import type { AbilityDefinition, AbilityEffect } from "./abilityCatalog";

export const ROM_KNIGHT_SCOUT_BLOOD_PUNISHMENT_TAG = "rom-blood-punishment";
export const ROM_SCOUT_BLOOD_ARROW_AURA_TAG = "rom-self-health-drain";

const BLOOD_PUNISHMENT_MODIFIERS = [
  { kind: "healing", direction: "taken", operation: "percent", value: 0.15 },
  { kind: "damage", direction: "dealt", school: "holy", operation: "percent", value: 0.05 },
] as const satisfies NonNullable<Extract<AbilityEffect, { kind: "apply-aura" }>["aura"]["modifiers"]>;

function hasPassive(tags: readonly string[] | ReadonlySet<string>): boolean {
  return Array.isArray(tags)
    ? tags.includes(ROM_KNIGHT_SCOUT_BLOOD_PUNISHMENT_TAG)
    : (tags as ReadonlySet<string>).has(ROM_KNIGHT_SCOUT_BLOOD_PUNISHMENT_TAG);
}

/**
 * Current CoA Blood Punishment modifies the active Blood Arrow aura itself.
 * Keeping both modifiers on the source aura makes them actor-local and gives
 * them the same removal/expiry lifecycle as Blood Arrow, without inventing a
 * second timer for the passive.
 */
export function romKnightScoutBloodPunishmentActivationEffects(
  ability: AbilityDefinition,
  effects: readonly AbilityEffect[],
  passiveTags: readonly string[] | ReadonlySet<string>,
): readonly AbilityEffect[] {
  if (ability.source !== "runewaker"
    || ability.classId !== "rom-scout"
    || ability.secondaryClassId !== undefined
    || ability.dbcSpellId !== 490434
    || !hasPassive(passiveTags)) return effects;

  let attachedToActiveArrow = false;
  const updated = effects.map((effect) => {
    if (effect.kind !== "apply-aura"
      || effect.recipient !== "caster"
      || !effect.aura.utilityTags?.includes(ROM_SCOUT_BLOOD_ARROW_AURA_TAG)) return effect;
    attachedToActiveArrow = true;
    const current = effect.aura.modifiers ?? [];
    const modifiers = BLOOD_PUNISHMENT_MODIFIERS.filter((addition) => !current.some((modifier) => {
      if (addition.kind === "healing") return modifier.kind === "healing"
        && modifier.direction === addition.direction
        && modifier.operation === addition.operation
        && modifier.value === addition.value;
      return modifier.kind === "damage"
        && modifier.direction === addition.direction
        && modifier.school === addition.school
        && modifier.operation === addition.operation
        && modifier.value === addition.value;
    }));
    return modifiers.length === 0 ? effect : {
      ...effect,
      aura: { ...effect.aura, modifiers: [...current, ...modifiers] },
    };
  });
  return attachedToActiveArrow ? updated : effects;
}