const VOC_SOCIAL_API_ROOT = 'https://server.fmode.cn/api/voc-social';
const XIAOHONGSHU_APP_BASE_URL = `${VOC_SOCIAL_API_ROOT}/xiaohongshu/app`;

function buildUrl(baseUrl, path, query = {}) {
  const url = new URL(`${baseUrl.replace(/\/$/, '')}/${path.replace(/^\//, '')}`);
  Object.entries(query).forEach(([key, value]) => {
    if (value !== undefined && value !== null && value !== '') {
      url.searchParams.set(key, String(value));
    }
  });
  return url.toString();
}

function unwrapData(json) {
  if (!json || typeof json !== 'object') return {};
  return json.data?.data || json.data || json;
}

function pickBusinessStatus(json) {
  const topCode = Number(json?.code);
  if (Number.isFinite(topCode) && topCode !== 0 && topCode !== 200) {
    return topCode;
  }
  const nestedCode = Number(json?.data?.status_code);
  if (Number.isFinite(nestedCode) && nestedCode !== 0 && nestedCode !== 200) {
    return nestedCode;
  }
  return 0;
}

function redactSecret(value) {
  return String(value || '')
    .replace(/Bearer\s+[^"'\s,}]+/gi, 'Bearer [REDACTED]')
    .replace(/\bsk-[A-Za-z0-9_-]{6,}\b/g, 'sk-[REDACTED]')
    .replace(/\br:[A-Za-z0-9]{4,}\b/g, 'r:[REDACTED]')
    .replace(/("Authorization"\s*:\s*")([^"]+)(")/gi, '$1[REDACTED]$3')
    .replace(/("api[_-]?token"\s*:\s*")([^"]+)(")/gi, '$1[REDACTED]$3');
}

async function requestJson(url, token) {
  const response = await fetch(url, {
    method: 'GET',
    headers: {
      Authorization: `Bearer ${token}`,
      Accept: 'application/json'
    }
  });
  const text = await response.text();
  let json;
  try {
    json = JSON.parse(text);
  } catch {
    json = undefined;
  }
  const businessStatus = pickBusinessStatus(json);
  if (!response.ok || businessStatus) {
    const message = json?.message || json?.msg || json?.data?.msg || text || `HTTP ${response.status}`;
    const error = new Error(redactSecret(message));
    error.httpStatus = businessStatus || response.status || 500;
    error.responseBody = redactSecret(text);
    throw error;
  }
  return { json, data: unwrapData(json), rawText: text };
}

class XiaohongshuApi {
  constructor(options = {}) {
    this.baseUrl = options.baseUrl || process.env.XIAOHONGSHU_API_BASE_URL || XIAOHONGSHU_APP_BASE_URL;
    this.token = options.token;
  }

  async searchNotes({ keyword, page = 1, sort = 'popularity_descending', noteType = '_0' }) {
    const url = buildUrl(this.baseUrl, 'search_notes', {
      keyword,
      page,
      sort,
      note_type: noteType
    });
    return requestJson(url, this.token);
  }

  async getNoteDetail({ noteId }) {
    const url = buildUrl(this.baseUrl, 'get_note_info', {
      note_id: noteId
    });
    return requestJson(url, this.token);
  }

  async getNoteComments({ noteId, cursor = '' }) {
    const url = buildUrl(this.baseUrl, 'get_note_comments', {
      note_id: noteId,
      cursor
    });
    return requestJson(url, this.token);
  }
}

module.exports = {
  VOC_SOCIAL_API_ROOT,
  XIAOHONGSHU_APP_BASE_URL,
  XiaohongshuApi
};