"use client";

import { useState, useRef, useEffect, type FormEvent, type ChangeEvent } from "react";
import { Link } from "@/i18n/navigation";
import { getPayEnv, getRecommendedChannel, mustUseWxPay, type PayChannel, type PayEnv } from "../../lib/payEnv";

const genderOptions = ["男", "女"];
const singleOptions = ["单身", "恋爱中", "已婚"];
const educationOptions = ["高中及以下", "大专", "本科", "硕士", "博士"];
const graduationYears = Array.from({ length: 41 }, (_, i) => String(2026 - i));

interface FormData {
  nickname: string;
  gender: string;
  single: string;
  profession: string;
  intro: string;
  wechat: string;
  education: string;
  graduationYear: string;
  phone: string;
}

interface MediaInfo {
  preview: string;
  url: string;
  type: "image" | "video";
}

export default function JoinPage() {
  const [form, setForm] = useState<FormData>({
    nickname: "",
    gender: "",
    single: "",
    profession: "",
    intro: "",
    wechat: "",
    education: "",
    graduationYear: "",
    phone: "",
  });
  const [media, setMedia] = useState<MediaInfo | null>(null);
  const [uploading, setUploading] = useState(false);
  const fileRef = useRef<HTMLInputElement>(null);
  const [submitted, setSubmitted] = useState(false);
  const [submitting, setSubmitting] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [payRedirecting, setPayRedirecting] = useState(false);
  const [payEnv, setPayEnv] = useState<PayEnv | null>(null);
  const [payChannel, setPayChannel] = useState<PayChannel>("alipay");

  useEffect(() => {
    if (typeof window !== "undefined" && new URLSearchParams(window.location.search).get("paid") === "1") {
      setSubmitted(true);
    }
  }, []);

  useEffect(() => {
    if (typeof window === "undefined") return;
    const env = getPayEnv();
    setPayEnv(env);
    setPayChannel(getRecommendedChannel(env));
  }, []);

  const set = (key: keyof FormData, value: string) =>
    setForm((prev) => ({ ...prev, [key]: value }));

  const handleSubmit = async (e: FormEvent) => {
    e.preventDefault();
    setError(null);
    setSubmitting(true);
    try {
      const res = await fetch("/api/join", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ ...form, media: media?.url }),
      });
      const data = await res.json();
      if (!res.ok || !data?.ok) {
        throw new Error(data?.error || "提交失败，请稍后重试");
      }
      const userId = data.user_id;
      if (!userId) {
        setSubmitted(true);
        return;
      }
      setSubmitting(false);
      setPayRedirecting(true);
      const returnUrl = `${window.location.origin}${window.location.pathname}?paid=1`;
      const payForm = document.createElement("form");
      payForm.method = "POST";
      payForm.action = "/api/pay";
      payForm.target = "_self";
      payForm.style.display = "none";
      const env = getPayEnv();
      const channel = mustUseWxPay(env) ? "wxpay" : payChannel;
      const device = env === "pc" ? "pc" : "h5"; // PC 跳转 payurl，H5/微信 用 payurl/payurl2
      const fields: [string, string][] = [
        ["user_id", userId],
        ["total_fee", "80"],
        ["type", "meetup"],
        ["channel", channel],
        ["device", device],
        ["return_url", returnUrl],
        ["html", "1"],
      ];
      fields.forEach(([k, v]) => {
        const input = document.createElement("input");
        input.type = "hidden";
        input.name = k;
        input.value = v;
        payForm.appendChild(input);
      });
      document.body.appendChild(payForm);
      payForm.submit();
      return;
    } catch (err) {
      setError(err instanceof Error ? err.message : "网络错误，请重试");
    } finally {
      setSubmitting(false);
    }
  };

  if (submitted) {
    return (
      <div className="flex min-h-screen items-center justify-center bg-[#f0f4f8] px-4">
        <div className="w-full max-w-md animate-fade-in rounded-2xl bg-white p-10 text-center shadow-lg">
          <div className="mx-auto mb-5 flex h-20 w-20 items-center justify-center rounded-full bg-emerald-50 text-5xl">
            ✅
          </div>
          <h2 className="text-2xl font-bold text-slate-800">申请已提交</h2>
          <p className="mt-3 text-slate-500">
            我们会尽快审核你的信息
            <br />
            审核通过后将通过微信邀请你入群
          </p>
          <Link
            href="/"
            className="mt-8 inline-flex items-center gap-2 rounded-full bg-sky-500 px-8 py-3 font-semibold text-white transition-colors hover:bg-sky-600"
          >
            ← 返回首页
          </Link>
        </div>
      </div>
    );
  }

  return (
    <div className="min-h-screen bg-[#f0f4f8]">
      {/* ── PC: center column / H5: full width ── */}
      <div className="mx-auto max-w-2xl px-0 py-0 sm:px-6 sm:py-10 lg:py-14">
        {/* ── Banner ── */}
        <div className="overflow-hidden bg-white shadow-sm sm:rounded-t-2xl">
          {/* Hero image area */}
          <div className="relative h-40 overflow-hidden bg-gradient-to-br from-sky-400 via-cyan-500 to-teal-400 sm:h-52">
            <div className="absolute inset-0 flex flex-col items-center justify-center text-white">
              <div className="text-6xl sm:text-7xl">🌍</div>
              <div className="mt-2 text-sm font-medium opacity-80">
                Digital Nomad Community
              </div>
            </div>
            {/* Decorative blobs */}
            <div className="absolute -top-10 -left-10 h-40 w-40 rounded-full bg-white/10 blur-2xl" />
            <div className="absolute -right-10 -bottom-10 h-48 w-48 rounded-full bg-white/10 blur-2xl" />
          </div>

          {/* Title block */}
          <div className="px-5 py-5 text-center sm:px-8 sm:py-7">
            <h1 className="text-xl font-bold text-slate-800 sm:text-2xl">
              🌍 数字游民社区报名
            </h1>
            <p className="mt-3 whitespace-pre-line text-sm leading-relaxed text-slate-400 sm:text-base">
              {"💼 结识志同道合的伙伴\n📍 线下聚会 + 线上分享\n🤝 互助成长，资源共享"}
            </p>
          </div>
        </div>

        {/* ── Form card ── */}
        <form
          onSubmit={handleSubmit}
          className="mt-0 bg-white px-5 pb-8 pt-2 shadow-sm sm:mt-5 sm:rounded-2xl sm:px-8 sm:py-8 sm:shadow-md"
        >
          {/* ---- Row group: nickname + gender (PC side-by-side) ---- */}
          <div className="grid gap-0 sm:grid-cols-2 sm:gap-6">
            <Field label="🌟 昵称">
              <input
                type="text"
                maxLength={140}
                placeholder="请输入您的昵称"
                value={form.nickname}
                onChange={(e) => set("nickname", e.target.value)}
                required
                className="form-input"
              />
            </Field>

            <Field label="👤 性别">
              <select
                value={form.gender}
                onChange={(e) => set("gender", e.target.value)}
                required
                className={`form-input appearance-none ${
                  form.gender ? "text-slate-800" : "text-slate-400"
                }`}
              >
                <option value="" disabled>
                  请选择
                </option>
                {genderOptions.map((o) => (
                  <option key={o} value={o}>
                    {o}
                  </option>
                ))}
              </select>
              <ChevronDown />
            </Field>
          </div>

          {/* ---- Row group: single + profession ---- */}
          <div className="grid gap-0 sm:grid-cols-2 sm:gap-6">
            <Field label="💕 感情状态">
              <select
                value={form.single}
                onChange={(e) => set("single", e.target.value)}
                required
                className={`form-input appearance-none ${
                  form.single ? "text-slate-800" : "text-slate-400"
                }`}
              >
                <option value="" disabled>
                  请选择
                </option>
                {singleOptions.map((o) => (
                  <option key={o} value={o}>
                    {o}
                  </option>
                ))}
              </select>
              <ChevronDown />
            </Field>

            <Field label="💼 职业">
              <input
                type="text"
                maxLength={140}
                placeholder="您的职业或专业"
                value={form.profession}
                onChange={(e) => set("profession", e.target.value)}
                required
                className="form-input"
              />
            </Field>
          </div>

          {/* ---- wechat + phone ---- */}
          <div className="grid gap-0 sm:grid-cols-2 sm:gap-6">
            <Field label="💬 微信号">
              <input
                type="text"
                maxLength={140}
                placeholder="用于拉群"
                value={form.wechat}
                onChange={(e) => set("wechat", e.target.value)}
                required
                className="form-input"
              />
            </Field>

            <Field label="📱 手机号">
              <input
                type="tel"
                maxLength={11}
                pattern="^1[3-9]\d{9}$"
                placeholder="请输入11位中国手机号"
                value={form.phone}
                onChange={(e) => {
                  const v = e.target.value.replace(/\D/g, "").slice(0, 11);
                  set("phone", v);
                }}
                className="form-input"
              />
            </Field>
          </div>

          {/* ---- Intro (full width) ---- */}
          <div className="border-b border-slate-100 py-4 sm:border-b-0 sm:py-5">
            <label className="mb-2 block text-base font-bold text-slate-700 sm:text-[17px]">
              📝 自我介绍
            </label>
            <div className="relative">
              <textarea
                maxLength={500}
                rows={5}
                placeholder="分享您的经历、兴趣或加入原因，越详细越好哦~"
                value={form.intro}
                onChange={(e) => set("intro", e.target.value)}
                className="form-input min-h-[120px] resize-none sm:min-h-[140px]"
              />
              <span className="absolute right-3 bottom-3 text-xs text-slate-300">
                {form.intro.length}/500
              </span>
            </div>
          </div>

          {/* ---- Row group: education + graduation ---- */}
          <div className="grid gap-0 sm:grid-cols-2 sm:gap-6">
            <Field label="🎓 学历">
              <select
                value={form.education}
                onChange={(e) => set("education", e.target.value)}
                className={`form-input appearance-none ${
                  form.education ? "text-slate-800" : "text-slate-400"
                }`}
              >
                <option value="" disabled>
                  请选择
                </option>
                {educationOptions.map((o) => (
                  <option key={o} value={o}>
                    {o}
                  </option>
                ))}
              </select>
              <ChevronDown />
            </Field>

            <Field label="📅 毕业时间">
              <select
                value={form.graduationYear}
                onChange={(e) => set("graduationYear", e.target.value)}
                className={`form-input appearance-none ${
                  form.graduationYear ? "text-slate-800" : "text-slate-400"
                }`}
              >
                <option value="" disabled>
                  请选择
                </option>
                {graduationYears.map((y) => (
                  <option key={y} value={y}>
                    {y}
                  </option>
                ))}
              </select>
              <ChevronDown />
            </Field>
          </div>

          {/* ---- Media upload (optional) ---- */}
          <div className="py-4 sm:py-5">
            <label className="mb-1 block text-[15px] font-bold text-slate-700 sm:text-[17px]">
              📷 头像 / 自拍视频
              <span className="ml-2 text-xs font-normal text-slate-400">
                （可选）
              </span>
            </label>
            <p className="mb-3 text-xs text-slate-400">
              支持图片（JPG/PNG）或短视频（MP4），最大 20MB
            </p>

            <input
              ref={fileRef}
              type="file"
              accept="image/jpeg,image/png,image/webp,video/mp4,video/quicktime"
              className="hidden"
              onChange={async (e: ChangeEvent<HTMLInputElement>) => {
                const file = e.target.files?.[0];
                if (!file) return;
                if (file.size > 20 * 1024 * 1024) {
                  alert("文件大小不能超过 20MB");
                  return;
                }
                const isVideo = file.type.startsWith("video/");
                const preview = URL.createObjectURL(file);
                setMedia({ preview, url: "", type: isVideo ? "video" : "image" });
                setUploading(true);
                try {
                  const fd = new FormData();
                  fd.append("file", file);
                  const res = await fetch("/api/upload-media", {
                    method: "POST",
                    body: fd,
                  });
                  const data = await res.json();
                  if (!res.ok || !data?.ok) {
                    throw new Error(data?.error || "上传失败");
                  }
                  setMedia((m) => (m ? { ...m, url: data.url } : null));
                } catch (err) {
                  alert(err instanceof Error ? err.message : "上传失败");
                  URL.revokeObjectURL(preview);
                  setMedia(null);
                  if (fileRef.current) fileRef.current.value = "";
                } finally {
                  setUploading(false);
                }
              }}
            />

            {media ? (
              <div className="relative inline-block">
                {uploading && (
                  <div className="absolute inset-0 z-10 flex items-center justify-center rounded-xl bg-black/40 text-sm font-medium text-white">
                    上传中…
                  </div>
                )}
                {media.type === "image" ? (
                  // eslint-disable-next-line @next/next/no-img-element
                  <img
                    src={media.preview}
                    alt="preview"
                    className="h-32 w-32 rounded-xl border border-slate-200 object-cover sm:h-40 sm:w-40"
                  />
                ) : (
                  <video
                    src={media.preview}
                    className="h-32 w-32 rounded-xl border border-slate-200 object-cover sm:h-40 sm:w-40"
                    muted
                    playsInline
                    controls
                  />
                )}
                <button
                  type="button"
                  disabled={uploading}
                  onClick={() => {
                    URL.revokeObjectURL(media.preview);
                    setMedia(null);
                    if (fileRef.current) fileRef.current.value = "";
                  }}
                  className="absolute -top-2 -right-2 flex h-6 w-6 items-center justify-center rounded-full bg-red-500 text-xs text-white shadow-md transition-colors hover:bg-red-600 disabled:opacity-50"
                >
                  ✕
                </button>
              </div>
            ) : (
              <button
                type="button"
                disabled={uploading}
                onClick={() => fileRef.current?.click()}
                className="flex h-32 w-32 flex-col items-center justify-center gap-2 rounded-xl border-2 border-dashed border-slate-200 text-slate-400 transition-colors hover:border-sky-300 hover:text-sky-500 disabled:opacity-50 sm:h-40 sm:w-40"
              >
                <svg className="h-8 w-8" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={1.5} d="M12 4v16m8-8H4" />
                </svg>
                <span className="text-xs">{uploading ? "上传中…" : "点击上传"}</span>
              </button>
            )}
          </div>

          {/* ── 支付通道选择（PC/H5 可选，微信内强制微信支付）── */}
          <div className="mt-6 rounded-xl border border-slate-100 bg-slate-50/50 px-4 py-4 sm:px-5">
            <p className="mb-3 text-sm font-bold text-slate-700">💳 支付方式</p>
            {payEnv === "wechat" ? (
              <p className="text-sm text-slate-500">
                当前在微信内打开，将使用 <span className="font-medium text-emerald-600">微信支付</span>
              </p>
            ) : (
              <div className="flex gap-3">
                <label className="flex flex-1 cursor-pointer items-center gap-2 rounded-lg border-2 px-4 py-3 transition-colors has-[:checked]:border-sky-500 has-[:checked]:bg-sky-50">
                  <input
                    type="radio"
                    name="payChannel"
                    value="alipay"
                    checked={payChannel === "alipay"}
                    onChange={() => setPayChannel("alipay")}
                    className="h-4 w-4 border-slate-300 text-sky-500"
                  />
                  <span className="text-sm font-medium text-slate-700">支付宝</span>
                </label>
                <label className="flex flex-1 cursor-pointer items-center gap-2 rounded-lg border-2 px-4 py-3 transition-colors has-[:checked]:border-emerald-500 has-[:checked]:bg-emerald-50">
                  <input
                    type="radio"
                    name="payChannel"
                    value="wxpay"
                    checked={payChannel === "wxpay"}
                    onChange={() => setPayChannel("wxpay")}
                    className="h-4 w-4 border-slate-300 text-emerald-500"
                  />
                  <span className="text-sm font-medium text-slate-700">微信支付</span>
                </label>
              </div>
            )}
          </div>

          {/* ── Submit ── */}
          <div className="mt-8 sm:mt-10">
            {error && (
              <p className="mb-4 rounded-lg bg-red-50 px-4 py-3 text-center text-sm text-red-600">
                {error}
              </p>
            )}
            <button
              type="submit"
              disabled={submitting || uploading || payRedirecting}
              className="w-full rounded-full bg-[#1aad19] py-3.5 text-lg font-semibold text-white shadow-md shadow-emerald-500/20 transition-all hover:bg-[#179b16] hover:shadow-lg hover:shadow-emerald-500/25 active:scale-[0.98] disabled:cursor-not-allowed disabled:opacity-70 sm:py-4"
            >
              {uploading ? "媒体上传中…" : payRedirecting ? "跳转支付中…" : submitting ? "提交中…" : "提交申请"}
            </button>

          </div>
        </form>

        {/* ── Back link (PC) ── */}
        <div className="mt-6 hidden text-center sm:block">
          <Link
            href="/"
            className="text-sm text-slate-400 transition-colors hover:text-sky-500"
          >
            ← 返回首页
          </Link>
        </div>

        <div className="mt-4 pb-6 text-center sm:hidden">
          <Link
            href="/"
            className="text-sm text-slate-400 transition-colors hover:text-sky-500"
          >
            ← 返回首页
          </Link>
        </div>
      </div>
    </div>
  );
}

/* ─── Reusable field wrapper ─── */
function Field({
  label,
  children,
  noBorder,
}: {
  label: string;
  children: React.ReactNode;
  noBorder?: boolean;
}) {
  return (
    <div
      className={`relative flex items-center gap-3 py-3.5 sm:flex-col sm:items-stretch sm:gap-0 sm:py-4 ${
        noBorder ? "" : "border-b border-slate-100 sm:border-b-0"
      }`}
    >
      <label className="w-[90px] shrink-0 text-[15px] font-bold text-slate-700 sm:mb-2 sm:w-auto sm:text-[17px]">
        {label}
      </label>
      <div className="relative min-w-0 flex-1">{children}</div>
    </div>
  );
}

/* ─── Chevron icon for selects ─── */
function ChevronDown() {
  return (
    <svg
      className="pointer-events-none absolute top-1/2 right-2 h-4 w-4 -translate-y-1/2 text-slate-400 sm:right-3"
      fill="none"
      viewBox="0 0 24 24"
      stroke="currentColor"
    >
      <path
        strokeLinecap="round"
        strokeLinejoin="round"
        strokeWidth={2}
        d="M19 9l-7 7-7-7"
      />
    </svg>
  );
}