"use client";

import { useMemo, useState, useEffect } from "react";
import Link from "next/link";
import { useRouter } from "next/navigation";
import { api } from "@/lib/api";
import { useToast } from "@/lib/toast";
import { useAuth } from "@/lib/auth";
import { useI18n } from "@/lib/i18n";
import type { Meetup } from "@/lib/types";
import NewsletterSubscribe from "@/components/NewsletterSubscribe";
import RingNext from "@/components/RingNext";
import { useRingSteps } from "@/lib/rings";

const MODE_LABELS: Record<string, string> = {
  online: "💻 线上",
  offline: "📍 线下",
  hybrid: "🔀 混合",
};

interface Props {
  meetups: Meetup[];
}

export default function MeetupsClient({ meetups }: Props) {
  const { t } = useI18n();
  const rings = useRingSteps();
  const { toast } = useToast();
  const { token } = useAuth();
  const router = useRouter();
  const [mode, setMode] = useState<"all" | Meetup["mode"]>("all");
  const [rsvpIds, setRsvpIds] = useState<Set<string>>(new Set());
  const [busyId, setBusyId] = useState<string | null>(null);

  useEffect(() => {
    if (!token) {
      setRsvpIds(new Set());
      return;
    }
    api.getMyRsvps(token).then((r) => setRsvpIds(new Set(r.ids))).catch(() => {});
  }, [token]);

  const filtered = useMemo(() => {
    if (mode === "all") return meetups;
    return meetups.filter((m) => m.mode === mode);
  }, [meetups, mode]);

  const handleRsvp = async (meetup: Meetup) => {
    if (!token) {
      toast("登录后报名，名额才会保留", "info");
      router.push(`/login?next=${encodeURIComponent("/meetups")}`);
      return;
    }
    if (rsvpIds.has(meetup.id)) {
      setBusyId(meetup.id);
      try {
        await api.cancelMeetupRsvp(token, meetup.id);
        const next = new Set(rsvpIds);
        next.delete(meetup.id);
        setRsvpIds(next);
        toast("已取消报名", "success");
      } catch {
        toast(t.meetups.rsvpFail, "error");
      } finally {
        setBusyId(null);
      }
      return;
    }
    setBusyId(meetup.id);
    try {
      const res = await api.rsvpMeetup(meetup.id, undefined, token);
      setRsvpIds(new Set(rsvpIds).add(meetup.id));
      toast(res.message || t.meetups.rsvpOk, "success");
    } catch {
      toast(t.meetups.rsvpFail, "error");
    } finally {
      setBusyId(null);
    }
  };

  return (
    <div className="meetups-page">
      <div className="container">
        <nav className="detail-nav">
          <Link href="/">{t.common.backHome}</Link>
          <span> · </span>
          <Link href="/community">{t.nav.community}</Link>
        </nav>

        <div className="section-header reveal">
          <span className="section-tag">{t.meetups.tag}</span>
          <h1>{t.meetups.title}</h1>
          <p>{t.meetups.subtitle}</p>
          {!token && (
            <p className="meetups-login-hint">
              <Link href="/login?next=/meetups">登录</Link> 后报名，名额会同步到你的账号
            </p>
          )}
        </div>

        <div className="meetups-toolbar reveal">
          <Link href="/meetups/host" className="btn btn-primary btn-sm">{t.meetups.hostBtn}</Link>
          {(["all", "online", "offline", "hybrid"] as const).map((m) => (
            <button
              key={m}
              type="button"
              className={`filter-btn${mode === m ? " active" : ""}`}
              onClick={() => setMode(m)}
            >
              {m === "all" ? t.meetups.all : MODE_LABELS[m]}
            </button>
          ))}
        </div>

        <div className="meetups-grid">
          {filtered.map((m) => {
            const joined = rsvpIds.has(m.id);
            return (
              <article key={m.id} className="meetup-card reveal">
                <div className="meetup-card-top">
                  <span className="meetup-emoji">{m.emoji}</span>
                  <div>
                    <h3>{m.title}</h3>
                    <p className="meetup-meta">
                      {MODE_LABELS[m.mode]} · {m.city} · {m.date} {m.time}
                    </p>
                  </div>
                </div>
                <p className="meetup-desc">{m.description}</p>
                <p className="meetup-venue">📍 {m.venue}</p>
                <div className="meetup-tags">
                  {m.tags.map((tag) => (
                    <span key={tag} className="meetup-tag">{tag}</span>
                  ))}
                </div>
                <footer className="meetup-footer">
                  <span>
                    {m.rsvp_count}/{m.max_attendees} {t.meetups.rsvp}
                  </span>
                  <span>{m.organizer}</span>
                  <div className="meetup-footer-actions">
                    {(m.mode === "online" || m.mode === "hybrid") && (
                      <Link href={`/meetups/${m.id}/live`} className="btn btn-sm meetup-live-btn">
                        {t.meetups.liveBtn}
                      </Link>
                    )}
                    <button
                      type="button"
                      className={`btn btn-sm${joined ? " btn-ghost is-done" : " btn-primary"}`}
                      onClick={() => handleRsvp(m)}
                      disabled={busyId === m.id}
                    >
                      {joined ? "取消报名" : t.meetups.rsvpBtn}
                    </button>
                  </div>
                </footer>
                {m.destination_slug && (
                  <Link href={`/destinations/${m.destination_slug}`} className="meetup-city-link">
                    {t.meetups.viewCity} →
                  </Link>
                )}
              </article>
            );
          })}
        </div>

        {filtered.length === 0 && (
          <div className="notif-empty reveal">
            <p className="dest-empty">{t.meetups.empty}</p>
            <div className="dating-empty-actions">
              {mode !== "all" && (
                <button type="button" className="btn btn-sm" onClick={() => setMode("all")}>
                  查看全部
                </button>
              )}
              <Link href="/meetups/host" className="btn btn-primary btn-sm">
                {t.meetups.hostBtn}
              </Link>
              <Link href="/community" className="btn btn-sm">
                {t.nav.community}
              </Link>
            </div>
          </div>
        )}

        <NewsletterSubscribe source="meetups" />
        <RingNext steps={rings.afterMeetups} />
      </div>
    </div>
  );
}