import 'dart:io';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:mymuseum_visitapp/Screens/Article/article.dart';
import 'package:qr_code_scanner/qr_code_scanner.dart';


class ScannerPage extends StatefulWidget {
  const ScannerPage({Key? key, required this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  State<ScannerPage> createState() => _ScannerPageState();
}

class _ScannerPageState extends State<ScannerPage> {
  Barcode? result;
  QRViewController? controller;
  final GlobalKey qrKey = GlobalKey(debugLabel: 'QR');

  // In order to get hot reload to work we need to pause the camera if the platform
  // is android, or resume the camera if the platform is iOS.
  @override
  void reassemble() {
    super.reassemble();
    if (Platform.isAndroid) {
      controller!.pauseCamera();
    }
    controller!.resumeCamera();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        children: <Widget>[
          Expanded(flex: 4, child: _buildQrView(context)),
          Expanded(
            flex: 1,
            child: FittedBox(
              fit: BoxFit.contain,
              child: Column(
                mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                children: <Widget>[
                  if (result != null)
                    Text(
                        'Barcode Type: ${describeEnum(result!.format)}   Data: ${result!.code}')
                  else
                    const Text('Scan a code'),
                  Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    crossAxisAlignment: CrossAxisAlignment.center,
                    children: <Widget>[
                      Container(
                        margin: const EdgeInsets.all(8),
                        child: ElevatedButton(
                            onPressed: () async {
                              await controller?.toggleFlash();
                              setState(() {});
                            },
                            child: FutureBuilder(
                              future: controller?.getFlashStatus(),
                              builder: (context, snapshot) {
                                return Icon(Icons.flash_on);
                              },
                            )),
                      ),
                      /*Container(
                        margin: const EdgeInsets.all(8),
                        child: ElevatedButton(
                            onPressed: () async {
                              await controller?.flipCamera();
                              setState(() {});
                            },
                            child: FutureBuilder(
                              future: controller?.getCameraInfo(),
                              builder: (context, snapshot) {
                                if (snapshot.data != null) {
                                  return Text(
                                      'Camera facing ${describeEnum(snapshot.data!)}');
                                } else {
                                  return const Text('loading');
                                }
                              },
                            )),
                      )*/
                    ],
                  ),
                  Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    crossAxisAlignment: CrossAxisAlignment.center,
                    children: <Widget>[
                      Container(
                        margin: const EdgeInsets.all(8),
                        child: ElevatedButton(
                          onPressed: () async {
                            await controller?.pauseCamera();
                          },
                          child: const Text('pause',
                              style: TextStyle(fontSize: 20)),
                        ),
                      ),
                      Container(
                        margin: const EdgeInsets.all(8),
                        child: ElevatedButton(
                          onPressed: () async {
                            await controller?.resumeCamera();
                          },
                          child: const Text('resume',
                              style: TextStyle(fontSize: 20)),
                        ),
                      )
                    ],
                  ),
                ],
              ),
            ),
          )
        ],
      ),
    );
  }

  Widget _buildQrView(BuildContext context) {
    // For this example we check how width or tall the device is and change the scanArea and overlay accordingly.
    var scanArea = (MediaQuery.of(context).size.width < 400 ||
        MediaQuery.of(context).size.height < 400)
        ? 225.0
        : 300.0;
    // To ensure the Scanner view is properly sizes after rotation
    // we need to listen for Flutter SizeChanged notification and update controller
    return QRView(
      key: qrKey,
      onQRViewCreated: _onQRViewCreated,
      overlay: QrScannerOverlayShape(
          borderColor: Colors.blueAccent,
          borderRadius: 10,
          borderLength: 25,
          borderWidth: 5,
          cutOutSize: 225.0),
      onPermissionSet: (ctrl, p) => _onPermissionSet(context, ctrl, p),
    );
  }

  void _onQRViewCreated(QRViewController controller) {
    setState(() {
      this.controller = controller;
    });

    controller.scannedDataStream.listen((scanData) {
      setState(() {
        result = scanData;
        print(result);
        if(result!.format == BarcodeFormat.qrcode) {
          controller!.pauseCamera();
          print("QR CODE FOUND");
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(content: Text('QR CODE FOUND')),
          );

          // TODO search in local if data == Id of Article
          // If so, navigate to article view
          Navigator.push(
              context,
              MaterialPageRoute(
                builder: (context) {
                  return ArticlePage(title: "test");
                },
              ),
          );
        }
      });
    });
  }

  void _onPermissionSet(BuildContext context, QRViewController ctrl, bool p) {
    //log('${DateTime.now().toIso8601String()}_onPermissionSet $p');
    if (!p) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('no Permission')),
      );
    }
  }

  @override
  void dispose() {
    controller?.dispose();
    super.dispose();
  }
}