/**
 * Crisis System — Chemical Plague
 *
 * When escalation reaches its threshold, a crisis activates.
 * The Chemical Plague poisons the atmosphere — player must craft
 * the correct neutralizing compound to stop it.
 */

import type { CrisisConfig } from './types';

// ─── Chemical Plague Configuration ───────────────────────────────

export const CHEMICAL_PLAGUE: CrisisConfig = {
  type: 'chemical-plague',
  name: 'Chemical Plague',
  nameRu: 'Химическая Чума',
  description: 'A chain reaction is poisoning the atmosphere. Neutralize it with the right compound!',
  descriptionRu: 'Цепная реакция отравляет атмосферу. Нейтрализуй правильным соединением!',
  triggerThreshold: 0.8,
  neutralizer: 'CaO',       // Calcium oxide (quicklime) — absorbs acid gases
  neutralizeAmount: 3,       // need 3 units to fully neutralize
};

// ─── Crisis State ────────────────────────────────────────────────

export interface CrisisState {
  config: CrisisConfig;
  active: boolean;
  /** Progress 0.0–1.0 — at 1.0 the world is fully poisoned */
  progress: number;
  resolved: boolean;
  /** How many neutralizer units have been applied */
  neutralizeApplied: number;
}

/** Damage growth rate per second during active crisis */
const CRISIS_DAMAGE_RATE = 0.01; // reaches 1.0 in ~100 seconds

/** Create a new crisis state from config */
export function createCrisisState(config: CrisisConfig): CrisisState {
  return {
    config,
    active: true,
    progress: 0,
    resolved: false,
    neutralizeApplied: 0,
  };
}

/** Advance crisis damage over time */
export function applyCrisisDamage(crisis: CrisisState, deltaMs: number): void {
  if (!crisis.active || crisis.resolved) return;
  const deltaSec = deltaMs / 1000;
  crisis.progress = Math.min(1.0, crisis.progress + CRISIS_DAMAGE_RATE * deltaSec);
}

/** Attempt to neutralize the crisis with a compound. Returns true if correct compound. */
export function attemptNeutralize(
  crisis: CrisisState,
  compoundId: string,
  amount: number,
): boolean {
  if (compoundId !== crisis.config.neutralizer) return false;
  if (crisis.resolved) return true;

  crisis.neutralizeApplied += amount;

  // Reduce progress proportionally
  const reductionPerUnit = 1.0 / crisis.config.neutralizeAmount;
  crisis.progress = Math.max(0, crisis.progress - amount * reductionPerUnit);

  // Check if fully neutralized
  if (crisis.neutralizeApplied >= crisis.config.neutralizeAmount) {
    crisis.resolved = true;
    crisis.active = false;
    crisis.progress = 0;
  }

  return true;
}

/** Check if crisis has been resolved */
export function isCrisisResolved(crisis: CrisisState): boolean {
  return crisis.resolved;
}