'use client';
import { useState, useEffect, useRef } from 'react';
import Link from 'next/link';
import { Search, X, Loader2, FileText } from 'lucide-react';

export default function SearchBox() {
  const [open, setOpen] = useState(false);
  const [q, setQ] = useState('');
  const [results, setResults] = useState([]);
  const [loading, setLoading] = useState(false);
  const inputRef = useRef(null);
  const debounceRef = useRef(null);

  // открытие хоткеем /
  useEffect(() => {
    const onKey = (e) => {
      if (e.key === '/' && !['INPUT','TEXTAREA'].includes(document.activeElement?.tagName)) {
        e.preventDefault();
        setOpen(true);
      }
      if (e.key === 'Escape') setOpen(false);
    };
    window.addEventListener('keydown', onKey);
    return () => window.removeEventListener('keydown', onKey);
  }, []);

  useEffect(() => {
    if (open) {
      setTimeout(() => inputRef.current?.focus(), 50);
      document.body.style.overflow = 'hidden';
    } else {
      document.body.style.overflow = '';
      setQ('');
      setResults([]);
    }
  }, [open]);

  // дебаунсовый поиск
  useEffect(() => {
    if (!open) return;
    if (debounceRef.current) clearTimeout(debounceRef.current);
    if (q.trim().length < 2) { setResults([]); setLoading(false); return; }
    setLoading(true);
    debounceRef.current = setTimeout(async () => {
      try {
        const r = await fetch(`/api/search?q=${encodeURIComponent(q.trim())}`);
        const data = await r.json();
        setResults(Array.isArray(data) ? data : []);
      } catch { setResults([]); }
      setLoading(false);
    }, 250);
  }, [q, open]);

  return (
    <>
      <button
        onClick={() => setOpen(true)}
        className="w-10 h-10 inline-flex items-center justify-center rounded-lg mute hover:ink hover:surface-2 transition-colors"
        aria-label="Поиск"
        title="Поиск (нажми /)"
      >
        <Search className="w-4 h-4" />
      </button>

      {open && (
        <div
          className="fixed inset-0 z-40 flex items-start justify-center p-4 sm:pt-[10vh]"
          style={{ background: 'rgb(0 0 0 / 0.5)', backdropFilter: 'blur(4px)' }}
          onClick={() => setOpen(false)}
        >
          <div
            className="w-full max-w-2xl rounded-2xl overflow-hidden flex flex-col"
            style={{ background: 'rgb(var(--surface))', border: '1px solid rgb(var(--border))', maxHeight: '85vh' }}
            onClick={e => e.stopPropagation()}
          >
            <div className="flex items-center gap-3 px-4 sm:px-5 py-3 border-b-soft">
              <Search className="w-5 h-5 mute flex-shrink-0" />
              <input
                ref={inputRef}
                value={q}
                onChange={e => setQ(e.target.value)}
                placeholder="Найти статью…"
                className="flex-1 bg-transparent outline-none text-base sm:text-lg ink placeholder:text-stone-400"
              />
              {loading && <Loader2 className="w-4 h-4 animate-spin mute" />}
              <button
                onClick={() => setOpen(false)}
                className="w-8 h-8 inline-flex items-center justify-center rounded-md mute hover:ink hover:surface-2"
                aria-label="Закрыть"
              >
                <X className="w-4 h-4" />
              </button>
            </div>

            <div className="overflow-y-auto flex-1">
              {q.trim().length < 2 && (
                <div className="px-5 py-8 text-sm mute text-center">
                  Введи минимум 2 символа. <span className="hidden sm:inline">Подсказка: <kbd className="px-1.5 py-0.5 rounded surface-2 text-xs">/</kbd> открывает поиск.</span>
                </div>
              )}
              {q.trim().length >= 2 && !loading && results.length === 0 && (
                <div className="px-5 py-8 text-sm mute text-center">Ничего не найдено</div>
              )}
              {results.length > 0 && (
                <ul className="py-2">
                  {results.map(a => (
                    <li key={a.id}>
                      <Link
                        href={`/blog/${a.slug}`}
                        onClick={() => setOpen(false)}
                        className="flex items-start gap-3 px-5 py-3 hover:surface-2 transition-colors"
                      >
                        <FileText className="w-4 h-4 mute flex-shrink-0 mt-1" />
                        <div className="min-w-0">
                          <div className="ink font-medium line-clamp-1">{a.title}</div>
                          {a.excerpt && <div className="mute text-sm line-clamp-2 mt-0.5">{a.excerpt}</div>}
                          {a.tags?.length > 0 && (
                            <div className="flex gap-1.5 mt-2">
                              {a.tags.slice(0, 3).map(t => <span key={t} className="tag text-[10px]">#{t}</span>)}
                            </div>
                          )}
                        </div>
                      </Link>
                    </li>
                  ))}
                </ul>
              )}
            </div>
          </div>
        </div>
      )}
    </>
  );
}