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

/** CoA tree node 5744 / source spell 804414: Decapitate is usable below 35% health. */
export const COA_BARBARIAN_DECAPITATE_TALENT_ENTRY_ID = 5744;
export const COA_BARBARIAN_DECAPITATE_HEALTH_THRESHOLD = 0.35;
/** Source node 6744 / spell 705222 refunds maximum Energy on a Decapitate kill. */
export const COA_BARBARIAN_BEHEADER_TALENT_ENTRY_ID = 6744;

type CoaBarbarianDecapitateIdentity = Pick<AbilityDefinition, "classId" | "talentEntryId">;

export interface CoaBarbarianExecuteTargetHealth {
  readonly health?: number;
  readonly maxHealth?: number;
  readonly dead?: boolean;
}

export function isCoaBarbarianDecapitate(
  ability: CoaBarbarianDecapitateIdentity | null | undefined,
): boolean {
  return ability?.classId === "barbarian"
    && ability.talentEntryId === COA_BARBARIAN_DECAPITATE_TALENT_ENTRY_ID;
}

/** Other actions pass through; Decapitate requires a living, valid target strictly below 35%. */
export function coaBarbarianDecapitateTargetAllowed(
  ability: CoaBarbarianDecapitateIdentity | null | undefined,
  target: CoaBarbarianExecuteTargetHealth | null | undefined,
): boolean {
  if (!isCoaBarbarianDecapitate(ability)) return true;
  if (!target || target.dead === true
    || !Number.isFinite(target.health) || !Number.isFinite(target.maxHealth)
    || target.health! <= 0 || target.maxHealth! <= 0) return false;
  return target.health! / target.maxHealth! < COA_BARBARIAN_DECAPITATE_HEALTH_THRESHOLD;
}

export function coaBarbarianBeheaderEnergyRefund(
  ability: CoaBarbarianDecapitateIdentity,
  talentRanks: Readonly<Record<string, number>>,
  maximumEnergy: number,
  result: { readonly amount: number; readonly killed: boolean },
): number {
  if (!isCoaBarbarianDecapitate(ability)
    || !(talentRanks[`coa-entry-${COA_BARBARIAN_BEHEADER_TALENT_ENTRY_ID}`] > 0)
    || !result.killed || !(result.amount > 0)
    || !Number.isFinite(maximumEnergy) || maximumEnergy <= 0) return 0;
  return maximumEnergy;
}