"use client";

import { useCallback, useState, useEffect, type FormEvent } from "react";
import { createPortal } from "react-dom";
import { useLocale } from "@/i18n/navigation";
import {
  getPayEnv,
  redirectToPay,
  getDeviceFromEnv,
} from "@/app/lib/payment";
import type { PayChannel, PayEnv } from "@/app/lib/payment";
import { apiUrl } from "@/app/lib/api-client";
import { googleLogin } from "@/app/lib/pocketbase";
import GoogleLoginButton from "./GoogleLoginButton";

interface JoinModalProps {
  isOpen: boolean;
  onClose: () => void;
  initialEmail?: string;
  /** 仅登录（已有 VIP 用户直接邮箱登录，不跳转支付） */
  vipOnly?: boolean;
}

const GOOGLE_CLIENT_ID = process.env.NEXT_PUBLIC_GOOGLE_CLIENT_ID || "";

export default function JoinModal({ isOpen, onClose, initialEmail = "", vipOnly = false }: JoinModalProps) {
  const locale = useLocale();
  const [email, setEmail] = useState(initialEmail);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    if (isOpen) {
      setEmail(initialEmail);
      setError(null);
    }
  }, [isOpen, initialEmail]);

  const saveAuth = useCallback(async (token: string, record: Record<string, unknown>) => {
    const { pbSaveAuth } = await import("@/app/lib/pocketbase");
    pbSaveAuth(token, record as { id: string; email: string; [key: string]: unknown });
    try {
      await fetch(apiUrl("/api/auth/sync-session"), {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ token, record }),
        credentials: "include",
      });
    } catch {
      /* local auth is already saved; backend cookie will be retried by the navbar */
    }
    if (typeof window !== "undefined") {
      window.dispatchEvent(new CustomEvent("auth:updated"));
    }
  }, []);

  const continueAfterAuth = useCallback((userId: string) => {
    if (vipOnly) {
      onClose();
      return;
    }
    const returnUrl = typeof window !== "undefined" ? `${window.location.origin}/${locale}/join/paid` : "/zh/join/paid";
    const env = getPayEnv();
    const channel: PayChannel = "wxpay";
    redirectToPay({
      user_id: userId,
      return_url: returnUrl,
      channel,
      device: getDeviceFromEnv(env),
      useJoinConfig: true,
    });
  }, [locale, onClose, vipOnly]);

  const handleSubmit = async (e: FormEvent) => {
    e.preventDefault();
    if (loading) return;
    const em = email.trim();
    if (!em) {
      setError(locale === "zh" ? "请输入邮箱" : "Please enter your email");
      return;
    }
    setError(null);
    setLoading(true);
    try {
      const res = await fetch(apiUrl("/api/meetup/ensure-user"), {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ email: em }),
        credentials: "include",
      });
      const data = await res.json();
      if (!res.ok || !data?.ok) {
        throw new Error(data?.error || (locale === "zh" ? "操作失败" : "Operation failed"));
      }
      await saveAuth(data.token, data.record);
      continueAfterAuth(String(data.user_id));
    } catch (err) {
      setError(err instanceof Error ? err.message : "操作失败");
    } finally {
      setLoading(false);
    }
  };

  const handleGoogleCredential = useCallback(async (credential: string) => {
    if (loading) return;
    setError(null);
    setLoading(true);
    try {
      const result = await googleLogin(credential);
      await saveAuth(result.token, result.record);
      continueAfterAuth(result.record.id);
    } catch (err) {
      setError(err instanceof Error ? err.message : "Google 登录失败");
    } finally {
      setLoading(false);
    }
  }, [continueAfterAuth, loading, saveAuth]);

  const [mounted, setMounted] = useState(false);
  useEffect(() => setMounted(true), []);

  if (!isOpen || !mounted) return null;

  const modalContent = (
    <div className="fixed inset-0 z-[9999] overflow-y-auto">
      <div className="fixed inset-0 bg-black/50" onClick={onClose} aria-hidden />
      <div className="flex min-h-svh items-center justify-center p-4 py-8">
        <div className="relative w-full max-w-sm rounded-2xl bg-white p-6 shadow-xl dark:bg-gray-900 dark:border dark:border-gray-700 shrink-0">
          <button
            onClick={onClose}
            className="absolute right-4 top-4 text-gray-400 hover:text-gray-600 dark:hover:text-gray-300"
            aria-label="关闭"
          >
            <svg className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
            </svg>
          </button>

          <h2 className="text-xl font-bold text-gray-800 dark:text-gray-100">
            {vipOnly ? (locale === "zh" ? "邮箱登录" : "Email login") : (locale === "zh" ? "加入游牧中国" : "Join Nomad China")}
          </h2>

          <form onSubmit={handleSubmit} className="mt-6 space-y-4">
            <div>
              <label className="mb-1 block text-sm font-medium text-gray-700 dark:text-gray-300">
                {locale === "zh" ? "邮箱" : "Email"}
              </label>
              <input
                type="email"
                value={email}
                onChange={(e) => { setEmail(e.target.value); setError(null); }}
                placeholder={locale === "zh" ? "输入你的邮箱..." : "Enter your email..."}
                required
                className="w-full rounded-lg border border-gray-200 px-4 py-2.5 text-gray-800 placeholder-gray-400 focus:border-[#ff4d4f] focus:outline-none focus:ring-1 focus:ring-[#ff4d4f] dark:border-gray-600 dark:bg-gray-800 dark:text-gray-100"
              />
            </div>
            {error && (
              <p className="rounded-lg bg-red-50 px-3 py-2 text-sm text-red-600 dark:bg-red-900/30 dark:text-red-400">{error}</p>
            )}
            <button
              type="submit"
              disabled={loading}
              className="w-full rounded-lg bg-[#ff4d4f] py-3 font-semibold text-white transition-colors hover:bg-[#ff3333] disabled:opacity-70"
            >
              {loading ? (locale === "zh" ? "处理中…" : "Processing…") : vipOnly ? (locale === "zh" ? "登录" : "Login") : (locale === "zh" ? "加入游牧中国 →" : "Join Nomad China →")}
            </button>
          </form>
          {GOOGLE_CLIENT_ID && (
            <>
              <div className="my-4 flex items-center gap-3">
                <div className="h-px flex-1 bg-gray-200 dark:bg-gray-700" />
                <span className="text-xs text-gray-400">or</span>
                <div className="h-px flex-1 bg-gray-200 dark:bg-gray-700" />
              </div>
              <GoogleLoginButton disabled={loading} onCredential={handleGoogleCredential} onError={setError} />
            </>
          )}
        </div>
      </div>
    </div>
  );

  return createPortal(modalContent, document.body);
}