HellionChat/HellionChat/AutoTellTabsService.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using Dalamud.Game.Text;
using Dalamud.Game.Text.SeStringHandling;
using Dalamud.Interface.ImGuiNotification;
using HellionChat.Code;
using HellionChat.GameFunctions.Types;
using HellionChat.Resources;
using HellionChat.Util;
using Microsoft.Extensions.Logging;

namespace HellionChat;

// Auto-Tell-Tabs: spawns session-only tabs per /tell partner.
// Subscribes to MessageManager.MessageProcessed and ClientState.Logout.
internal sealed class AutoTellTabsService : IDisposable
{
    private readonly Plugin _plugin;
    private readonly MessageManager _messageManager;
    private readonly MessageStore _store;
    private readonly ILogger<AutoTellTabsService> _logger;

    // Tabs-list structure lock now lives on Plugin (neutral owner) so the
    // MessageManager refilter can share it. See Plugin.TabsListLock / B3.
    private object TabsListLock => _plugin.TabsListLock;

    // Bumped whenever something wipes unpinned temp tabs wholesale (logout).
    // HandleTell reads it before releasing the lock and re-checks after, so a
    // tab built in between is discarded instead of outliving the wipe.
    private int _tabGeneration;

    // Hard cap on pinned TempTabs so the sidebar doesn't inflate over years
    // of usage. Separate pool from AutoTellTabsLimit (15) — pinned tabs live
    // in their own bucket. A configurable cap is a vault-backlog anchor for
    // a later cycle if tester feedback demands it.
    internal const int MaxPinnedTempTabs = 5;

    private bool _initialized;

    // Set when Initialize ran before a character was available; cleared once the
    // history has actually been loaded.
    private bool _rehydratePending;

    internal AutoTellTabsService(
        Plugin plugin,
        MessageManager messageManager,
        MessageStore store,
        ILogger<AutoTellTabsService> logger
    )
    {
        _plugin = plugin;
        _messageManager = messageManager;
        _store = store;
        _logger = logger;
    }

    // Derived from the tab list on read. Pin/Unpin/Promote/Logout simply
    // mutate IsPinned or remove tabs — the count adapts automatically.
    // Replaces the F2.1 Interlocked counter because the new pin-state
    // transitions are cold-path and don't need lock-free reads.
    internal int ActiveTempTabCount =>
        Plugin.Config.Tabs.Count(TabLifecycleHelpers.IsInUnpinnedPool);

    internal int PinnedTempTabCount => Plugin.Config.Tabs.Count(TabLifecycleHelpers.IsInPinnedPool);

    internal void Initialize()
    {
        if (_initialized)
        {
            return;
        }

        // Pinned tabs come out of the JSON with TellTarget set but
        // CurrentChannel reset (NonSerialized). Without re-seeding, the chat
        // input has no tell-target on the active pinned tab, and the
        // game-side channel hook only repaints CurrentChannel once the user
        // triggers a /tell or channel switch.
        RehydratePinnedTabs();

        _messageManager.MessageProcessed += HandleTell;
        Plugin.ClientState.Login += OnLogin;
        Plugin.ClientState.Logout += OnLogout;
        _initialized = true;
    }

    // Deferred when the plugin starts before a character is logged in, which is
    // the normal case: the game loads plugins at boot. CurrentContentId is 0
    // until then, so the history query would look up tells for character zero,
    // find none, and leave every pinned tab blank for the whole session.
    //
    // Only visible to someone who actually pins a tell tab AND starts the game
    // with the plugin already installed. Reloading the plugin in a running
    // session -- what a developer does all day -- hides it completely.
    private void RehydratePinnedTabs()
    {
        if (_messageManager.CurrentContentId == 0)
        {
            _logger.LogDebug("[Pin] Rehydrate deferred: no character yet, waiting for login");
            _rehydratePending = true;
            return;
        }

        _rehydratePending = false;

        var pinned = Plugin.Config.Tabs.Count(TabLifecycleHelpers.IsInPinnedPool);
        _logger.LogDebug($"[Pin] Rehydrate scan: {pinned} pinned tab(s) found");

        foreach (var tab in Plugin.Config.Tabs)
        {
            if (!TabLifecycleHelpers.IsInPinnedPool(tab))
                continue;

            if (tab.TellTarget is null || !tab.TellTarget.IsSet())
            {
                _logger.LogWarning(
                    $"[Pin] Pinned tab '{tab.Name}' has no usable TellTarget "
                        + $"(Name={tab.TellTarget?.Name ?? "<null>"} World={tab.TellTarget?.World ?? 0}). "
                        + "Chat input on this tab will be empty until the partner sends a tell or you /tell manually."
                );
                continue;
            }

            tab.Channel ??= InputChannel.Tell;
            tab.CurrentChannel.Channel = InputChannel.Tell;
            tab.CurrentChannel.TellTarget = tab.TellTarget.Clone();

            // MessageList is NonSerialized so pinned tabs come back empty.
            // Preload the same history window the spawn path uses so the user
            // sees the recent conversation, not a blank tab.
            PreloadHistory(tab, tab.TellTarget.Name, tab.TellTarget.World, Guid.Empty);

            _logger.LogDebug(
                $"[Pin] Rehydrated '{tab.Name}' -> Tell target {tab.TellTarget.Name}@{tab.TellTarget.World}"
            );
        }
    }

    public void Dispose()
    {
        if (!_initialized)
        {
            return;
        }

        Plugin.ClientState.Login -= OnLogin;
        Plugin.ClientState.Logout -= OnLogout;
        _messageManager.MessageProcessed -= HandleTell;
        _initialized = false;
    }

    internal void HandleTell(Message message)
    {
        if (!Plugin.Config.EnableAutoTellTabs)
        {
            return;
        }

        if (
            message.Code.Type != ChatType.TellIncoming
            && message.Code.Type != ChatType.TellOutgoing
        )
        {
            return;
        }

        var partner = ExtractTellPartner(message);
        if (partner == null)
        {
            // Diagnostics: helps detect regressions (FFXIV payload changes, new edge cases)
            _logger.LogWarning(
                $"[AutoTellTabs] Could not extract tell partner. type={message.Code.Type}, "
                    + $"senderChunks={message.Sender.Count}, contentChunks={message.Content.Count}, "
                    + $"senderSourcePayloads={message.SenderSource?.Payloads?.Count ?? 0}, "
                    + $"contentSourcePayloads={message.ContentSource?.Payloads?.Count ?? 0}"
            );
            return;
        }

        // Three steps, because building the tab pulls history out of the store and
        // that must not happen under TabsListLock (B3 rule; the query sorts the whole
        // receiver history). Step 1 and 3 are locked, step 2 is not.
        int generation;
        lock (TabsListLock)
        {
            var existing = FindTempTab(partner.Value.Name, partner.Value.World);
            if (existing != null)
            {
                // Already routed via MessageManager pipeline — no AddMessage here,
                // HandleTell runs after the delivery loop. Repair the tell-target if
                // the fallback hit a pinned tab whose TellTarget didn't survive a
                // previous round-trip — keeps FindTempTab fast on the next message.
                if (
                    existing.IsPinned
                    && (existing.TellTarget is null || !existing.TellTarget.IsSet())
                )
                {
                    existing.TellTarget = new TellTarget(
                        partner.Value.Name,
                        partner.Value.World,
                        0,
                        TellReason.Direct
                    );
                    _plugin.SaveConfig();
                }
                return;
            }

            generation = _tabGeneration;
        }

        var tab = BuildTempTabWithHistory(partner.Value, message);

        lock (TabsListLock)
        {
            // A logout in between wiped the unpinned pool; committing now would
            // resurrect a tab for a character we already left.
            if (generation != _tabGeneration)
                return;

            // Someone else (self-test, UI) may have created the tab while we built
            // ours. Hand the message to theirs and drop what we built — unlike the
            // early return above, this tab appeared after the delivery loop ran.
            var raced = FindTempTab(partner.Value.Name, partner.Value.World);
            if (raced != null)
            {
                raced.AddMessage(message, unread: true);
                return;
            }

            CommitTempTab(tab);
        }
    }

    private (string Name, uint World)? ExtractTellPartner(Message message)
    {
        if (message.Code.Type == ChatType.TellIncoming)
        {
            // Sender is the partner; check chunks first, then raw SeString as fallback
            var fromSender =
                ChunkUtil.TryGetPlayerPayload(message.Sender)
                ?? ChunkUtil.TryGetPlayerPayload(message.SenderSource);
            if (fromSender != null)
            {
                return (fromSender.PlayerName, fromSender.World.RowId);
            }
            return null;
        }

        // Outgoing tell: check content first, then channels's TellTarget as fallback
        var fromContent =
            ChunkUtil.TryGetPlayerPayload(message.Content)
            ?? ChunkUtil.TryGetPlayerPayload(message.ContentSource)
            ?? ChunkUtil.TryGetPlayerPayload(message.Sender)
            ?? ChunkUtil.TryGetPlayerPayload(message.SenderSource);
        if (fromContent != null)
        {
            return (fromContent.PlayerName, fromContent.World.RowId);
        }

        var current =
            _plugin.CurrentTab.CurrentChannel.TellTarget
            ?? _plugin.CurrentTab.CurrentChannel.TempTellTarget;
        if (current != null && current.IsSet())
        {
            return (current.Name, current.World);
        }

        return null;
    }

    internal static Tab? FindTempTab(string name, uint world)
    {
        var byTarget = Plugin.Config.Tabs.FirstOrDefault(t =>
            t.IsTempTab
            && t.TellTarget != null
            && string.Equals(t.TellTarget.Name, name, StringComparison.OrdinalIgnoreCase)
            && t.TellTarget.World == world
        );
        if (byTarget != null)
            return byTarget;

        // Fallback: match by tab name. Pinned tabs are named via
        // FormatTabName(player, world) at spawn time, so the name is a
        // stable secondary key when TellTarget didn't survive a save/load
        // (older configs from a renamed pin, malformed migrations, etc.).
        var expectedName = FormatTabName(name, world);
        return Plugin.Config.Tabs.FirstOrDefault(t =>
            t.IsTempTab && string.Equals(t.Name, expectedName, StringComparison.OrdinalIgnoreCase)
        );
    }

    // Lock-protected lookup for the framework-thread caller (TellRouterService).
    // Config.Tabs is mutated under the shared Plugin.TabsListLock on the worker thread,
    // so a framework-tick reader must take the same lock to avoid enumerating the list
    // mid-mutation.
    internal Tab? FindTempTabSafe(string name, uint world)
    {
        lock (TabsListLock)
            return FindTempTab(name, world);
    }

    internal void DropOldestTempTab()
    {
        // B3: lock the list-structure ops so the (currently caller-less) Unpin path
        // can't race the worker; re-entrant when HandleTell already holds the lock.
        lock (TabsListLock)
        {
            // Pinned tabs live in their own bucket (MaxPinnedTempTabs) and are
            // never drop candidates. They leave the bucket only via Unpin or
            // PromoteToPermanent.
            var victim = Plugin
                .Config.Tabs.Select((tab, idx) => (Tab: tab, Index: idx))
                .Where(t => TabLifecycleHelpers.IsInUnpinnedPool(t.Tab))
                .OrderByDescending(t => t.Tab.IsGreeted)
                .ThenBy(t => t.Tab.LastActivity)
                .FirstOrDefault();

            if (victim.Tab == null)
            {
                return;
            }

            var dropped = victim.Tab;
            // By reference, not by index: the index came from a Select() earlier in
            // this block and would point at the wrong tab if anything shifted the list.
            Plugin.Config.Tabs.Remove(dropped);

            // Re-anchor the UI selection if it pointed at the dropped tab, and close any
            // pop-out window the dropped tab owned. Both run on the PendingMessage worker
            // thread and touch window state the Draw path reads (OnTabActivated re-seed +
            // the pool's Unbind), so marshal onto the framework thread to serialize with
            // Draw (reference_dalamud_framework_thread). TryClose is idempotent: a tab that
            // was never popped is a silent no-op.
            Plugin.Framework.RunOnFrameworkThread(() =>
            {
                _plugin.ChannelPopoutPool.TryClose(dropped.Identifier);
                _plugin.MainWindow?.ResetActiveTabIfRemoved(dropped);
            });
        }
    }

    // Runs WITHOUT TabsListLock: PreloadHistory hits the store, which used to hold
    // the lock across a query that sorted the whole receiver history. The tab is not
    // public until CommitTempTab adds it, so building it unlocked is safe.
    private Tab BuildTempTabWithHistory((string Name, uint World) partner, Message currentMessage)
    {
        var tab = BuildTempTab(partner.Name, partner.World);

        // Preload history: chronological order with current message already persisted
        PreloadHistory(tab, partner.Name, partner.World, currentMessage.Id);

        tab.AddMessage(currentMessage, unread: true);

        // Flag the tab as a pop-out if configured; the marshalled TryOpen below reads
        // that flag to open the real window.
        if (Plugin.Config.AutoTellTabsOpenAsPopout)
        {
            tab.PopOut = true;
        }

        return tab;
    }

    // Caller MUST hold TabsListLock.
    private void CommitTempTab(Tab tab)
    {
        if (ActiveTempTabCount >= Plugin.Config.AutoTellTabsLimit)
        {
            DropOldestTempTab();
        }

        Plugin.Config.Tabs.Add(tab);

        // Actually open the pop-out window for the flagged tab — without this the
        // flag was dead (a PopOut tab with no window). CommitTempTab runs on the
        // PendingMessage worker thread under Plugin.TabsListLock; TryOpen does
        // OnTabActivated + Bind (window state Draw reads), so marshal onto the
        // framework thread. If the pool is full, drop the flag so it never claims a
        // window it didn't get (flag/window parity).
        if (tab.PopOut)
        {
            Plugin.Framework.RunOnFrameworkThread(() =>
            {
                if (!_plugin.ChannelPopoutPool.TryOpen(tab))
                    tab.PopOut = false;
            });
        }
    }

    private static Tab BuildTempTab(string playerName, uint worldRowId)
    {
        return new Tab
        {
            Name = FormatTabName(playerName, worldRowId),
            NameCameFromPartner = true,
            IsTempTab = true,
            AllSenderMessages = true,
            TellTarget = new TellTarget(playerName, worldRowId, 0, TellReason.Direct),
            Channel = InputChannel.Tell,
            DisplayTimestamp = true,
            UnreadMode = UnreadMode.Unseen,
            HideWhenInactive = false,
            SelectedChannels = new Dictionary<ChatType, (ChatSource, ChatSource)>
            {
                [ChatType.TellIncoming] = (ChatSourceExt.All, ChatSourceExt.All),
                [ChatType.TellOutgoing] = (ChatSourceExt.All, ChatSourceExt.All),
            },
        };
    }

    private static string FormatTabName(string playerName, uint worldRowId)
    {
        if (Sheets.WorldSheet.TryGetRow(worldRowId, out var worldRow))
        {
            return $"{playerName}@{worldRow.Name}";
        }
        // Fallback if world lookup misses (rare; only for unseen worlds)
        return $"{playerName}@World{worldRowId}";
    }

    private void PreloadHistory(Tab tab, string senderName, uint senderWorld, Guid currentMessageId)
    {
        var preloadCount = Plugin.Config.AutoTellTabsHistoryPreload;
        if (preloadCount <= 0)
        {
            return;
        }

        try
        {
            // Pull one extra row: current message is already in store and would eat a preload slot
            var history = _store.GetTellHistoryWithSender(
                _messageManager.CurrentContentId,
                senderName,
                senderWorld,
                preloadCount + 1
            );

            var historicMessages = history
                .Where(m => m.Id != currentMessageId)
                .Take(preloadCount)
                .ToList();

            if (historicMessages.Count == 0)
            {
                // No prior tells; leave tab empty to avoid orphaned "history loaded" marker
                return;
            }

            // History is oldest-first; add in order for chronological display
            foreach (var message in historicMessages)
            {
                tab.Messages.AddPrune(message, MessageManager.MessageDisplayLimit);
            }

            // Separator between history and live tell (sorts after history but before current)
            tab.Messages.AddPrune(
                MakeSystemMarker(HellionStrings.AutoTellTabs_HistorySeparator),
                MessageManager.MessageDisplayLimit
            );
        }
        catch (Exception ex)
        {
            // Non-fatal: tab still spawns with visible error notice instead of silent history loss
            _logger.LogError(ex, "[AutoTellTabs] History preload failed");
            tab.Messages.AddPrune(
                MakeSystemMarker(HellionStrings.AutoTellTabs_HistoryLoadError),
                MessageManager.MessageDisplayLimit
            );
        }
    }

    private static Message MakeSystemMarker(string text)
    {
        var seString = new SeStringBuilder().AddText(text).Build();
        var chunks = ChunkUtil.ToChunks(seString, ChunkSource.Content, ChatType.System).ToList();
        var code = new ChatCode((XivChatType)ChatType.System, 0, 0);
        return Message.FakeMessage(chunks, code);
    }

    internal void MarkGreeted(Tab tab)
    {
        SetGreeted(tab, true);
    }

    internal void UnmarkGreeted(Tab tab)
    {
        SetGreeted(tab, false);
    }

    internal bool IsGreeted(Tab tab)
    {
        return tab.IsGreeted;
    }

    private void SetGreeted(Tab tab, bool greeted)
    {
        if (tab == null)
        {
            return;
        }

        lock (TabsListLock)
        {
            // Guard against frame-race: sidebar might render a tab already removed by LRU or logout
            if (!Plugin.Config.Tabs.Contains(tab))
            {
                return;
            }

            tab.IsGreeted = greeted;
        }
    }

    // Fires on the login that follows a boot-time start, and on every character
    // switch after one. Guarded by the pending flag so a switch does not append
    // a second copy of the history to tabs that already have it.
    private void OnLogin()
    {
        if (!_rehydratePending)
            return;

        RehydratePinnedTabs();
    }

    private void OnLogout(int type, int code)
    {
        lock (TabsListLock)
        {
            // Pinned TempTabs must survive char-switch — that's the whole point
            // of pinning. Only unpinned ones get stripped.
            var active = _plugin.MainWindow?.ActiveTab;

            var poppedTempTabIds = Plugin
                .Config.Tabs.Where(t =>
                    TabLifecycleHelpers.IsInUnpinnedPool(t)
                    && _plugin.ChannelPopoutPool.IsOpen(t.Identifier)
                )
                .Select(t => t.Identifier)
                .ToList();

            // Close any pop-out window an unpinned temp tab owns before the tabs leave
            // the list. Filtering on the live pool (not the PopOut flag) also catches
            // manually right-clicked pop-outs, which never set the flag.
            foreach (var id in poppedTempTabIds)
                _plugin.ChannelPopoutPool.TryClose(id);

            Plugin.Config.Tabs.RemoveAll(TabLifecycleHelpers.IsInUnpinnedPool);

            // HandleTell builds a tab outside the lock; bumping here lets it detect
            // that the world moved on and drop what it built. Read and compared under
            // the same lock, so no volatile needed.
            _tabGeneration++;

            // Re-anchor the UI selection if the active tab was one of the stripped
            // unpinned temp tabs (reference predicate, not an index). Logout is a
            // framework-thread event, so this is already serialized with Draw — no
            // marshalling needed here, unlike the worker-thread eviction path.
            if (active is { } a && TabLifecycleHelpers.IsInUnpinnedPool(a))
            {
                _plugin.MainWindow?.ResetActiveTabIfRemoved(a);
            }
        }
    }

    internal bool TryPin(Tab tab)
    {
        if (!tab.IsTempTab || tab.IsPinned)
        {
            _logger.LogDebug(
                $"[Pin] TryPin skipped: IsTempTab={tab.IsTempTab} IsPinned={tab.IsPinned}"
            );
            return false;
        }

        // Count and flag under one lock so the cap can't be raced. SaveConfig stays
        // OUTSIDE -- holding TabsListLock across a save would put an fsync on the
        // click path, which is what B6 just removed elsewhere.
        lock (TabsListLock)
        {
            if (PinnedTempTabCount >= MaxPinnedTempTabs)
            {
                WrapperUtil.AddNotification(
                    string.Format(HellionStrings.PinTab_LimitReached, MaxPinnedTempTabs),
                    NotificationType.Warning
                );
                return false;
            }

            tab.IsPinned = true;
        }

        _logger.LogDebug(
            $"[Pin] Pinned tab '{tab.Name}' target={tab.TellTarget?.Name}@{tab.TellTarget?.World}"
        );
        _plugin.SaveConfig();
        return true;
    }

    internal void Unpin(Tab tab)
    {
        if (!tab.IsPinned)
        {
            return;
        }

        // If the unpinned pool is already full, dropping the oldest before
        // flipping the flag avoids counting the just-unpinned tab as a drop
        // candidate. Under lock, since DropOldestTempTab mutates the list.
        // SaveConfig stays outside, see TryPin.
        lock (TabsListLock)
        {
            if (ActiveTempTabCount >= Plugin.Config.AutoTellTabsLimit)
            {
                DropOldestTempTab();
            }

            tab.IsPinned = false;
        }

        _logger.LogDebug("[Pin] Unpinned tab '{TabName}'", tab.Name);
        _plugin.SaveConfig();
    }

    internal void PromoteToPermanent(Tab tab)
    {
        if (!tab.IsTempTab)
        {
            return;
        }

        // Drops the temp/pin flags, the persisted tell target AND the runtime
        // channel's tell state. The runtime-channel clear is the CORR-1 guard —
        // see StripTellBindingOnPromote; clearing Tab.TellTarget alone would leave
        // CurrentChannel.Channel == Tell + a stale target and route a typed line
        // silently as /tell to the old partner.
        // Flips IsTempTab/IsPinned, which decide pool membership and whether a save
        // strips the tab. Under lock so a concurrent save sees one or the other, never
        // half. SaveConfig stays outside, see TryPin.
        lock (TabsListLock)
            TabLifecycleHelpers.StripTellBindingOnPromote(tab);

        _logger.LogDebug($"[Pin] Promoted tab '{tab.Name}' to permanent (tell-binding dropped)");
        _plugin.SaveConfig();
    }
}