import { countries, type Country } from "~/data/countries";

/**
 * 🌍 useCountries composable
 * 提供国家相关的搜索、过滤、分组、查找等功能
 */
export const useCountries = () => {
  /**
   * 获取全部国家
   */
  const getAll = (): Country[] => countries;

  /**
   * 按洲分组
   */
  const groupedByContinent = computed(() => {
    const groups: Record<string, Country[]> = {};
    for (const c of countries) {
      const key = c.continent || "Unknown";
      if (!groups[key]) groups[key] = [];
      groups[key].push(c);
    }
    return groups;
  });

  /**
   * 按名称搜索（支持多语言字段）
   * @param query 搜索关键字
   */
  const search = (query: string) => {
    if (!query) return countries;
    const q = query.toLowerCase();
    return countries.filter((c) =>
      Object.values(c.name).some((name) => name.toLowerCase().includes(q))
    );
  };

  /**
   * 根据国家代码查找
   * @param code ISO Alpha-2 或 Alpha-3 代码
   */
  const findByCode = (code: string) => {
    const upper = code.toUpperCase();
    return countries.find((c) => c.code === upper || c.iso3 === upper);
  };

  /**
   * 获取特定语言的显示名称
   * @param country 国家对象
   * @param lang 语言代码（默认为 en）
   */
  const getDisplayName = (
    country: Country,
    lang: keyof Country["name"] = "en"
  ) => {
    return country.name?.[lang] || country.name.en;
  };

  /**
   * 根据洲名筛选
   * @param continent 洲名（如 'Asia'、'Europe'）
   */
  const filterByContinent = (continent: string) => {
    const key = continent.trim().toLowerCase();
    return countries.filter((c) => c.continent.toLowerCase() === key);
  };

  return {
    getAll,
    groupedByContinent,
    search,
    findByCode,
    filterByContinent,
    getDisplayName,
  };
};