lingyue-zhibao/frontend/lib/widgets/business/upload_zone.dart

import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter_lucide/flutter_lucide.dart';
import '../../theme/app_colors.dart';

/// 文件上传区域组件
class UploadZone extends StatefulWidget {
  final Function(List<File>)? onUpload;
  final Function(double)? onProgress;
  final List<String>? accept;
  final double? maxSize;

  const UploadZone({
    Key? key,
    this.onUpload,
    this.onProgress,
    this.accept,
    this.maxSize,
  }) : super(key: key);

  @override
  State<UploadZone> createState() => _UploadZoneState();
}

class _UploadZoneState extends State<UploadZone> {
  bool _isDragging = false;
  bool _isUploading = false;
  double _uploadProgress = 0.0;

  @override
  Widget build(BuildContext context) {
    return DragTarget<List<File>>(
      onWillAccept: (data) {
        setState(() => _isDragging = true);
        return true;
      },
      onLeave: (data) {
        setState(() => _isDragging = false);
      },
      onAccept: (files) {
        setState(() => _isDragging = false);
        _handleFiles(files);
      },
      builder: (context, candidateData, rejectedData) {
        return GestureDetector(
          onTap: _isUploading ? null : _pickFiles,
          child: Container(
            width: double.infinity,
            height: 300,
            decoration: BoxDecoration(
              color: _isDragging
                  ? AppColors.primary.withOpacity(0.1)
                  : Colors.white,
              border: Border.all(
                color: _isDragging ? AppColors.primary : AppColors.border,
                width: 2,
                style: BorderStyle.solid,
              ),
              borderRadius: BorderRadius.circular(12),
            ),
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                Icon(
                  LucideIcons.upload,
                  size: 64,
                  color:
                      _isDragging ? AppColors.primary : AppColors.textSecondary,
                ),
                const SizedBox(height: 16),
                Text(
                  _isDragging ? '释放以上传文件' : '拖拽文件到此处',
                  style: TextStyle(
                    fontSize: 18,
                    fontWeight: FontWeight.w600,
                    color:
                        _isDragging ? AppColors.primary : AppColors.textPrimary,
                  ),
                ),
                const SizedBox(height: 8),
                Text(
                  '或点击选择文件',
                  style: TextStyle(
                    fontSize: 14,
                    color: AppColors.textSecondary,
                  ),
                ),
                const SizedBox(height: 16),
                Text(
                  '支持格式：${widget.accept?.join(', ') ?? 'PDF, Word, 图片'}',
                  style: TextStyle(
                    fontSize: 12,
                    color: AppColors.textSecondary,
                  ),
                ),
                if (_isUploading) ...[
                  const SizedBox(height: 24),
                  SizedBox(
                    width: 200,
                    child: LinearProgressIndicator(
                      value: _uploadProgress,
                      backgroundColor: AppColors.borderLight,
                      valueColor: const AlwaysStoppedAnimation<Color>(
                        AppColors.primary,
                      ),
                    ),
                  ),
                  const SizedBox(height: 8),
                  Text(
                    '${(_uploadProgress * 100).toInt()}%',
                    style: const TextStyle(
                      fontSize: 12,
                      color: AppColors.textSecondary,
                    ),
                  ),
                ],
              ],
            ),
          ),
        );
      },
    );
  }

  Future<void> _pickFiles() async {
    // 这里应该使用 file_picker，但为了演示使用静态数据
    // 实际项目中应该调用 FilePicker.platform.pickFiles()
    _simulateUpload();
  }

  Future<void> _handleFiles(List<File> files) async {
    _simulateUpload();
  }

  Future<void> _simulateUpload() async {
    setState(() {
      _isUploading = true;
      _uploadProgress = 0.0;
    });

    // 模拟上传进度
    for (int i = 0; i <= 100; i += 20) {
      await Future.delayed(const Duration(milliseconds: 60));
      setState(() {
        _uploadProgress = i / 100;
      });
      widget.onProgress?.call(_uploadProgress);
    }

    setState(() {
      _isUploading = false;
      _uploadProgress = 0.0;
    });

    // 模拟文件对象
    widget.onUpload?.call([]);
  }
}