// Live mode: the real Claude, called straight from this browser with the
// visitor's own API key. The key stays in memory for this page only. It is
// never saved and never sent anywhere except api.anthropic.com.

let sdk; // loaded on first use, so Watch mode never downloads it

export async function makeClaude({ apiKey, model, signal, onParams }) {
  sdk ??= await import("@anthropic-ai/sdk");
  const Anthropic = sdk.default;
  const client = new Anthropic({ apiKey, dangerouslyAllowBrowser: true });

  return async function callModel({ system, tools, messages }) {
    const params = {
      model,
      max_tokens: 16000,
      system,
      tools,
      messages,
      // Adaptive thinking, with a readable summary so the page can show it.
      thinking: { type: "adaptive", display: "summarized" },
      // A small task: low effort keeps each turn quick and cheap.
      output_config: { effort: "low" },
      // Cache the growing prefix, so each turn re-reads history at the cached rate.
      cache_control: { type: "ephemeral" },
    };
    // If a safety classifier declines, retry on Anthropic's recommended
    // fallback model. Haiku has no server-side fallback, so it skips this.
    if (model !== "claude-haiku-5-5") {
      params.betas = ["server-side-fallback-2026-07-01"];
      params.fallbacks = "default";
    }
    onParams?.(params); // lets the page show the exact request body
    return client.beta.messages.create(params, { signal });
  };
}

// Turn SDK errors into one plain sentence for the page.
export function describeError(err) {
  if (!sdk || !(err instanceof sdk.default.APIError)) return err?.message || String(err);
  const A = sdk.default;
  if (err instanceof A.AuthenticationError) return "That API key was not accepted. Check it and try again.";
  if (err instanceof A.PermissionDeniedError) return "This key doesn't have access to that model.";
  if (err instanceof A.NotFoundError) return "That model isn't available to this key.";
  if (err instanceof A.RateLimitError) return "Rate limited, even after retries. Wait a minute and run it again.";
  if (err instanceof A.APIConnectionError) return "Couldn't reach the API. Check your connection.";
  if (err instanceof A.BadRequestError) return `The API rejected the request: ${err.message}`;
  return `API error ${err.status ?? ""}: ${err.message}`;
}