"use client";

import { useState, useEffect, type FormEvent } from "react";
import Link from "next/link";
import SessionCoverImage from "../components/SessionCoverImage";
import { SESSIONS } from "@/config/home.config";
import CitySelect from "../components/CitySelect";
import ThemeToggle from "../components/ThemeToggle";

const ageOptions = ["18-24", "25-30", "31-35", "36-40", "40+"];
const statusOptions = [
  { value: "student", label: "学生" },
  { value: "working", label: "上班" },
  { value: "freelance", label: "自由职业" },
  { value: "startup", label: "创业" },
  { value: "other", label: "其他" },
];
const activityTypeOptions = [
  { value: "loft", label: "loft民宿" },
  { value: "side-hustle", label: "轻副业交流" },
  { value: "any", label: "都可以" },
];
const firstTimeOptions = ["是，第一次参加", "否，参加过类似活动"];
const availableTimeOptions = [
  { value: "sat-pm", label: "周六下午" },
  { value: "sun-pm", label: "周日下午" },
  { value: "both", label: "都可以" },
];

const REGIONS: Record<string, string[]> = {
  深圳: ["南山区", "福田区", "罗湖区", "宝安区", "龙岗区", "其他"],
};

interface FormData {
  city: string;
  session: string;
  ageRange: string;
  status: string;
  activityType: string;
  intro: string;
  whyJoin: string;
  nickname: string;
  wechatOrPhone: string;
  xiaohongshuUrl: string;
  region: string;
  firstTime: string;
  availableTime: string;
  agreeRules: boolean;
}

function getSessionFromUrl(): string {
  if (typeof window === "undefined") return "";
  return new URLSearchParams(window.location.search).get("session") || "";
}

function getSessionInfo(sessionId: string) {
  return SESSIONS.find((s) => s.id === sessionId);
}

export default function JoinPage() {
  const [step, setStep] = useState<1 | 2>(1);
  const [form, setForm] = useState<FormData>({
    city: "",
    session: "",
    ageRange: "",
    status: "",
    activityType: "",
    intro: "",
    whyJoin: "",
    nickname: "",
    wechatOrPhone: "",
    xiaohongshuUrl: "",
    region: "",
    firstTime: "",
    availableTime: "",
    agreeRules: false,
  });
  const [submitted, setSubmitted] = useState(false);
  const [submitting, setSubmitting] = useState(false);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    const sid = getSessionFromUrl();
    if (sid) {
      const s = SESSIONS.find((x) => x.id === sid);
      setForm((prev) => ({
        ...prev,
        session: sid,
        city: s?.city || prev.city,
      }));
    }
  }, []);

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

  const canProceedStep1 = form.city && form.session && form.ageRange && form.status && form.activityType && form.intro.trim() && form.whyJoin.trim();

  const handleSubmit = async (e: FormEvent) => {
    e.preventDefault();
    setError(null);
    setSubmitting(true);
    try {
      const reasonParts = [
        form.intro,
        form.whyJoin,
        form.status && `状态: ${statusOptions.find((o) => o.value === form.status)?.label || form.status}`,
        form.activityType && `活动偏好: ${activityTypeOptions.find((o) => o.value === form.activityType)?.label || form.activityType}`,
        form.region && `常活动区域: ${form.region}`,
        form.availableTime && `可参加时间: ${availableTimeOptions.find((o) => o.value === form.availableTime)?.label || form.availableTime}`,
      ].filter(Boolean);

      const res = await fetch("/api/join", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({
          city: form.city,
          session: form.session,
          nickname: form.nickname,
          age_range: form.ageRange,
          wechat_or_phone: form.wechatOrPhone,
          xiaohongshu_url: form.xiaohongshuUrl.trim(),
          intro: reasonParts.join(" | "),
          first_time: form.firstTime,
          agree_rules: form.agreeRules,
          status: form.status,
          activity_type: form.activityType,
          why_join: form.whyJoin,
          region: form.region,
          available_time: form.availableTime,
        }),
      });
      const data = await res.json();
      if (!res.ok || !data?.ok) {
        throw new Error(data?.error || "提交失败，请稍后重试");
      }
      setSubmitted(true);
    } catch (err) {
      setError(err instanceof Error ? err.message : "网络错误，请重试");
    } finally {
      setSubmitting(false);
    }
  };

  const selectedSession = getSessionInfo(form.session);
  const regions = form.city ? (REGIONS[form.city] || []) : [];

  if (submitted) {
    return (
      <div className="flex min-h-screen items-center justify-center bg-[#faf8f5] dark:bg-stone-950 px-4 py-8">
        <div className="w-full max-w-md animate-fade-in rounded-2xl bg-white dark:bg-stone-900 p-6 sm:p-10 text-center shadow-lg border border-stone-200 dark:border-stone-800">
          <div className="mx-auto mb-4 sm:mb-5 flex h-16 w-16 sm:h-20 sm:w-20 items-center justify-center rounded-full bg-emerald-50 dark:bg-emerald-900/30 text-4xl sm:text-5xl">
            ✅
          </div>
          <h2 className="text-xl sm:text-2xl font-bold text-stone-800 dark:text-stone-100">报名成功</h2>
          <p className="mt-2 sm:mt-3 text-sm sm:text-base text-stone-500 dark:text-stone-400">
            我们会尽快通过您留下的联系方式与您确认。不是所有报名都会自动确认，我们会根据场次与匹配度联系合适报名者。
          </p>
          <Link
            href="/"
            className="mt-6 sm:mt-8 inline-flex items-center gap-2 rounded-xl bg-amber-600 px-6 sm:px-8 py-2.5 sm:py-3 font-medium text-white text-sm sm:text-base transition-colors hover:bg-amber-700"
          >
            ← 返回首页
          </Link>
        </div>
      </div>
    );
  }

  return (
    <div className="min-h-screen bg-[#faf8f5] dark:bg-stone-950">
      {/* 顶部栏 */}
      <header className="sticky top-0 z-40 w-full border-b border-stone-200/80 dark:border-stone-800 bg-[#faf8f5]/95 dark:bg-stone-950/95 backdrop-blur">
        <div className="max-w-2xl mx-auto px-4 h-12 sm:h-14 flex items-center justify-between">
          <Link href="/" className="text-sm font-medium text-stone-600 dark:text-stone-400">
            ← 返回
          </Link>
          <ThemeToggle />
        </div>
      </header>

      <div className="mx-auto max-w-2xl px-0 py-0 sm:px-6 sm:py-8 lg:py-10">
        {/* Trust bar */}
        <div className="mx-4 sm:mx-0 mt-4 flex flex-wrap justify-center gap-x-6 gap-y-2 text-xs sm:text-sm text-stone-600 dark:text-stone-400 py-3">
          <span>📍 公开场地</span>
          <span>👥 6–8 人小组</span>
          <span>🆓 不收费</span>
          <span>🤝 尊重边界</span>
        </div>

        <div className="overflow-hidden bg-white dark:bg-stone-900 shadow-sm sm:rounded-t-2xl">
          <div className="relative h-28 sm:h-36 md:h-44 overflow-hidden bg-gradient-to-br from-amber-500 via-amber-600 to-amber-700">
            <div className="absolute inset-0 flex flex-col items-center justify-center text-white">
              <div className="text-4xl sm:text-5xl md:text-6xl" aria-hidden>☕</div>
              <div className="mt-1.5 sm:mt-2 text-xs sm:text-sm font-medium opacity-90 flex items-center gap-1.5">
                <span>📍</span> 深圳
              </div>
            </div>
          </div>

          <div className="px-4 sm:px-6 py-4 sm:py-5 text-center">
            <h1 className="text-lg sm:text-xl md:text-2xl font-bold text-stone-800 dark:text-stone-100">
              报名参加
            </h1>
            <p className="mt-2 sm:mt-3 text-xs sm:text-sm leading-relaxed text-stone-500 dark:text-stone-400">
              填个表，我们会根据场次联系你～
            </p>
            <p className="mt-1.5 text-xs text-stone-400 dark:text-stone-500">
              不是所有报名都会确认，看场次匹配
            </p>

            {/* 进度提示 */}
            <div className="mt-4 flex items-center justify-center gap-2">
              <div className={`h-1.5 flex-1 max-w-[120px] rounded-full transition-colors ${step === 1 ? "bg-amber-500" : "bg-amber-200 dark:bg-amber-800"}`} />
              <span className="text-xs font-medium text-stone-500 dark:text-stone-400">
                {step === 1 ? "第一步" : "第二步"}
              </span>
              <div className={`h-1.5 flex-1 max-w-[120px] rounded-full transition-colors ${step === 2 ? "bg-amber-500" : "bg-stone-200 dark:bg-stone-700"}`} />
            </div>
          </div>
        </div>

        {selectedSession && (
          <div className="mt-4 sm:mt-5 mx-4 sm:mx-0 rounded-xl bg-white dark:bg-stone-900 px-4 sm:px-5 py-3 sm:py-4 shadow-sm border border-stone-200 dark:border-stone-800 flex gap-3">
            {selectedSession.coverImage && (
              <div className="relative w-16 h-16 sm:w-20 sm:h-20 shrink-0 rounded-lg overflow-hidden">
                <SessionCoverImage src={selectedSession.coverImage} alt="" type={selectedSession.type} fill sizes="72px" className="object-cover" />
              </div>
            )}
            <div className="min-w-0 flex-1 text-left">
              <p className="text-[10px] sm:text-xs text-stone-500 dark:text-stone-500 mb-0.5">已选场次</p>
              <p className="font-medium text-stone-800 dark:text-stone-100 text-sm sm:text-base">{selectedSession.title}</p>
              <p className="text-xs sm:text-sm text-stone-500 dark:text-stone-500">{selectedSession.date} {selectedSession.time} · {selectedSession.place}</p>
            </div>
          </div>
        )}

        <form
          onSubmit={handleSubmit}
          className="mt-0 sm:mt-5 bg-white dark:bg-stone-900 px-4 sm:px-6 md:px-8 pb-8 pt-6 sm:pt-8 shadow-sm sm:rounded-b-2xl sm:shadow-md border border-t-0 sm:border border-stone-200 dark:border-stone-800"
        >
          {step === 1 ? (
            <div className="space-y-6">
              <div className="space-y-4">
                <h3 className="text-sm font-semibold text-stone-700 dark:text-stone-300">基本信息</h3>
                <Field label="城市">
                  <CitySelect value={form.city} onChange={(v) => set("city", v)} required />
                </Field>
                <Field label="想参加的场次">
                  <select
                    value={form.session}
                    onChange={(e) => {
                      const sid = e.target.value;
                      const s = SESSIONS.find((x) => x.id === sid);
                      setForm((prev) => ({ ...prev, session: sid, city: s?.city || prev.city }));
                    }}
                    required
                    className={`form-input appearance-none ${form.session ? "text-stone-800 dark:text-stone-100" : "text-stone-400 dark:text-stone-500"}`}
                  >
                    <option value="" disabled>请选择</option>
                    {SESSIONS.map((s) => (
                      <option key={s.id} value={s.id}>
                        {s.title} · {s.city} · {s.date} {s.time}
                      </option>
                    ))}
                  </select>
                </Field>
                <Field label="年龄段">
                  <select
                    value={form.ageRange}
                    onChange={(e) => set("ageRange", e.target.value)}
                    required
                    className={`form-input appearance-none ${form.ageRange ? "text-stone-800 dark:text-stone-100" : "text-stone-400 dark:text-stone-500"}`}
                  >
                    <option value="" disabled>请选择</option>
                    {ageOptions.map((o) => (
                      <option key={o} value={o}>{o}</option>
                    ))}
                  </select>
                </Field>
                <Field label="当前状态">
                  <select
                    value={form.status}
                    onChange={(e) => set("status", e.target.value)}
                    required
                    className={`form-input appearance-none ${form.status ? "text-stone-800 dark:text-stone-100" : "text-stone-400 dark:text-stone-500"}`}
                  >
                    <option value="" disabled>请选择</option>
                    {statusOptions.map((o) => (
                      <option key={o.value} value={o.value}>{o.label}</option>
                    ))}
                  </select>
                </Field>
                <Field label="想参加的活动类型">
                  <select
                    value={form.activityType}
                    onChange={(e) => set("activityType", e.target.value)}
                    required
                    className={`form-input appearance-none ${form.activityType ? "text-stone-800 dark:text-stone-100" : "text-stone-400 dark:text-stone-500"}`}
                  >
                    <option value="" disabled>请选择</option>
                    {activityTypeOptions.map((o) => (
                      <option key={o.value} value={o.value}>{o.label}</option>
                    ))}
                  </select>
                </Field>
              </div>

              <div className="pt-4 border-t border-stone-100 dark:border-stone-700 space-y-4">
                <h3 className="text-sm font-semibold text-stone-700 dark:text-stone-300">简单介绍</h3>
                <Field label="一句话介绍自己">
                  <input
                    type="text"
                    maxLength={140}
                    placeholder="简单介绍一下自己"
                    value={form.intro}
                    onChange={(e) => set("intro", e.target.value)}
                    required
                    className="form-input"
                  />
                </Field>
                <Field label="为什么想参加">
                  <input
                    type="text"
                    maxLength={200}
                    placeholder="简单说说你的期待"
                    value={form.whyJoin}
                    onChange={(e) => set("whyJoin", e.target.value)}
                    required
                    className="form-input"
                  />
                </Field>
              </div>

              <button
                type="button"
                onClick={() => setStep(2)}
                disabled={!canProceedStep1}
                className="w-full rounded-xl bg-amber-600 py-3 sm:py-3.5 text-base font-medium text-white transition-colors hover:bg-amber-700 active:scale-[0.98] disabled:cursor-not-allowed disabled:opacity-50 disabled:hover:bg-amber-600 mt-6"
              >
                下一步：填写联系方式
              </button>
            </div>
          ) : (
            <div className="space-y-6">
              <button
                type="button"
                onClick={() => setStep(1)}
                className="text-sm text-stone-500 dark:text-stone-400 hover:text-amber-600 dark:hover:text-amber-400"
              >
                ← 返回上一步
              </button>

              <div className="space-y-4">
                <h3 className="text-sm font-semibold text-stone-700 dark:text-stone-300">联系方式与确认</h3>
                <Field label="昵称">
                  <input
                    type="text"
                    maxLength={40}
                    placeholder="活动中使用的称呼"
                    value={form.nickname}
                    onChange={(e) => set("nickname", e.target.value)}
                    required
                    className="form-input"
                  />
                </Field>
                <Field label="微信号或手机号">
                  <div>
                    <input
                      type="text"
                      maxLength={50}
                      placeholder="用于活动联系"
                      value={form.wechatOrPhone}
                      onChange={(e) => set("wechatOrPhone", e.target.value)}
                      required
                      className="form-input"
                    />
                    <p className="mt-1.5 text-xs text-stone-500 dark:text-stone-400">
                      仅用于活动确认，不会公开给其他报名者
                    </p>
                  </div>
                </Field>
                <Field label="小红书主页地址">
                  <div>
                    <input
                      type="url"
                      maxLength={200}
                      placeholder="https://www.xiaohongshu.com/user/profile/xxx"
                      value={form.xiaohongshuUrl}
                      onChange={(e) => set("xiaohongshuUrl", e.target.value)}
                      required
                      className="form-input"
                    />
                    <p className="mt-1.5 text-xs text-stone-500 dark:text-stone-400">
                      用于展示头像与昵称，提交前会校验
                    </p>
                  </div>
                </Field>
                <Field label="平时常活动区域">
                  <select
                    value={form.region}
                    onChange={(e) => set("region", e.target.value)}
                    className={`form-input appearance-none ${form.region ? "text-stone-800 dark:text-stone-100" : "text-stone-400 dark:text-stone-500"}`}
                  >
                    <option value="">请选择（选填）</option>
                    {regions.map((r) => (
                      <option key={r} value={r}>{r}</option>
                    ))}
                  </select>
                </Field>
                <Field label="是否第一次参加类似活动">
                  <select
                    value={form.firstTime}
                    onChange={(e) => set("firstTime", e.target.value)}
                    required
                    className={`form-input appearance-none ${form.firstTime ? "text-stone-800 dark:text-stone-100" : "text-stone-400 dark:text-stone-500"}`}
                  >
                    <option value="" disabled>请选择</option>
                    {firstTimeOptions.map((o) => (
                      <option key={o} value={o}>{o}</option>
                    ))}
                  </select>
                </Field>
                <Field label="可参加时间">
                  <select
                    value={form.availableTime}
                    onChange={(e) => set("availableTime", e.target.value)}
                    className={`form-input appearance-none ${form.availableTime ? "text-stone-800 dark:text-stone-100" : "text-stone-400 dark:text-stone-500"}`}
                  >
                    <option value="">请选择（选填）</option>
                    {availableTimeOptions.map((o) => (
                      <option key={o.value} value={o.value}>{o.label}</option>
                    ))}
                  </select>
                </Field>
              </div>

              <div className="pt-4 border-t border-stone-100 dark:border-stone-700">
                <label className="flex items-start gap-3 cursor-pointer">
                  <input
                    type="checkbox"
                    checked={form.agreeRules}
                    onChange={(e) => set("agreeRules", e.target.checked)}
                    required
                    className="mt-1 rounded border-stone-300 text-amber-600 focus:ring-amber-500"
                  />
                  <span className="text-xs sm:text-sm text-stone-600 dark:text-stone-400">
                    我已阅读并同意活动规则（公开场地、尊重边界、如有不适可随时离开）
                  </span>
                </label>
              </div>

              <p className="text-xs text-stone-500 dark:text-stone-400">
                提交后我们会根据场次与匹配度联系合适报名者，通过微信/短信确认地点与时间。若当前场次不匹配，不会反复打扰。
              </p>

              <div className="pt-2">
                {error && (
                  <p className="mb-4 rounded-lg bg-red-50 dark:bg-red-900/30 px-4 py-3 text-center text-sm text-red-600 dark:text-red-400">
                    {error}
                  </p>
                )}
                <button
                  type="submit"
                  disabled={submitting}
                  className="w-full rounded-xl bg-amber-600 py-3 sm:py-3.5 sm:py-4 text-base sm:text-lg font-medium text-white transition-colors hover:bg-amber-700 active:scale-[0.98] disabled:cursor-not-allowed disabled:opacity-70"
                >
                  {submitting ? "提交中…" : "提交报名"}
                </button>
              </div>
            </div>
          )}
        </form>

        <div className="mt-4 sm:mt-6 text-center px-4">
          <Link href="/" className="text-xs sm:text-sm text-stone-400 dark:text-stone-500 transition-colors hover:text-amber-600">
            ← 返回首页
          </Link>
        </div>
      </div>
    </div>
  );
}

function Field({
  label,
  children,
}: {
  label: string;
  children: React.ReactNode;
}) {
  return (
    <div className="flex flex-col gap-2 py-3">
      <label className="text-sm sm:text-base font-medium text-stone-700 dark:text-stone-300">
        {label}
      </label>
      <div className="min-w-0">{children}</div>
    </div>
  );
}