import { NextRequest, NextResponse } from "next/server";
import { getAdminToken } from "@/app/lib/pocketbase/admin";
import { getPocketBaseConfig } from "@/config/services.config";
import { SESSIONS } from "@/config/home.config";
import { getThisWeekRangeChinaStr, getThisWeekRangeISO } from "@/app/lib/dates";
import { getSalonApi } from "@/app/lib/salonApi";

export const dynamic = "force-dynamic";

/** 按场次返回报名人数和最近报名者，仅限中国日历本周（周一到周日）报名的记录。优先 salonapi，失败时回退直连 PocketBase */
export async function GET(request: NextRequest) {
  try {
    const { status, data } = await getSalonApi(request, "/api/salon/join/stats", {
      timeoutMs: 8000,
    });
    if (status === 200 && data && typeof data === "object") {
      const payload = data as { ok?: boolean; stats?: Record<string, { count: number; joiners: { nickname: string; avatar?: string; xiaohongshu_url?: string }[] }> };
      if (payload?.stats && typeof payload.stats === "object") {
        return NextResponse.json({ ok: true, stats: payload.stats });
      }
    }
  } catch {
    /* salonapi 不可用，回退直连 PocketBase */
  }

  const token = await getAdminToken();
  if (!token) {
    return NextResponse.json(
      { ok: true, stats: getEmptyStats() },
      { status: 200 }
    );
  }

  const pb = getPocketBaseConfig();
  const base = pb.url.replace(/\/$/, "");

  const stats: Record<string, { count: number; joiners: { nickname: string; avatar?: string; xiaohongshu_url?: string }[] }> = {};

  const { start: weekStartCn, end: weekEndCn } = getThisWeekRangeChinaStr();
  const { start: weekStartUtc, end: weekEndUtc } = getThisWeekRangeISO();

  const results = await Promise.all(
    SESSIONS.map(async (s) => {
      try {
        // session-1 周六 / session-2 周日；meetupdate 含关键词或为空（兼容旧记录）
        const dayKeyword = s.id === "session-1" ? "周六" : "周日";
        const meetupdatePart = s.id === "session-1"
          ? `(meetupdate ~ "${dayKeyword}" || meetupdate = "")`
          : `meetupdate ~ "${dayKeyword}"`;
        // 本周：submitted_at_cn（中国公历）或 created（UTC 兼容旧记录），两路查询合并
        const filterSubmitted = encodeURIComponent(
          `${meetupdatePart} && submitted_at_cn >= "${weekStartCn}" && submitted_at_cn <= "${weekEndCn}"`
        );
        const filterCreated = encodeURIComponent(
          `${meetupdatePart} && created >= "${weekStartUtc}" && created <= "${weekEndUtc}"`
        );
        const [res1, res2] = await Promise.all([
          fetch(`${base}/api/collections/${pb.joinCollection}/records?filter=${filterSubmitted}&sort=-created&perPage=6`, {
            headers: { Authorization: `Bearer ${token}` },
            cache: "no-store",
          }),
          fetch(`${base}/api/collections/${pb.joinCollection}/records?filter=${filterCreated}&sort=-created&perPage=6`, {
            headers: { Authorization: `Bearer ${token}` },
            cache: "no-store",
          }),
        ]);
        const data1 = res1.ok ? await res1.json() : { items: [], totalItems: 0 };
        const data2 = res2.ok ? await res2.json() : { items: [], totalItems: 0 };
        const seen = new Set<string>();
        const merged: typeof data1.items = [];
        for (const r of [...(data1.items || []), ...(data2.items || [])]) {
          if (r?.id && !seen.has(r.id)) {
            seen.add(r.id);
            merged.push(r);
          }
        }
        merged.sort((a: { created?: string }, b: { created?: string }) => (b?.created || "").localeCompare(a?.created || ""));
        const items = merged.slice(0, 6);
        const total = Math.max(data1.totalItems || 0, data2.totalItems || 0, merged.length);
        return {
          id: s.id,
          stat: {
            count: total,
            joiners: items.map((r: { nickname?: string; xiaohongshu_nickname?: string; xiaohongshu_avatar?: string; xiaohongshu_url?: string; media?: string }) => ({
              nickname: String(r?.xiaohongshu_nickname || r?.nickname || "").trim() || "匿名",
              avatar: String(r?.xiaohongshu_avatar || r?.media || "").trim() || undefined,
              xiaohongshu_url: String(r?.xiaohongshu_url || "").trim() || undefined,
            })),
          },
        };
      } catch {
        return { id: s.id, stat: { count: 0, joiners: [] } };
      }
    })
  );

  for (const { id, stat } of results) {
    stats[id] = stat;
  }

  return NextResponse.json({ ok: true, stats });
}

function getEmptyStats() {
  const stats: Record<string, { count: number; joiners: { nickname: string; avatar?: string; xiaohongshu_url?: string }[] }> = {};
  for (const s of SESSIONS) {
    stats[s.id] = { count: 0, joiners: [] };
  }
  return stats;
}