"use client";

import { useState, useEffect } from "react";
import { useRouter } from "next/navigation";
import Link from "next/link";
import { ChevronRight } from "lucide-react";
import { apiChangePassword, apiMe, type User } from "@/lib/api";
import Avatar from "@/components/Avatar";

export default function SettingsPage() {
  const router = useRouter();
  const [user, setUser] = useState<User | null>(null);
  const [oldPassword, setOldPassword] = useState("");
  const [newPassword, setNewPassword] = useState("");
  const [confirmPassword, setConfirmPassword] = useState("");
  const [submitting, setSubmitting] = useState(false);
  const [error, setError] = useState("");
  const [success, setSuccess] = useState(false);

  useEffect(() => {
    apiMe()
      .then((res) => {
        if (!res.user) {
          router.push("/login");
          return;
        }
        setUser(res.user);
      })
      .catch(() => router.push("/login"));
  }, [router]);

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

    if (newPassword.length < 6) {
      setError("新密码至少 6 位");
      return;
    }
    if (newPassword !== confirmPassword) {
      setError("两次输入的新密码不一致");
      return;
    }

    setSubmitting(true);
    try {
      const res = await apiChangePassword(oldPassword, newPassword);
      if (res.message) {
        setSuccess(true);
        // 后端已使全部 token 失效并清 cookie，刷新 layout 让 Header 回到游客态
        router.refresh();
        setTimeout(() => router.push("/login"), 1500);
      } else {
        setError(res.error || "修改失败");
      }
    } catch (e) {
      setError("网络错误，请重试");
    } finally {
      setSubmitting(false);
    }
  };

  if (!user) {
    return (
      <div className="max-w-md mx-auto text-center py-20">
        <p className="meta">正在加载…</p>
      </div>
    );
  }

  return (
    <div className="max-w-md mx-auto">
      <nav className="meta mb-5 flex items-center gap-1.5 text-[13px]">
        <Link href="/" className="hover:text-[var(--accent)] transition-colors">首页</Link>
        <ChevronRight size={13} />
        <span style={{ color: "var(--accent)" }}>账号设置</span>
      </nav>

      <div className="mb-7">
        <h1 className="text-[26px] sm:text-[30px] font-extrabold tracking-tight" style={{ color: "var(--ink)" }}>
          账号设置
        </h1>
      </div>

      <div className="panel p-5 mb-7 flex items-center gap-4">
        <Avatar name={user.nickname || user.username} size={46} />
        <div className="min-w-0">
          <div className="font-bold truncate" style={{ color: "var(--ink)" }}>
            {user.nickname}
          </div>
          <div className="meta">@{user.username} · {user.role === "admin" ? "管理员" : "普通用户"}</div>
        </div>
      </div>

      <p className="font-bold text-[15px] mb-3.5" style={{ color: "var(--ink)" }}>修改密码</p>

      <form onSubmit={handleSubmit} className="panel p-5 sm:p-6 space-y-4">
        {success && <div className="alert-ok">密码修改成功，正在跳转登录页...</div>}
        {error && <div className="alert-error">{error}</div>}
        <div>
          <label className="field-label">当前密码</label>
          <input
            type="password"
            value={oldPassword}
            onChange={(e) => setOldPassword(e.target.value)}
            required
            className="field"
          />
        </div>
        <div>
          <label className="field-label">新密码（至少 6 位）</label>
          <input
            type="password"
            value={newPassword}
            onChange={(e) => setNewPassword(e.target.value)}
            required
            minLength={6}
            className="field"
          />
        </div>
        <div>
          <label className="field-label">确认新密码</label>
          <input
            type="password"
            value={confirmPassword}
            onChange={(e) => setConfirmPassword(e.target.value)}
            required
            minLength={6}
            className="field"
          />
        </div>
        <button
          type="submit"
          disabled={submitting || success}
          className="btn btn-primary w-full justify-center mt-2"
        >
          {submitting ? "提交中..." : "修改密码"}
        </button>
      </form>
    </div>
  );
}