function normalizeApiBase(apiBase) {
  const base = String(apiBase ?? '/api').trim() || '/api';
  return base.replace(/\/$/, '');
}

export function buildPageDataAuthPath(apiBase, pageId) {
  const base = normalizeApiBase(apiBase);
  return `${base}/public/pages/${encodeURIComponent(String(pageId ?? '').trim())}/data-auth`;
}

export function buildPageDataPublicPath(apiBase, pageId, dataset, suffix = '') {
  const base = normalizeApiBase(apiBase);
  const safePageId = encodeURIComponent(String(pageId ?? '').trim());
  const safeDataset = encodeURIComponent(String(dataset ?? '').trim());
  const tail = suffix ? (suffix.startsWith('/') ? suffix : `/${suffix}`) : '';
  return `${base}/public/pages/${safePageId}/data/${safeDataset}${tail}`;
}

function buildAuthHeaders(token) {
  const headers = { accept: 'application/json' };
  if (token) headers['x-page-data-token'] = token;
  return headers;
}

async function parseJsonResponse(response) {
  const payload = await response.json().catch(() => ({}));
  if (!response.ok) {
    const error = payload?.error ?? {};
    throw Object.assign(new Error(error.message ?? '页面数据请求失败'), {
      code: error.code ?? 'page_data_failed',
      status: response.status,
    });
  }
  return payload?.data ?? payload;
}

export function createPageDataBrowserClient({
  pageId,
  apiBase = '/api',
  token = null,
  fetchImpl = globalThis.fetch,
} = {}) {
  if (!pageId) throw new Error('pageId 不能为空');
  if (typeof fetchImpl !== 'function') throw new Error('fetch 不可用');

  let sessionToken = token;

  async function request(method, path, { body, query, auth = true, extraHeaders = {} } = {}) {
    const url = new URL(path, typeof window !== 'undefined' ? window.location.origin : 'http://localhost');
    if (query && typeof query === 'object') {
      for (const [key, value] of Object.entries(query)) {
        if (value == null || value === '') continue;
        url.searchParams.set(key, String(value));
      }
    }
    const headers = {
      ...(body ? { 'content-type': 'application/json' } : {}),
      ...(auth ? buildAuthHeaders(sessionToken) : { accept: 'application/json' }),
      ...(extraHeaders && typeof extraHeaders === 'object' ? extraHeaders : {}),
    };
    const response = await fetchImpl(url.toString(), {
      method,
      headers,
      credentials: 'include',
      body: body ? JSON.stringify(body) : undefined,
    });
    return parseJsonResponse(response);
  }

  return {
    get pageId() {
      return pageId;
    },
    get token() {
      return sessionToken;
    },
    setToken(nextToken) {
      sessionToken = nextToken ? String(nextToken) : null;
    },
    async authenticate(password) {
      const result = await request('POST', buildPageDataAuthPath(apiBase, pageId), {
        body: { password },
        auth: false,
      });
      if (result?.token) sessionToken = result.token;
      return result;
    },
    async listRows(dataset, query = {}) {
      return request('GET', buildPageDataPublicPath(apiBase, pageId, dataset), { query });
    },
    async getSchema(dataset) {
      return request('GET', buildPageDataPublicPath(apiBase, pageId, dataset, 'schema'));
    },
    async getStats(dataset) {
      return request('GET', buildPageDataPublicPath(apiBase, pageId, dataset, 'stats'));
    },
    async insertRow(dataset, row, options = {}) {
      const captchaToken =
        options.captchaToken ?? options.turnstileToken ?? options.captcha_token ?? null;
      const extraHeaders = captchaToken ? { 'x-page-data-captcha': String(captchaToken) } : {};
      return request('POST', buildPageDataPublicPath(apiBase, pageId, dataset, 'rows'), {
        body: row,
        extraHeaders,
      });
    },
    async updateRow(dataset, rowId, row) {
      return request('PATCH', buildPageDataPublicPath(apiBase, pageId, dataset, `rows/${rowId}`), { body: row });
    },
    async deleteRow(dataset, rowId) {
      return request('DELETE', buildPageDataPublicPath(apiBase, pageId, dataset, `rows/${rowId}`));
    },
  };
}