import { useEffect, useMemo, useRef, useState } from 'react';
import { IconHash } from '@tabler/icons-react';

function CommunityAutocompleteInput({
  value,
  onChange,
  communities = [],
  placeholder = '',
  className = 'form-control',
  onSelectMeta,
  maxSuggestions = 8,
  useShortValue = false, // если true, передавать только короткую часть community (120 вместо 65000:120)
}) {
  const containerRef = useRef(null);
  const inputRef = useRef(null);
  const [open, setOpen] = useState(false);
  const [activeIndex, setActiveIndex] = useState(-1);

  const suggestions = useMemo(() => {
    const q = String(value || '').toLowerCase();
    if (!q) return communities.slice(0, maxSuggestions);
    const filtered = communities.filter((c) => {
      const v = (c.value || '').toLowerCase();
      const n = (c.name || '').toLowerCase();
      const d = (c.description || '').toLowerCase();
      const t = Array.isArray(c.tags) ? c.tags.join(' ').toLowerCase() : '';
      return v.includes(q) || n.includes(q) || d.includes(q) || t.includes(q);
    });
    return filtered.slice(0, maxSuggestions);
  }, [value, communities, maxSuggestions]);

  useEffect(() => {
    const handleOutside = (e) => {
      if (!containerRef.current) return;
      if (!containerRef.current.contains(e.target)) setOpen(false);
    };
    document.addEventListener('click', handleOutside);
    return () => document.removeEventListener('click', handleOutside);
  }, []);

  const selectItem = (item) => {
    // Если useShortValue=true, извлекаем только часть после двоеточия (если есть)
    let valueToSet = item.value;
    if (useShortValue && typeof item.value === 'string' && item.value.includes(':')) {
      valueToSet = item.value.split(':')[1] || item.value;
    }
    onChange(valueToSet);
    if (onSelectMeta) onSelectMeta(item);
    setOpen(false);
    setActiveIndex(-1);
    if (inputRef.current) inputRef.current.focus();
  };

  const handleKeyDown = (e) => {
    if (!open && (e.key === 'ArrowDown' || e.key === 'ArrowUp')) {
      setOpen(true);
      return;
    }
    if (!open) return;
    if (e.key === 'ArrowDown') {
      e.preventDefault();
      setActiveIndex((prev) => Math.min(prev + 1, suggestions.length - 1));
    } else if (e.key === 'ArrowUp') {
      e.preventDefault();
      setActiveIndex((prev) => Math.max(prev - 1, 0));
    } else if (e.key === 'Enter') {
      if (activeIndex >= 0 && activeIndex < suggestions.length) {
        e.preventDefault();
        selectItem(suggestions[activeIndex]);
      }
    } else if (e.key === 'Escape') {
      setOpen(false);
      setActiveIndex(-1);
    }
  };

  return (
    <div ref={containerRef} className="position-relative" style={{ width: '100%' }}>
      <input
        ref={inputRef}
        type="text"
        className={className}
        placeholder={placeholder}
        value={value}
        onChange={(e) => {
          onChange(e.target.value);
          setOpen(true);
        }}
        onFocus={() => setOpen(true)}
        onKeyDown={handleKeyDown}
        autoComplete="off"
      />

      {open && suggestions.length > 0 && (
        <div
          className="dropdown-menu show"
          style={{
            display: 'block',
            width: '100%',
            maxHeight: 280,
            overflowY: 'auto',
          }}
        >
          {suggestions.map((s, idx) => {
            const label = s.name ? `${s.value} - ${s.name}` : `${s.value}`;
            const description = s.description || '';
            const tags = Array.isArray(s.tags) ? s.tags : [];
            return (
              <button
                type="button"
                key={`${s.value}-${idx}`}
                className={`dropdown-item${idx === activeIndex ? ' active' : ''}`}
                onMouseDown={(e) => { e.preventDefault(); selectItem(s); }}
                onMouseEnter={() => setActiveIndex(idx)}
              >
                <div className="d-flex align-items-start">
                  <span className="avatar me-2 bg-blue-lt text-blue border-0" style={{ width: 22, height: 22 }}>
                    <IconHash size={14} />
                  </span>
                  <div className="flex-fill text-start">
                    <div className="fw-medium">{label}</div>
                    {(description || tags.length > 0) && (
                      <div className="text-muted small text-truncate" style={{ maxWidth: '100%' }}>
                        {description}
                        {tags.length > 0 && (
                          <> ({tags.join(', ')})</>
                        )}
                      </div>
                    )}
                  </div>
                </div>
              </button>
            );
          })}
        </div>
      )}
    </div>
  );
}

export default CommunityAutocompleteInput;