'use client';

import { useState, useEffect } from 'react';
import { useLocale } from './LocaleProvider';
import { ts } from '@/lib/i18n';
import { LOCALES, Locale } from '@/lib/i18n';

const NAV_ITEMS = [
  { key: 'nav_home' as const, href: '#hero' },
  { key: 'nav_calendar' as const, href: '#calendar' },
  { key: 'nav_fullmoons' as const, href: '#fullmoons' },
  { key: 'nav_simulator' as const, href: '#simulator' },
  { key: 'nav_articles' as const, href: '#articles' },
  { key: 'nav_quiz' as const, href: '#quiz' },
];

export default function Navigation() {
  const { locale, setLocale } = useLocale();
  const [scrolled, setScrolled] = useState(false);
  const [menuOpen, setMenuOpen] = useState(false);
  const [langOpen, setLangOpen] = useState(false);

  useEffect(() => {
    const onScroll = () => setScrolled(window.scrollY > 50);
    window.addEventListener('scroll', onScroll);
    return () => window.removeEventListener('scroll', onScroll);
  }, []);

  return (
    <>
      <header
        className={`fixed top-0 left-0 right-0 z-50 transition-all duration-300 ${
          scrolled ? 'bg-[rgba(10,10,26,0.95)] backdrop-blur-xl shadow-lg shadow-indigo-500/5' : 'bg-transparent'
        }`}
      >
        <nav className="max-w-7xl mx-auto px-4 py-3 flex items-center justify-between">
          <a href="#hero" className="flex items-center gap-2 text-lg font-bold text-white">
            <span className="text-2xl">🌕</span>
            <span className="hidden sm:inline gradient-text-brand">
              Moon Phases
            </span>
          </a>

          {/* Desktop nav */}
          <div className="hidden md:flex items-center gap-1">
            {NAV_ITEMS.map((item) => (
              <a key={item.key} href={item.href} className="nav-link">
                {ts(item.key, locale)}
              </a>
            ))}
          </div>

          <div className="flex items-center gap-2">
            {/* Language selector */}
            <div className="relative">
              <button
                onClick={() => setLangOpen(!langOpen)}
                className="flex items-center gap-1 px-3 py-1.5 rounded-full text-sm bg-white/5 border border-white/10 hover:border-indigo-400/50 transition-all"
                aria-label="Select language"
              >
                {LOCALES.find(l => l.code === locale)?.flag} <span className="hidden sm:inline text-xs uppercase">{locale}</span>
              </button>

              {langOpen && (
                <div className="absolute right-0 top-full mt-2 w-48 glass-card p-2 grid grid-cols-2 gap-1 max-h-64 overflow-y-auto">
                  {LOCALES.map((l) => (
                    <button
                      key={l.code}
                      onClick={() => { setLocale(l.code as Locale); setLangOpen(false); }}
                      className={`flex items-center gap-2 px-3 py-2 rounded-lg text-sm transition-all hover:bg-indigo-500/20 ${
                        locale === l.code ? 'bg-indigo-500/20 text-indigo-300' : 'text-white/70'
                      }`}
                    >
                      <span>{l.flag}</span>
                      <span className="truncate">{l.name}</span>
                    </button>
                  ))}
                </div>
              )}
            </div>

            {/* Mobile menu button */}
            <button
              onClick={() => setMenuOpen(!menuOpen)}
              className="md:hidden p-2 rounded-lg hover:bg-white/10 transition-all"
              aria-label="Menu"
            >
              <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                {menuOpen ? (
                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
                ) : (
                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 6h16M4 12h16M4 18h16" />
                )}
              </svg>
            </button>
          </div>
        </nav>

        {/* Mobile menu */}
        {menuOpen && (
          <div className="md:hidden bg-[rgba(10,10,26,0.98)] backdrop-blur-xl border-t border-white/10 px-4 py-4">
            {NAV_ITEMS.map((item) => (
              <a
                key={item.key}
                href={item.href}
                onClick={() => setMenuOpen(false)}
                className="block py-3 px-4 text-white/70 hover:text-indigo-300 hover:bg-indigo-500/10 rounded-lg transition-all"
              >
                {ts(item.key, locale)}
              </a>
            ))}
          </div>
        )}
      </header>

      {/* Mobile bottom nav */}
      <div className="mobile-nav">
        {NAV_ITEMS.slice(0, 5).map((item) => (
          <a
            key={item.key}
            href={item.href}
            className="flex flex-col items-center gap-0.5 text-xs text-white/50 hover:text-indigo-300 transition-all py-1"
          >
            <span className="text-base">
              {item.key === 'nav_home' ? '🏠' :
               item.key === 'nav_calendar' ? '📅' :
               item.key === 'nav_fullmoons' ? '🌕' :
               item.key === 'nav_simulator' ? '🔭' : '🌐'}
            </span>
            <span className="truncate max-w-15">{ts(item.key, locale)}</span>
          </a>
        ))}
      </div>
    </>
  );
}