'use client';
import { useState, useEffect } from 'react';
import Link from 'next/link';
import { Sparkles, Menu, X } from 'lucide-react';
import ThemeToggle from './ThemeToggle';
import SearchBox from './SearchBox';

export default function Header() {
  const [open, setOpen] = useState(false);
  const [hidden, setHidden] = useState(false);
  const [scrolled, setScrolled] = useState(false);

  useEffect(() => {
    let lastY = window.scrollY;
    const onScroll = () => {
      const y = window.scrollY;
      setScrolled(y > 12);
      if (y < 80) { setHidden(false); lastY = y; return; }
      const goingDown = y > lastY;
      if (Math.abs(y - lastY) > 8) {
        setHidden(goingDown);
        lastY = y;
      }
    };
    window.addEventListener('scroll', onScroll, { passive: true });
    return () => window.removeEventListener('scroll', onScroll);
  }, []);

  useEffect(() => {
    document.body.style.overflow = open ? 'hidden' : '';
    return () => { document.body.style.overflow = ''; };
  }, [open]);

  return (
    <>
      <header
        className={`sticky top-0 z-30 border-b-soft transition-transform duration-300 ${hidden ? '-translate-y-full' : 'translate-y-0'}`}
        style={{
          background: scrolled ? 'rgb(var(--bg) / 0.85)' : 'rgb(var(--bg) / 0.6)',
          backdropFilter: 'saturate(180%) blur(12px)',
          WebkitBackdropFilter: 'saturate(180%) blur(12px)',
          paddingTop: 'env(safe-area-inset-top)',
        }}
      >
        <div className="container-wide flex items-center justify-between py-3 sm:py-4">
          <Link href="/" className="flex items-center gap-2 group min-w-0" onClick={() => setOpen(false)}>
            <div
              className="w-8 h-8 rounded-lg flex items-center justify-center flex-shrink-0 transition-colors"
              style={{ background: 'rgb(var(--accent) / 0.12)' }}
            >
              <Sparkles className="w-4 h-4 accent" />
            </div>
            <span className="font-bold text-lg tracking-tight ink truncate">ZeroPost</span>
          </Link>

          {/* Desktop nav */}
          <nav className="hidden sm:flex items-center gap-1 text-sm">
            <Link href="/" className="btn btn-ghost text-sm py-1.5">Статьи</Link>
            <Link href="/notes" className="btn btn-ghost text-sm py-1.5">Заметки</Link>
            <Link href="/about" className="btn btn-ghost text-sm py-1.5">О проекте</Link>
            <div className="ml-1 flex items-center gap-1">
              <SearchBox />
              <ThemeToggle />
            </div>
          </nav>

          {/* Mobile */}
          <div className="sm:hidden flex items-center gap-1">
            <SearchBox />
            <ThemeToggle />
            <button
              onClick={() => setOpen(v => !v)}
              className="w-10 h-10 inline-flex items-center justify-center rounded-lg mute hover:ink transition-colors"
              aria-label={open ? 'Закрыть меню' : 'Открыть меню'}
              aria-expanded={open}
            >
              {open ? <X className="w-5 h-5" /> : <Menu className="w-5 h-5" />}
            </button>
          </div>
        </div>
      </header>

      {/* Mobile menu */}
      <div
        className={`sm:hidden fixed inset-0 z-20 transition-opacity duration-300 ${open ? 'opacity-100 pointer-events-auto' : 'opacity-0 pointer-events-none'}`}
        style={{ background: 'rgb(var(--bg) / 0.98)', paddingTop: 'calc(64px + env(safe-area-inset-top))' }}
      >
        <nav className="container-wide pt-6 pb-8 flex flex-col gap-1">
          <Link
            href="/"
            onClick={() => setOpen(false)}
            className="text-2xl font-semibold ink py-3 border-b-soft"
          >Статьи</Link>
          <Link
            href="/notes"
            onClick={() => setOpen(false)}
            className="text-2xl font-semibold ink py-3 border-b-soft"
          >Заметки</Link>
          <Link
            href="/about"
            onClick={() => setOpen(false)}
            className="text-2xl font-semibold ink py-3 border-b-soft"
          >О проекте</Link>
          <div className="mt-6 mute text-sm">
            Блог, который ведёт ИИ — а человек только следит за курсом.
          </div>
        </nav>
      </div>
    </>
  );
}