import React, { useState } from 'react';
import { Box, Typography, Paper } from '@mui/material';
import Swal from 'sweetalert2';
import ImageGallery from './ImageGallery';

/**
 * Manages image descriptions with save functionality
 * Wraps ImageGallery and provides batch save for all descriptions
 * 
 * @param mode - 'manage' (uses token) or 'moderate' (uses groupId)
 */
function ImageDescriptionManager({ 
  images, 
  token,
  groupId,
  enableReordering = false,
  onReorder,
  onRefresh,
  mode = 'manage'
}) {
  const [imageDescriptions, setImageDescriptions] = useState({});
  const [originalDescriptions, setOriginalDescriptions] = useState({});
  const [isEditMode, setIsEditMode] = useState(false);
  const [saving, setSaving] = useState(false);

  // Handle deleting a single image
  const handleDeleteImage = async (imageId) => {
    const result = await Swal.fire({
      title: 'Bild löschen?',
      text: 'Möchten Sie dieses Bild wirklich löschen? Diese Aktion kann nicht rückgängig gemacht werden.',
      icon: 'warning',
      showCancelButton: true,
      confirmButtonColor: '#d33',
      cancelButtonColor: '#3085d6',
      confirmButtonText: 'Ja, löschen',
      cancelButtonText: 'Abbrechen'
    });

    if (!result.isConfirmed) return;

    try {
      // Different API endpoints for manage vs moderate
      const endpoint = mode === 'moderate' 
        ? `/groups/${groupId}/images/${imageId}`
        : `/api/manage/${token}/images/${imageId}`;

      const res = await fetch(endpoint, {
        method: 'DELETE'
      });

      if (!res.ok) {
        const body = await res.json().catch(() => ({}));
        throw new Error(body.error || 'Fehler beim Löschen des Bildes');
      }

      await Swal.fire({
        icon: 'success',
        title: 'Gelöscht',
        text: 'Bild wurde erfolgreich gelöscht.',
        timer: 2000,
        showConfirmButton: false
      });

      // Refresh data
      if (onRefresh) {
        await onRefresh();
      }

    } catch (error) {
      console.error('Error deleting image:', error);
      Swal.fire({
        icon: 'error',
        title: 'Fehler',
        text: error.message || 'Bild konnte nicht gelöscht werden'
      });
    }
  };

  // Initialize descriptions from images
  React.useEffect(() => {
    if (images && images.length > 0) {
      const descriptions = {};
      images.forEach(img => {
        descriptions[img.id] = img.imageDescription || '';
      });
      setImageDescriptions(descriptions);
      setOriginalDescriptions(descriptions);
    }
  }, [images]);

  const handleDescriptionChange = (imageId, description) => {
    setImageDescriptions(prev => ({
      ...prev,
      [imageId]: description
    }));
  };

  const hasChanges = () => {
    return JSON.stringify(imageDescriptions) !== JSON.stringify(originalDescriptions);
  };

  const handleSave = async () => {
    if (!hasChanges()) {
      Swal.fire({
        icon: 'info',
        title: 'Keine Änderungen',
        text: 'Es wurden keine Änderungen an den Beschreibungen vorgenommen.'
      });
      return;
    }

    try {
      setSaving(true);

      // Build descriptions array for API
      const descriptions = Object.entries(imageDescriptions).map(([imageId, description]) => ({
        imageId: parseInt(imageId),
        description: description || null
      }));

      // Different API endpoints for manage vs moderate
      const endpoint = mode === 'moderate' 
        ? `/groups/${groupId}/images/batch-description`
        : `/api/manage/${token}/images/descriptions`;
      
      const method = mode === 'moderate' ? 'PATCH' : 'PUT';

      const res = await fetch(endpoint, {
        method: method,
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ descriptions })
      });

      if (!res.ok) {
        const body = await res.json().catch(() => ({}));
        throw new Error(body.error || 'Fehler beim Speichern der Beschreibungen');
      }

      await Swal.fire({
        icon: 'success',
        title: 'Gespeichert',
        text: 'Bildbeschreibungen wurden erfolgreich aktualisiert.',
        timer: 2000,
        showConfirmButton: false
      });

      // Update original descriptions
      setOriginalDescriptions(imageDescriptions);

      // Refresh data if callback provided
      if (onRefresh) {
        await onRefresh();
      }

    } catch (error) {
      console.error('Error saving descriptions:', error);
      Swal.fire({
        icon: 'error',
        title: 'Fehler',
        text: error.message || 'Beschreibungen konnten nicht gespeichert werden'
      });
    } finally {
      setSaving(false);
    }
  };

  const handleDiscard = () => {
    setImageDescriptions(originalDescriptions);
    setIsEditMode(false);
  };

  const handleEditToggle = () => {
    if (isEditMode && hasChanges()) {
      // Warn user if trying to leave edit mode with unsaved changes
      Swal.fire({
        icon: 'warning',
        title: 'Ungespeicherte Änderungen',
        text: 'Du hast ungespeicherte Änderungen. Bitte speichere oder verwerfe sie zuerst.',
        confirmButtonText: 'OK'
      });
      return; // Don't toggle edit mode
    }
    
    if (isEditMode) {
      // Discard changes when leaving edit mode without saving
      setImageDescriptions({ ...originalDescriptions });
    }
    setIsEditMode(!isEditMode);
  };

  return (
    <Paper 
      sx={{ 
        p: 3, 
        borderRadius: '12px', 
        boxShadow: '0 2px 8px rgba(0,0,0,0.1)',
        border: '2px solid #e0e0e0'
      }}
    >
      {/* Component Header */}
      <Typography variant="h6" gutterBottom sx={{ fontWeight: 600, mb: 2 }}>
        Bildbeschreibungen
      </Typography>

      <ImageGallery 
        items={images}
        mode="preview"
        isEditMode={isEditMode}
        onEditMode={handleEditToggle}
        enableReordering={enableReordering}
        onReorder={onReorder}
        imageDescriptions={imageDescriptions}
        onDescriptionChange={handleDescriptionChange}
        onDelete={handleDeleteImage}
      />

      {hasChanges() && (
        <Box sx={{ mt: 2, display: 'flex', gap: 1, justifyContent: 'center' }}>
          <button
            className="btn btn-success"
            onClick={handleSave}
            disabled={saving}
          >
            {saving ? '⏳ Speichern...' : '💾 Beschreibungen speichern'}
          </button>
          
          <button
            className="btn btn-secondary"
            onClick={handleDiscard}
            disabled={saving}
          >
            ↩ Verwerfen
          </button>
        </Box>
      )}
    </Paper>
  );
}

export default ImageDescriptionManager;