package org.schabi.newpipe;


import android.app.NotificationManager;
import android.content.Context;
import android.content.SharedPreferences;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.AsyncTask;
import android.preference.PreferenceManager;
import android.support.v4.app.NotificationCompat;
import android.util.Log;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.UnknownHostException;

import javax.net.ssl.HttpsURLConnection;

import info.guardianproject.netcipher.NetCipher;

/**
 * Created by Christian Schabesberger on 14.08.15.
 *
 * Copyright (C) Christian Schabesberger 2015 <chris.schabesberger@mailbox.org>
 * Downloader.java is part of NewPipe.
 *
 * NewPipe is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * NewPipe is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with NewPipe.  If not, see <http://www.gnu.org/licenses/>.
 */

public class Downloader extends AsyncTask<Void, Integer, Void> {
    public static final String TAG = "Downloader";
    private static final String USER_AGENT = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:43.0) Gecko/20100101 Firefox/43.0";

    private NotificationManager nm;
    private NotificationCompat.Builder builder;
    private int notifyId = 0x1234;
    private int fileSize = 0xffffffff;

    private final Context context;
    private final String fileURL;
    private final File saveFilePath;
    private final String title;

    private final String debugContext;

    public Downloader(Context context, String fileURL, File saveFilePath, String title) {
        this.context = context;
        this.fileURL = fileURL;
        this.saveFilePath = saveFilePath;
        this.title = title;

        this.debugContext = "'" + fileURL +
                "' => '" + saveFilePath + "'";
    }

    /**Download the text file at the supplied URL as in download(String),
     * but set the HTTP header field "Accept-Language" to the supplied string.
     * @param siteUrl the URL of the text file to return the contents of
     * @param language the language (usually a 2-character code) to set as the preferred language
     * @return the contents of the specified text file*/
    public static String download(String siteUrl, String language) {
        String ret = "";
        try {
            URL url = new URL(siteUrl);
            //HttpsURLConnection con = (HttpsURLConnection) url.openConnection();
            HttpsURLConnection con = NetCipher.getHttpsURLConnection(url);
            con.setRequestProperty("Accept-Language", language);
            ret = dl(con);
        }
        catch(Exception e) {
            e.printStackTrace();
        }
        return ret;
    }

    /**Common functionality between download(String url) and download(String url, String language)*/
    private static String dl(HttpsURLConnection con) throws IOException {
        StringBuilder response = new StringBuilder();

        try {
            con.setRequestMethod("GET");
            con.setRequestProperty("User-Agent", USER_AGENT);

            BufferedReader in = new BufferedReader(
                    new InputStreamReader(con.getInputStream()));
            String inputLine;

            while((inputLine = in.readLine()) != null) {
                response.append(inputLine);
            }
            in.close();

        }
        catch(UnknownHostException uhe) {//thrown when there's no internet connection
            uhe.printStackTrace();
            //Toast.makeText(getActivity(), uhe.getMessage(), Toast.LENGTH_LONG).show();
        }

        return response.toString();
    }

/**Download (via HTTP) the text file located at the supplied URL, and return its contents.
 * Primarily intended for downloading web pages.
 * @param siteUrl the URL of the text file to download
 * @return the contents of the specified text file*/
    public static String download(String siteUrl) {
        String ret = "";

        try {
            URL url = new URL(siteUrl);
            HttpsURLConnection con = (HttpsURLConnection) url.openConnection();
            //HttpsURLConnection con = NetCipher.getHttpsURLConnection(url);
            ret = dl(con);
        }
        catch(Exception e) {
            e.printStackTrace();
        }

        return ret;
    }

    /**
     * Downloads a file from a URL in the background using an {@link AsyncTask}.
     *
     * @param fileURL      HTTP URL of the file to be downloaded
     * @param saveFilePath path of the directory to save the file
     * @param title
     * @throws IOException
     */
    public static void downloadFile(final Context context, final String fileURL, final File saveFilePath, String title) {
        new Downloader(context, fileURL, saveFilePath, title).execute();
    }

    /** AsyncTask impl: executed in gui thread */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        nm = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        Drawable icon = context.getResources().getDrawable(R.mipmap.ic_launcher);
        builder = new NotificationCompat.Builder(context)
                .setSmallIcon(android.R.drawable.stat_sys_download)
                .setLargeIcon(((BitmapDrawable) icon).getBitmap())
                .setContentTitle(saveFilePath.getName())
                .setContentText(saveFilePath.getAbsolutePath())
                .setProgress(fileSize, 0, false);
        nm.notify(notifyId, builder.build());
    }

    /** AsyncTask impl: executed in background thread does the download */
    @Override
    protected Void doInBackground(Void... voids) {
        HttpsURLConnection con = null;
        InputStream inputStream = null;
        FileOutputStream outputStream = null;
        try {
            con = NetCipher.getHttpsURLConnection(fileURL);
            int responseCode = con.getResponseCode();

            // always check HTTP response code first
            if (responseCode == HttpURLConnection.HTTP_OK) {
                fileSize = con.getContentLength();
                inputStream = new BufferedInputStream(con.getInputStream());
                outputStream = new FileOutputStream(saveFilePath);

                int bufferSize = 8192;
                int downloaded = 0;

                int bytesRead = -1;
                byte[] buffer = new byte[bufferSize];
                while ((bytesRead = inputStream.read(buffer)) != -1) {
                    outputStream.write(buffer, 0, bytesRead);
                    downloaded += bytesRead;
                    if (downloaded % 50000 < bufferSize) {
                        publishProgress(downloaded);
                    }
                }

                publishProgress(bufferSize);

            } else {
                Log.i(TAG, "No file to download. Server replied HTTP code: " + responseCode);
            }
        } catch (IOException e) {
            Log.e(TAG, "No file to download. Server replied HTTP code: ", e);
            e.printStackTrace();
        } finally {
            try {
                if (outputStream != null) {
                    outputStream.close();
                }
                if (inputStream != null) {
                    inputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (con != null) {
                con.disconnect();
            }
        }
        return null;
    }

    @Override
    protected void onProgressUpdate(Integer... progress) {
        builder.setProgress(fileSize, progress[0], false);
        nm.notify(notifyId, builder.build());
    }

    @Override
    protected void onPostExecute(Void aVoid) {
        super.onPostExecute(aVoid);
        nm.cancel(notifyId);
    }

}