"use client";

import { useEffect, useState } from "react";
import { useRouter, useSearchParams } from "next/navigation";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card";
import { getErrorMessage, postAPI } from "@/lib/api";
import Link from "next/link";
import type { LoginResponse } from "@/lib/types";

export default function ActivatePage() {
  const [inviteCode, setInviteCode] = useState("");
  const [studentId, setStudentId] = useState("");
  const [email, setEmail] = useState("");
  const [password, setPassword] = useState("");
  const [confirmPassword, setConfirmPassword] = useState("");
  const [error, setError] = useState("");
  const [loading, setLoading] = useState(false);
  const router = useRouter();
  const searchParams = useSearchParams();

  useEffect(() => {
    const code = searchParams.get("code")?.trim();
    if (code) {
      setInviteCode(code.toUpperCase());
    }
  }, [searchParams]);

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    setError("");

    if (password !== confirmPassword) {
      setError("两次密码输入不一致");
      return;
    }
    if (password.length < 8) {
      setError("密码至少8位");
      return;
    }

    setLoading(true);
    try {
      const res = await postAPI<LoginResponse>("/api/auth/activate", {
        invite_code: inviteCode,
        student_id: studentId,
        email,
        password,
      });

      if (res.token) {
        localStorage.setItem("auth_token", res.token);
        localStorage.setItem("auth_user", JSON.stringify(res.user));
        router.push("/");
      } else {
        router.push("/login");
      }
    } catch (err: unknown) {
      setError(getErrorMessage(err, "激活失败"));
    } finally {
      setLoading(false);
    }
  };

  return (
    <div className="relative min-h-screen overflow-hidden bg-[linear-gradient(180deg,#f7efe2_0%,#f4ebdf_38%,#f9f5ee_100%)] px-4 py-10">
      <div className="absolute inset-x-0 top-0 h-72 bg-[radial-gradient(circle_at_top,rgba(115,25,37,0.18),transparent_60%)]" />
      <div className="relative mx-auto flex min-h-[calc(100vh-5rem)] max-w-6xl items-center justify-center">
        <div className="grid w-full items-center gap-10 lg:grid-cols-[1.05fr_0.95fr]">
          <div className="hidden lg:block">
            <div className="inline-flex items-center rounded-full border border-[#c9ac82] bg-white/55 px-4 py-1.5 text-[11px] uppercase tracking-[0.28em] text-[#84553c]">
              HKU ICB Cohort Access
            </div>
            <h1 className="mt-6 max-w-2xl text-5xl font-semibold leading-tight text-[#4e1d1a]">
              完成账号激活，进入你的班级空间
            </h1>
            <p className="mt-5 max-w-xl text-base leading-8 text-[#775a4a]">
              成员导入后，只需使用激活码与学号确认身份，再补全邮箱和密码即可启用账号。若从邀请链接进入，激活码会自动填入。
            </p>
          </div>

          <Card className="mx-auto w-full max-w-md bg-[#fffaf3]">
        <CardHeader className="text-center">
          <div className="text-[11px] uppercase tracking-[0.24em] text-[#976746]">Activate Account</div>
          <CardTitle className="text-3xl text-[#4e1d1a]">激活账号</CardTitle>
          <CardDescription className="text-[#7a5e4f]">输入班级激活码与学号，完成账号启用</CardDescription>
        </CardHeader>
        <CardContent>
          <form onSubmit={handleSubmit} className="space-y-4">
            <div className="space-y-2">
              <Label htmlFor="inviteCode">邀请码</Label>
              <Input
                id="inviteCode"
                placeholder="请输入班级邀请码"
                value={inviteCode}
                onChange={(e) => setInviteCode(e.target.value.toUpperCase())}
                required
              />
            </div>
            <div className="space-y-2">
              <Label htmlFor="studentId">学号</Label>
              <Input
                id="studentId"
                placeholder="请输入学号"
                value={studentId}
                onChange={(e) => setStudentId(e.target.value)}
                required
              />
            </div>
            <div className="space-y-2">
              <Label htmlFor="email">邮箱</Label>
              <Input
                id="email"
                type="email"
                placeholder="your@email.com"
                value={email}
                onChange={(e) => setEmail(e.target.value)}
                required
              />
            </div>
            <div className="space-y-2">
              <Label htmlFor="password">密码</Label>
              <Input
                id="password"
                type="password"
                placeholder="至少8位"
                value={password}
                onChange={(e) => setPassword(e.target.value)}
                required
              />
            </div>
            <div className="space-y-2">
              <Label htmlFor="confirmPassword">确认密码</Label>
              <Input
                id="confirmPassword"
                type="password"
                placeholder="再次输入密码"
                value={confirmPassword}
                onChange={(e) => setConfirmPassword(e.target.value)}
                required
              />
            </div>
            {error && (
              <p className="rounded-2xl bg-red-50 p-3 text-sm text-red-600">
                {error}
              </p>
            )}
            <Button type="submit" className="w-full" disabled={loading}>
              {loading ? "激活中..." : "激活账号"}
            </Button>
          </form>
          <div className="mt-5 text-center text-sm text-[#6f5648]">
            已有账号？{" "}
            <Link href="/login" className="text-[#8a4527] hover:underline">
              登录
            </Link>
          </div>
        </CardContent>
      </Card>
        </div>
      </div>
    </div>
  );
}