feat(mosstank): the button is Force Buff — always recast everything

Virindi Tank's own term: Force Buff recasts the lot rather than only what has
lapsed. The button now does that, and says so.

BuffPlan gained a force flag that skips the already-in-force check. Forcing
means "ignore what is already up", NOT "ignore the settings" -- the trained-
skill filter, the attribute toggle and the difficulty margin all still apply,
and there is a test pinning that.

The loop had to change shape for this. It used to re-derive the plan every
tick and treat "plan is empty" as done, which works only because the ordinary
plan shrinks as buffs land. A forced plan never shrinks -- that is the point --
so the same loop would have cast forever. A pass now captures a queue at the
start and works through it by index, which is also cheaper: no rebuilding 80-odd
buff lines every frame.

A spell that will not go now advances the queue rather than blocking it. One
missing component used to mean everything behind it waited for the stall
timeout; now the status line names the refusal and the pass carries on.

Solution builds clean; 14,440 tests pass on the standard hermetic lane filter,
0 failures.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/AcDream.Plugins.MossTank/BuffPlan.cs

@@ -38,12 +38,18 @@ public sealed class BuffSettings
 /// </remarks>
 public static class BuffPlan
 {
+    /// <param name="force">
+    /// Virindi Tank's Force Buff: queue every wanted line at its best castable
+    /// tier, ignoring what is already in force and how long it has left. The
+    /// ordinary path skips buffs that are already covered; forcing does not.
+    /// </param>
     public static List<PluginSpellInfo> Build(
         IReadOnlyList<BuffLine> lines,
         IReadOnlyList<PluginSkillInfo> skills,
         IReadOnlyList<PluginAttributeInfo> attributes,
         IReadOnlyList<PluginActiveEnchantment> active,
-        BuffSettings settings)
+        BuffSettings settings,
+        bool force = false)
     {
         var trainedSkills = new Dictionary<string, PluginSkillInfo>(
             StringComparer.OrdinalIgnoreCase);
@@ -96,7 +102,8 @@ public static class BuffPlan
             if (!TryPickTier(line, skillLevels, settings, out PluginSpellInfo pick))
                 continue;
 
-            if (inForce.TryGetValue(line.Family, out var held)
+            if (!force
+                && inForce.TryGetValue(line.Family, out var held)
                 && held.Tier >= pick.Tier
                 && held.Seconds >= settings.RebuffWhenUnderSeconds)
             {

src/AcDream.Plugins.MossTank/MossTankPanel.cs

@@ -24,8 +24,12 @@ internal sealed class MossTankPanel
     private readonly BuffSettings _buffSettings = new();
     private readonly VitalSettings _vitalSettings = new();
 
-    private List<PluginSpellInfo> _plan = new();
-    private int _planIndex;
+    // A pass works through a queue captured at the start rather than a plan
+    // re-derived each tick. Force Buff deliberately ignores what is already in
+    // force, so a re-derived plan would never shrink and the pass could never
+    // reach "done" -- it would cast forever.
+    private List<PluginSpellInfo> _queue = new();
+    private int _queueIndex;
     private bool _running;
     private double _sinceProgress;
     private int _castThisPass;
@@ -44,7 +48,8 @@ internal sealed class MossTankPanel
     public bool MainVisible => _host.Automation.IsAvailable && !SettingsOpen;
     public bool SettingsVisible => _host.Automation.IsAvailable && SettingsOpen;
 
-    public string ButtonText => _running ? "Stop" : "Buff";
+    /// <summary>The button is Force Buff; while a pass runs it cancels.</summary>
+    public string ButtonText => _running ? "Stop" : "Force Buff";
     public string Status => _status;
 
     /// <summary>Vitals line, using the same numbers the character panel shows.</summary>
@@ -168,33 +173,38 @@ internal sealed class MossTankPanel
             return;
         }
 
-        _plan = BuildPlan(automation);
-        _planIndex = 0;
+        // Always a force pass: the button is Virindi Tank's Force Buff, which
+        // recasts everything rather than only what has lapsed.
+        _queue = BuildPlan(automation, force: true);
+        _queueIndex = 0;
         _castThisPass = 0;
         _sinceProgress = 0;
-        _running = true;
-        _status = _plan.Count == 0 ? "Checking…" : $"Buffing 0/{_plan.Count}…";
-        _host.Log.Info($"MossTank: pass started, {_plan.Count} buff(s) queued");
-        Announce(_plan.Count == 0
-            ? "Buffing — checking what needs recasting."
-            : $"Buffing — {_plan.Count} spell(s) to cast.");
+        _running = _queue.Count > 0;
+        _status = _queue.Count == 0
+            ? "Nothing to buff."
+            : $"Force buffing 0/{_queue.Count}…";
+        _host.Log.Info($"MossTank: force pass started, {_queue.Count} buff(s) queued");
+        Announce(_queue.Count == 0
+            ? "Nothing to buff — no known self-buffs match your skills."
+            : $"Force buffing — {_queue.Count} spell(s).");
     }
 
     private void Stop(string status)
     {
         _running = false;
-        _plan = new List<PluginSpellInfo>();
-        _planIndex = 0;
+        _queue = new List<PluginSpellInfo>();
+        _queueIndex = 0;
         _status = status;
     }
 
-    private List<PluginSpellInfo> BuildPlan(IAutomationSurface automation) =>
+    private List<PluginSpellInfo> BuildPlan(IAutomationSurface automation, bool force) =>
         BuffPlan.Build(
             BuffProfile.Build(automation.Spells.KnownSelfBuffs),
             automation.Character.Skills,
             automation.Character.Attributes,
             automation.Character.ActiveEnchantments,
-            _buffSettings);
+            _buffSettings,
+            force);
 
     private Dictionary<uint, uint> SkillLevels(IAutomationSurface automation)
     {
@@ -235,26 +245,20 @@ internal sealed class MossTankPanel
         if (TryVitalUpkeep(automation))
             return;
 
-        // Re-derive against current enchantments so anything that landed since
-        // the pass began drops out rather than being cast twice.
-        _plan = BuildPlan(automation);
-
-        if (_plan.Count == 0)
+        if (_queueIndex >= _queue.Count)
         {
             Stop($"Done — {_castThisPass} cast(s).");
-            _host.Log.Info($"MossTank: pass complete ({_castThisPass} cast)");
-            Announce(_castThisPass == 0
-                ? "Already fully buffed."
-                : $"Finished — {_castThisPass} spell(s) cast.");
+            _host.Log.Info($"MossTank: force pass complete ({_castThisPass} cast)");
+            Announce($"Finished — {_castThisPass} spell(s) cast.");
             return;
         }
 
-        if (_planIndex >= _plan.Count)
-            _planIndex = 0;
-
-        PluginSpellInfo next = _plan[_planIndex];
-        if (!TryCast(automation, next, $"Buffing {_castThisPass + 1}/{_plan.Count}"))
-            _planIndex++;
+        PluginSpellInfo next = _queue[_queueIndex];
+        // Advance on both outcomes. A spell that will not go now (missing
+        // components, a gate that stays shut) must not block the rest of the
+        // queue behind it; the status line names why it was skipped.
+        TryCast(automation, next, $"Force buffing {_castThisPass + 1}/{_queue.Count}");
+        _queueIndex++;
     }
 
     private bool TryVitalUpkeep(IAutomationSurface automation)
@@ -297,7 +301,6 @@ internal sealed class MossTankPanel
 
         _castThisPass++;
         _sinceProgress = 0;
-        _planIndex = 0;
         _status = $"{label}: {spell.Name}";
         _host.Log.Info($"MossTank: casting {spell.Name} (0x{spell.SpellId:X4})");
         return true;

tests/AcDream.Plugins.MossTank.Tests/BuffPlanTests.cs

@@ -202,6 +202,40 @@ public class BuffPlanTests
         Assert.Equal(new uint[] { 2, 3, 1 }, plan.Select(s => s.SpellId).ToArray());
     }
 
+    [Fact]
+    public void ForceQueuesBuffsThatAreAlreadyInForce()
+    {
+        // Virindi Tank's Force Buff recasts everything rather than only what
+        // has lapsed, which is what the Buff button does.
+        var lines = Lines(
+            Spell(1, 47, 4, "Increases the caster's Life Magic skill by 10 points.",
+                difficulty: 100, school: LifeMagicSkill));
+        var skills = new[] { Skill(LifeMagicSkill, "Life Magic", PluginSkillTraining.Trained) };
+        var active = new[] { new PluginActiveEnchantment(1, 47, 4, 1800) };
+
+        Assert.Empty(BuffPlan.Build(lines, skills, Array.Empty<PluginAttributeInfo>(),
+            active, Default));
+        Assert.Single(BuffPlan.Build(lines, skills, Array.Empty<PluginAttributeInfo>(),
+            active, Default, force: true));
+    }
+
+    [Fact]
+    public void ForceStillRespectsSkillAndTrainingFilters()
+    {
+        // Forcing means "ignore what is already up", not "ignore the settings".
+        var lines = Lines(
+            Spell(1, 71, 1, "Increases the caster's Leadership skill by 10 points."));
+
+        var plan = BuffPlan.Build(
+            lines,
+            new[] { Skill(35, "Leadership", PluginSkillTraining.Untrained) },
+            Array.Empty<PluginAttributeInfo>(),
+            Array.Empty<PluginActiveEnchantment>(),
+            Default, force: true);
+
+        Assert.Empty(plan);
+    }
+
     [Fact]
     public void EmptySpellbookProducesNoPlan()
     {