import type { MobCombatState } from "./combatStore";
import type {
  ManastormEncounterDefinition,
  ManastormPhase,
} from "./manastorm";

/**
 * Ascension's published Chapter 2 tuning: each remaining Chaotic Link stack
 * grants roughly 25% boss health and 10% boss damage. The number of stacks is
 * approximately half of the creatures between the party and the boss.
 */
export const MANASTORM_CHAOTIC_LINK_HEALTH_PER_STACK = 0.25;
export const MANASTORM_CHAOTIC_LINK_DAMAGE_PER_STACK = 0.10;

export interface ManastormChaoticLinkState {
  readonly guardianCount: number;
  readonly defeatedGuardians: number;
  readonly requiredGuardianKills: number;
  readonly activeStacks: number;
  readonly broken: boolean;
  readonly bossHealthMultiplier: number;
  readonly bossDamageMultiplier: number;
}

function uniqueGuardianIds(
  encounter: ManastormEncounterDefinition,
): readonly string[] {
  return [...new Set(
    (encounter.trashRuntimeIds ?? [])
      .filter((runtimeId) => Boolean(runtimeId) && runtimeId !== encounter.bossRuntimeId),
  )];
}

/**
 * Missing guardian registrations count as alive. This prevents a partially
 * mounted scene from prematurely breaking the link before its actors exist.
 */
export function manastormChaoticLinkState(
  encounter: ManastormEncounterDefinition,
  mobs: Readonly<Record<string, MobCombatState>>,
): ManastormChaoticLinkState {
  const guardianIds = uniqueGuardianIds(encounter);
  const guardianCount = guardianIds.length;
  const defeatedGuardians = guardianIds.filter(
    (runtimeId) => mobs[runtimeId]?.dead === true,
  ).length;
  const requiredGuardianKills = encounter.chaoticLinkEnabled === false
    ? 0
    : Math.max(
      0,
      Math.min(
        guardianCount,
        Math.trunc(encounter.requiredGuardianKills ?? Math.ceil(guardianCount / 2)),
      ),
    );
  const activeStacks = Math.max(0, requiredGuardianKills - defeatedGuardians);
  return Object.freeze({
    guardianCount,
    defeatedGuardians,
    requiredGuardianKills,
    activeStacks,
    broken: activeStacks === 0,
    bossHealthMultiplier:
      1 + activeStacks * MANASTORM_CHAOTIC_LINK_HEALTH_PER_STACK,
    bossDamageMultiplier:
      1 + activeStacks * MANASTORM_CHAOTIC_LINK_DAMAGE_PER_STACK,
  });
}

/**
 * Chaotic Link requires the boss and its linked creatures to coexist. The boss
 * may be challenged immediately at full strength; killing approximately half
 * of the linked guardians first removes the aura.
 */
export function manastormChaoticLinkRuntimeIds(
  encounter: ManastormEncounterDefinition | null,
  phase: ManastormPhase,
): readonly string[] {
  if (
    !encounter
    || phase === "idle"
    || phase === "next"
    || phase === "failed"
    || phase === "complete"
  ) {
    return [];
  }
  return [...new Set([
    ...(encounter.trashRuntimeIds ?? []),
    encounter.bossRuntimeId,
  ])];
}