/**
 * 员工管理页前端请求辅助（与 admin.html 内联函数保持一致，供自动化检查引用）。
 * 零 npm 依赖。
 */
'use strict';

function adminApiUrl(apiPath, pagePath) {
  const pathname = pagePath != null
    ? pagePath
    : (typeof location !== 'undefined' ? location.pathname : '/');
  let prefix = String(pathname || '/');
  if (prefix.length > 1 && prefix.endsWith('/')) prefix = prefix.slice(0, -1);
  if (prefix === '/admin' || prefix.endsWith('/admin')) {
    prefix = prefix.slice(0, -6);
  }
  if (prefix === '/') prefix = '';
  const route = apiPath.charAt(0) === '/' ? apiPath : '/' + apiPath;
  return prefix + route;
}

function httpStatusHint(status) {
  const n = Number(status);
  if (n === 401) return '管理口令错误或未提供';
  if (n === 403) return '没有权限执行此操作';
  if (n === 404) return '接口地址不正确，请从管理页重新打开';
  if (n === 502 || n === 503 || n === 504) return '服务暂时不可用，请稍后重试';
  if (n >= 500) return '服务暂时出错，请稍后重试';
  if (n >= 400) return '请求失败，请稍后重试';
  return '';
}

function toUserMessage(err) {
  const raw = err && typeof err === 'object' && err.message != null
    ? String(err.message)
    : String(err || '');
  const s = raw.trim();
  if (!s) return '请求失败，请稍后重试';
  if (/unexpected end of json|failed to execute ['"]json['"]|json parse|not valid json|unexpected token/i.test(s)) {
    return '服务器返回了无法识别的内容';
  }
  if (/failed to fetch|networkerror|load failed|network request failed/i.test(s)) {
    return '网络异常，请检查连接后重试';
  }
  return s;
}

async function readAdminJson(res) {
  const status = res.status;
  const ctype = String((res.headers && res.headers.get && res.headers.get('content-type')) || '').toLowerCase();
  let text = '';
  try {
    text = await res.text();
  } catch {
    throw new Error(httpStatusHint(status) || '无法读取服务器响应');
  }
  const trimmed = (text || '').trim();
  if (!trimmed) {
    throw new Error(httpStatusHint(status) || '服务器没有返回内容');
  }
  const looksJson = ctype.indexOf('json') !== -1 || trimmed.charAt(0) === '{' || trimmed.charAt(0) === '[';
  if (!looksJson) {
    throw new Error(httpStatusHint(status) || '服务器返回了无法识别的内容');
  }
  let j;
  try {
    j = JSON.parse(trimmed);
  } catch {
    throw new Error(httpStatusHint(status) || '服务器返回了无法识别的内容');
  }
  if (!j || typeof j !== 'object') {
    throw new Error(httpStatusHint(status) || '服务器返回了无法识别的内容');
  }
  if (j.code !== 0) {
    throw new Error(j.msg || httpStatusHint(status) || '请求失败');
  }
  return j.data;
}

module.exports = { adminApiUrl, httpStatusHint, toUserMessage, readAdminJson };