const { useState, useEffect, useRef } = React;

function DraggableTable({ drawingId, position, onPositionChange, children }) {
    const tableRef = useRef(null);
    const [isDragging, setIsDragging] = useState(false);
    const [offset, setOffset] = useState({ x: 0, y: 0 });

    const handleMouseDown = (e) => {
        if (!tableRef.current) return;
        setIsDragging(true);
        const rect = tableRef.current.getBoundingClientRect();
        setOffset({
            x: e.clientX - rect.left,
            y: e.clientY - rect.top,
        });
        e.preventDefault();
    };

    const handleMouseMove = (e) => {
        if (!isDragging || !tableRef.current) return;
        const parentRect = tableRef.current.parentElement.getBoundingClientRect();
        
        // 计算新的 left 和 bottom
        let newX = e.clientX - parentRect.left - offset.x;
        let newY = parentRect.height - (e.clientY - parentRect.top) - tableRef.current.offsetHeight + offset.y;

        // 边界检测
        newX = Math.max(0, Math.min(newX, parentRect.width - tableRef.current.offsetWidth));
        newY = Math.max(0, Math.min(newY, parentRect.height - tableRef.current.offsetHeight));

        onPositionChange(drawingId, { x: newX, y: newY });
        e.preventDefault();
    };

    const handleMouseUp = () => {
        setIsDragging(false);
    };
    
    useEffect(() => {
        if (isDragging) {
            document.addEventListener('mousemove', handleMouseMove);
            document.addEventListener('mouseup', handleMouseUp);
        } else {
            document.removeEventListener('mousemove', handleMouseMove);
            document.removeEventListener('mouseup', handleMouseUp);
        }

        return () => {
            document.removeEventListener('mousemove', handleMouseMove);
            document.removeEventListener('mouseup', handleMouseUp);
        };
    }, [isDragging, handleMouseMove, handleMouseUp]);

    return React.createElement('div', {
        ref: tableRef,
        className: `absolute bg-white border border-gray-300 shadow-lg p-2 rounded-lg ${isDragging ? 'cursor-grabbing' : 'cursor-grab'}`,
        style: { left: `${position.x}px`, bottom: `${position.y}px` },
        onMouseDown: handleMouseDown
    }, children);
}

function DrawingViewer({ drawing, item, items, tablePositions, setTablePositions, drawings, onItemUpdate, onBindDrawing, onItemRename, onCycleDrawing }) {
    const [editedItemId, setEditedItemId] = React.useState('');

    React.useEffect(() => {
        if (item) {
            setEditedItemId(item.id);
        }
    }, [item]);
    
    if (!item) {
        return React.createElement('div', { className: 'workspace-panel flex items-center justify-center h-full' },
            React.createElement('p', { className: 'text-gray-500' }, '请在左侧选择一个件号')
        );
    }
    
    if (!drawing) {
        return React.createElement('div', { className: 'workspace-panel flex flex-col items-center justify-center h-full' },
            React.createElement('p', { className: 'text-gray-500 mb-4' }, `件号 "${item.id}" 尚未绑定图纸`),
            // 假设我们总是可以绑定到一张默认图纸上，或者需要一个图纸选择器
            // 这里为了简化，我们假设绑定到 'drawing-1'
            React.createElement('button', { 
                className: 'btn-primary',
                onClick: () => onBindDrawing(item.id, 'drawing-1') 
            }, '为此件号绑定图纸')
        );
    }
    
    const tablePos = tablePositions[drawing.id] || { x: 50, y: 50 };
    
    // 获取子项
    const childItems = item.children.map(childId => items[childId]);

    const handleRenameItem = () => {
        if (!editedItemId.trim() || editedItemId.trim() === item.id) return;
        onItemRename(item.id, editedItemId.trim());
    };

    const isRoot = item && item.isRoot;

    return React.createElement('div', { className: 'workspace-panel h-full p-4 relative bg-gray-50 overflow-hidden' },
        !isRoot && React.createElement('div', { className: 'absolute top-4 left-4 z-10 bg-white p-2 rounded-lg shadow-md flex items-center gap-2' },
            React.createElement('span', { className: 'text-sm font-medium mr-2' }, '修改件号:'),
            React.createElement('input', {
                type: 'text',
                placeholder: '输入新件号',
                className: 'form-input w-48',
                value: editedItemId,
                onChange: (e) => setEditedItemId(e.target.value),
                onBlur: handleRenameItem, // 失去焦点时也触发
                onKeyPress: (e) => { if (e.key === 'Enter') handleRenameItem() } // 回车触发
            }),
            React.createElement('button', { className: 'btn-primary', onClick: handleRenameItem }, '确认')
        ),
        React.createElement('button', { 
            className: 'absolute left-4 top-1/2 -translate-y-1/2 z-10 p-3 bg-white/60 rounded-full hover:bg-white transition-colors shadow-md',
            onClick: () => onCycleDrawing(-1)
        }, React.createElement('i', { className: 'lucide lucide-chevron-left w-8 h-8' })),
        React.createElement('button', { 
            className: 'absolute right-4 top-1/2 -translate-y-1/2 z-10 p-3 bg-white/60 rounded-full hover:bg-white transition-colors shadow-md',
            onClick: () => onCycleDrawing(1)
        }, React.createElement('i', { className: 'lucide lucide-chevron-right w-8 h-8' })),
        drawing.url ?
            React.createElement('img', { src: drawing.url, className: 'w-full h-full object-contain' }) :
            React.createElement('div', { className: 'absolute inset-0 flex items-center justify-center' },
                React.createElement('h2', {className: 'text-9xl font-bold text-gray-200 select-none'}, drawing.drawingNumber)
            ),
        React.createElement(DraggableTable, {
            drawingId: drawing.id,
            position: tablePos,
            onPositionChange: (drawingId, newPos) => {
                setTablePositions(prev => ({...prev, [drawingId]: newPos}))
            }
        },
            React.createElement('table', { className: 'w-full text-sm text-left' },
                React.createElement('thead', {}, 
                    React.createElement('tr', { className: 'bg-gray-100' },
                        React.createElement('th', {className: 'p-2'}, '件号'),
                        React.createElement('th', {className: 'p-2'}, '名称'),
                        React.createElement('th', {className: 'p-2'}, '数量'),
                        React.createElement('th', {className: 'p-2'}, '重量'),
                        React.createElement('th', {className: 'p-2'}, '图号')
                    )
                ),
                React.createElement('tbody', {},
                    childItems.map(child => React.createElement('tr', { key: child.id, className: 'border-b' },
                        React.createElement('td', {className: 'p-2'}, child.id),
                        React.createElement('td', {className: 'p-2'}, child.name),
                        React.createElement('td', {className: 'p-2'}, child.quantity),
                        React.createElement('td', {className: 'p-2'}, child.weight.toFixed(2)),
                        React.createElement('td', {className: 'p-2'}, drawings[child.drawingId]?.drawingNumber || 'N/A')
                    ))
                )
            )
        )
    );
}