using System;
using System.IO;
using AcDream.App.UI;
using AcDream.App.UI.Layout;
using DatReaderWriter;
using DatReaderWriter.Options;
using Xunit;

namespace AcDream.App.Tests.UI.Layout;

/// <summary>
/// Real-dat smoke test for the gmInventoryUI frame (0x21000023) import + the sub-window
/// mount. Locks the #145-continuation fix: the mount keeps each mounted panel slot's OWN
/// frame ZLevel instead of inheriting the sub-window root's ZLevel 1000. Before the fix the
/// merge's zero-wins-base rule gave the slots ZLevel 1000 → the #145 ZOrder fold
/// (ReadOrder − ZLevel·10000) sank them to ≈ −10,000,000, BEHIND the frame's Alphablend
/// backdrop (ZLevel 100 → ≈ −1,000,000), and the backdrop washed out the panels' captions,
/// burden meter, and item cells. Skips when the live dat directory is absent (CI).
/// </summary>
public class InventoryFrameImportProbe
{
    private const uint Frame          = 0x21000023u;
    private const uint Backdrop       = 0x100001D0u;   // full-window Alphablend backdrop (ZLevel 100)
    private const uint BackpackPanel  = 0x100001CEu;   // mounted gmBackpackUI slot
    private const uint ItemsPanel     = 0x100001CFu;   // mounted gm3DItemsUI slot
    private const uint PaperdollPanel = 0x100001CDu;   // mounted gmPaperDollUI slot
    private const uint BurdenMeter    = 0x100001D9u;   // backpack content (proves the mount attached it)
    private const uint ContentsGrid   = 0x100001C6u;   // 3D-items content

    private static string? DatDir()
    {
        var d = Environment.GetEnvironmentVariable("ACDREAM_DAT_DIR")
            ?? Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile),
                            "Documents", "Asheron's Call");
        return Directory.Exists(d) ? d : null;
    }

    [Fact]
    public void Paperdoll_equip_slots_resolve_to_item_lists()
    {
        var datDir = DatDir();
        if (datDir is null) return;   // CI: no live dat — skip

        using var dats = new DatCollection(datDir, DatAccessType.Read);
        var layout = LayoutImporter.Import(dats, Frame, _ => (0u, 0, 0), null);
        Assert.NotNull(layout);

        // A representative spread across the slot grid (head, shield, the weapon composite, cloak,
        // trinket, a finger). All inherit base 0x100001E4 → 0x2100003D (Type 0x10000031 = UIElement_ItemList).
        foreach (uint id in new[] { 0x100005ABu, 0x100001E1u, 0x100001DFu, 0x100005E9u, 0x1000058Eu, 0x100001DCu })
        {
            var el = layout!.FindElement(id);
            Assert.True(el is UiItemList,
                $"equip slot 0x{id:X8} resolved to {el?.GetType().Name ?? "null"}, expected UiItemList");
        }
    }

    [Fact]
    public void Mounted_panels_sit_in_front_of_the_backdrop()
    {
        var datDir = DatDir();
        if (datDir is null) return;   // CI: no live dat — skip (this is a smoke test)

        using var dats = new DatCollection(datDir, DatAccessType.Read);
        var layout = LayoutImporter.Import(dats, Frame, _ => (0u, 0, 0), null);
        Assert.NotNull(layout);

        var backdrop = layout!.FindElement(Backdrop);
        Assert.NotNull(backdrop);   // the full-window backdrop is a direct child of the frame

        // The sub-window mount brings each panel's content into the by-id index.
        Assert.NotNull(layout.FindElement(BurdenMeter));    // backpack burden meter
        Assert.NotNull(layout.FindElement(ContentsGrid));   // 3D-items contents grid

        // The fix: every mounted panel slot must draw IN FRONT of the backdrop
        // (higher ZOrder = painted later = on top), so the backdrop sits behind the content.
        foreach (var (id, name) in new[]
        {
            (BackpackPanel, "backpack"), (ItemsPanel, "3D-items"), (PaperdollPanel, "paperdoll"),
        })
        {
            var panel = layout.FindElement(id);
            Assert.True(panel is not null, $"{name} panel 0x{id:X8} missing from the imported tree");
            Assert.True(panel!.ZOrder > backdrop!.ZOrder,
                $"{name} panel ZOrder {panel.ZOrder} must be > backdrop ZOrder {backdrop.ZOrder} " +
                "(else the Alphablend backdrop overpaints/washes out the panel content)");
        }
    }
}