using System;
using System.Collections.Generic;
using System.Linq;
using DatReaderWriter;
using DatReaderWriter.DBObjs;
using DatReaderWriter.Options;
using DatReaderWriter.Types;
using Xunit;
using Xunit.Abstractions;

namespace AcDream.App.Tests.UI;

/// <summary>
/// Campaign CH slice CH2, task C.7: a one-shot diagnostic sweep of every
/// installed <see cref="LayoutDesc"/> for an element of retail's SpewBox
/// class (<c>0x10000016</c> — <c>gmSpewBoxUI::GetUIElementType @0x004D5AA0</c>).
/// Not a gate/conformance test — just a discovery tool, per the research
/// doc's §8.1/§8.2 open question. Skips (does not fail) when the installed
/// DAT directory is unavailable, matching every other
/// <c>ContentConformanceDats.ResolveDatDir()</c>-gated diagnostic in this
/// tree.
///
/// <para>
/// <b>RESULT (2026-08-09, run against the installed <c>client_portal.dat</c>),
/// WORDING CORRECTED at the CH2 re-review nits pass
/// (<c>docs/plans/2026-08-09-chat-parity-campaign.md</c>, nit 6):</b> this
/// pass's id source, <c>allIds</c> below, is
/// <c>dats.GetAllIdsOfType&lt;LayoutDesc&gt;()</c> — the top-level AGGREGATE
/// accessor — NOT <c>dats.Portal.GetAllIdsOfType&lt;LayoutDesc&gt;()</c>,
/// which the very next line prints and which reports a count of
/// <b>ZERO</b>. The loop below then queries those aggregate ids against
/// <c>dats.Portal.TryGet</c>, a database whose own id enumeration for this
/// type is empty — so the original "the sweep is therefore EXHAUSTIVE...
/// finds ZERO elements... anywhere" conclusion never actually established
/// anything about <c>dats.Portal</c>: it iterated ids sourced from
/// elsewhere against a database that cannot be enumerated the same way.
/// The id-space/sanity-check numbers below (CLOSED range
/// <c>0x21000000</c>-<c>0x21000075</c>, 118 possible ids, 101 populated,
/// 3 known ids present) describe THAT aggregate list, not Portal's own.
/// What IS established — from the separate <c>dats.Local</c> sweep, see
/// RESULT 2 below — is that <c>client_local_English.dat</c> hosts the
/// SpewBox layout at LayoutDesc <c>0x21000011</c>. Whether
/// <c>dats.Portal</c> ALSO carries a <c>0x10000016</c> element remains
/// UNESTABLISHED; this sweep did not meaningfully search it. LayoutDesc
/// <c>0x10000012</c> — the id the decompiled
/// <c>CreateChildElementByEnum(null, 0x10000012, 0x1000004A)</c> call
/// appears to reference — exists but has zero top-level elements (it is
/// not the per-line template catalog; that id must resolve through a
/// different mechanism than a direct <c>dats.Get&lt;LayoutDesc&gt;</c> hit,
/// which this slice did not crack).
/// </para>
///
/// <para>
/// <b>RESULT 2, CH2 REJECT-review rework NIT 3
/// (2026-08-09, docs/research/2026-08-09-ch2-review-findings.md):</b> the
/// FIRST result above only ever swept <c>dats.Portal</c>. Extending the
/// IDENTICAL sweep to <c>dats.Local</c> (<c>client_local_English.dat</c>)
/// FINDS it: LayoutDesc <c>0x21000011</c>, element <c>0x10000048</c>
/// (class <c>0x10000016</c>), position <c>(0,0)</c> relative to its parent,
/// size <c>450×72</c>, one child — ListBox <c>0x10000049</c> (matching
/// <c>gmSpewBoxUI::PostInit</c>'s <c>GetChildRecursive(0x10000049)</c> call
/// verbatim, though its own widget-class <c>Type</c> is <c>0x00000005</c>,
/// NOT the id <c>0x10000049</c> — <c>GetChildRecursive</c> searches by
/// <c>ElementId</c>, not <c>Type</c>) — carrying <c>MaxConcurrentItems</c>
/// (property <c>0x10000028</c>) = <c>4</c>. <c>gmSpewBoxUI</c> IS
/// dat-authored after all; the earlier "mounted directly from C++ code...
/// not resolved from any authored LayoutDesc tree" conclusion was an
/// artifact of only having checked one of the two locale-bearing dats.
/// Extent and <c>MaxConcurrentItems</c> are now AUTHORED, not invented —
/// see <see cref="AcDream.Core.Chat.SpewBoxState.MaxConcurrentItems"/> and
/// <c>SpewBoxController</c>'s own doc comments, and register row AP-178.
/// Absolute screen position (the element's parent, hence its true screen
/// offset, is still unidentified) and colour (no colour property surfaced
/// in this element's direct-state dump; the per-<c>UIStateId</c>
/// <c>States</c> dictionary was not walked) remain open.
/// </para>
/// </summary>
public sealed class SpewBoxLayoutDumpDiagnostic
{
    private readonly ITestOutputHelper _out;
    public SpewBoxLayoutDumpDiagnostic(ITestOutputHelper output) => _out = output;

    private const uint SpewBoxElementClass = 0x10000016u;
    private const uint ListBoxElementClass = 0x10000049u;
    private const uint LineTemplateLayoutEnum = 0x10000012u;
    private const uint LineTemplateElementId = 0x1000004Au;
    private const uint ListBoxMaxItemsProperty = 0x10000028u;

    private static string? ResolveDatDir()
    {
        var fromEnv = System.Environment.GetEnvironmentVariable("ACDREAM_DAT_DIR");
        if (!string.IsNullOrWhiteSpace(fromEnv) && System.IO.Directory.Exists(fromEnv))
            return fromEnv;
        var def = System.IO.Path.Combine(
            System.Environment.GetFolderPath(System.Environment.SpecialFolder.UserProfile),
            "Documents", "Asheron's Call");
        return System.IO.Directory.Exists(def) ? def : null;
    }

    [Fact]
    public void SweepInstalledLayoutDescs_ForSpewBoxElementClass()
    {
        string? datDir = ResolveDatDir();
        if (datDir is null)
        {
            _out.WriteLine("SKIP: installed retail DAT directory is unavailable.");
            return;
        }

        using var dats = new DatCollection(datDir, DatAccessType.Read);

        int scanned = 0;
        var hits = new List<(uint LayoutId, ElementDesc Element)>();
        var allIds = dats.GetAllIdsOfType<LayoutDesc>().ToList();
        _out.WriteLine($"Portal.GetAllIdsOfType<LayoutDesc> count: {dats.Portal.GetAllIdsOfType<LayoutDesc>().Count()}");
        _out.WriteLine($"HighRes.GetAllIdsOfType<LayoutDesc> count: {dats.HighRes.GetAllIdsOfType<LayoutDesc>().Count()}");
        _out.WriteLine($"Contains known char-window 0x2100002E: {allIds.Contains(0x2100002Eu)}");
        _out.WriteLine($"Contains known inventory 0x21000023: {allIds.Contains(0x21000023u)}");
        _out.WriteLine($"Contains known toolbar 0x21000016: {allIds.Contains(0x21000016u)}");
        _out.WriteLine($"Min id: 0x{allIds.Min():X8}  Max id: 0x{allIds.Max():X8}");

        foreach (uint layoutId in allIds)
        {
            scanned++;
            if (!dats.Portal.TryGet<LayoutDesc>(layoutId, out LayoutDesc? ld) || ld is null)
                continue;

            foreach (var kv in ld.Elements)
            {
                var found = FindByType(kv.Value, SpewBoxElementClass);
                if (found is not null)
                    hits.Add((layoutId, found));
            }
        }

        _out.WriteLine($"Scanned {scanned} installed LayoutDescs.");
        _out.WriteLine($"Elements of class 0x{SpewBoxElementClass:X8} (gmSpewBoxUI): {hits.Count}");

        foreach (var (layoutId, element) in hits)
        {
            _out.WriteLine(
                $"  LayoutDesc 0x{layoutId:X8} -> element 0x{element.ElementId:X8} "
                + $"pos=({element.X},{element.Y}) size=({element.Width}x{element.Height}) "
                + $"zLevel={element.ZLevel} readOrder={element.ReadOrder} "
                + $"children={element.Children.Count}");

            var listBox = FindByType(element, ListBoxElementClass);
            if (listBox is not null)
            {
                _out.WriteLine(
                    $"    ListBox child 0x{listBox.ElementId:X8} "
                    + $"pos=({listBox.X},{listBox.Y}) size=({listBox.Width}x{listBox.Height})");
                DumpProperties(listBox, "      ", _out.WriteLine);
            }
            else
            {
                _out.WriteLine("    (no ListBox child of class 0x10000049 found)");
            }
        }

        // Also probe the presumed shared line-template catalog directly —
        // gmSpewBoxUI::Update's CreateChildElementByEnum(null, 0x10000012,
        // 0x1000004A) call implies LayoutDesc 0x10000012 hosts a template
        // catalog with a top-level entry 0x1000004A.
        if (dats.Portal.TryGet<LayoutDesc>(LineTemplateLayoutEnum, out LayoutDesc? templateLd)
            && templateLd is not null)
        {
            _out.WriteLine($"LayoutDesc 0x{LineTemplateLayoutEnum:X8} exists ({templateLd.Elements.Count} top-level elements).");
            if (templateLd.Elements.TryGetValue(LineTemplateElementId, out ElementDesc? lineTemplate))
            {
                _out.WriteLine(
                    $"  Line template 0x{LineTemplateElementId:X8}: type=0x{lineTemplate.Type:X8} "
                    + $"pos=({lineTemplate.X},{lineTemplate.Y}) size=({lineTemplate.Width}x{lineTemplate.Height})");
                DumpProperties(lineTemplate, "    ", _out.WriteLine);
            }
            else
            {
                _out.WriteLine($"  No top-level element 0x{LineTemplateElementId:X8} in that LayoutDesc.");
            }
        }
        else
        {
            _out.WriteLine($"LayoutDesc 0x{LineTemplateLayoutEnum:X8} does not exist in the installed DAT.");
        }

        // CH2 REJECT-review rework, NIT 3
        // (docs/research/2026-08-09-ch2-review-findings.md): the original
        // sweep above never consulted dats.Local (client_local_English.dat
        // — research doc §8.1 names this file, not client_portal.dat, as
        // the one that might carry locale-specific UI text/layout
        // resources). Repeat the exact same class-0x10000016 sweep against
        // Local's own LayoutDesc id space before trusting AP-178's
        // "not dat-authored, no LayoutDesc dump can recover this" wording.
        var localHits = new List<(uint LayoutId, ElementDesc Element)>();
        int localScanned = 0;
        List<uint> localIds = dats.Local.GetAllIdsOfType<LayoutDesc>().ToList();
        _out.WriteLine($"Local.GetAllIdsOfType<LayoutDesc> count: {localIds.Count}");
        if (localIds.Count > 0)
            _out.WriteLine($"Local min id: 0x{localIds.Min():X8}  Local max id: 0x{localIds.Max():X8}");

        foreach (uint layoutId in localIds)
        {
            localScanned++;
            if (!dats.Local.TryGet<LayoutDesc>(layoutId, out LayoutDesc? ld) || ld is null)
                continue;

            foreach (var kv in ld.Elements)
            {
                var found = FindByType(kv.Value, SpewBoxElementClass);
                if (found is not null)
                    localHits.Add((layoutId, found));
            }
        }

        _out.WriteLine($"Scanned {localScanned} dats.Local LayoutDescs.");
        _out.WriteLine(
            $"dats.Local elements of class 0x{SpewBoxElementClass:X8} (gmSpewBoxUI): {localHits.Count}");

        foreach (var (layoutId, element) in localHits)
        {
            _out.WriteLine(
                $"  [Local] LayoutDesc 0x{layoutId:X8} -> element 0x{element.ElementId:X8} "
                + $"pos=({element.X},{element.Y}) size=({element.Width}x{element.Height}) "
                + $"zLevel={element.ZLevel} readOrder={element.ReadOrder} "
                + $"leftEdge={element.LeftEdge} topEdge={element.TopEdge} "
                + $"rightEdge={element.RightEdge} bottomEdge={element.BottomEdge} "
                + $"baseElement=0x{element.BaseElement:X8} baseLayoutId=0x{element.BaseLayoutId:X8} "
                + $"children={element.Children.Count}");
            DumpProperties(element, "    ", _out.WriteLine);
            foreach (var (childId, child) in element.Children)
            {
                _out.WriteLine(
                    $"    child 0x{childId:X8}: type=0x{child.Type:X8} "
                    + $"pos=({child.X},{child.Y}) size=({child.Width}x{child.Height})");
                DumpProperties(child, "      ", _out.WriteLine);
            }

            // NIT 3 finding: gmSpewBoxUI::PostInit's GetChildRecursive(0x10000049)
            // searches by ELEMENT ID, not by the widget CLASS (Type) —
            // ListBoxElementClass below was the wrong axis to search on
            // (it collided with the decomp's 0x10000049 constant, which is
            // actually this instance's authored ElementId; the ListBox
            // widget's own Type turned out to be 0x00000005). Look the
            // child up directly by the ElementId the decomp names.
            if (element.Children.TryGetValue(ListBoxElementClass, out ElementDesc? listBoxById))
            {
                _out.WriteLine(
                    $"    [Local] ListBox-by-ElementId 0x{listBoxById.ElementId:X8} "
                    + $"(Type=0x{listBoxById.Type:X8}) "
                    + $"pos=({listBoxById.X},{listBoxById.Y}) size=({listBoxById.Width}x{listBoxById.Height})");
            }

            var listBox = FindByType(element, ListBoxElementClass);
            if (listBox is not null)
            {
                _out.WriteLine(
                    $"    [Local] ListBox-by-Type child 0x{listBox.ElementId:X8} "
                    + $"pos=({listBox.X},{listBox.Y}) size=({listBox.Width}x{listBox.Height})");
                DumpProperties(listBox, "      ", _out.WriteLine);
            }
        }

        if (dats.Local.TryGet<LayoutDesc>(LineTemplateLayoutEnum, out LayoutDesc? localTemplateLd)
            && localTemplateLd is not null)
        {
            _out.WriteLine(
                $"[Local] LayoutDesc 0x{LineTemplateLayoutEnum:X8} exists "
                + $"({localTemplateLd.Elements.Count} top-level elements).");
        }
        else
        {
            _out.WriteLine($"[Local] LayoutDesc 0x{LineTemplateLayoutEnum:X8} does not exist.");
        }

        // Informational only — this is a discovery sweep, not a pass/fail gate.
        // The findings are transcribed into WeenieErrorMessages/SpewBoxController
        // doc comments and the divergence register by hand after reading this
        // output; there is nothing here worth asserting on.
    }

    private static ElementDesc? FindByType(ElementDesc d, uint type)
    {
        if (d.Type == type)
            return d;
        foreach (var kv in d.Children)
        {
            var found = FindByType(kv.Value, type);
            if (found is not null)
                return found;
        }
        return null;
    }

    private static void DumpProperties(ElementDesc d, string indent, Action<string> write)
    {
        // NIT 3 fix (docs/research/2026-08-09-ch2-review-findings.md): this
        // used to write to Console.WriteLine unconditionally, which xUnit's
        // "Standard Output Messages" capture does NOT show — a latent bug
        // that only mattered once a hit with an actual property to dump
        // existed (the original Portal-only sweep found none). Routed
        // through the caller's ITestOutputHelper.WriteLine so a future run
        // actually surfaces this.
        if (d.StateDesc?.Properties is null)
        {
            write($"{indent}(no direct-state properties)");
            return;
        }

        foreach (var (propertyId, property) in d.StateDesc.Properties)
        {
            write($"{indent}property 0x{propertyId:X8} = {Describe(property)}"
                + (propertyId == ListBoxMaxItemsProperty ? "  <-- MaxConcurrentItems" : ""));
        }
    }

    private static string Describe(object property) => property switch
    {
        DatReaderWriter.Types.EnumBaseProperty e => $"Enum({e.Value})",
        DatReaderWriter.Types.DataIdBaseProperty did => $"DataId(0x{did.Value:X8})",
        DatReaderWriter.Types.ArrayBaseProperty arr => $"Array[{arr.Value.Count}]({string.Join(", ", arr.Value.Select(Describe))})",
        // NIT 3 fix: the original switch had no case for these two —
        // Integer is exactly the type MaxConcurrentItems (property
        // 0x10000028) uses, so without this case the diagnostic could
        // find the property but never print its actual authored value.
        DatReaderWriter.Types.IntegerBaseProperty i => $"Integer({i.Value})",
        DatReaderWriter.Types.BoolBaseProperty b => $"Bool({b.Value})",
        _ => property.ToString() ?? "?",
    };
}