Battle formulas: action values as stat formulas, costs from stat pools, MP gauge for party members, action schema

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/PoolGauge.cs

@@ -0,0 +1,42 @@
+namespace Cthangover.Mods.BattleFormulas
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Linq;
+    using Cthangover.Core.Battle;
+    using Cthangover.Core.Characters;
+    using Cthangover.Core.Events;
+    using Cthangover.Mods.Stats;
+
+    /// <summary>
+    /// The pool stats (<c>"Pool": true</c>, like mana) of party members who take part in
+    /// the stats, as bars of the battle cores: current = what is left after spending, max =
+    /// the sheet value. Hidden stats and enemies (they never pay costs) get none.
+    /// </summary>
+    public class PoolGauge : IBattleUnitGauge
+    {
+        /// <inheritdoc />
+        public int Order => 100;
+
+        /// <inheritdoc />
+        public IEnumerable<BattleGauge> Read(Character unit)
+        {
+            if (unit?.ID == null || StatsService.RosterEntry(unit.ID) == null || !StatsService.Participates(unit.ID))
+                yield break;
+            var sheet = StatsService.Sheet(unit.ID);
+            foreach (var def in StatsService.Definitions.Where(d => d.Pool && !d.Hidden && sheet.Has(d.ID)))
+            {
+                yield return new BattleGauge
+                {
+                    Id = def.ID,
+                    Label = string.IsNullOrWhiteSpace(def.Short) ? def.Name ?? def.ID : def.Short,
+                    Current = (int)Math.Round(StatPools.Current(unit.ID, def.ID), MidpointRounding.AwayFromZero),
+                    Max = sheet.Rounded(def.ID),
+                };
+            }
+        }
+
+        /// <summary>Stats changed (mana spent or refilled): the cores redraw that unit's bars.</summary>
+        public static void OnStatsChanged(StatsChangedEvent evt) => BattleUnitGauges.NotifyChanged(evt?.CharacterId);
+    }
+}