HellionChat/HellionChat/Ui/CommandHelpWindow.cs

using System.Numerics;
using Dalamud.Bindings.ImGui;
using Dalamud.Interface.Utility;
using Dalamud.Interface.Windowing;
using Dalamud.Utility;
using HellionChat.Ui.Components;
using HellionChat.Util;
using Lumina.Text.ReadOnly;
using Microsoft.Extensions.Logging;

namespace HellionChat.Ui;

internal sealed class CommandHelpWindow : Window
{
    private readonly ChunkRenderer _chunkRenderer;
    private readonly ILogger<CommandHelpWindow> _logger;

    // Setter-injected post-ctor to break the InputBar -> CommandHelpWindow ->
    // MainWindow -> InputBar singleton cycle (MS.DI does not detect cycles
    // through FactoryCallSite registrations). Wired in
    // CommandHelpWindowInitHostedService.StartAsync, same setter-injection pattern as
    // MessageList.AttachPayloadHandler.
    private Windows.MainWindow? _mainWindow;

    private ReadOnlySeString? _commandDescription;

    internal CommandHelpWindow(ChunkRenderer chunkRenderer, ILogger<CommandHelpWindow> logger)
        : base("command help##chat2-commandhelp")
    {
        _chunkRenderer = chunkRenderer;
        _logger = logger;

        Flags =
            ImGuiWindowFlags.NoSavedSettings
            | ImGuiWindowFlags.NoTitleBar
            | ImGuiWindowFlags.NoMove
            | ImGuiWindowFlags.NoResize
            | ImGuiWindowFlags.NoFocusOnAppearing
            | ImGuiWindowFlags.AlwaysAutoResize;

        RespectCloseHotkey = false;
        DisableWindowSounds = true;

        // Logger injected for future diagnostic hooks; no call sites yet.
        _ = _logger;
    }

    internal void AttachMainWindow(Windows.MainWindow mainWindow) => _mainWindow = mainWindow;

    public void UpdateContent(ReadOnlySeString commandDesc)
    {
        // Loud-fail if the HostedService didn't run AttachMainWindow before
        // the first slash-command call — better than a silent NullRef during
        // input draw.
        if (_mainWindow is null)
            throw new InvalidOperationException(
                "CommandHelpWindow.UpdateContent called before AttachMainWindow."
            );

        _commandDescription = commandDesc;

        var width = 350;
        var scaledWidth = width * ImGuiHelpers.GlobalScale;
        var pos = _mainWindow.LastWindowPos;
        switch (Plugin.Config.CommandHelpSide)
        {
            case CommandHelpSide.Right:
                pos.X += _mainWindow.LastWindowSize.X;
                break;
            case CommandHelpSide.Left:
                pos.X -= scaledWidth;
                break;
            case CommandHelpSide.None:
            default:
                IsOpen = false;
                return;
        }

        Position = pos;
        SizeConstraints = new WindowSizeConstraints
        {
            // scaledWidth keeps size constraints in the same coordinate space as
            // Position so the help window stays correct width at non-100% DPI.
            MinimumSize = new Vector2(scaledWidth, 0),
            MaximumSize = _mainWindow.LastWindowSize with { X = scaledWidth },
        };

        IsOpen = true;
    }

    public override void Draw()
    {
        if (_commandDescription == null)
            return;

        var chunks = ChunkUtil
            .ToChunks(_commandDescription.Value.ToDalamudString(), ChunkSource.None, null)
            .ToList();

        // Command-help chunks are read-only description text — no click-targets.
        _chunkRenderer.DrawChunks(chunks, wrap: true, handler: null, lineWidth: 0f);
    }
}