const API_BASE_URL = import.meta.env.VITE_API_BASE_URL || "/api";
const TOKEN_KEY = "hyapp-admin.access-token";
const APP_CODE_KEY = "hyapp-admin.app-code";
const APP_CODE_HEADER = "X-App-Code";

export function getCurrentAppCode() {
  return normalizeAppCode(window.localStorage.getItem(APP_CODE_KEY) || "lalu");
}

export async function fetchStatisticsOverview({ appCode, countryId, endMs, startMs }) {
  const query = new URLSearchParams();
  query.set("app_code", normalizeAppCode(appCode) || "lalu");
  if (startMs) {
    query.set("start_ms", String(startMs));
  }
  if (endMs) {
    query.set("end_ms", String(endMs));
  }
  if (countryId) {
    query.set("country_id", String(countryId));
  }

  const response = await fetch(`${API_BASE_URL}/v1/statistics/overview?${query.toString()}`, {
    credentials: "include",
    headers: requestHeaders(appCode)
  });
  const payload = await readJSON(response);
  if (!response.ok || payload.code !== 0) {
    throw new Error(payload.message || response.statusText || "请求失败");
  }
  return payload.data;
}

function requestHeaders(appCode) {
  const headers = {};
  const token = window.localStorage.getItem(TOKEN_KEY);
  if (token) {
    headers.Authorization = `Bearer ${token}`;
  }
  const normalized = normalizeAppCode(appCode);
  if (normalized) {
    headers[APP_CODE_HEADER] = normalized;
  }
  return headers;
}

async function readJSON(response) {
  const text = await response.text();
  if (!text) {
    return {};
  }
  try {
    return JSON.parse(text);
  } catch {
    return { code: response.ok ? 0 : response.status, message: text };
  }
}

function normalizeAppCode(value) {
  return String(value || "").trim().toLowerCase();
}