/** Current CoA Priest/Scout Saint's Blessing's conditional damage rider. */
export const ROM_PRIEST_SCOUT_SAINTS_BLESSING_DAMAGE = Object.freeze({
  passiveSpellId: 493_039,
  targetHealthThreshold: 0.3,
  damageBonus: 0.28,
});

export interface RomPriestScoutSaintsBlessingDamageContext {
  readonly primaryClassId: string;
  readonly secondaryClassId?: string;
  readonly learnedPassiveSpellIds: readonly number[];
  /** Target's current health divided by its maximum health at damage resolution. */
  readonly targetHealthPercent: number;
}

/**
 * Return the current CoA multiplier for a damage packet resolved against a
 * living target below 30% maximum health. The caller should evaluate this at
 * each damage event so the threshold follows the target's live health.
 */
export function romPriestScoutSaintsBlessingDamageMultiplier(
  context: RomPriestScoutSaintsBlessingDamageContext,
): number {
  if (context.primaryClassId !== "rom-priest"
    || context.secondaryClassId !== "rom-scout"
    || !context.learnedPassiveSpellIds.includes(ROM_PRIEST_SCOUT_SAINTS_BLESSING_DAMAGE.passiveSpellId)
    || !Number.isFinite(context.targetHealthPercent)
    || context.targetHealthPercent <= 0
    || context.targetHealthPercent >= ROM_PRIEST_SCOUT_SAINTS_BLESSING_DAMAGE.targetHealthThreshold) {
    return 1;
  }

  return 1 + ROM_PRIEST_SCOUT_SAINTS_BLESSING_DAMAGE.damageBonus;
}