app/src/main/java/com/stoutner/privacybrowser/coroutines/SaveUrlCoroutine.kt

   1 /*
   2  * Copyright 2020-2023 Soren Stoutner <soren@stoutner.com>.
   3  *
   4  * This file is part of Privacy Browser Android <https://www.stoutner.com/privacy-browser-android>.
   5  *
   6  * Privacy Browser Android is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * Privacy Browser Android is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with Privacy Browser Android.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 package com.stoutner.privacybrowser.coroutines
  21
  22 import android.app.Activity
  23 import android.content.Context
  24 import android.net.Uri
  25 import android.os.Build
  26 import android.provider.OpenableColumns
  27 import android.util.Base64
  28 import android.webkit.CookieManager
  29
  30 import com.google.android.material.snackbar.Snackbar
  31
  32 import com.stoutner.privacybrowser.R
  33 import com.stoutner.privacybrowser.helpers.ProxyHelper
  34 import com.stoutner.privacybrowser.views.NoSwipeViewPager
  35
  36 import kotlinx.coroutines.CoroutineScope
  37 import kotlinx.coroutines.Dispatchers
  38 import kotlinx.coroutines.launch
  39 import kotlinx.coroutines.withContext
  40
  41 import java.io.BufferedInputStream
  42 import java.io.InputStream
  43 import java.net.HttpURLConnection
  44 import java.net.URL
  45 import java.text.NumberFormat
  46
  47 class SaveUrlCoroutine {
  48     fun save(context: Context, activity: Activity, urlString: String, fileUri: Uri, userAgent: String, cookiesEnabled: Boolean) {
  49         // Use a coroutine to save the URL.
  50         CoroutineScope(Dispatchers.Main).launch {
  51             // Create a file name string.
  52             val fileNameString: String
  53
  54             // Query the exact file name if the API >= 26.
  55             if (Build.VERSION.SDK_INT >= 26) {
  56                 // Get a cursor from the content resolver.
  57                 val contentResolverCursor = activity.contentResolver.query(fileUri, null, null, null)!!
  58
  59                 // Move to the first row.
  60                 contentResolverCursor.moveToFirst()
  61
  62                 // Get the file name from the cursor.
  63                 fileNameString = contentResolverCursor.getString(contentResolverCursor.getColumnIndexOrThrow(OpenableColumns.DISPLAY_NAME))
  64
  65                 // Close the cursor.
  66                 contentResolverCursor.close()
  67             } else {
  68                 // Use the file URI last path segment as the file name string.
  69                 fileNameString = fileUri.lastPathSegment!!
  70             }
  71
  72             // Get a handle for the no swipe view pager.
  73             val noSwipeViewPager = activity.findViewById<NoSwipeViewPager>(R.id.webviewpager)
  74
  75             // Create a saving file snackbar.
  76             val savingFileSnackbar = Snackbar.make(noSwipeViewPager, activity.getString(R.string.saving_file, 0, fileNameString), Snackbar.LENGTH_INDEFINITE)
  77
  78             // Display the saving file snackbar.
  79             savingFileSnackbar.show()
  80
  81             // Download the URL on the IO thread.
  82             withContext(Dispatchers.IO) {
  83                 try {
  84                     // Open an output stream.
  85                     val outputStream = activity.contentResolver.openOutputStream(fileUri)!!
  86
  87                     // Save the URL.
  88                     if (urlString.startsWith("data:")) {  // The URL contains the entire data of an image.
  89                         // Get the Base64 data, which begins after a `,`.
  90                         val base64DataString = urlString.substring(urlString.indexOf(",") + 1)
  91
  92                         // Decode the Base64 string to a byte array.
  93                         val base64DecodedDataByteArray = Base64.decode(base64DataString, Base64.DEFAULT)
  94
  95                         // Write the Base64 byte array to the output stream.
  96                         outputStream.write(base64DecodedDataByteArray)
  97                     } else {  // The URL points to the data location on the internet.
  98                         // Get the URL from the calling activity.
  99                         val url = URL(urlString)
 100
 101                         // Instantiate the proxy helper.
 102                         val proxyHelper = ProxyHelper()
 103
 104                         // Get the current proxy.
 105                         val proxy = proxyHelper.getCurrentProxy(context)
 106
 107                         // Open a connection to the URL.  No data is actually sent at this point.
 108                         val httpUrlConnection = url.openConnection(proxy) as HttpURLConnection
 109
 110                         // Add the user agent to the header property.
 111                         httpUrlConnection.setRequestProperty("User-Agent", userAgent)
 112
 113                         // Add the cookies if they are enabled.
 114                         if (cookiesEnabled) {
 115                             // Get the cookies for the current domain.
 116                             val cookiesString = CookieManager.getInstance().getCookie(url.toString())
 117
 118                             // Only add the cookies if they are not null.
 119                             if (cookiesString != null) {
 120                                 // Add the cookies to the header property.
 121                                 httpUrlConnection.setRequestProperty("Cookie", cookiesString)
 122                             }
 123                         }
 124
 125                         // Create the file size value.
 126                         val fileSize: Long
 127
 128                         // Create the formatted file size variable.
 129                         var formattedFileSize = ""
 130
 131                         // The actual network request is in a `try` bracket so that `disconnect()` is run in the `finally` section even if an error is encountered in the main block.
 132                         try {
 133                             // Get the content length header, which causes the connection to the server to be made.
 134                             val contentLengthString = httpUrlConnection.getHeaderField("Content-Length")
 135
 136                             // Check to see if the content length is populated.
 137                             if (contentLengthString != null) {  // The content length is populated.
 138                                 // Convert the content length to an long.
 139                                 fileSize = contentLengthString.toLong()
 140
 141                                 // Format the file size for display.
 142                                 formattedFileSize = NumberFormat.getInstance().format(fileSize)
 143                             } else {  // The content length is null.
 144                                 // Set the file size to be `-1`.
 145                                 fileSize = -1
 146                             }
 147
 148                             // Get the response body stream.
 149                             val inputStream: InputStream = BufferedInputStream(httpUrlConnection.inputStream)
 150
 151                             // Initialize the conversion buffer byte array.
 152                             // This is set to a megabyte so that frequent updating of the snackbar doesn't freeze the interface on download.  <https://redmine.stoutner.com/issues/709>
 153                             val conversionBufferByteArray = ByteArray(1048576)
 154
 155                             // Initialize the downloaded kilobytes counter.
 156                             var downloadedKilobytesCounter: Long = 0
 157
 158                             // Define the buffer length variable.
 159                             var bufferLength: Int
 160
 161                             // Attempt to read data from the input stream and store it in the output stream.  Also store the amount of data read in the buffer length variable.
 162                             while (inputStream.read(conversionBufferByteArray).also { bufferLength = it } > 0) {  // Proceed while the amount of data stored in the buffer in > 0.
 163                                 // Write the contents of the conversion buffer to the file output stream.
 164                                 outputStream.write(conversionBufferByteArray, 0, bufferLength)
 165
 166                                 // Update the downloaded kilobytes counter.
 167                                 downloadedKilobytesCounter += bufferLength
 168
 169                                 // Format the number of bytes downloaded.
 170                                 val formattedNumberOfBytesDownloadedString = NumberFormat.getInstance().format(downloadedKilobytesCounter)
 171
 172                                 // Update the UI.
 173                                 withContext(Dispatchers.Main) {
 174                                     // Check to see if the file size is known.
 175                                     if (fileSize == -1L) {  // The size of the download file is not known.
 176                                         // Update the snackbar.
 177                                         savingFileSnackbar.setText(activity.getString(R.string.saving_file_progress, formattedNumberOfBytesDownloadedString, fileNameString))
 178                                     } else {  // The size of the download file is known.
 179                                         // Calculate the download percentage.
 180                                         val downloadPercentage = downloadedKilobytesCounter * 100 / fileSize
 181
 182                                         // Update the snackbar.
 183                                         savingFileSnackbar.setText(activity.getString(R.string.saving_file_percentage_progress, downloadPercentage, formattedNumberOfBytesDownloadedString, formattedFileSize,
 184                                             fileNameString)
 185                                         )
 186                                     }
 187                                 }
 188                             }
 189
 190                             // Close the input stream.
 191                             inputStream.close()
 192                         } finally {
 193                             // Disconnect the HTTP URL connection.
 194                             httpUrlConnection.disconnect()
 195                         }
 196                     }
 197
 198                     // Close the output stream.
 199                     outputStream.close()
 200
 201                     // Update the UI.
 202                     withContext(Dispatchers.Main) {
 203                         // Dismiss the saving file snackbar.
 204                         savingFileSnackbar.dismiss()
 205
 206                         // Display the file saved snackbar.
 207                         Snackbar.make(noSwipeViewPager, activity.getString(R.string.saved, fileNameString), Snackbar.LENGTH_LONG).show()
 208                     }
 209                 } catch (exception: Exception) {
 210                     // Update the UI.
 211                     withContext(Dispatchers.Main) {
 212                         // Dismiss the saving file snackbar.
 213                         savingFileSnackbar.dismiss()
 214
 215                         // Display the file saving error.
 216                         Snackbar.make(noSwipeViewPager, activity.getString(R.string.error_saving_file, fileNameString, exception), Snackbar.LENGTH_INDEFINITE).show()
 217                     }
 218                 }
 219             }
 220         }
 221     }
 222 }