"use client";

import React, { useState, useEffect } from "react";
import type { NavItem } from "../types";
import { LangSwitch } from "./LangSwitch";

export interface MainNavProps {
  items: NavItem[];
  basePath?: string; // e.g. /zh-CN
  locale?: string; // zh-CN | en
}

export function MainNav({ items, basePath = "", locale = "zh-CN" }: MainNavProps) {
  const [mobileMenuOpen, setMobileMenuOpen] = useState(false);
  const [currentPath, setCurrentPath] = useState("");

  useEffect(() => {
    const updatePath = () => {
      setCurrentPath(window.location.pathname);
    };
    updatePath();
    
    // 监听浏览器前进/后退
    window.addEventListener("popstate", updatePath);
    
    // 监听点击事件（处理 Next.js 客户端导航）
    const handleClick = (e: MouseEvent) => {
      const target = e.target as HTMLElement;
      const link = target.closest("a");
      if (link && link.href) {
        setTimeout(() => {
          updatePath();
        }, 100);
      }
    };
    
    document.addEventListener("click", handleClick);
    
    return () => {
      window.removeEventListener("popstate", updatePath);
      document.removeEventListener("click", handleClick);
    };
  }, []);

  const isActive = (href: string) => {
    if (!currentPath) return false;
    if (href.startsWith("#")) return false;
    
    const fullPath = `${basePath}${href}`;
    // 首页匹配
    if (href === "/" || href === "") {
      return currentPath === basePath || currentPath === `${basePath}/`;
    }
    // 精确匹配或作为路径前缀匹配
    return currentPath === fullPath || currentPath.startsWith(`${fullPath}/`);
  };
  
  return (
    <header className="w-full bg-huilong-bg fixed top-0 left-0 right-0 z-50 border-b border-[rgba(255,255,255,0.02)]">
      <div className="max-w-[1200px] mx-auto px-4 md:px-6 py-3 md:py-5 flex items-center justify-between">
        <a href={basePath || "/"} className="flex items-center gap-2 md:gap-3 no-underline flex-shrink-0">
          <div className="bg-gradient-to-b from-huilong-gold to-[#a8823d] px-2 md:px-[10px] py-1 md:py-[6px] rounded text-xs md:text-sm font-bold text-huilong-bg">
            {locale === "en" ? "HL" : "汇龙"}
          </div>
          <div className="font-semibold tracking-wide text-white text-sm md:text-base hidden sm:block">Huilong Xingda</div>
        </a>
        
        {/* PC端导航菜单 */}
        <nav className="hidden md:flex items-center gap-3 lg:gap-4">
          {items.map((item) => {
            const isCta = item.href === "/contact";
            const isAnchor = item.href.startsWith("#");
            const href = isAnchor ? item.href : `${basePath}${item.href}`;
            const active = isActive(item.href);
            return (
              <a
                key={item.label}
                href={href}
                className={`no-underline transition-colors text-sm lg:text-base ${
                  isCta
                    ? `px-3 py-2 rounded-md border ${
                        active
                          ? "border-huilong-gold bg-huilong-gold/10 text-huilong-gold"
                          : "border-[rgba(196,161,75,0.12)] text-huilong-gold"
                      }`
                    : active
                    ? "mr-2 lg:mr-3.5 text-white font-medium"
                    : "mr-2 lg:mr-3.5 text-huilong-muted hover:text-white"
                }`}
              >
                {item.label}
              </a>
            );
          })}
        </nav>
        
        <div className="flex items-center gap-3">
          <LangSwitch basePath={basePath} locale={locale} />
          
          {/* 移动端菜单按钮 */}
          <button
            onClick={() => setMobileMenuOpen(!mobileMenuOpen)}
            className="md:hidden p-2 text-huilong-muted hover:text-white focus:outline-none"
            aria-label="Toggle menu"
          >
            <svg
              className="w-6 h-6"
              fill="none"
              strokeLinecap="round"
              strokeLinejoin="round"
              strokeWidth="2"
              viewBox="0 0 24 24"
              stroke="currentColor"
            >
              {mobileMenuOpen ? (
                <path d="M6 18L18 6M6 6l12 12" />
              ) : (
                <path d="M4 6h16M4 12h16M4 18h16" />
              )}
            </svg>
          </button>
        </div>
      </div>
      
      {/* 移动端导航菜单 */}
      {mobileMenuOpen && (
        <div className="md:hidden bg-huilong-bg border-t border-[rgba(255,255,255,0.02)] max-h-[calc(100vh-80px)] overflow-y-auto">
          <nav className="max-w-[1200px] mx-auto px-4 md:px-6 py-4 space-y-2">
            {items.map((item) => {
              const isCta = item.href === "/contact";
              const isAnchor = item.href.startsWith("#");
              const href = isAnchor ? item.href : `${basePath}${item.href}`;
              const active = isActive(item.href);
              return (
                <a
                  key={item.label}
                  href={href}
                  className={`block py-2 px-2 rounded ${
                    isCta
                      ? `border ${
                          active
                            ? "border-huilong-gold bg-huilong-gold/10 text-huilong-gold"
                            : "border-[rgba(196,161,75,0.12)] text-huilong-gold"
                        }`
                      : active
                      ? "text-white font-medium bg-[rgba(196,161,75,0.05)]"
                      : "text-huilong-muted hover:text-white"
                  }`}
                  onClick={() => setMobileMenuOpen(false)}
                >
                  {item.label}
                </a>
              );
            })}
          </nav>
        </div>
      )}
    </header>
  );
}


