stegapp.dart

// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:convert';
import 'dart:math';
import 'dart:ui';
import 'package:flutter/services.dart';
import 'package:image/image.dart' as A;
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'dart:io';
import 'package:path_provider/path_provider.dart';
import 'package:color/color.dart';
void main() => runApp(MyApp());

// #docregion MyApp
class MyApp extends StatelessWidget {
  // #docregion build
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Startup Name Generator',
      home: MyHomePage(),
    );
  }
}
  class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
  }

  class _MyHomePageState extends State<MyHomePage> {
  File _image;
  final picker = ImagePicker();
  bool _btnEnabled = false;
  final myController = TextEditingController();
  String tempPath;

  Future getImage() async {
  final pickedFile = await picker.getImage(source: ImageSource.gallery);

  setState(() {
  _image = File(pickedFile.path);
  });
  }

  String MessageToBinaryString(String pMessage){
    String Result;
    Result="";
    List<int> bytes = utf8.encode(pMessage);
    bytes.forEach((item) { Result+=item.toRadixString(2).padLeft(8,'0');});
    return Result;
  }
  Future<void> steggapp(File pImage, String pMessage) async {
    //Declaration
    String ImagePath;
    String binaryStringmessage;
    String binaryStringImage;
    String binaryStringData;
    Directory tempDir = await getTemporaryDirectory();
    tempPath  = tempDir.path;
    print(tempPath);
    List<List<int>> DataList =  List<List<int> >();

    //Initialisation




    //get the two binary string from parameters
    binaryStringmessage= MessageToBinaryString(pMessage);
    ImagePath = pImage.path;

    File image =new File(ImagePath);

    var decodedImage =await  decodeImageFromList(image.readAsBytesSync());
    ByteData imgbyte=await decodedImage.toByteData();
    var imgintlist = imgbyte.buffer.asUint8List();


    A.Image aimage =A.Image.fromBytes(decodedImage.width,decodedImage.height, imgintlist, format: A.Format.rgba);
    A.Image resisedimage=A.copyResize(aimage,width:1000);

    String RRGGBBString;
    String RedBinString;
    String BlueBinString;
    String GreenBinString;
    String PixelString;
    String MegaString;

    MegaString="";
    for (int i = 0;i < resisedimage.length;i++){
      RRGGBBString=resisedimage[i].toRadixString(2).padLeft(32, '0').substring(8);
      PixelString=RRGGBBString.substring(16,24)+RRGGBBString.substring(8,16)+RRGGBBString.substring(0,8);
      MegaString+=PixelString;

    }
    int messaggelength=0;
    String messagetohide=binaryStringmessage;
    String substringtoFind;
    substringtoFind=messagetohide.substring(0,1);

    String Stringbuilttest="";
    var offsetarray = new List();
    int offsettostore;
    int lengthtostore;
    int offset;
    String Megastringtosearch= MegaString.substring((MegaString.length/4).round());
    //print("performing data calculation");
    while(messaggelength < binaryStringmessage.length ) {
      offsettostore=Megastringtosearch.indexOf(substringtoFind);

      //print(Megastringtosearch.substring(offsettostore,offsettostore+substringtoFind.length));
      while(offsettostore !=-1 && substringtoFind.length<=messagetohide.length-1){
          lengthtostore = substringtoFind.length;
          offset = offsettostore;
          substringtoFind = messagetohide.substring(0, substringtoFind.length + 1);
          offsettostore = Megastringtosearch.indexOf(substringtoFind);
        }


    if(substringtoFind.length == messagetohide.length  ){
      int lastoffsettostore=Megastringtosearch.indexOf(substringtoFind);
      if(lastoffsettostore==-1){
        offsetarray.add([offset, lengthtostore]);
        offsetarray.add([Megastringtosearch.indexOf(substringtoFind[-1]),1]);

        Stringbuilttest+=Megastringtosearch.substring(Megastringtosearch.indexOf(substringtoFind[-1]),(Megastringtosearch.indexOf(substringtoFind[-1])+lengthtostore));
      }
      else{
        offsetarray.add([Megastringtosearch.indexOf(substringtoFind),substringtoFind.length]);
        var lastitem=offsetarray.last;
        Stringbuilttest+=Megastringtosearch.substring(Megastringtosearch.indexOf(substringtoFind),(offsettostore+substringtoFind.length));
      }
      messaggelength+=substringtoFind.length;
    }
    else {
      messagetohide = messagetohide.substring(substringtoFind.length - 1);
      messaggelength += substringtoFind.length;
      Stringbuilttest +=
          Megastringtosearch.substring(offset, (offset + lengthtostore));
      offsetarray.add([offset, lengthtostore]);

      offsettostore = 0;
      lengthtostore = 1;
      offset = 0;

      substringtoFind = messagetohide.substring(0, 1);
    }


  }


    int offsetdatasize=resisedimage.length*8*3;

    int lenghtdatasize=binaryStringmessage.length;
    int lenghtsizebit=lenghtdatasize.toRadixString(2).length;;
    int datasizebit= offsetdatasize.toRadixString(2).length;

    String stringtowrite="";

    stringtowrite+=offsetarray.length.toRadixString(2).padLeft(datasizebit,'0')+lenghtsizebit.toRadixString(2).padLeft(datasizebit,'0');

    offsetarray.forEach((listofdata){
//      listofdata.forEach((data){
//        print(data.toRadixString(2).padLeft(datasizebit,'0'));
        stringtowrite+=listofdata[0].toRadixString(2).padLeft(datasizebit,'0')+listofdata[1].toRadixString(2).padLeft(lenghtsizebit,'0');
      });
    int lengthofmodifiedstring=stringtowrite.length;
    List<int> pixelvalue= new List();
    int compteur = 0;
    int missingsize;

    String finaleImageString;
    finaleImageString=stringtowrite+MegaString.substring(stringtowrite.length);
    int limit;
    limit=stringtowrite.length;
    while(compteur <limit){
      try {

        pixelvalue.add(int.parse(stringtowrite.substring(0, 8),radix: 2));
        stringtowrite=stringtowrite.substring(8);
        compteur+=8;

      }
      on RangeError {
        missingsize=8-stringtowrite.length;
        pixelvalue.add(int.parse(stringtowrite+finaleImageString.substring(compteur+stringtowrite.length,compteur+stringtowrite.length+missingsize),radix: 2));
       compteur+=8;
      }
    }

    A.Image imagetosave;
    int compteurpixel;
    imagetosave= resisedimage.clone();
    compteurpixel =0;
    List<int> lastpixellist = new List();
    for(int iz=0;iz<pixelvalue.length;iz+=3){
      try{
        var testpixel=pixelvalue[iz+2];
        imagetosave.data[compteurpixel]=A.getColor(pixelvalue[iz],pixelvalue[iz+1], pixelvalue[iz+2]);
        compteurpixel+=1;
      }
      on RangeError{
        pixelvalue=pixelvalue.sublist(iz);
        var basixpixellist=imagetosave.data[compteurpixel].toRadixString(2).padLeft(32, '0').substring(8);
        int RedChannelint=int.parse(basixpixellist.substring(16,24),radix: 2);
        int GreenChannelint=int.parse(basixpixellist.substring(16,24),radix: 2);
        int BlueChannelint=int.parse(basixpixellist.substring(16,24),radix: 2);
        List<int> originalpixelvalue = [RedChannelint,GreenChannelint,BlueChannelint];
        for(int ze=0;ze<=2;ze++){
          if (ze > pixelvalue.length-1){
          lastpixellist.add(originalpixelvalue[ze]);
          }  else {
            lastpixellist.add(pixelvalue[ze]);
          }
        }
        imagetosave.data[compteurpixel]=A.getColor(lastpixellist[0],lastpixellist[1], lastpixellist[2]);
      }
    }

    Directory documentD= await getExternalStorageDirectory();
    new File(documentD.path+'/thumbnail-test.png')..writeAsBytesSync(A.encodePng(imagetosave));

    //binaryStringImage =ImageToBinary(pImage);
//
//    //calculate the list [numberofbytestoread,[offset,len],[offset,len],...]
//
//    DataList=stegalg(binaryStringmessage,binaryStringImage);
//
//    //convert DataList to binary Stream
//
//    binaryStringData=ListToBin(DataList);
//
//    //Apply this binary List to pixel Array
//    pixelArray=incorporateData(binaryStringData,binaryStringImage);
//
//    //Generate and save the image
//    Targetimage= GenerateImage(pixelArray);

  }

  @override
  Widget build(BuildContext context) {
  return Scaffold(
  appBar: AppBar(
  title: Text('Steganausorus App'),
  ),
  body: Column(
    crossAxisAlignment: CrossAxisAlignment.center,
    mainAxisAlignment: MainAxisAlignment.spaceEvenly,
    children: <Widget>[
      Text('Select the message you want to hide'),
      TextFormField(
        controller: myController,
        autovalidate: true,
        validator:(String txt){
           bool isValid = txt.length >= 1;
           if(isValid != _btnEnabled){
            WidgetsBinding.instance.addPostFrameCallback((_) {setState(() {
              _btnEnabled =txt.length >= 1;
            });});
        }
    },

        textAlign: TextAlign.center,
        decoration: InputDecoration(

            border: UnderlineInputBorder(),
            hintText: 'I am a very well hidden message',
        ),
      ),
      Text('Select the target Image :'),
     _image == null
         ? Text('No image selected.')
          : Image.file(_image),

      RaisedButton(onPressed: _btnEnabled == true && _image != null ?  () {steggapp(_image, myController.text);} : null ,
        child: const Text('Start Hide & seek game', style: TextStyle(fontSize: 20)),),
    ],

  ),
  floatingActionButton: FloatingActionButton(
  onPressed: getImage,
  tooltip: 'Pick Image',
  child: Icon(Icons.add_a_photo),
  ),
  );
  }
  }