import Anthropic from '@anthropic-ai/sdk';

/**
 * The client, or null when there is no key.
 *
 * Null rather than a throw, because an unconfigured environment is a working
 * one: submissions still arrive and wait undrafted. The worker treats null
 * exactly as it treats a failed call, which keeps one path rather than two.
 *
 * Constructed once and cached. The SDK holds a connection pool, and building
 * one per submission would be wasteful on a route a stranger can trigger.
 */
let cached: Anthropic | null = null;
let resolved = false;

export function getAnthropicClient(): Anthropic | null {
  if (resolved) return cached;

  const key = process.env.ANTHROPIC_API_KEY;
  cached = key !== undefined && key.trim() !== '' ? new Anthropic({ apiKey: key }) : null;
  resolved = true;

  return cached;
}

/** Exposed for tests, which need a fresh decision per case. */
export function resetAnthropicClient(): void {
  cached = null;
  resolved = false;
}