qr scanner

package com.co.ximmoz.FireFy.ui.views.Activities;

import android.Manifest;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.PointF;
import android.os.Build;

import android.os.Bundle;
import android.widget.Button;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

import com.co.ximmoz.FireFy.ui.views.auth.LoginActivity;
import com.co.ximmoz.FireFy.utils.RedeemToken;
import com.co.ximmoz.FireFy.data.models.User;
import com.co.ximmoz.adfy.R;
import com.dlazaro66.qrcodereaderview.QRCodeReaderView;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;

public class ScanQrActivity extends AppCompatActivity implements QRCodeReaderView.OnQRCodeReadListener {

    private static final int PERMISSION_REQUEST_CODE = 200;

    private QRCodeReaderView qrCodeReaderView;
    private DatabaseReference databaseReference;
    private RedeemToken token_data;
    private Button Dashboardd;
    private double final_amount_of_token=0;

    @Override
    protected void onStart() {
        super.onStart();
        FirebaseUser user=FirebaseAuth.getInstance().getCurrentUser();
        if(user==null){
            startActivity(new Intent(ScanQrActivity.this, LoginActivity.class));
            finish();
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_scan_qr);
        databaseReference= FirebaseDatabase.getInstance().getReference();
        qrCodeReaderView = findViewById(R.id.qrdecoderview);


        if (checkPermission()) {
            qrCodeReaderView.setOnQRCodeReadListener(this);

            // Use this function to enable/disable decoding
            qrCodeReaderView.setQRDecodingEnabled(true);

            //Use this to set the image to display in the background_green.
            //qrCodeReaderView.setBackgroundResource(R.drawable.qr_background);

            // Use this function to change the autofocus interval (default is 5 secs)
            qrCodeReaderView.setAutofocusInterval(5000L);

            // Use this function to enable/disable Torch
            qrCodeReaderView.setTorchEnabled(true);

            // Use this function to set front camera preview
            qrCodeReaderView.setPreviewCameraId(0);

            qrCodeReaderView.setFrontCamera();

            // Use this function to set back camera preview
            qrCodeReaderView.setBackCamera();

        } else {
            requestPermission();
        }

    }
    private boolean checkPermission() {
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
                != PackageManager.PERMISSION_GRANTED) {
            // Permission is not granted
            return false;
        }
        return true;
    }
    private void requestPermission() {

        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.CAMERA},
                PERMISSION_REQUEST_CODE);
    }

    @Override
    public void onQRCodeRead(final String token_text, PointF[] points) {

        final String user_id=FirebaseAuth.getInstance().getCurrentUser().getUid();
        if(token_text.toLowerCase().endsWith("bat"))
        {
            databaseReference.child("Redeem").child(token_text).child(user_id).addListenerForSingleValueEvent(new ValueEventListener() {
                @Override
                public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                    if(dataSnapshot.exists())
                    {
                        Toast.makeText(ScanQrActivity.this, "You have already redeemed" , Toast.LENGTH_SHORT).show();
                        startActivity(new Intent(ScanQrActivity.this, UserDashboardActivity.class));
                        finish();
                    }
                    else
                    {
                        databaseReference.child("Redeem").child(token_text).addListenerForSingleValueEvent(new ValueEventListener() {
                            @Override
                            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                                if(!dataSnapshot.exists())
                                {
                                    Toast.makeText(ScanQrActivity.this, "None Redeemable Code Detected", Toast.LENGTH_SHORT).show();
                                    return;
                                }
                                token_data=dataSnapshot.getValue(RedeemToken.class);
                                databaseReference.child("USERS").child(user_id).addListenerForSingleValueEvent(new ValueEventListener() {
                                    @Override
                                    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                                        User user=dataSnapshot.getValue(User.class);
                                        double amount_to_award_user=user.getAccountBalance()+token_data.getAmount_to_award();
                                        final double final_amount_of_token1=token_data.getAccount_balance()-token_data.getAmount_to_award();
                                        databaseReference.child("USERS").child(user_id).child("accountBalance").setValue(amount_to_award_user).addOnCompleteListener(new OnCompleteListener<Void>() {
                                            @Override
                                            public void onComplete(@NonNull Task<Void> task) {
                                                if(task.isSuccessful())
                                                {
                                                    databaseReference.child("Redeem").child(token_text).child(user_id).setValue(true).addOnCompleteListener(new OnCompleteListener<Void>() {
                                                        @Override
                                                        public void onComplete(@NonNull Task<Void> task) {
                                                            if(task.isSuccessful())
                                                            {

                                                                databaseReference.child("Redeem").child(token_text).child("account_balance").setValue(final_amount_of_token1).addOnCompleteListener(new OnCompleteListener<Void>() {
                                                                    @Override
                                                                    public void onComplete(@NonNull Task<Void> task) {
                                                                        if(task.isSuccessful())
                                                                        {
                                                                            Toast.makeText(ScanQrActivity.this, "DONEEEEE", Toast.LENGTH_SHORT).show();
                                                                        }
                                                                        else
                                                                        {
                                                                            Toast.makeText(ScanQrActivity.this, "failed for some reason", Toast.LENGTH_SHORT).show();
                                                                        }

                                                                    }
                                                                });

                                                            }
                                                            else
                                                            {
                                                                Toast.makeText(ScanQrActivity.this, "FAILEDDDDD", Toast.LENGTH_SHORT).show();
                                                            }
                                                        }
                                                    });
                                                }
                                                else
                                                {
                                                    Toast.makeText(ScanQrActivity.this, "Something Went Wrong", Toast.LENGTH_SHORT).show();
                                                    return;
                                                }
                                            }
                                        });
                                    }

                                    @Override
                                    public void onCancelled(@NonNull DatabaseError databaseError) {
                                        Toast.makeText(ScanQrActivity.this, "Something Went Wrong", Toast.LENGTH_SHORT).show();
                                    }
                                });

                            }

                            @Override
                            public void onCancelled(@NonNull DatabaseError databaseError) {
                                Toast.makeText(ScanQrActivity.this, "Something Went Wrong", Toast.LENGTH_SHORT).show();
                            }
                        });
                    }
                }

                @Override
                public void onCancelled(@NonNull DatabaseError databaseError) {
                    Toast.makeText(ScanQrActivity.this, "Something Went Wrong", Toast.LENGTH_SHORT).show();
                }
            });

        }
        else {
            databaseReference.child("SHOPS").child(token_text).addListenerForSingleValueEvent(new ValueEventListener() {
                @Override
                public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                    if(dataSnapshot.exists())
                    {
                        Intent intent =new Intent(ScanQrActivity.this, shopOwnerRedeemActivity.class);
                        intent.putExtra("ShopID",token_text);
                        startActivity(intent);
                        finish();
                    }
                    else
                    {
                        Toast.makeText(ScanQrActivity.this, "Business Not Registered", Toast.LENGTH_SHORT).show();
                        startActivity(new Intent(ScanQrActivity.this, UserDashboardActivity.class));
                        finish();

                    }
                }

                @Override
                public void onCancelled(@NonNull DatabaseError databaseError) {
                    startActivity(new Intent(ScanQrActivity.this, UserDashboardActivity.class));
                    finish();
                }
            });
        }



    }







    @Override
    public void onBackPressed() {
        startActivity(new Intent(ScanQrActivity.this, UserDashboardActivity.class));
        finish();
    }

    @Override
    protected void onResume() {
        super.onResume();
        qrCodeReaderView.startCamera();
    }

    @Override
    protected void onPause() {
        super.onPause();
        qrCodeReaderView.stopCamera();
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode) {
            case PERMISSION_REQUEST_CODE:
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    return;
                } else {
                    Toast.makeText(getApplicationContext(), "Permission Denied", Toast.LENGTH_SHORT).show();
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
                                != PackageManager.PERMISSION_GRANTED) {
                            showMessageOKCancel("Camera access needed to capture QR Codes",
                                    new DialogInterface.OnClickListener() {
                                        @Override
                                        public void onClick(DialogInterface dialog, int which) {
                                            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                                                requestPermission();
                                            }
                                        }
                                    });
                        }
                    }
                }
                break;
        }
    }
    private void showMessageOKCancel(String message, DialogInterface.OnClickListener okListener) {
        new AlertDialog.Builder(ScanQrActivity.this)
                .setMessage(message)
                .setPositiveButton("OK", okListener)
                .setNegativeButton("Cancel", null)
                .create()
                .show();
    }
}