'use client';

import { useState, useEffect, useCallback } from 'react';
import { StaticLink } from '@/components/ui/static-link';
import Image from 'next/image';
import { usePathname } from 'next/navigation';
import { Menu, X, MessageCircle } from 'lucide-react';
import { AnimatePresence, motion } from 'framer-motion';
import { Button } from '@/components/ui/button';
import { useSiteConfig, type NavigationItem } from '@/lib/site-config';
import { MegaDropdown } from '@/components/layout/mega-dropdown';
import { useFocusTrap } from '@/hooks/use-focus-trap';
import { cn } from '@/lib/utils';
import { ThemeToggle } from '@/components/theme/theme-toggle';

function HeaderContent() {
  const [isOpen, setIsOpen] = useState(false);
  const [isScrolled, setIsScrolled] = useState(false);
  const [openDropdown, setOpenDropdown] = useState<string | null>(null);
  const pathname = usePathname();
  const focusTrapRef = useFocusTrap<HTMLDivElement>(isOpen);

  useEffect(() => {
    const handleScroll = () => {
      setIsScrolled(window.scrollY > 20);
    };

    const handleGlobalKeyDown = (e: KeyboardEvent) => {
      if (e.key === 'Escape' && isOpen) {
        setIsOpen(false);
      }
    };

    window.addEventListener('scroll', handleScroll, { passive: true });
    window.addEventListener('keydown', handleGlobalKeyDown);

    return () => {
      window.removeEventListener('scroll', handleScroll);
      window.removeEventListener('keydown', handleGlobalKeyDown);
    };
  }, [isOpen]);

  const handleKeyDown = useCallback((e: React.KeyboardEvent) => {
    // Escape 关闭菜单；Enter/Space 已由原生 button 的 onClick 处理，
    // 此处不再拦截，避免键盘操作时重复触发 toggle。
    if (e.key === 'Escape' && isOpen) {
      e.preventDefault();
      setIsOpen(false);
    }
  }, [isOpen]);

  const config = useSiteConfig();

  const handleNavClick = useCallback(() => {
    // StaticLink 新契约：onClick 先于导航执行，不调 preventDefault 即由
    // next/link 完成客户端跳转，此处只负责关闭抽屉。
    setIsOpen(false);
  }, []);

  const isActive = useCallback((item: NavigationItem) => {
    if (item.id === 'contact') {
      return pathname === '/contact';
    }
    if (item.id === 'home') {
      return pathname === '/';
    }
    if (item.id === 'products') {
      return pathname === '/products' || pathname.startsWith('/products/');
    }
    if (item.id === 'solutions') {
      return pathname === '/solutions' || pathname.startsWith('/solutions/');
    }
    if (item.id === 'cases') {
      return pathname === '/cases' || pathname.startsWith('/cases/');
    }
    if (item.id === 'services') {
      return pathname === '/services' || pathname.startsWith('/services/');
    }
    return pathname === `/${item.id}`;
  }, [pathname]);

  return (
    <>
      <motion.header
        initial={false}
        animate={{
          height: isScrolled ? 64 : 80,
        }}
        transition={{ duration: 0.3, ease: [0.22, 1, 0.36, 1] }}
        className="fixed top-0 left-0 right-0 z-50 transition-colors duration-300 bg-bg-primary border-b border-border-primary"
      >
        <div className="max-w-container mx-auto px-4 sm:px-6 lg:px-10">
          <div className="flex items-center justify-between h-16 md:h-full">
            <StaticLink
              href="/"
              className="relative flex items-center group/logo"
              aria-label="返回首页"
            >
              {/* Logo 明暗双版：浅色背景用 logo.svg（黑字），深色背景用 logo-white.svg（白字）。
                  按 html[data-theme] 显隐（规则见 globals.css），修复黑字在深色背景被吞的 bug。 */}
              <Image
                src="/logo.svg"
                alt={config.name}
                width={160}
                height={40}
                className="logo-on-light relative transition-all duration-300 ease-out group-hover/logo:scale-[1.02] w-auto h-8 md:h-10"
                loading="eager"
                priority
                suppressHydrationWarning
              />
              <Image
                src="/logo-white.svg"
                alt={config.name}
                width={160}
                height={40}
                className="logo-on-dark relative transition-all duration-300 ease-out group-hover/logo:scale-[1.02] w-auto h-8 md:h-10"
                loading="eager"
                suppressHydrationWarning
              />
            </StaticLink>

            <nav className="hidden md:flex items-center gap-0.5" role="navigation" aria-label="主导航" data-testid="desktop-navigation">
              {config.mainNav.map((item) => (
                item.hasDropdown ? (
                  <MegaDropdown
                    key={item.id}
                    label={item.label}
                    groups={config.megaDropdown[item.dropdownKey!] ?? []}
                    isOpen={openDropdown === item.id}
                    isActive={isActive(item)}
                    onToggle={() => {
                      setOpenDropdown((prev) => prev === item.id ? null : item.id);
                    }}
                    onOpen={() => setOpenDropdown(item.id)}
                    onClose={() => setOpenDropdown((prev) => prev === item.id ? null : prev)}
                  />
                ) : (
                  <div key={item.id} className="relative -mx-2 px-2 py-2">
                    <StaticLink
                      href={item.href}
                      onClick={handleNavClick}
                      className={cn(
                        'relative inline-flex items-center px-3 py-2 text-sm font-medium',
                        'transition-all duration-300 ease-out',
                        isActive(item)
                          ? 'text-text-primary'
                          : 'text-text-secondary hover:text-text-primary hover:bg-bg-secondary'
                      )}
                      aria-current={isActive(item) ? 'page' : undefined}
                    >
                      {item.label}
                      <span
                        className={cn(
                          'absolute -bottom-0.5 left-3 right-3 h-0.5 bg-brand',
                          'transition-all duration-300 ease-out',
                          isActive(item)
                            ? 'opacity-100 scale-x-100'
                            : 'opacity-0 scale-x-0'
                        )}
                      />
                    </StaticLink>
                  </div>
                )
              ))}
            </nav>

            <div className="hidden md:flex items-center gap-3">
              <ThemeToggle />
              <Button
                size="sm"
                asChild
                className=""
              >
                <StaticLink href="/contact" data-testid="consult-button" aria-label="预约咨询">
                  <MessageCircle className="w-4 h-4" />
                  <span className="hidden lg:inline">预约咨询</span>
                  <span className="lg:hidden" aria-hidden="true">咨询</span>
                </StaticLink>
              </Button>
            </div>

            <button
              className="md:hidden p-2 -mr-2 text-text-secondary hover:text-text-primary hover:bg-bg-secondary rounded-sm transition-all duration-300 ease-out active:scale-95"
              onClick={() => setIsOpen(!isOpen)}
              onKeyDown={handleKeyDown}
              aria-expanded={isOpen}
              aria-controls="mobile-menu"
              aria-label={isOpen ? '关闭菜单' : '打开菜单'}
              data-testid="mobile-menu-button"
              style={{ minWidth: '44px', minHeight: '44px' }}
            >
              {isOpen ? <X className="w-5 h-5" /> : <Menu className="w-5 h-5" />}
            </button>
          </div>
        </div>
      </motion.header>

      <AnimatePresence mode="wait">
        {isOpen && (
          <motion.div
            ref={focusTrapRef}
            initial={{ opacity: 0 }}
            animate={{ opacity: 1 }}
            exit={{ opacity: 0 }}
            transition={{ duration: 0.2 }}
            className="fixed inset-0 z-40 md:hidden"
          >
            <div
              className="absolute inset-0 bg-black/50 backdrop-blur-sm"
              onClick={() => setIsOpen(false)}
              aria-hidden="true"
            />
            <motion.div
              initial={{ x: '100%' }}
              animate={{ x: 0 }}
              exit={{ x: '100%' }}
              transition={{ duration: 0.25, ease: [0.22, 1, 0.36, 1] }}
              className="absolute top-16 right-0 bottom-0 left-0 bg-bg-primary/98 backdrop-blur-xl overflow-y-auto"
              id="mobile-menu"
              role="navigation"
              aria-label="移动端导航"
              data-testid="mobile-navigation"
            >
              <nav className="max-w-container mx-auto px-4 sm:px-6 py-6">
                {config.mainNav.map((item, index) => (
                  <motion.div
                    key={item.id}
                    initial={{ x: 20, opacity: 0 }}
                    animate={{ x: 0, opacity: 1 }}
                    transition={{ delay: index * 0.05 }}
                  >
                    <StaticLink
                      href={item.href}
                      onClick={handleNavClick}
                      className={`
                        block px-4 py-4 text-base font-medium
                        transition-all duration-300 ease-out
                        ${isActive(item)
                          ? 'text-text-primary bg-bg-secondary'
                          : 'text-text-secondary hover:text-text-primary hover:bg-bg-secondary'
                        }
                      `}
                      style={{ minHeight: '48px', display: 'flex', alignItems: 'center' }}
                    >
                      {item.label}
                    </StaticLink>
                  </motion.div>
                ))}
                <div className="mt-6 px-4 pt-6 border-t border-border-primary">
                  <Button
                    className="w-full"
                    asChild
                    size="lg"
                  >
                    <StaticLink href="/contact" onClick={() => setIsOpen(false)}>
                      <MessageCircle className="w-4 h-4" />
                      预约咨询
                    </StaticLink>
                  </Button>
                </div>
              </nav>
            </motion.div>
          </motion.div>
        )}
      </AnimatePresence>
    </>
  );
}

export function Header() {
  return <HeaderContent />;
}