import React from 'react';
import PropTypes from 'prop-types';
import { 
    DndContext, 
    closestCenter, 
    KeyboardSensor, 
    PointerSensor, 
    useSensor, 
    useSensors 
} from '@dnd-kit/core';
import { 
    arrayMove, 
    SortableContext, 
    sortableKeyboardCoordinates, 
    rectSortingStrategy 
} from '@dnd-kit/sortable';
import ImageGalleryCard from './ImageGalleryCard';
import './Css/ImageGallery.css';

const ImageGallery = ({ 
    items, 
    onApprove, 
    onViewImages, 
    onDelete, 
    isPending,
    showActions,
    mode,
    title,
    emptyMessage = 'Keine Elemente vorhanden',
    enableReordering = false,
    onReorder = null,
    isEditMode = false,
    onEditMode = null,
    imageDescriptions = {},
    onDescriptionChange = null
}) => {
    // Sensors for drag and drop (touch-friendly)
    const sensors = useSensors(
        useSensor(PointerSensor, {
            activationConstraint: {
                distance: 8, // Require 8px movement before drag starts
            },
        }),
        useSensor(KeyboardSensor, {
            coordinateGetter: sortableKeyboardCoordinates,
        })
    );

    const handleDragEnd = (event) => {
        const { active, over } = event;
        
        if (active.id !== over?.id && onReorder) {
            const oldIndex = items.findIndex(item => 
                (item.id || item.groupId) === active.id
            );
            const newIndex = items.findIndex(item => 
                (item.id || item.groupId) === over.id
            );
            
            if (oldIndex !== -1 && newIndex !== -1) {
                const reorderedItems = arrayMove(items, oldIndex, newIndex);
                onReorder(reorderedItems, oldIndex, newIndex);
            }
        }
    };

    if (!items || items.length === 0) {
        return (
            <div className="image-gallery-empty">
                <p>{emptyMessage}</p>
            </div>
        );
    }

    const itemIds = items.map(item => item.id || item.groupId);

    const galleryContent = (
        <div className="image-gallery-grid">
            {items.map((item, index) => (
                <ImageGalleryCard
                    key={item.id || item.groupId || index}
                    item={item}
                    index={index}
                    onApprove={onApprove}
                    onViewImages={onViewImages}
                    onDelete={onDelete}
                    isPending={isPending}
                    showActions={showActions}
                    mode={mode}
                    enableReordering={enableReordering}
                    isEditMode={isEditMode}
                    onEditMode={onEditMode}
                    imageDescription={imageDescriptions[item.id || item.groupId] || ''}
                    onDescriptionChange={onDescriptionChange}
                />
            ))}
        </div>
    );

    return (
        <div className="image-gallery-container">
            {title && (
                <h2 className="image-gallery-title">{title}</h2>
            )}
            
            {enableReordering ? (
                <DndContext 
                    sensors={sensors}
                    collisionDetection={closestCenter}
                    onDragEnd={handleDragEnd}
                >
                    <SortableContext 
                        items={itemIds}
                        strategy={rectSortingStrategy}
                    >
                        {galleryContent}
                    </SortableContext>
                </DndContext>
            ) : (
                galleryContent
            )}
        </div>
    );
};

ImageGallery.propTypes = {
    items: PropTypes.array.isRequired,
    onApprove: PropTypes.func,
    onViewImages: PropTypes.func,
    onDelete: PropTypes.func,
    isPending: PropTypes.bool,
    showActions: PropTypes.bool,
    mode: PropTypes.oneOf(['group', 'moderation', 'preview', 'single-image']),
    title: PropTypes.string,
    emptyMessage: PropTypes.string,
    enableReordering: PropTypes.bool,
    onReorder: PropTypes.func,
    isEditMode: PropTypes.bool,
    onEditMode: PropTypes.func,
    imageDescriptions: PropTypes.object,
    onDescriptionChange: PropTypes.func
};

ImageGallery.defaultProps = {
    onApprove: () => {},
    onViewImages: () => {},
    onDelete: () => {},
    isPending: false,
    showActions: true,
    mode: 'group',
    enableReordering: false,
    onReorder: null,
    isEditMode: false,
    onEditMode: null,
    imageDescriptions: {},
    onDescriptionChange: null
};

export default ImageGallery;