package com.example.sergey.kitty1;

import android.Manifest;
import android.app.Activity;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.ImageView;
import android.widget.Toast;

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;

public class MainActivity extends Activity /*AppCompatActivity*/ {

    final private int REQUEST_INTERNET = 1001;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (ContextCompat.checkSelfPermission(this,
                Manifest.permission.INTERNET)
                != PackageManager.PERMISSION_GRANTED) {

            Log.d("PERM", "requesting permission");

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

        } else{
            new DownloadImageTask().execute(getResources().getString(R.string.url));
        }

    }

    // This actually compiles and runs, despite AS warnings!
    //  AS warnings go away when AppCompatActivity is changed to Activty
    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        Log.d( "PERM", "in onRequestPermissionsResult");
        switch (requestCode) {
            case REQUEST_INTERNET:
                if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                    new DownloadImageTask().execute(getResources().getString(R.string.url));

                } else {
                    Toast.makeText(MainActivity.this, "Permission Denied", Toast.LENGTH_SHORT).show();
                }
                break;
            default:
                super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        }
    }

    private InputStream OpenHttpConnection(String urlString) throws IOException
    {
        InputStream in = null;
        int response = -1;

        URL url = new URL(urlString);
        URLConnection conn = url.openConnection();

        if (!(conn instanceof HttpURLConnection))
            throw new IOException("Not an HTTP connection");
        try{
            HttpURLConnection httpConn = (HttpURLConnection) conn;
            httpConn.setAllowUserInteraction(false);
            httpConn.setInstanceFollowRedirects(true);
            httpConn.setRequestMethod("GET");
            httpConn.connect();
            response = httpConn.getResponseCode();
            if (response == HttpURLConnection.HTTP_OK) {
                in = httpConn.getInputStream();
            }
        }
        catch (Exception ex)
        {
            Log.d("Networking", ex.getLocalizedMessage());
            throw new IOException("Error connecting");
        }
        return in;
    }

    private Bitmap DownloadImage(String URL)
    {
        Bitmap bitmap = null;
        InputStream in;
        try {
            in = OpenHttpConnection(URL);
            bitmap = BitmapFactory.decodeStream(in);
            in.close();
        } catch (IOException e1) {
            Log.d("NetworkingActivity", e1.getLocalizedMessage());
        }
        return bitmap;
    }

    private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {

        protected Bitmap doInBackground(String... urls) {
            return DownloadImage(urls[0]);
        }

        protected void onPostExecute(Bitmap result) {
            ImageView img = findViewById(R.id.imageView);
            img.setImageBitmap(result);
        }
    }
}