HellionChat/HellionChat/Ui/Windows/ChannelPopoutPool.cs

using HellionChat.Util;
using Microsoft.Extensions.Logging;

namespace HellionChat.Ui.Windows;

// Central orchestration: pre-allocates Config.MaxParallelPopouts pop-out
// windows via the injected factory, all registered once in the WindowSystem
// (PluginLifecycle.RegisterWindows, framework thread). Open/Close is IsOpen +
// Bind/Unbind only — NEVER runtime AddWindow/RemoveWindow (v1.4.9 Stage-2
// freeze lesson). Pure DI-sink: no PayloadHandler in the ctor.
internal sealed class ChannelPopoutPool
{
    private readonly List<ChannelPopoutWindow> _instances;
    private readonly PopoutSlotMap _slots;
    private readonly ILogger<ChannelPopoutPool> _logger;
    private readonly int _capacity;

    public ChannelPopoutPool(
        Func<int, ChannelPopoutWindow> windowFactory,
        ILogger<ChannelPopoutPool> logger
    )
    {
        _logger = logger;
        var capacity = Plugin.Config.MaxParallelPopouts;
        _capacity = capacity;
        _instances = new List<ChannelPopoutWindow>(capacity);
        for (var i = 0; i < capacity; i++)
            _instances.Add(windowFactory(i));
        _slots = new PopoutSlotMap(capacity);

        // Route each window's in-body close through the pool so closing releases
        // the slot. Wired here (post-construction) rather than via ctor to avoid
        // a Window->Pool edge that would re-enter pool resolution.
        foreach (var window in _instances)
            window.CloseRequested = TryClose;
    }

    // Iterated once by PluginLifecycle.RegisterWindows (framework thread) and
    // by ChannelPopoutInitHostedService (PayloadHandler setter).
    public IReadOnlyList<ChannelPopoutWindow> Instances => _instances;

    public bool TryOpen(Tab tab)
    {
        // A popped tab gets its own input bar, so strip stale tell state first —
        // otherwise a popped-out stale-tell tab would be a send surface that
        // bypasses the click-path activation strip. Previous = the main window's
        // active tab; popping the active tab itself must not strip (TR-4 guard).
        TabLifecycleHelpers.OnTabActivated(tab, Plugin.Instance.MainWindow?.ActiveTab);

        var slot = _slots.TryReserve(tab.Identifier);
        if (slot < 0)
        {
            _logger.LogWarning(
                "Channel popout pool is full ({Capacity} slots); ignoring open for {Name}.",
                _capacity,
                tab.Name
            );
            return false;
        }

        _instances[slot].Bind(tab);
        return true;
    }

    public void TryClose(Guid id)
    {
        var slot = _slots.Release(id);
        if (slot < 0)
            return; // idempotent: unknown/unbound id is a silent no-op

        _instances[slot].Unbind();
    }

    public bool IsOpen(Guid id) => _slots.IsActive(id);
}