"use client";

import { useState, useEffect } from "react";
import { Link } from "@/i18n/navigation";
import { HERO_CONFIG, CURRICULUM_CONFIG } from "@/config/course";
import { useAuthAndVip } from "@/app/lib/useAuthAndVip";
import { getStoredToken, getStoredUser } from "@/app/lib/pocketbase";
import { getLastWatched, getProgress } from "@/app/lib/learning";
import AuthModal from "@/app/components/AuthModal";
import {
  getPayEnv,
  redirectToPay,
  getDeviceFromEnv,
} from "@/app/lib/payment";

const TOTAL_LESSONS = CURRICULUM_CONFIG.modules.reduce((s, m) => s + m.lessons.length, 0);

export function CourseHero() {
  const { user, vip, refetch } = useAuthAndVip();
  const [last, setLast] = useState<ReturnType<typeof getLastWatched>>(null);
  const [progress, setProgress] = useState({ completed: 0, percent: 0 });
  const [authOpen, setAuthOpen] = useState(false);
  const [payRedirecting, setPayRedirecting] = useState(false);

  useEffect(() => {
    setLast(getLastWatched());
    setProgress(getProgress(TOTAL_LESSONS));
    const onProgress = () => {
      setLast(getLastWatched());
      setProgress(getProgress(TOTAL_LESSONS));
    };
    window.addEventListener("learning:progress", onProgress);
    return () => window.removeEventListener("learning:progress", onProgress);
  }, []);

  const paid = !!user && vip;

  const startPay = (userId: string) => {
    const env = getPayEnv();
    const channel = "wxpay";
    const device = getDeviceFromEnv(env);
    const returnUrl = `${window.location.origin}/`;

    redirectToPay({
      user_id: userId,
      return_url: returnUrl,
      channel,
      device,
      type: "video",
      useJoinConfig: true,
    });
  };

  const handleEnroll = async () => {
    if (payRedirecting) return;
    setPayRedirecting(true);

    try {
      // 先验证登录态
      let meRes = await fetch("/api/auth/me", { credentials: "include" });
      let meData = await meRes.json().catch(() => ({}));
      if (meData?.user?.id) {
        // 已登录：先校验 VIP，已是 VIP 则无需支付
        const vipRes = await fetch(`/api/vip/check?email=${encodeURIComponent(meData.user.email)}`, { credentials: "include" });
        const vipData = await vipRes.json().catch(() => ({}));
        if (vipData?.vip) {
          await refetch();
          return;
        }
        startPay(meData.user.id);
        return;
      }

      const storedUser = getStoredUser();
      const storedToken = getStoredToken();
      if (storedUser?.id && storedToken) {
        await fetch("/api/auth/sync-session", {
          method: "POST",
          headers: { "Content-Type": "application/json" },
          body: JSON.stringify({ token: storedToken, record: storedUser }),
          credentials: "include",
        }).catch(() => null);
        meRes = await fetch("/api/auth/me", { credentials: "include" });
        meData = await meRes.json().catch(() => ({}));
        if (meData?.user?.id) {
          const vipRes = await fetch(`/api/vip/check?email=${encodeURIComponent(meData.user.email)}`, { credentials: "include" });
          const vipData = await vipRes.json().catch(() => ({}));
          if (vipData?.vip) {
            await refetch();
            return;
          }
          startPay(meData.user.id);
          return;
        }
      }

      setAuthOpen(true);
    } finally {
      setPayRedirecting(false);
    }
  };

  return (
    <section className="relative overflow-hidden pt-24 pb-16 sm:pt-28 sm:pb-20 md:pt-32 md:pb-24">
      <div className="absolute inset-0 bg-[radial-gradient(ellipse_80%_50%_at_50%_-20%,var(--gradient-accent),transparent)] animate-gradient" />
      <div className="relative mx-auto max-w-4xl px-4 text-center sm:px-6">
        <h1 className="mb-4 text-3xl font-bold tracking-tight sm:text-4xl md:text-5xl lg:text-6xl">
          {HERO_CONFIG.title}
        </h1>
        <p className="mb-10 text-lg text-[var(--muted-foreground)] sm:mb-12 sm:text-xl md:text-2xl">
          {HERO_CONFIG.subtitle}
        </p>
        <div className="mb-10 flex flex-wrap justify-center gap-6 sm:mb-12 sm:gap-8">
          {HERO_CONFIG.stats.map((s) => (
            <div key={s.label} className="text-center transition-transform duration-300 hover:scale-105">
              <div className="text-2xl font-bold text-[var(--accent)] sm:text-3xl md:text-4xl">{s.value}</div>
              <div className="mt-1 text-xs text-[var(--muted-foreground)] sm:text-sm">{s.label}</div>
            </div>
          ))}
        </div>
        <div className="flex flex-wrap justify-center gap-3 sm:gap-4">
          {paid && last ? (
            <Link
              href={`/course/${last.moduleIndex}/${last.lessonIndex}`}
              className="inline-flex shrink-0 items-center gap-2 rounded-full bg-[var(--accent)] px-8 py-4 text-lg font-semibold text-[var(--accent-foreground)] transition hover:opacity-90 sm:px-10"
            >
              继续学习 →
            </Link>
          ) : paid ? (
            <Link
              href="/course/0/0"
              className="inline-flex shrink-0 items-center gap-2 rounded-full bg-[var(--accent)] px-8 py-4 text-lg font-semibold text-[var(--accent-foreground)] transition hover:opacity-90 sm:px-10"
            >
              进入课程 →
            </Link>
          ) : (
            <button
              type="button"
              onClick={handleEnroll}
              disabled={payRedirecting}
              className="inline-flex shrink-0 items-center gap-2 rounded-full bg-[var(--accent)] px-8 py-4 text-lg font-semibold text-[var(--accent-foreground)] transition hover:opacity-90 disabled:opacity-70 sm:px-10"
            >
              {payRedirecting ? "跳转支付中..." : "立即报名 →"}
            </button>
          )}
        </div>
        {paid && progress.completed > 0 && (
          <div className="mt-6 w-full max-w-xs">
            <div className="mb-1 flex justify-between text-xs text-[var(--muted-foreground)]">
              <span>学习进度</span>
              <span>{progress.completed}/{TOTAL_LESSONS} 节</span>
            </div>
            <div className="h-2 overflow-hidden rounded-full bg-[var(--muted)]">
              <div className="h-full rounded-full bg-[var(--accent)] transition-all" style={{ width: `${progress.percent}%` }} />
            </div>
          </div>
        )}
      </div>
      <AuthModal
        isOpen={authOpen}
        onClose={() => setAuthOpen(false)}
        onSuccess={() => {
          setAuthOpen(false);
          void refetch();
        }}
      />
    </section>
  );
}