"use client";
import Link from "next/link";
import React, { useEffect, useState } from "react";
import { usePathname } from "next/navigation";
// !text-[var(--current-color)]
export default function Nav({ color = "#fab758" }) {
  const [menu, setMenu] = useState([]);
  const pathname = usePathname();

  useEffect(() => {
    // 获取菜单数据
    fetch("/api/get-menu")
      .then((res) => res.json())
      .then((data) => setMenu(data.menu || []));

    // 点击外部区域关闭下拉菜单
    const handleClickOutside = (event) => {
      if (!event.target.closest('.dropdown')) {
        document.querySelectorAll('.dropdown-menu').forEach(menu => {
          menu.style.display = 'none';
        });
      }
    };

    // 为多级下拉菜单添加事件监听器
    const handleDropdownEvents = () => {
      document.querySelectorAll('.dropdown-submenu').forEach(submenu => {
        submenu.addEventListener('mouseenter', function() {
          const dropdownMenu = this.querySelector('.dropdown-menu');
          if (dropdownMenu) {
            dropdownMenu.style.display = 'block';
          }
        });
        
        submenu.addEventListener('mouseleave', function() {
          const dropdownMenu = this.querySelector('.dropdown-menu');
          if (dropdownMenu) {
            dropdownMenu.style.display = 'none';
          }
        });
      });
    };

    // 等待 DOM 加载完成后初始化
    if (document.readyState === 'loading') {
      document.addEventListener('DOMContentLoaded', handleDropdownEvents);
    } else {
      // 延迟执行，确保菜单已经渲染
      setTimeout(handleDropdownEvents, 100);
    }

    // 添加全局点击事件监听器
    document.addEventListener('click', handleClickOutside);

    return () => {
      // 清理事件监听器
      document.removeEventListener('click', handleClickOutside);
      document.querySelectorAll('.dropdown-submenu').forEach(submenu => {
        submenu.removeEventListener('mouseenter', handleDropdownEvents);
        submenu.removeEventListener('mouseleave', handleDropdownEvents);
      });
    };
  }, []);

  // 只在顶级菜单过滤 position
  const filterHeaderMenu = (items) => {
    return items.filter(item => item.position === 'Header');
  };

  // 递归渲染菜单
  const renderMenu = (items, level = 0) => {
    // 顶级菜单过滤 position
    if (level === 0) items = filterHeaderMenu(items);
    return items.map((item) => {
      const hasChildren = item.children && item.children.length > 0;
      const hasHref = !!item.href && item.href !== "#";
      if (hasChildren) {
        return (
          <li key={item.id} className={`nav-item dropdown${level > 0 ? " dropdown-submenu dropend" : ""}`}>
            <div style={{ display: 'flex', alignItems: 'center' }}>
              {/* 如果有href，左侧为可点击跳转，始终用当前item的href */}
              {hasHref && (
                <Link
                  className={`${level > 0 ? "dropdown-item" : "nav-link"} !text-[.7rem] !tracking-[normal] hover:!text-[var(--current-color)] after:!text-[var(--current-color)] ${pathname === item.href ? "!text-[var(--current-color)]" : ""}`}
                  href={item.href}
                  style={{ paddingRight: 0 }}
                >
                  {item.label}
                </Link>
              )}
              {/* 右侧小三角，负责展开下拉 */}
              <a
                className={`${hasHref ? "dropdown-toggle" : (level > 0 ? "dropdown-item" : "nav-link")} !text-[.7rem] !tracking-[normal] hover:!text-[var(--current-color)] after:!text-[var(--current-color)] ${!hasHref && pathname === item.href ? "!text-[var(--current-color)]" : ""}`}
                href="#"
                onClick={(e) => {
                  e.preventDefault();
                  const dropdownMenu = e.target.closest('.dropdown').querySelector('.dropdown-menu');
                  if (dropdownMenu) {
                    dropdownMenu.style.display = dropdownMenu.style.display === 'block' ? 'none' : 'block';
                  }
                }}
                style={hasHref ? { paddingLeft: 8, minWidth: 24 } : {}}
              >
                {hasHref ? <span className="sr-only">展开</span> : item.label}
              </a>
            </div>
            <ul className={`dropdown-menu${level > 0 ? " submenu" : ""}`}>
              {renderMenu(item.children, level + 1)}
            </ul>
          </li>
        );
      } else {
        return (
          <li key={item.id} className="nav-item">
            <Link
              className={`${level > 0 ? "dropdown-item" : "nav-link"} !text-[.7rem] !tracking-[normal] hover:!text-[var(--current-color)] after:!text-[var(--current-color)] ${pathname === item.href ? "!text-[var(--current-color)]" : ""}`}
              href={item.href || "#"}
            >
              {item.label}
            </Link>
          </li>
        );
      }
    });
  };

  return (
    <ul className="navbar-nav" style={{ "--current-color": color }}>
      {renderMenu(menu)}
      <style jsx>{`
        .navbar-nav .dropdown-submenu {
          position: relative;
        }
        
        .navbar-nav .dropdown-submenu .dropdown-menu {
          top: 0;
          left: 100%;
          margin-top: -1px;
          display: none;
          position: absolute;
          z-index: 1000;
        }
        
        .navbar-nav .dropdown-submenu:hover > .dropdown-menu {
          display: block;
        }
        
        .dropdown-submenu.dropend .dropdown-menu {
          left: 100%;
          top: 0;
        }
        
        .dropdown-submenu > .dropdown-toggle::after {
          display: inline-block;
          margin-left: 0.255em;
          vertical-align: 0.255em;
          content: "";
          border-top: 0.3em solid transparent;
          border-right: 0;
          border-bottom: 0.3em solid transparent;
          border-left: 0.3em solid;
        }
        
        .dropdown-menu {
          display: none;
          position: absolute;
          z-index: 1000;
          min-width: 10rem;
          padding: 0.5rem 0;
          margin: 0;
          font-size: 1rem;
          color: #212529;
          text-align: left;
          list-style: none;
          background-color: #fff;
          background-clip: padding-box;
          border: 1px solid rgba(0, 0, 0, 0.15);
          border-radius: 0.375rem;
          box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.15);
        }
        
        .dropdown-menu.show {
          display: block;
        }
        
        .dropdown-item {
          display: block;
          width: 100%;
          padding: 0.25rem 1rem;
          clear: both;
          font-weight: 400;
          color: #212529;
          text-align: inherit;
          text-decoration: none;
          white-space: nowrap;
          background-color: transparent;
          border: 0;
        }
        
        .dropdown-item:hover,
        .dropdown-item:focus {
          color: #1e2125;
          background-color: #e9ecef;
        }
        
        .nav-link {
          color: #6c757d;
          text-decoration: none;
          padding: 0.5rem 1rem;
        }
        
        .nav-link:hover {
          color: var(--current-color);
        }
        
        .dropdown-submenu .dropdown-submenu .dropdown-menu {
          z-index: 1001;
        }
        
        /* 确保顶级下拉菜单正确显示 */
        .navbar-nav > .dropdown > .dropdown-menu {
          top: 100%;
          left: 0;
          margin-top: 0;
        }
        
        /* 添加下拉箭头指示器 */
        .dropdown-toggle::after {
          display: inline-block;
          margin-left: 0.255em;
          vertical-align: 0.255em;
          content: "";
          border-top: 0.3em solid;
          border-right: 0.3em solid transparent;
          border-bottom: 0;
          border-left: 0.3em solid transparent;
        }
      `}</style>
    </ul>
  );
}