/** ZPLCraft saved-label API client. Save as zplcraft.mjs. Node.js 20+; server-side only. */
export class ZplCraftError extends Error {
  constructor(status, details, retryAfter = null) {
    super(typeof details?.error === 'string' ? details.error : `ZPLCraft request failed (${status}).`);
    this.name = 'ZplCraftError';
    this.status = status;
    this.code = details?.code ?? null;
    this.fields = Array.isArray(details?.fields) ? details.fields : [];
    this.requiredScope = details?.required_scope ?? null;
    this.retryAfter = retryAfter;
  }
}

const UUID = /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;
function labelPath(id) {
  if (typeof id !== 'string' || !UUID.test(id)) throw new TypeError('A label UUID is required.');
  return `/labels/${id}`;
}

export class ZplCraftClient {
  #baseUrl;
  #apiKey;
  #fetch;
  #timeoutMs;

  constructor({ baseUrl, apiKey, timeoutMs = 30000, fetch: fetchImpl = globalThis.fetch }) {
    const url = new URL(baseUrl);
    const local = ['localhost', '127.0.0.1', '[::1]'].includes(url.hostname);
    if ((url.protocol !== 'https:' && !(url.protocol === 'http:' && local)) || url.username || url.password || url.search || url.hash) {
      throw new TypeError('Use an HTTPS API base URL without credentials, query or fragment.');
    }
    if (typeof apiKey !== 'string' || !/^zplc_[0-9a-f]{48}$/.test(apiKey)) throw new TypeError('A valid ZPLCraft API key is required.');
    if (!Number.isFinite(timeoutMs) || timeoutMs < 1 || timeoutMs > 2147483647) throw new TypeError('timeoutMs must be between 1 and 2147483647.');
    if (typeof fetchImpl !== 'function') throw new TypeError('A fetch implementation is required.');
    this.#baseUrl = url.toString().replace(/\/+$/, '');
    this.#apiKey = apiKey;
    this.#fetch = fetchImpl;
    this.#timeoutMs = timeoutMs;
  }

  async #request(path, { body, json = false } = {}) {
    const response = await this.#fetch(`${this.#baseUrl}${path}`, {
      method: body === undefined ? 'GET' : 'POST',
      headers: { 'x-api-key': this.#apiKey, ...(body === undefined ? {} : { 'Content-Type': 'application/json' }) },
      ...(body === undefined ? {} : { body: JSON.stringify(body) }),
      redirect: 'error',
      signal: AbortSignal.timeout(this.#timeoutMs),
    });
    if (!response.ok) {
      let details;
      try { details = await response.json(); } catch { details = {}; }
      const rawRetry = response.headers.get('Retry-After');
      const retry = rawRetry && /^\d+$/.test(rawRetry) ? Number(rawRetry) : null;
      throw new ZplCraftError(response.status, details, retry);
    }
    if (json) return response.json();
    const contentType = (response.headers.get('Content-Type') || '').split(';')[0].trim();
    const data = ['text/plain', 'application/vnd.zebra-zpl'].includes(contentType)
      ? await response.text() : new Uint8Array(await response.arrayBuffer());
    const count = response.headers.get('X-ZPLCraft-Label-Count');
    return {
      data,
      contentType,
      outputFormat: response.headers.get('X-ZPLCraft-Output-Format'),
      labelCount: count && /^\d+$/.test(count) ? Number(count) : null,
    };
  }

  listLabels({ limit = 50, offset = 0 } = {}) {
    if (!Number.isInteger(limit) || limit < 1 || limit > 100 || !Number.isInteger(offset) || offset < 0 || offset > 10000) {
      throw new RangeError('limit must be 1–100 and offset must be 0–10000.');
    }
    return this.#request(`/labels?limit=${limit}&offset=${offset}`, { json: true });
  }

  getLabel(id) { return this.#request(labelPath(id), { json: true }); }
  getStoredZpl(id) { return this.#request(`${labelPath(id)}/zpl`); }
  render(id, { variables = {}, format = 'zpl' } = {}) {
    if (!['zpl', 'png', 'pdf'].includes(format)) throw new TypeError('format must be zpl, png or pdf.');
    return this.#request(`${labelPath(id)}/render`, { body: { variables, format } });
  }
  createPrintJob(id, options = {}) {
    if (options.variables !== undefined && options.records !== undefined) throw new TypeError('Use variables or records, not both.');
    return this.#request(`${labelPath(id)}/print`, { body: options });
  }
}