import type {
  ContentItem,
  ListQuery,
  ListResult,
  SectionKey,
  SinglePage,
} from "@/types/content";
import { products } from "@/data/products";
import { solutions } from "@/data/solutions";
import { cases } from "@/data/cases";
import { news } from "@/data/news";
import { events } from "@/data/events";
import { singlePages } from "@/data/pages";

/**
 * 内容数据访问层
 * 目前读取本地 mock 数据，接入后端 CMS 后只需把下面几个方法
 * 换成 request.get("/cms/...") 即可，调用方无需改动。
 */

const registry: Record<SectionKey, ContentItem[]> = {
  news,
  products,
  solutions,
  cases,
  events,
};

/** 模拟一次异步请求，保证调用方始终按异步处理 */
const tick = () => new Promise<void>((resolve) => setTimeout(resolve, 0));

/** 列表 / 分类 / 搜索（带分页） */
export async function fetchList(query: ListQuery): Promise<ListResult> {
  await tick();

  const { section, category, keyword, page = 1, pageSize = 6 } = query;
  let list = [...(registry[section] ?? [])];

  if (category) {
    list = list.filter((item) => item.category === category);
  }

  const kw = keyword?.trim().toLowerCase();
  if (kw) {
    list = list.filter((item) =>
      [item.title, item.subtitle, item.summary, ...(item.tags ?? [])]
        .join(" ")
        .toLowerCase()
        .includes(kw)
    );
  }

  list.sort((a, b) => (b.date ?? "").localeCompare(a.date ?? ""));

  const total = list.length;
  const totalPages = Math.max(1, Math.ceil(total / pageSize));
  const safePage = Math.min(Math.max(1, page), totalPages);
  const start = (safePage - 1) * pageSize;

  return {
    list: list.slice(start, start + pageSize),
    total,
    page: safePage,
    pageSize,
    totalPages,
  };
}

/** 详情 */
export async function fetchDetail(
  section: SectionKey,
  slug: string
): Promise<ContentItem | undefined> {
  await tick();
  return (registry[section] ?? []).find((item) => item.slug === slug);
}

/** 相关推荐：同分类优先，不足时用同栏目其它内容补齐 */
export async function fetchRelated(
  section: SectionKey,
  slug: string,
  limit = 3
): Promise<ContentItem[]> {
  await tick();

  const all = registry[section] ?? [];
  const current = all.find((item) => item.slug === slug);
  if (!current) return all.slice(0, limit);

  const sameCategory = all.filter(
    (item) => item.slug !== slug && item.category === current.category
  );
  const others = all.filter(
    (item) => item.slug !== slug && item.category !== current.category
  );

  return [...sameCategory, ...others].slice(0, limit);
}

/** 统计各分类下的内容数量，用于筛选条上的角标 */
export async function fetchCategoryCounts(
  section: SectionKey
): Promise<Record<string, number>> {
  await tick();

  const counts: Record<string, number> = {};
  (registry[section] ?? []).forEach((item) => {
    counts[item.category] = (counts[item.category] ?? 0) + 1;
  });
  counts.__all__ = (registry[section] ?? []).length;
  return counts;
}

/** 单页：key 为去掉前导斜杠的路径，例如 about、support/docs */
export async function fetchSinglePage(
  key: string
): Promise<SinglePage | undefined> {
  await tick();
  return singlePages[key];
}