"use client";
import Link from "next/link";
import { usePathname } from "next/navigation";
import { useState, useCallback } from "react";
import { motion } from "framer-motion";

// 导航链接配置
const NAV_LINKS = [{ path: "/", label: "首页" }];

export default function Header() {
  const pathname = usePathname();
  const [isMenuOpen, setIsMenuOpen] = useState(false);

  const toggleMenu = useCallback(() => {
    setIsMenuOpen((prev) => !prev);
  }, []);

  const closeMenu = useCallback(() => {
    setIsMenuOpen(false);
  }, []);

  const sidebarVariants = {
    open: {
      x: 0,
      transition: {
        type: "spring" as const,
        stiffness: 300,
        damping: 30,
        staggerChildren: 0.1,
        delayChildren: 0.1,
      },
    },
    closed: {
      x: "100%",
      transition: {
        type: "spring" as const,
        stiffness: 300,
        damping: 30,
        staggerChildren: 0.05,
        staggerDirection: -1,
      },
    },
  };

  const menuItemVariants = {
    open: {
      y: 0,
      opacity: 1,
      transition: {
        y: { stiffness: 1000, velocity: -100 },
      },
    },
    closed: {
      y: 20,
      opacity: 0,
      transition: {
        y: { stiffness: 1000 },
      },
    },
  };

  // 导航链接组件
  const NavLink = ({ href, children, className, onClick }: { href: string; children: React.ReactNode; className?: string; onClick?: () => void }) => (
    <Link href={href} className={pathname === href ? "no-underline" : ""} onClick={onClick}>
      <motion.div className={className} whileHover={{ scale: 1.05 }} whileTap={{ scale: 0.95 }} initial={false}>
        {children}
      </motion.div>
    </Link>
  );

  // 按钮组件
  const NavButton = ({ onClick, children, className }: { onClick: () => void; children: React.ReactNode; className?: string }) => (
    <button onClick={onClick} className={className}>
      <motion.div whileHover={{ scale: 1.05 }} whileTap={{ scale: 0.95 }} initial={false}>
        {children}
      </motion.div>
    </button>
  );

  return (
    <div className="pb-24">
      <header className="w-full fixed top-0 left-0 right-0 bg-white/80 dark:bg-black/80 py-3 z-50 backdrop-blur-md border-b border-transparent dark:border-gray-800 transition-colors duration-300">
        <nav className="mx-auto max-w-7xl flex justify-between items-center px-4 md:px-6">
          <div className="flex items-center min-w-0">
            <Link href="/" className="truncate">
              <motion.h1 className="text-xl font-bold text-gray-900 dark:text-white truncate" whileHover={{ scale: 1.02 }} whileTap={{ scale: 0.98 }}>
                智能计算实验室
              </motion.h1>
            </Link>
          </div>

          {/* 桌面端导航 */}
          <div className="hidden md:flex space-x-6 shrink-0">
            {NAV_LINKS.map((link) => (
              <NavLink
                key={link.path}
                href={link.path}
                className={`text-sm font-medium text-gray-600 dark:text-gray-400 hover:text-black dark:hover:text-white transition-colors duration-200 ${
                  pathname === link.path ? "text-black dark:text-white font-bold" : ""
                }`}
              >
                {link.label}
              </NavLink>
            ))}
          </div>

          {/* 移动端菜单按钮 */}
          <NavButton className="flex items-center md:hidden focus:outline-none shrink-0 ml-4" onClick={toggleMenu}>
            <svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" aria-label="打开导航菜单" className="text-gray-900 dark:text-white">
              <path d="M4 6h16M4 12h16M4 18h16" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round" />
            </svg>
          </NavButton>
        </nav>
      </header>

      {/* 遮罩层 */}
      <div
        className={`md:hidden fixed inset-0 bg-black/50 z-40 transition-opacity duration-300 ${isMenuOpen ? "opacity-100" : "opacity-0 pointer-events-none"}`}
        onClick={closeMenu}
        aria-hidden="true"
      />

      {/* 移动端侧边菜单 */}
      <motion.div
        className="md:hidden fixed top-[57px] right-0 bottom-0 w-full max-w-xs bg-white/80 dark:bg-black/80 backdrop-blur-md border-l border-gray-200 dark:border-gray-800 shadow-2xl z-40"
        initial="closed"
        animate={isMenuOpen ? "open" : "closed"}
        variants={sidebarVariants}
        role="dialog"
        aria-modal="true"
        aria-label="导航菜单"
      >
        <div className="px-6 py-8 flex flex-col gap-2 h-full overflow-y-auto">
          {NAV_LINKS.map((link) => (
            <motion.div key={link.path} variants={menuItemVariants}>
              <NavLink
                href={link.path}
                className={`block py-4 px-4 rounded-0 text-lg transition-all duration-200 ${
                  pathname === link.path
                    ? "bg-gray-100 dark:bg-gray-800 text-black dark:text-white font-bold"
                    : "text-gray-600 dark:text-gray-400 hover:bg-gray-50 dark:hover:bg-gray-900 hover:text-black dark:hover:text-white"
                }`}
                onClick={closeMenu}
              >
                {link.label}
              </NavLink>
            </motion.div>
          ))}
        </div>
      </motion.div>
    </div>
  );
}