feat: add ds4 specific tiebreaker functionality

src/data/documents/combat.ts

@@ -84,7 +84,14 @@ const CombatMixin = (BaseCombat: typeof Combat) => {
         c.data.update({ initiative: null });
       }
       return this.update(
-        { turn: 0, combatants: this.combatants.toObject(), flags: { [packageId]: { started: false } } },
+        {
+          turn: 0,
+          combatants: this.combatants.toObject().map((combatant) => {
+            if (combatant.flags.tickwerk.tiebreaker) delete combatant.flags.tickwerk.tiebreaker;
+            return { ...combatant, [`flags.${packageId}.-=tiebreaker`]: null };
+          }),
+          flags: { [packageId]: { started: false } },
+        },
         { diff: false },
       );
     }

src/data/documents/combatant.ts

@@ -107,12 +107,14 @@ const CombatantMixin = (BaseCombatant: typeof Combatant) => {
       await this.#updateTiebreakerData(args[0]);
     }
 
-    protected override _onCreate(): void {
+    protected override _onCreate(...args: Parameters<Combatant['_onCreate']>): void {
+      super._onCreate(...args);
       this._newInitiative = undefined;
       this._newTiebreaker = undefined;
     }
 
-    protected override _onUpdate(): void {
+    protected override _onUpdate(...args: Parameters<Combatant['_onUpdate']>): void {
+      super._onUpdate(...args);
       this._newInitiative = undefined;
       this._newTiebreaker = undefined;
     }

src/systems/ds4.ts

@@ -12,15 +12,57 @@ export const registerDS4SpecificFunctionality = () => {
 };
 
 const getTiebreaker = async (combatant: TickwerkCombatant, combatants: TickwerkCombatant[]): Promise<number> => {
+  const ds4combatant = combatant as DS4TickwerkCombatant;
+  const ds4combatants = combatants as DS4TickwerkCombatant[];
   if (combatants.length === 0) return 0;
-  const tiebreakers = combatants.map((combatant) => {
-    return (
-      (combatant._newTiebreaker !== undefined
-        ? combatant._newTiebreaker
-        : combatant.getFlag(packageId, 'tiebreaker')) ?? 0
-    );
+
+  const lowerBounds: number[] = [];
+  const upperBounds: number[] = [];
+  const equals: number[] = [];
+
+  for (const combatant of ds4combatants) {
+    const tiebreaker = combatant._newTiebreaker ?? combatant.getFlag(packageId, 'tiebreaker') ?? 0;
+    if (
+      (combatant.actor?.data.data.combatValues.initiative.total ?? -Infinity) >
+      (ds4combatant.actor?.data.data.combatValues.initiative.total ?? -Infinity)
+    ) {
+      lowerBounds.push(tiebreaker);
+    } else if (
+      (combatant.actor?.data.data.combatValues.initiative.total ?? -Infinity) <
+      (ds4combatant.actor?.data.data.combatValues.initiative.total ?? -Infinity)
+    ) {
+      upperBounds.push(tiebreaker);
+    } else {
+      equals.push(tiebreaker);
+    }
+  }
+
+  equals.sort();
+  const positionAmongEquals = Math.floor(twist.random() * (equals.length + 1));
+
+  equals.forEach((equal, index) => {
+    if (index < positionAmongEquals) {
+      lowerBounds.push(equal);
+    } else {
+      upperBounds.push(equal);
+    }
   });
-  return Math.max(...tiebreakers) + 1;
+  const lowerBound = Math.max(...lowerBounds);
+  const upperBound = Math.min(...upperBounds);
+
+  if (lowerBound === -Infinity) {
+    if (upperBound === Infinity) {
+      return 0;
+    } else {
+      return upperBound - 1;
+    }
+  } else {
+    if (upperBound === Infinity) {
+      return lowerBound + 1;
+    } else {
+      return (lowerBound + upperBound) / 2;
+    }
+  }
 };
 
 const getInitiativeFormula = (combatant: TickwerkCombatant) => {
@@ -29,3 +71,13 @@ const getInitiativeFormula = (combatant: TickwerkCombatant) => {
   const tickValue = combatant.combat?.round ?? 0;
   return `max(${tickValue} + 10 - @combatValues.initiative.total, ${tickValue})`;
 };
+
+type DS4TickwerkCombatant = TickwerkCombatant & { actor: (Actor & { data: { data: ActorData } }) | null };
+
+interface ActorData {
+  combatValues: {
+    initiative: {
+      total: number;
+    };
+  };
+}