Armor, 200u, 500),
        });
        h.ItemList.GetItem(0)!.Clicked?.Invoke();
        Assert.True(h.Window.IsVisible);
        Assert.NotEqual(string.Empty, GetText(h.ItemNameText));

        h.State.Close();

        Assert.False(h.Window.IsVisible);
        Assert.Equal(0, h.ItemList.GetNumUIItems());
        Assert.Equal(string.Empty, GetText(h.ItemNameText));
        Assert.Equal(string.Empty, GetText(h.ItemCostText));
        Assert.Empty(h.TypeMenu.Items);
    }

    [Fact]
    public void Reset_HidesWindowAndClearsContent()
    {
        var h = new Harness();
        h.State.Apply(VendorGuid, Profile(), new[]
        {
            new VendorShopItem(ArmorItemGuid, -1, 2u, "Chainmail", (uint)ItemType.Armor, 200u, 500),
        });

        h.State.Reset();

        Assert.False(h.Window.IsVisible);
        Assert.Equal(0, h.ItemList.GetNumUIItems());
    }

    [Fact]
    public void SelectingItem_ShowsRetailCorrectPerUnitPrice_ForStackedItem()
    {
        var h = new Harness();
        h.State.Apply(VendorGuid, Profile(sellRate: 2.0f), new[]
        {
            // Value=1000 is the STACK-TOTAL wire value for a 100-unit stack;
            // per-unit = 1000/100 = 10. SellPrice = ceil(2.0*10*1 - 0.1) = 20
            // (VendorPricing.SellPrice, ShopSystem::SellPrice pc:702107).
            new VendorShopItem(
                StackedItemGuid, -1, 3u, "Arrows", (uint)ItemType.MissileWeapon, 300u, 1000,
                DescStackSize: 100),
        });

        h.ItemList.GetItem(0)!.Clicked?.Invoke();

        Assert.Equal("Arrows", GetText(h.ItemNameText));
        Assert.Equal("20", GetText(h.ItemCostText));
    }

    [Fact]
    public void SelectingItem_WithAlternateCurrency_AppendsCurrencyName()
    {
        var h = new Harness();
        h.State.Apply(
            VendorGuid,
            Profile(sellRate: 1.0f, altCurrency: 0x12345678u, altName: "Trade Notes"),
            new[]
            {
                new VendorShopItem(ArmorItemGuid, -1, 2u, "Chainmail", (uint)ItemType.Armor, 200u, 50),
            });

        h.ItemList.GetItem(0)!.Clicked?.Invoke();

        Assert.Equal("50 Trade Notes", GetText(h.ItemCostText));
    }

    [Fact]
    public void SelectingDifferentCategory_FiltersItemListToThatCategoryOnly()
    {
        var h = new Harness();
        var armor = new VendorShopItem(ArmorItemGuid, -1, 2u, "Chainmail", (uint)ItemType.Armor, 200u, 500);
        var food = new VendorShopItem(FoodItemGuid, -1, 1u, "Bread", (uint)ItemType.Food, 100u, 5);
        h.State.Apply(VendorGuid, Profile(), new[] { armor, food });
        Assert.Equal(ArmorItemGuid, h.ItemList.GetItem(0)!.ItemId); // default: Armor (table order)

        object? foodPayload = h.TypeMenu.Items.First(i => i.Label == "Food").Payload;
        h.TypeMenu.OnSelect!.Invoke(foodPayload);

        Assert.Equal(1, h.ItemList.GetNumUIItems());
        Assert.Equal(FoodItemGuid, h.ItemList.GetItem(0)!.ItemId);
    }

    [Fact]
    public void CloseButton_RoutesThroughVendorStateClose_NotADirectFieldWrite()
    {
        var h = new Harness();
        h.State.Apply(VendorGuid, Profile(), new[]
        {
            new VendorShopItem(ArmorItemGuid, -1, 2u, "Chainmail", (uint)ItemType.Armor, 200u, 500),
        });

        h.CloseButton.OnClick!.Invoke();

        // The panel never mutates VendorState directly — the ONLY path from
        // the close button to a cleared session is VendorState.Close()
        // itself, so VendorId reads back 0 through the owner's own public
        // surface, not a private field poke.
        Assert.Equal(0u, h.State.VendorId);
        Assert.False(h.Window.IsVisible);
    }

    [Fact]
    public void SellingTab_SwitchesPageButPopulatesNoSellContent()
    {
        var h = new Harness();
        h.State.Apply(VendorGuid, Profile(), new[]
        {
            new VendorShopItem(ArmorItemGuid, -1, 2u, "Chainmail", (uint)ItemType.Armor, 200u, 500),
        });

        h.SellingTab.OnClick!.Invoke();

        Assert.True(h.SellingPage.Visible);
        Assert.False(h.ItemsPage.Visible);
        Assert.False(h.BuyingPage.Visible);
        // Slice 6 fence: no sell-list/price/button wiring exists at all —
        // the page is exactly the authored-empty container it started as.
        Assert.Empty(h.SellingPage.Children);
    }

    [Fact]
    public void BuyingTab_SwitchesPageButPopulatesNoBuyContent()
    {
        var h = new Harness();
        h.State.Apply(VendorGuid, Profile(), new[]
        {
            new VendorShopItem(ArmorItemGuid, -1, 2u, "Chainmail", (uint)ItemType.Armor, 200u, 500),
        });

        h.BuyingTab.OnClick!.Invoke();

        Assert.True(h.BuyingPage.Visible);
        Assert.False(h.ItemsPage.Visible);
        Assert.Empty(h.BuyingPage.Children);
    }

    [Fact]
    public void ItemsTab_ReselectedAfterVisitingOtherTabs_ShowsBrowseListAgain()
    {
        var h = new Harness();
        h.State.Apply(VendorGuid, Profile(), new[]
        {
            new VendorShopItem(ArmorItemGuid, -1, 2u, "Chainmail", (uint)ItemType.Armor, 200u, 500),
        });
        h.SellingTab.OnClick!.Invoke();

        h.ItemsTab.OnClick!.Invoke();

        Assert.True(h.ItemsPage.Visible);
        Assert.False(h.SellingPage.Visible);
        Assert.Equal(1, h.ItemList.GetNumUIItems());
    }
}