QinGang_interested/lib/pages/WebViewInteractionPage.dart

import 'dart:convert';
import 'dart:typed_data';

import 'package:dart_sm/dart_sm.dart';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'package:webview_flutter/webview_flutter.dart';

class WebViewMediaBridgePage extends StatefulWidget {
  const WebViewMediaBridgePage({super.key, required this.userId});

  final String userId;

  @override
  State<WebViewMediaBridgePage> createState() => _WebViewMediaBridgePageState();
}

class _WebViewMediaBridgePageState extends State<WebViewMediaBridgePage> {
  static const _jsChannelName = 'WebViewBridge';
  static const _publicKey =
      '049818e94f1abefab63d7193dd71b16241b5e721ab936eb1d4abb84f5024cb5d5b503a1776163cce4dd0f0ffdc612329f3497da3ac9b643306d5bfbe844459d186';
  static const _baseUrl =
      'http://121.22.11.43:8091/emisApp/#/pages/index?user=';

  final ImagePicker _imagePicker = ImagePicker();
  late final WebViewController _controller;

  @override
  void initState() {
    super.initState();
    final encryptedUser = SM2.encrypt(widget.userId, _publicKey);
    final targetUrl = '$_baseUrl$encryptedUser';

    _controller =
        WebViewController()
          ..setJavaScriptMode(JavaScriptMode.unrestricted)
          ..setBackgroundColor(Colors.white)
          ..setNavigationDelegate(
            NavigationDelegate(
              onPageFinished: (_) => _injectBridge(),
              onWebResourceError: (error) {
                debugPrint('设备管理 WebView 加载错误: ${error.description}');
              },
            ),
          )
          ..addJavaScriptChannel(
            _jsChannelName,
            onMessageReceived: (message) => _handleWebMessage(message.message),
          )
          ..loadRequest(Uri.parse(targetUrl));
  }

  Future<void> _injectBridge() {
    return _controller.runJavaScript('''
      window.flutterSendToDart = function(message) {
        if (window.$_jsChannelName && window.$_jsChannelName.postMessage) {
          window.$_jsChannelName.postMessage(String(message));
        }
      };
    ''');
  }

  Future<void> _handleWebMessage(String raw) async {
    Map<String, dynamic> data;
    try {
      data = jsonDecode(raw) as Map<String, dynamic>;
    } catch (_) {
      data = {'action': raw};
    }

    final action = data['action']?.toString();
    final callbackId = data['callbackId']?.toString();
    switch (action) {
      case 'camera':
        await _pickImageAndCallback(ImageSource.camera, callbackId);
        return;
      case 'gallery':
        await _pickImageAndCallback(ImageSource.gallery, callbackId);
        return;
      case 'back':
        if (mounted) Navigator.of(context).pop();
        return;
      case 'ping':
        await _replyToWeb(callbackId, {
          'ok': true,
          'message': 'pong from flutter',
          'time': DateTime.now().toIso8601String(),
        });
        return;
      default:
        debugPrint('设备管理 WebView 未知 action: $action');
    }
  }

  Future<void> _pickImageAndCallback(
    ImageSource source,
    String? callbackId,
  ) async {
    try {
      final file = await _imagePicker.pickImage(
        source: source,
        imageQuality: 85,
      );
      if (file == null) {
        await _replyToWeb(callbackId, {
          'ok': false,
          'cancelled': true,
          'message': '用户取消选择',
        });
        return;
      }

      final Uint8List bytes = await file.readAsBytes();
      final base64Data = base64Encode(bytes);
      final mimeType = _guessMimeType(file.path);
      await _replyToWeb(callbackId, {
        'ok': true,
        'name': file.name,
        'path': file.path,
        'mimeType': mimeType,
        'base64': base64Data,
        'dataUrl': 'data:$mimeType;base64,$base64Data',
      });
    } catch (error) {
      debugPrint('设备管理图片选择失败: $error');
      await _replyToWeb(callbackId, {'ok': false, 'message': error.toString()});
    }
  }

  String _guessMimeType(String path) {
    final lower = path.toLowerCase();
    if (lower.endsWith('.png')) return 'image/png';
    if (lower.endsWith('.webp')) return 'image/webp';
    if (lower.endsWith('.gif')) return 'image/gif';
    if (lower.endsWith('.heic')) return 'image/heic';
    return 'image/jpeg';
  }

  Future<void> _replyToWeb(String? callbackId, Map<String, dynamic> payload) {
    final jsonText = jsonEncode(payload);
    if (callbackId == null || callbackId.isEmpty) {
      return _controller.runJavaScript('''
        if (window.onFlutterResult) window.onFlutterResult($jsonText);
      ''');
    }
    return _controller.runJavaScript('''
      if (window.WebViewCallbacks && window.WebViewCallbacks['$callbackId']) {
        window.WebViewCallbacks['$callbackId']($jsonText);
        delete window.WebViewCallbacks['$callbackId'];
      } else if (window.onFlutterResult) {
        window.onFlutterResult($jsonText);
      }
    ''');
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        top: false,
        bottom: false,
        child: WebViewWidget(controller: _controller),
      ),
    );
  }
}