import React, { useState, useCallback } from 'react';
import { useLanguage } from '../../../providers/language/LanguageContext';
import styles from './DragDropOverlay.module.css';
import { IoFolderOpen } from 'react-icons/io5';

export interface DragDropConfig {
  enabled: boolean;
  onDrop?: (files: File[]) => Promise<void> | void;
  accept?: string; // MIME types or file extensions
  multiple?: boolean;
  disabled?: boolean;
  overlayText?: string;
  overlaySubtext?: string;
}

interface DragDropOverlayProps {
  config: DragDropConfig;
  children: React.ReactNode;
  className?: string;
}

export function DragDropOverlay({ 
  config, 
  children, 
  className = '' 
}: DragDropOverlayProps) {
  const { t } = useLanguage();
  const [isDragOver, setIsDragOver] = useState(false);
  const [isProcessing, setIsProcessing] = useState(false);

  const handleDragEnter = useCallback((e: React.DragEvent) => {
    e.preventDefault();
    e.stopPropagation();
    
    if (config.disabled || !config.enabled) return;
    
    setIsDragOver(true);
  }, [config.disabled, config.enabled]);

  const handleDragLeave = useCallback((e: React.DragEvent) => {
    e.preventDefault();
    e.stopPropagation();
    
    // Only hide overlay if we're leaving the container entirely
    if (!e.currentTarget.contains(e.relatedTarget as Node)) {
      setIsDragOver(false);
    }
  }, []);

  const handleDragOver = useCallback((e: React.DragEvent) => {
    e.preventDefault();
    e.stopPropagation();
  }, []);

  const handleDrop = useCallback(async (e: React.DragEvent) => {
    e.preventDefault();
    e.stopPropagation();
    
    if (config.disabled || !config.enabled) return;
    
    setIsDragOver(false);
    setIsProcessing(true);
    
    try {
      const files = Array.from(e.dataTransfer.files);
      
      // Filter files by accept type if specified
      let filteredFiles = files;
      if (config.accept && config.accept !== '*/*') {
        filteredFiles = files.filter(file => {
          const acceptTypes = config.accept!.split(',').map(type => type.trim());
          return acceptTypes.some(acceptType => {
            // Handle MIME types
            if (acceptType.startsWith('.')) {
              return file.name.toLowerCase().endsWith(acceptType.toLowerCase());
            }
            // Handle MIME types like "image/*" or "application/pdf"
            if (acceptType.includes('*')) {
              const baseType = acceptType.split('/')[0];
              return file.type.startsWith(baseType);
            }
            return file.type === acceptType;
          });
        });
      }
      
      console.log('🔍 DragDropOverlay file filtering:', {
        originalFiles: files.length,
        filteredFiles: filteredFiles.length,
        accept: config.accept,
        fileDetails: files.map(f => ({ name: f.name, type: f.type }))
      });
      
      // Respect multiple setting
      const filesToProcess = config.multiple ? filteredFiles : filteredFiles.slice(0, 1);
      
      if (filesToProcess.length > 0 && config.onDrop) {
        console.log('🎯 DragDropOverlay calling onDrop with files:', filesToProcess);
        await config.onDrop(filesToProcess);
        console.log('✅ DragDropOverlay onDrop completed');
      } else {
        console.log('⚠️ DragDropOverlay: No files to process or no onDrop handler');
        console.log('Files to process:', filesToProcess.length);
        console.log('Has onDrop:', !!config.onDrop);
      }
    } catch (error) {
      console.error(t('Fehler beim Verarbeiten der Dateien'), error);
    } finally {
      setIsProcessing(false);
    }
  }, [config, t]);

  const handleFileInputChange = useCallback(async (e: React.ChangeEvent<HTMLInputElement>) => {
    if (config.disabled || !config.enabled) return;
    
    const files = Array.from(e.target.files || []);
    console.log('🔍 DragDropOverlay file input:', {
      fileCount: files.length,
      accept: config.accept,
      fileDetails: files.map(f => ({ name: f.name, type: f.type }))
    });
    
    if (files.length > 0 && config.onDrop) {
      setIsProcessing(true);
      try {
        await config.onDrop(files);
      } catch (error) {
        console.error(t('Fehler beim Verarbeiten der Dateien'), error);
      } finally {
        setIsProcessing(false);
        // Reset input
        e.target.value = '';
      }
    }
  }, [config, t]);

  if (!config.enabled) {
    return <>{children}</>;
  }

  return (
    <div 
      className={`${styles.dragDropContainer} ${className}`}
      onDragEnter={handleDragEnter}
      onDragLeave={handleDragLeave}
      onDragOver={handleDragOver}
      onDrop={handleDrop}
    >
      {children}
      
      {/* Hidden file input for click-to-upload */}
      <input
        type="file"
        accept={config.accept}
        multiple={config.multiple}
        onChange={handleFileInputChange}
        className={styles.hiddenFileInput}
        disabled={config.disabled}
      />
      
      {/* Drag overlay */}
      {isDragOver && (
        <div className={styles.dragOverlay}>
          <div className={styles.dragOverlayContent}>
            <div className={styles.dragIcon}>
                <IoFolderOpen />
            </div>
            <div className={styles.dragText}>
              {config.overlayText || t('Dateien hier ablegen')}
            </div>
            {(config.overlaySubtext || !config.overlayText) && (
              <div className={styles.dragSubtext}>
                {config.overlaySubtext || t('Sie können auch auf den Upload-Button klicken')}
              </div>
            )}
          </div>
        </div>
      )}
      
      {/* Processing overlay */}
      {isProcessing && (
        <div className={styles.processingOverlay}>
          <div className={styles.processingContent}>
            <div className={styles.spinner}></div>
            <div className={styles.processingText}>
              {t('Dateien werden verarbeitet...')}
            </div>
          </div>
        </div>
      )}
    </div>
  );
}

export default DragDropOverlay;
