import React, { useState, useEffect, useRef } from 'react';
import { useNavigate, useLocation, Link } from 'react-router-dom';

const Header: React.FC = () => {
  const navigate = useNavigate();
  const location = useLocation();
  const [isMenuOpen, setIsMenuOpen] = useState(false);
  const [isBuySimExpanded, setIsBuySimExpanded] = useState(false);
  const [isGuideExpanded, setIsGuideExpanded] = useState(false);
  const [isBuySimMegaVisible, setIsBuySimMegaVisible] = useState(false);
  const [isGuideMegaVisible, setIsGuideMegaVisible] = useState(false);
  const [isLangMenuOpen, setIsLangMenuOpen] = useState(false);
  const [selectedLang, setSelectedLang] = useState<'en' | 'vi'>('en');
  const [activeDesktopTab, setActiveDesktopTab] = useState<'popular' | 'region'>('popular');
  const [isScrolled, setIsScrolled] = useState(false);
  
  const langMenuRef = useRef<HTMLDivElement>(null);

  const countries = [
    { name: 'China', flag: 'cn' },
    { name: 'Hong Kong', flag: 'hk' },
    { name: 'Japan', flag: 'jp' },
    { name: 'Singapore', flag: 'sg' },
    { name: 'South Korea', flag: 'kr' },
    { name: 'Taiwan', flag: 'tw' },
    { name: 'Thailand', flag: 'th' },
    { name: 'United States', flag: 'us' },
  ];

  const regionList = [
    "Americas", "Asia", "Asia 11 countries", "Asialink 7 countries",
    "Australia & New Zealand", "EU 33 countries", "EU 40 countries", "Eurolink",
    "Europe", "Europe 33 countries", "Hong Kong & Macau", "Middle East and Africa",
    "North America & Canada", "North America A", "Oceania", "Singapore & Malaysia"
  ];

  const guideItems = [
    { label: "What is eSIM", path: "/support" },
    { label: "Installation instructions", path: "/support" },
    { label: "Support", path: "/support" },
    { label: "Order Tracking Search", path: "/support" }
  ];

  const languages = [
    { code: 'en', label: 'English', flag: 'us' },
    { code: 'vi', label: 'Tiếng Việt', flag: 'vn' }
  ];

  useEffect(() => {
    const handleScroll = () => {
      setIsScrolled(window.scrollY > 300);
    };
    window.addEventListener('scroll', handleScroll);
    return () => window.removeEventListener('scroll', handleScroll);
  }, []);

  const handleCountryClick = (c: { name: string; flag: string }) => {
    navigate(`/product/${c.name.toLowerCase()}`, { state: { country: c.name, flag: c.flag } });
    setIsBuySimMegaVisible(false);
    setIsMenuOpen(false);
  };

  const handleRegionClick = (region: string) => {
    navigate(`/product/${region.toLowerCase()}`, { state: { country: region, flag: 'un' } });
    setIsBuySimMegaVisible(false);
    setIsMenuOpen(false);
  };

  useEffect(() => {
    const handleClickOutside = (event: MouseEvent) => {
      if (langMenuRef.current && !langMenuRef.current.contains(event.target as Node)) {
        setIsLangMenuOpen(false);
      }
    };
    document.addEventListener('mousedown', handleClickOutside);
    return () => document.removeEventListener('mousedown', handleClickOutside);
  }, []);

  useEffect(() => {
    const handleResize = () => {
      if (window.innerWidth >= 1024) setIsMenuOpen(false);
    };
    window.addEventListener('resize', handleResize);
    return () => window.removeEventListener('resize', handleResize);
  }, []);

  const currentLangObj = languages.find(l => l.code === selectedLang) || languages[0];

  const isActive = (path: string) => location.pathname === path;

  return (
    <>
      <header className="sticky top-0 z-[60] w-full bg-white border-b border-slate-100 shadow-sm transition-all duration-300">
        <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8">
          <div className="flex justify-between items-center h-20">
            {/* Logo */}
            <Link to="/" className="flex-shrink-0 flex items-center">
              <div className="flex items-center space-x-1">
                <svg className="w-8 h-8 text-[#EE0434]" viewBox="0 0 24 24" fill="currentColor">
                  <path d="M12 2L2 7l10 5 10-5-10-5zM2 17l10 5 10-5M2 12l10 5 10-5" />
                </svg>
                <span className="text-2xl font-bold tracking-tighter">
                  <span className="text-[#EE0434]">Infi</span>
                  <span className="text-[#333]">Gate</span>
                </span>
              </div>
            </Link>

            {/* Desktop Search on Scroll */}
            <div className={`hidden lg:flex items-center transition-all duration-500 overflow-hidden ${isScrolled ? 'flex-1 max-w-md mx-8 opacity-100' : 'max-w-0 opacity-0 pointer-events-none'}`}>
               <div className="relative w-full">
                 <input 
                   type="text" 
                   placeholder="Search country..." 
                   className="w-full bg-slate-50 border border-slate-200 rounded-full py-2.5 px-6 pl-12 text-sm focus:outline-none focus:ring-2 focus:ring-red-100 focus:border-[#EE0434] transition-all"
                 />
                 <svg className="absolute left-4 top-1/2 -translate-y-1/2 w-4 h-4 text-slate-400" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2.5} d="M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z"/></svg>
               </div>
            </div>

            {/* Desktop Nav */}
            <nav className={`hidden lg:flex items-center h-full transition-all duration-300 ${isScrolled ? 'space-x-4' : 'space-x-8'}`}>
              <Link to="/" className={`text-[17px] font-bold ${isActive('/') ? 'text-[#EE0434]' : 'text-slate-700 hover:text-[#EE0434]'}`}>Home</Link>
              
              <div 
                className="relative h-full flex items-center"
                onMouseEnter={() => setIsBuySimMegaVisible(true)}
                onMouseLeave={() => setIsBuySimMegaVisible(false)}
              >
                <Link 
                  to="/buy-sim"
                  className={`flex items-center text-[17px] font-bold transition-colors ${isActive('/buy-sim') ? 'text-[#EE0434]' : 'text-slate-700 hover:text-[#EE0434]'}`}
                >
                  Buy SIM <svg className={`ml-1 w-4 h-4 transition-transform ${isBuySimMegaVisible ? 'rotate-180' : ''}`} fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" /></svg>
                </Link>

                {isBuySimMegaVisible && (
                  <div className="absolute top-full left-1/2 -translate-x-1/2 w-[950px] bg-white rounded-[32px] shadow-[0_30px_60px_-15px_rgba(0,0,0,0.15)] border border-slate-100 mt-0 overflow-hidden flex animate-in fade-in slide-in-from-top-2 duration-300">
                    <div className="w-[280px] bg-red-50 p-10 flex flex-col">
                      <h3 className="text-4xl font-black text-slate-900 mb-4">Buy SIM</h3>
                      <button 
                        onClick={() => {
                          navigate('/buy-sim');
                          setIsBuySimMegaVisible(false);
                        }}
                        className="text-[#EE0434] font-bold text-xl flex items-center group mb-8"
                      >
                        View all <svg className="ml-2 w-5 h-5 transition-transform group-hover:translate-x-1" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={3} d="M9 5l7 7-7 7" /></svg>
                      </button>
                    </div>
                    <div className="flex-1 p-10">
                      <div className="flex space-x-4 mb-10">
                        <button 
                          onClick={() => setActiveDesktopTab('popular')} 
                          className={`px-8 py-3 rounded-full text-base font-bold transition-all ${activeDesktopTab === 'popular' ? 'bg-[#EE0434] text-white shadow-lg shadow-red-100' : 'bg-slate-50 text-slate-900 hover:bg-slate-100'}`}
                        >
                          Most Popular
                        </button>
                        <button 
                          onClick={() => setActiveDesktopTab('region')} 
                          className={`px-8 py-3 rounded-full text-base font-bold transition-all ${activeDesktopTab === 'region' ? 'bg-[#EE0434] text-white shadow-lg shadow-red-100' : 'bg-slate-50 text-slate-900 hover:bg-slate-100'}`}
                        >
                          Region
                        </button>
                      </div>

                      {activeDesktopTab === 'popular' ? (
                        <div className="grid grid-cols-4 gap-y-8 gap-x-4">
                          {countries.map((c) => (
                            <div key={c.name} onClick={() => handleCountryClick(c)} className="flex items-center space-x-3 group cursor-pointer hover:bg-slate-50 p-2 rounded-xl transition-colors">
                              <div className="w-7 h-7 rounded-full overflow-hidden border border-slate-200 shadow-sm shrink-0">
                                 <img src={`https://flagcdn.com/w40/${c.flag}.png`} alt={c.name} className="w-full h-full object-cover" />
                              </div>
                              <span className="text-[16px] font-bold text-slate-700 group-hover:text-[#EE0434] transition-colors">{c.name}</span>
                            </div>
                          ))}
                        </div>
                      ) : (
                        <div className="grid grid-cols-4 gap-y-6 gap-x-2">
                          {regionList.map((region) => (
                            <div 
                              key={region} 
                              onClick={() => handleRegionClick(region)} 
                              className="flex items-center space-x-3 group cursor-pointer hover:bg-slate-50 p-2 rounded-xl transition-colors min-w-0"
                            >
                              <div className="w-7 h-7 rounded-full bg-red-50 flex items-center justify-center shrink-0 border border-red-100/50">
                                <svg className="w-4 h-4 text-red-300" fill="currentColor" viewBox="0 0 24 24">
                                  <path d="M12 2C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2zm-1 17.93c-3.95-.49-7.01-3.55-7.5-7.5H7v-1H3.5c.49-3.95 3.55-7.01 7.5-7.5v3.5h1V3.5c3.95.49 7.01 3.55 7.5 7.5H17v1h3.5c-.49 3.95-3.55-7.01-7.5 7.5v-3.5h-1v3.5z"/>
                                </svg>
                              </div>
                              <span className="text-[16px] font-bold text-slate-700 group-hover:text-[#EE0434] transition-colors truncate">
                                {region}
                              </span>
                            </div>
                          ))}
                        </div>
                      )}
                    </div>
                  </div>
                )}
              </div>

              <div 
                className="relative h-full flex items-center"
                onMouseEnter={() => setIsGuideMegaVisible(true)}
                onMouseLeave={() => setIsGuideMegaVisible(false)}
              >
                <Link 
                  to="/support"
                  className={`flex items-center text-[17px] font-bold transition-colors ${isActive('/support') ? 'text-[#EE0434]' : 'text-slate-700 hover:text-[#EE0434]'}`}
                >
                  Guide <svg className={`ml-1 w-4 h-4 transition-transform ${isGuideMegaVisible ? 'rotate-180' : ''}`} fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" /></svg>
                </Link>

                {isGuideMegaVisible && (
                  <div className="absolute top-full left-0 w-[600px] bg-white rounded-[32px] shadow-2xl border border-slate-100 mt-0 overflow-hidden flex animate-in fade-in slide-in-from-top-2 duration-300">
                    <div className="flex-1 py-10 px-6 flex flex-col">
                      {guideItems.map((item, idx) => (
                        <button 
                          key={item.label} 
                          onClick={() => {
                            navigate(item.path);
                            setIsGuideMegaVisible(false);
                          }}
                          className={`w-full text-left px-6 py-4 rounded-2xl text-base font-medium transition-all text-slate-600 hover:bg-slate-50 hover:text-[#EE0434]`}
                        >
                          {item.label}
                        </button>
                      ))}
                    </div>
                  </div>
                )}
              </div>

              <Link 
                to="/news"
                className={`text-[17px] font-bold transition-colors ${isActive('/news') ? 'text-[#EE0434]' : 'text-slate-700 hover:text-[#EE0434]'}`}
              >
                News
              </Link>
              
              <Link 
                to="/contact"
                className={`text-[17px] font-bold transition-colors ${isActive('/contact') ? 'text-[#EE0434]' : 'text-slate-700 hover:text-[#EE0434]'}`}
              >
                Contact
              </Link>
            </nav>

            {/* Icons */}
            <div className="flex items-center space-x-5">
              <Link 
                to="/login"
                className="p-2 text-slate-700 hover:text-[#EE0434] transition-colors"
              >
                <svg className="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M16 7a4 4 0 11-8 0 4 4 0 018 0zM12 14a7 7 0 00-7 7h14a7 7 0 00-7-7z" /></svg>
              </Link>
              <button className="hidden sm:flex p-2 text-slate-700 hover:text-[#EE0434] relative">
                <svg className="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M3 3h2l.4 2M7 13h10l4-8H5.4M7 13L5.4 5M7 13l-2.293 2.293c-.63.63-.184 1.707.707 1.707H17m0 0a2 2 0 100 4 2 2 0 000-4zm-8 2a2 2 0 11-4 0 2 2 0 014 0z" /></svg>
                <span className="absolute top-1 right-1 w-4 h-4 bg-[#EE0434] text-white text-[10px] flex items-center justify-center rounded-full font-black">0</span>
              </button>

              <div className="relative" ref={langMenuRef}>
                <button 
                  onClick={() => setIsLangMenuOpen(!isLangMenuOpen)}
                  className="bg-white p-1 rounded-2xl border border-slate-100 shadow-sm hover:shadow-md transition-all flex items-center justify-center"
                >
                  <div className="w-8 h-8 rounded-full overflow-hidden border border-slate-50">
                    <img 
                      src={`https://flagcdn.com/w80/${currentLangObj.flag}.png`} 
                      alt={currentLangObj.label} 
                      className="w-full h-full object-cover"
                    />
                  </div>
                </button>

                {isLangMenuOpen && (
                  <div className="absolute top-full right-0 mt-3 w-48 bg-white rounded-[24px] shadow-[0_20px_40px_rgba(0,0,0,0.1)] border border-slate-50 overflow-hidden animate-in fade-in slide-in-from-top-2 duration-200">
                    <div className="flex flex-col">
                      {languages.map((lang) => (
                        <button
                          key={lang.code}
                          onClick={() => {
                            setSelectedLang(lang.code as 'en' | 'vi');
                            setIsLangMenuOpen(false);
                          }}
                          className={`flex items-center space-x-3 px-5 py-4 w-full text-left transition-colors ${
                            selectedLang === lang.code ? 'bg-slate-50' : 'hover:bg-slate-50/50'
                          }`}
                        >
                          <div className="w-7 h-7 rounded-full overflow-hidden border border-slate-100 shadow-sm">
                            <img 
                              src={`https://flagcdn.com/w80/${lang.flag}.png`} 
                              alt={lang.label} 
                              className="w-full h-full object-cover"
                            />
                          </div>
                          <span className={`text-[15px] font-bold ${selectedLang === lang.code ? 'text-slate-900' : 'text-slate-500'}`}>
                            {lang.label}
                          </span>
                        </button>
                      ))}
                    </div>
                  </div>
                )}
              </div>

              <button onClick={() => setIsMenuOpen(true)} className="lg:hidden p-2 text-slate-900">
                <svg className="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2.5} d="M4 6h16M4 12h16m-7 6h7" /></svg>
              </button>
            </div>
          </div>
        </div>
      </header>

      {/* Full-Screen Mobile Menu with Slide-Right Transition */}
      <div className={`fixed inset-0 z-[100] lg:hidden transition-all duration-500 ease-in-out ${isMenuOpen ? 'opacity-100 pointer-events-auto' : 'opacity-0 pointer-events-none'}`}>
        <div className={`absolute inset-0 bg-white flex flex-col transform transition-transform duration-500 ease-out ${isMenuOpen ? 'translate-x-0' : '-translate-x-full'}`}>
          {/* Mobile Menu Header */}
          <div className="flex justify-between items-center p-6 border-b border-slate-50">
            <Link to="/" onClick={() => setIsMenuOpen(false)} className="flex items-center space-x-1">
              <svg className="w-7 h-7 text-[#EE0434]" viewBox="0 0 24 24" fill="currentColor">
                <path d="M12 2L2 7l10 5 10-5-10-5zM2 17l10 5 10-5M2 12l10 5 10-5" />
              </svg>
              <span className="text-xl font-black tracking-tighter">
                <span className="text-[#EE0434]">Infi</span>
                <span className="text-[#333]">Gate</span>
              </span>
            </Link>
            <button onClick={() => setIsMenuOpen(false)} className="p-2 text-slate-400 hover:text-[#EE0434] transition-colors rounded-full hover:bg-slate-100">
              <svg className="w-8 h-8" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" /></svg>
            </button>
          </div>

          <div className="flex-1 overflow-y-auto px-6 py-8 space-y-6">
            <div className="flex flex-col items-center space-y-4">
              <Link 
                to="/" 
                onClick={() => setIsMenuOpen(false)}
                className={`w-full text-center py-5 px-6 rounded-3xl text-2xl font-black transition-all ${isActive('/') ? 'bg-red-50 text-[#EE0434]' : 'text-slate-800 hover:bg-slate-50'}`}
              >
                Home
              </Link>
              
              <div className="w-full">
                <button 
                  onClick={() => setIsBuySimExpanded(!isBuySimExpanded)}
                  className={`w-full flex items-center justify-center space-x-3 py-5 px-6 rounded-3xl text-2xl font-black transition-all ${isActive('/buy-sim') ? 'bg-red-50 text-[#EE0434]' : 'text-slate-800 hover:bg-slate-50'}`}
                >
                  <span>Buy SIM</span>
                  <svg className={`w-6 h-6 transition-transform duration-300 ${isBuySimExpanded ? 'rotate-180' : ''}`} fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2.5} d="M19 9l-7 7-7-7" /></svg>
                </button>
                <div className={`overflow-hidden transition-all duration-300 ease-in-out ${isBuySimExpanded ? 'max-h-[1000px] opacity-100 mt-4' : 'max-h-0 opacity-0'}`}>
                  <div className="grid grid-cols-2 gap-3 px-2">
                    <button 
                      onClick={() => { navigate('/buy-sim'); setIsMenuOpen(false); }}
                      className="col-span-2 text-center py-4 bg-slate-50 rounded-2xl text-[#EE0434] font-black text-sm uppercase tracking-wider shadow-sm"
                    >
                      View All Destinations →
                    </button>
                    {countries.map(c => (
                      <button 
                        key={c.name}
                        onClick={() => handleCountryClick(c)}
                        className="flex flex-col items-center justify-center space-y-2 py-5 rounded-2xl bg-white border border-slate-100 shadow-sm active:bg-slate-50"
                      >
                        <img src={`https://flagcdn.com/w80/${c.flag}.png`} alt={c.name} className="w-10 h-10 rounded-full object-cover border-2 border-slate-50" />
                        <span className="text-sm font-bold text-slate-700">{c.name}</span>
                      </button>
                    ))}
                  </div>
                </div>
              </div>

              <div className="w-full">
                <button 
                  onClick={() => setIsGuideExpanded(!isGuideExpanded)}
                  className={`w-full flex items-center justify-center space-x-3 py-5 px-6 rounded-3xl text-2xl font-black transition-all ${isActive('/support') ? 'bg-red-50 text-[#EE0434]' : 'text-slate-800 hover:bg-slate-50'}`}
                >
                  <span>Guide</span>
                  <svg className={`w-6 h-6 transition-transform duration-300 ${isGuideExpanded ? 'rotate-180' : ''}`} fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2.5} d="M19 9l-7 7-7-7" /></svg>
                </button>
                <div className={`overflow-hidden transition-all duration-300 ease-in-out ${isGuideExpanded ? 'max-h-[400px] opacity-100 mt-4' : 'max-h-0 opacity-0'}`}>
                  <div className="flex flex-col space-y-2 px-2">
                    {guideItems.map(item => (
                      <button 
                        key={item.label}
                        onClick={() => { navigate(item.path); setIsMenuOpen(false); }}
                        className="w-full text-center py-4 rounded-2xl bg-slate-50 text-slate-600 font-bold hover:text-[#EE0434] active:bg-red-50"
                      >
                        {item.label}
                      </button>
                    ))}
                  </div>
                </div>
              </div>

              <Link 
                to="/news" 
                onClick={() => setIsMenuOpen(false)}
                className={`w-full text-center py-5 px-6 rounded-3xl text-2xl font-black transition-all ${isActive('/news') ? 'bg-red-50 text-[#EE0434]' : 'text-slate-800 hover:bg-slate-50'}`}
              >
                News
              </Link>
              
              <Link 
                to="/contact" 
                onClick={() => setIsMenuOpen(false)}
                className={`w-full text-center py-5 px-6 rounded-3xl text-2xl font-black transition-all ${isActive('/contact') ? 'bg-red-50 text-[#EE0434]' : 'text-slate-800 hover:bg-slate-50'}`}
              >
                Contact
              </Link>

              <div className="w-full pt-4">
                 <p className="text-center text-slate-400 font-bold text-xs uppercase tracking-widest mb-4">Select Language</p>
                 <div className="flex justify-center space-x-4">
                    {languages.map(lang => (
                      <button
                        key={lang.code}
                        onClick={() => setSelectedLang(lang.code as 'en' | 'vi')}
                        className={`flex items-center space-x-2 px-4 py-2 rounded-2xl transition-all border ${selectedLang === lang.code ? 'bg-red-50 border-[#EE0434] text-[#EE0434]' : 'bg-white border-slate-100 text-slate-500'}`}
                      >
                        <img src={`https://flagcdn.com/w40/${lang.flag}.png`} alt={lang.label} className="w-6 h-6 rounded-full object-cover border border-slate-100" />
                        <span className="font-bold">{lang.label}</span>
                      </button>
                    ))}
                 </div>
              </div>
            </div>
          </div>

          <div className="p-8 border-t border-slate-50 bg-slate-50/50">
            <Link 
              to="/login"
              onClick={() => setIsMenuOpen(false)}
              className="w-full bg-gradient-to-r from-[#E21c34] to-[#500B28] text-white py-5 rounded-[40px] font-black text-2xl shadow-xl active:scale-[0.98] transition-all flex justify-center"
            >
              Login / Register
            </Link>
          </div>
        </div>
      </div>
    </>
  );
};

export default Header;