daggerheart/module/data/adversaryRoll.mjs

export default class DhpAdversaryRoll extends foundry.abstract.TypeDataModel {
    static defineSchema() {
      const fields = foundry.data.fields;

      return {
        roll: new fields.StringField({}),
        total: new fields.NumberField({ integer: true }),
        modifiers: new fields.ArrayField(new fields.SchemaField({
            value: new fields.NumberField({ integer: true }),
            label: new fields.StringField({}),
            title: new fields.StringField({}),
        })),
        diceResults: new fields.ArrayField(new fields.SchemaField({
          value: new fields.NumberField({ integer: true }),
          discarded: new fields.BooleanField({ initial: false }),
        })),
        targets: new fields.ArrayField(new fields.SchemaField({
          id: new fields.StringField({}),
          name: new fields.StringField({}),
          img: new fields.StringField({}),
          difficulty: new fields.NumberField({ integer: true, nullable: true }),
          evasion: new fields.NumberField({ integer: true }),
          hit: new fields.BooleanField({ initial: false }),
        })),
        damage: new fields.SchemaField({
          value: new fields.StringField({}),
          type: new fields.StringField({ choices: Object.keys(SYSTEM.GENERAL.damageTypes), integer: false }),
        }, { nullable: true, initial: null })
      }
    }

    prepareDerivedData(){
      const diceKeys = Object.keys(this.diceResults);
      const highestIndex = 0;
      for(var index in diceKeys){
        const resultIndex = Number.parseInt(index);
        if(highestIndex === resultIndex) continue;

        const current = this.diceResults[resultIndex];
        const highest = this.diceResults[highestIndex];

        if(current.value > highest.value) this.diceResults[highestIndex].discarded = true;
        else this.diceResults[resultIndex].discarded = true;
      }

      this.targets.forEach(target => {
        target.hit = target.difficulty ? this.total >= target.difficulty : this.total >= target.evasion;
      });
    }
}