'use client';

import React, { useState, KeyboardEvent, useEffect, useRef } from 'react';
import { X, Hash, Search, TrendingUp } from 'lucide-react';

interface Props {
  value: string[];
  onChange: (value: string[]) => void;
  label?: string;
  placeholder?: string;
  suggestions?: string[];
  onlySuggestions?: boolean;
}

export default function TagInput({ value, onChange, label, placeholder, suggestions = [], onlySuggestions = false }: Props) {
  const [inputValue, setInputValue] = useState('');
  const [filteredSuggestions, setFilteredSuggestions] = useState<string[]>([]);
  const [showSuggestions, setShowSuggestions] = useState(false);
  const [selectedIndex, setSelectedIndex] = useState(-1);
  const containerRef = useRef<HTMLDivElement>(null);

  useEffect(() => {
    if (inputValue.trim()) {
      const filtered = suggestions
        .filter(tag => 
          tag.toLowerCase().includes(inputValue.toLowerCase()) && 
          !value.includes(tag.toLowerCase())
        )
        .slice(0, 10);
      setFilteredSuggestions(filtered);
      setShowSuggestions(filtered.length > 0);
    } else if (showSuggestions && suggestions.length > 0) {
      const filtered = suggestions
        .filter(tag => !value.includes(tag.toLowerCase()))
        .slice(0, 8);
      setFilteredSuggestions(filtered);
      setShowSuggestions(filtered.length > 0);
    } else {
      setFilteredSuggestions([]);
      setShowSuggestions(false);
    }
    setSelectedIndex(-1);
  }, [inputValue, suggestions, value, showSuggestions]);

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

  const addTag = (tagToAdd?: string) => {
    if (onlySuggestions && !tagToAdd) return;
    
    const tag = (tagToAdd || inputValue).trim().toLowerCase();
    
    // If restricted, check if tag exists in suggestions
    if (onlySuggestions && tagToAdd && !suggestions.some(s => s.toLowerCase() === tag)) {
      return;
    }

    if (tag && !value.includes(tag)) {
      onChange([...value, tag]);
    }
    setInputValue('');
    if (tagToAdd) setShowSuggestions(true);
  };

  const removeTag = (tagToRemove: string) => {
    onChange(value.filter(tag => tag !== tagToRemove));
  };

  const handleKeyDown = (e: KeyboardEvent<HTMLInputElement>) => {
    if (e.key === 'Enter') {
      e.preventDefault();
      if (selectedIndex >= 0 && filteredSuggestions[selectedIndex]) {
        addTag(filteredSuggestions[selectedIndex]);
      } else if (!onlySuggestions) {
        addTag();
      }
    } else if ((e.key === ',' || e.key === ';') && !onlySuggestions) {
      e.preventDefault();
      addTag();
    } else if (e.key === 'ArrowDown') {
      e.preventDefault();
      if (!showSuggestions && suggestions.length > 0) {
        setShowSuggestions(true);
      } else {
        setSelectedIndex(prev => (prev < filteredSuggestions.length - 1 ? prev + 1 : prev));
      }
    } else if (e.key === 'ArrowUp') {
      e.preventDefault();
      setSelectedIndex(prev => (prev > -1 ? prev - 1 : -1));
    } else if (e.key === 'Escape') {
      setShowSuggestions(false);
    } else if (e.key === 'Backspace' && !inputValue && value.length > 0) {
      removeTag(value[value.length - 1]);
    }
  };

  return (
    <div className="space-y-2 relative" ref={containerRef}>
      {label && <label className="text-sm font-medium text-gray-700">{label}</label>}
      
      <div 
        className="min-h-[48px] p-2 bg-white border border-gray-300 rounded-lg flex flex-wrap gap-2 items-center focus-within:border-brand-500 focus-within:ring-1 focus-within:ring-brand-500 transition-all cursor-text shadow-sm"
        onClick={() => {
          const input = containerRef.current?.querySelector('input');
          input?.focus();
        }}
      >
        {value.map((tag) => (
          <span 
            key={tag} 
            className="flex items-center gap-1 bg-brand-50 text-brand-700 border border-brand-100 px-2.5 py-1 rounded-md text-sm font-medium animate-in zoom-in-95 duration-200"
          >
            <Hash className="w-3 h-3 opacity-50" />
            {tag}
            <button
              type="button"
              onClick={(e) => {
                e.stopPropagation();
                removeTag(tag);
              }}
              className="hover:text-red-500 transition-colors ml-1"
            >
              <X className="w-3.5 h-3.5" />
            </button>
          </span>
        ))}
        <input
          type="text"
          value={inputValue}
          onChange={(e) => setInputValue(e.target.value)}
          onKeyDown={handleKeyDown}
          onFocus={() => setShowSuggestions(true)}
          placeholder={value.length === 0 ? (placeholder || "Ajouter des tags...") : ""}
          className="flex-1 bg-transparent border-none outline-none text-gray-900 text-sm min-w-[120px] p-1 placeholder:text-gray-400"
        />
      </div>

      {showSuggestions && filteredSuggestions.length > 0 && (
        <div className="absolute z-50 w-full mt-1 bg-white border border-gray-200 rounded-lg shadow-xl overflow-hidden animate-in fade-in slide-in-from-top-1 duration-200">
          <div className="p-2 border-b border-gray-100 bg-gray-50 flex items-center justify-between">
            <p className="text-[10px] font-bold text-gray-500 uppercase tracking-widest flex items-center gap-1.5">
              {inputValue ? <Search className="w-3 h-3" /> : <TrendingUp className="w-3 h-3" />}
              {inputValue ? 'Suggestions' : 'Tags populaires'}
            </p>
          </div>
          <div className="max-h-60 overflow-y-auto">
            {filteredSuggestions.map((suggestion, index) => (
              <button
                key={suggestion}
                type="button"
                onClick={(e) => {
                  e.stopPropagation();
                  addTag(suggestion);
                }}
                onMouseEnter={() => setSelectedIndex(index)}
                className={`w-full text-left px-4 py-2.5 text-sm flex items-center justify-between transition-colors ${
                  index === selectedIndex ? 'bg-brand-600 text-white' : 'text-gray-700 hover:bg-gray-100'
                }`}
              >
                <span className="flex items-center gap-2">
                  <Hash className={`w-3.5 h-3.5 ${index === selectedIndex ? 'text-white/50' : 'text-gray-400'}`} />
                  {suggestion}
                </span>
                {index === selectedIndex && (
                  <span className="text-[10px] bg-white/20 px-1.5 py-0.5 rounded font-bold uppercase">Entrée</span>
                )}
              </button>
            ))}
          </div>
        </div>
      )}
    </div>
  );
}