tsx
import React, { useCallback } from 'react'
import { useAppStore } from '@/store/useAppStore'
import { CHARACTER_LIMITS } from '@/utils/constants'
import { getCharacterWarnings } from '@/utils/validation'
import { AlertTriangle, Info } from 'lucide-react'

/**
 * Component for prompt input with character counting and validation
 */
export function PromptInput() {
  const {
    prompt,
    characterCount,
    setPrompt,
    validation
  } = useAppStore()

  const validationResult = validation()
  const characterWarnings = getCharacterWarnings(characterCount)

  /**
   * Handle input change with debouncing
   */
  const handleChange = useCallback((e: React.ChangeEvent<HTMLTextAreaElement>) => {
    setPrompt(e.target.value)
  }, [setPrompt])

  /**
   * Get character count color based on limits
   */
  const getCharacterCountColor = () => {
    if (characterCount > CHARACTER_LIMITS.WARNING) {
      return 'text-yellow-600 dark:text-yellow-400'
    }
    if (characterCount > CHARACTER_LIMITS.INPUT * 0.9) {
      return 'text-red-600 dark:text-red-400'
    }
    return 'text-gray-600 dark:text-gray-400'
  }

  /**
   * Get character count background color
   */
  const getCharacterCountBg = () => {
    if (characterCount > CHARACTER_LIMITS.WARNING) {
      return 'bg-yellow-100 dark:bg-yellow-900'
    }
    if (characterCount > CHARACTER_LIMITS.INPUT * 0.9) {
      return 'bg-red-100 dark:bg-red-900'
    }
    return 'bg-gray-100 dark:bg-gray-700'
  }

  return (
    <div className="space-y-4">
      {/* Character Counter */}
      <div className="flex items-center justify-between">
        <div className={`px-3 py-1 rounded-full text-sm font-medium ${getCharacterCountBg()} ${getCharacterCountColor()}`}>
          {characterCount.toLocaleString()} / {CHARACTER_LIMITS.INPUT.toLocaleString()} Zeichen
        </div>
        
        {characterCount > CHARACTER_LIMITS.WARNING && (
          <div className="flex items-center text-yellow-600 dark:text-yellow-400 text-sm">
            <AlertTriangle className="w-4 h-4 mr-1" />
            Langer Prompt
          </div>
        )}
      </div>

      {/* Main Textarea */}
      <div className="relative">
        <textarea
          value={prompt}
          onChange={handleChange}
          placeholder="Gib hier deinen Prompt ein, den du optimieren möchtest..."
          className="input-field min-h-[200px] resize-none text-base leading-relaxed"
          maxLength={CHARACTER_LIMITS.INPUT}
          aria-label="Prompt Eingabefeld"
          aria-describedby="prompt-help prompt-warnings"
        />
        
        {/* Character progress bar */}
        <div className="absolute bottom-0 left-0 right-0 h-1 bg-gray-200 dark:bg-gray-700 rounded-b-lg overflow-hidden">
          <div 
            className={`h-full transition-all duration-300 ${
              characterCount > CHARACTER_LIMITS.INPUT ? 'bg-red-500' :
              characterCount > CHARACTER_LIMITS.WARNING ? 'bg-yellow-500' :
              'bg-green-500'
            }`}
            style={{ width: `${Math.min((characterCount / CHARACTER_LIMITS.INPUT) * 100, 100)}%` }}
          />
        </div>
      </div>

      {/* Helper Text */}
      <div id="prompt-help" className="text-sm text-gray-600 dark:text-gray-400">
        <p className="mb-2">
          <strong>Tipps für bessere Prompts:</strong>
        </p>
        <ul className="list-disc list-inside space-y-1 ml-2">
          <li>Sei spezifisch über das gewünschte Ergebnis</li>
          <li>Füge Kontext und Hintergrundinformationen hinzu</li>
          <li>Definiere das gewünschte Ausgabeformat</li>
          <li>Verwende Beispiele, wo es hilfreich ist</li>
        </ul>
      </div>

      {/* Warnings */}
      {characterWarnings.length > 0 && (
        <div id="prompt-warnings" className="space-y-2">
          {characterWarnings.map((warning, index) => (
            <div key={index} className="flex items-start space-x-2 p-3 bg-yellow-50 dark:bg-yellow-900/20 border border-yellow-200 dark:border-yellow-800 rounded-lg">
              <AlertTriangle className="w-5 h-5 text-yellow-600 dark:text-yellow-400 flex-shrink-0 mt-0.5" />
              <div>
                <p className="text-sm font-medium text-yellow-800 dark:text-yellow-200">
                  {warning.type === 'error' ? 'Fehler:' : 'Warnung:'}
                </p>
                <p className="text-sm text-yellow-700 dark:text-yellow-300">
                  {warning.message}
                </p>
              </div>
            </div>
          ))}
        </div>
      )}

      {/* Validation Errors */}
      {validationResult.errors.length > 0 && (
        <div className="space-y-2">
          {validationResult.errors.map((error, index) => (
            <div key={index} className="flex items-start space-x-2 p-3 bg-red-50 dark:bg-red-900/20 border border-red-200 dark:border-red-800 rounded-lg">
              <AlertTriangle className="w-5 h-5 text-red-600 dark:text-red-400 flex-shrink-0 mt-0.5" />
              <p className="text-sm text-red-700 dark:text-red-300">{error}</p>
            </div>
          ))}
        </div>
      )}

      {/* Suggestions */}
      {validationResult.suggestions.length > 0 && (
        <div className="p-4 bg-blue-50 dark:bg-blue-900/20 border border-blue-200 dark:border-blue-800 rounded-lg">
          <div className="flex items-start space-x-2">
            <Info className="w-5 h-5 text-blue-600 dark:text-blue-400 flex-shrink-0 mt-0.5" />
            <div>
              <p className="text-sm font-medium text-blue-800 dark:text-blue-200 mb-2">
                Verbesserungsvorschläge:
              </p>
              <ul className="text-sm text-blue-700 dark:text-blue-300 space-y-1">
                {validationResult.suggestions.map((suggestion, index) => (
                  <li key={index} className="flex items-start">
                    <span className="text-blue-500 mr-2">•</span>
                    <span>{suggestion}</span>
                  </li>
                ))}
              </ul>
            </div>
          </div>
        </div>
      )}

      {/* Quick Actions */}
      <div className="flex flex-wrap gap-2">
        <button
          type="button"
          onClick={() => setPrompt('Erstelle einen detaillierten Plan für ein umfassendes Marketing-Konzept für ein nachhaltiges E-Commerce-Unternehmen.')}
          className="text-xs px-3 py-1 bg-gray-100 dark:bg-gray-700 text-gray-700 dark:text-gray-300 rounded-full hover:bg-gray-200 dark:hover:bg-gray-600 transition-colors"
        >
          Marketing Beispiel
        </button>
        <button
          type="button"
          onClick={() => setPrompt('Entwickle eine React-Komponente für einen Dark-Mode Toggle mit Tailwind CSS.')}
          className="text-xs px-3 py-1 bg-gray-100 dark:bg-gray-700 text-gray-700 dark:text-gray-300 rounded-full hover:bg-gray-200 dark:hover:bg-gray-600 transition-colors"
        >
          Code Beispiel
        </button>
        <button
          type="button"
          onClick={() => setPrompt('Erstelle ein professionelles Porträt einer Frau im Alter von 30 Jahren in einem modernen Büro.')}
          className="text-xs px-3 py-1 bg-gray-100 dark:bg-gray-700 text-gray-700 dark:text-gray-300 rounded-full hover:bg-gray-200 dark:hover:bg-gray-600 transition-colors"
        >
          Bild Beispiel
        </button>
      </div>
    </div>
  )
}

</html>