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 InventoryControllerTests
{
    private const uint Player = 0x50000001u;

    // UiElement is abstract — a concrete, parameterless stand-in for the root + caption hosts
    // (the real captions are Type-0 → UiDatElement; in tests we only need a host that holds children).
    private sealed class TestElement : UiElement { }

    // Element ids (spec §1).
    private const uint ContentsGrid    = 0x100001C6u;
    private const uint ContainerList   = 0x100001CAu;
    private const uint TopContainer    = 0x100001C9u;
    private const uint BurdenMeter     = 0x100001D9u;
    private const uint BurdenText      = 0x100001D8u;
    private const uint BurdenCaption   = 0x100001D7u;
    private const uint ContentsCaption = 0x100001C5u;

    private static (ImportedLayout layout, UiItemList grid, UiItemList containers,
                    UiItemList top, UiMeter meter, UiElement burdenText,
                    UiElement burdenCap, UiElement contentsCap) BuildLayout()
    {
        var grid        = new UiItemList { Width = 192, Height = 96 };
        var containers  = new UiItemList { Width = 36,  Height = 252 };
        var top         = new UiItemList { Width = 36,  Height = 36 };
        var meter       = new UiMeter    { Width = 11,  Height = 58 };
        var burdenText  = new TestElement { Width = 36,  Height = 15 };
        var burdenCap   = new TestElement { Width = 36,  Height = 15 };
        var contentsCap = new TestElement { Width = 192, Height = 15 };
        var root        = new TestElement { Width = 300, Height = 362 };
        root.AddChild(grid); root.AddChild(containers); root.AddChild(top);
        root.AddChild(meter); root.AddChild(burdenText); root.AddChild(burdenCap);
        root.AddChild(contentsCap);
        var byId = new Dictionary<uint, UiElement>
        {
            [ContentsGrid]    = grid, [ContainerList] = containers, [TopContainer] = top,
            [BurdenMeter]     = meter, [BurdenText] = burdenText, [BurdenCaption] = burdenCap,
            [ContentsCaption] = contentsCap,
        };
        return (new ImportedLayout(root, byId), grid, containers, top, meter,
                burdenText, burdenCap, contentsCap);
    }

    private static InventoryController Bind(ImportedLayout layout, ClientObjectTable objects,
        int? strength = 100)
        => InventoryController.Bind(layout, objects, () => Player,
            iconIds: (_, _, _, _, _) => 0u,        // no real GL upload in tests
            strength: () => strength, datFont: null);

    // Place an object in a container at a slot via the faithful production path:
    // AddOrUpdate registers it, MoveItem sets ContainerId+ContainerSlot and calls Reindex
    // (the same machinery server-driven moves use), so GetContents returns it slot-ordered.
    private static void SeedContained(ClientObjectTable t, uint guid, uint container, int slot,
        int burden = 0, ItemType type = ItemType.None)
    {
        t.AddOrUpdate(new ClientObject { ObjectId = guid, Burden = burden, Type = type });
        t.MoveItem(guid, container, slot);
    }

    [Fact]
    public void Populate_fills_contents_grid_with_loose_items_only()
    {
        var (layout, grid, containers, _, _, _, _, _) = BuildLayout();
        var objects = new ClientObjectTable();
        // Seed via the indexed path: AddOrUpdate registers the object, MoveItem places it in
        // the container at a slot (the faithful "server moved item into container" flow that
        // calls Reindex). GetContents — retail's per-container list — then returns them ordered.
        SeedContained(objects, 0xA, Player, slot: 0, burden: 10);                // loose
        SeedContained(objects, 0xB, Player, slot: 1, burden: 20);                // loose
        SeedContained(objects, 0xC, Player, slot: 2, type: ItemType.Container);  // side bag

        Bind(layout, objects);

        Assert.Equal(2, grid.GetNumUIItems());          // 2 loose
        Assert.Equal(0xAu, grid.GetItem(0)!.ItemId);
        Assert.Equal(0xBu, grid.GetItem(1)!.ItemId);
        Assert.Equal(1, containers.GetNumUIItems());     // 1 side bag
        Assert.Equal(0xCu, containers.GetItem(0)!.ItemId);
    }

    [Fact]
    public void Equipped_items_are_excluded_from_the_grid_and_selector()
    {
        var (layout, grid, containers, _, _, _, _, _) = BuildLayout();
        var objects = new ClientObjectTable();
        SeedContained(objects, 0xA, Player, slot: 0);                 // loose pack item
        // A self-wielded item: MoveItem with an equip location indexes it under the player
        // (the live wield path), but it must NOT show in the pack grid or the selector.
        objects.AddOrUpdate(new ClientObject { ObjectId = 0xD });
        objects.MoveItem(0xD, Player, newSlot: 1, newEquipLocation: EquipMask.MeleeWeapon);

        Bind(layout, objects);

        Assert.Equal(1, grid.GetNumUIItems());          // only the loose item
        Assert.Equal(0xAu, grid.GetItem(0)!.ItemId);
        Assert.Equal(0, containers.GetNumUIItems());    // equipped item is not a side bag either
    }

    [Fact]
    public void Grid_is_six_columns_thirtytwo_px()
    {
        var (layout, grid, _, _, _, _, _, _) = BuildLayout();
        Bind(layout, new ClientObjectTable());
        Assert.Equal(6, grid.Columns);
        Assert.Equal(32f, grid.CellWidth);
        Assert.Equal(32f, grid.CellHeight);
    }

    [Fact]
    public void ObjectAdded_for_player_item_rebuilds_grid()
    {
        var (layout, grid, _, _, _, _, _, _) = BuildLayout();
        var objects = new ClientObjectTable();
        Bind(layout, objects);
        Assert.Equal(0, grid.GetNumUIItems());

        objects.Ingest(new WeenieData(0xA, "Sword", ItemType.MeleeWeapon, 1, 0, 0, 0, 0,
            null, null, null, 5, Player, null, null, null, null, null, null, null, null, null));

        Assert.Equal(1, grid.GetNumUIItems());
        Assert.Equal(0xAu, grid.GetItem(0)!.ItemId);
    }

    [Fact]
    public void Burden_meter_fill_and_percent_from_load()
    {
        var (layout, _, _, _, meter, burdenText, _, _) = BuildLayout();
        var objects = new ClientObjectTable();
        // Str 100 → capacity 15000. Carried 7500 → load 0.5 → fill 0.1667, "50%".
        objects.AddOrUpdate(new ClientObject { ObjectId = 0xA, ContainerId = Player, Burden = 7500 });
        Bind(layout, objects, strength: 100);

        Assert.Equal(0.16667f, meter.Fill() ?? -1f, 3);
        Assert.True(meter.Vertical);
        // The % text caption child reads "50%".
        Assert.Contains("50%", CaptionText(burdenText));
    }

    [Fact]
    public void Captions_render_known_strings()
    {
        var (layout, _, _, _, _, _, burdenCap, contentsCap) = BuildLayout();
        Bind(layout, new ClientObjectTable());
        Assert.Contains("Burden", CaptionText(burdenCap));
        Assert.Contains("Contents of Backpack", CaptionText(contentsCap));
    }

    // Reads the text of the UiText caption child attached by the controller.
    private static string CaptionText(UiElement host)
    {
        foreach (var c in host.Children)
            if (c is UiText t)
            {
                var lines = t.LinesProvider();
                if (lines.Count > 0) return lines[0].Text;
            }
        return "";
    }
}