Move password export to the IO dispatcher (#918)

* Move password export to the IO dispatcher

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

* Simplify snackbars and disable exit operations during export

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

* Move export password logic to service

Signed-off-by: Aditya Wasan <adityawasan55@gmail.com>

* Reformat

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

* Use explicit null check

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

* Remove unneeded hack

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

* Fixup strings

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

* Don't use coroutines in a service

Signed-off-by: Aditya Wasan <adityawasan55@gmail.com>

* Update notification icon

Signed-off-by: Aditya Wasan <adityawasan55@gmail.com>

* Rollback unwanted formatting

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

Co-authored-by: Aditya Wasan <adityawasan55@gmail.com>

6 files changed, 185 insertions, 77 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ebf699d3..f9691e18 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@ All notable changes to this project will be documented in this file.
 -   Top-level password names had inconsistent top margin making them look askew
 -   Autofill can now be made more reliable in Chrome by enabling an accessibility service that works around known Chrome limitations
 -   Password Store no longer ignores the selected OpenKeychain key
+-   Password export now happens in a separate process, preventing possible freezes
 
 ### Added
 
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 1a49b017..4e6ea102 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -116,6 +116,9 @@
             android:name=".ClipboardService"
             android:process=":clipboard_service_process" />
         <service
+            android:name=".PasswordExportService"
+            android:process=":password_export_service_process" />
+        <service
             android:name=".autofill.oreo.OreoAutofillService"
             android:permission="android.permission.BIND_AUTOFILL_SERVICE">
             <intent-filter>
diff --git a/app/src/main/java/com/zeapo/pwdstore/PasswordExportService.kt b/app/src/main/java/com/zeapo/pwdstore/PasswordExportService.kt
new file mode 100644
index 00000000..e877a77a
--- /dev/null
+++ b/app/src/main/java/com/zeapo/pwdstore/PasswordExportService.kt
@@ -0,0 +1,152 @@
+package com.zeapo.pwdstore
+
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.Service
+import android.content.Intent
+import android.net.Uri
+import android.os.Build
+import android.os.IBinder
+import androidx.core.app.NotificationCompat
+import androidx.core.content.getSystemService
+import androidx.documentfile.provider.DocumentFile
+import com.github.ajalt.timberkt.d
+import com.zeapo.pwdstore.utils.PasswordRepository
+import java.time.LocalDateTime
+import java.time.format.DateTimeFormatter
+import java.util.Calendar
+import java.util.TimeZone
+
+class PasswordExportService : Service() {
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        if (intent != null) {
+            when (intent.action) {
+                ACTION_EXPORT_PASSWORD -> {
+                    val uri = intent.getParcelableExtra<Uri>("uri")
+                    if (uri != null) {
+                        val targetDirectory = DocumentFile.fromTreeUri(applicationContext, uri)
+
+                        if (targetDirectory != null) {
+                            createNotification()
+                            exportPasswords(targetDirectory)
+                            stopSelf()
+                            return START_NOT_STICKY
+                        }
+                    }
+                }
+            }
+        }
+        return super.onStartCommand(intent, flags, startId)
+    }
+
+    override fun onBind(intent: Intent?): IBinder? {
+        return null
+    }
+
+    /**
+     * Exports passwords to the given directory.
+     *
+     * Recursively copies the existing password store to an external directory.
+     *
+     * @param targetDirectory directory to copy password directory to.
+     */
+    private fun exportPasswords(targetDirectory: DocumentFile) {
+
+        val repositoryDirectory = requireNotNull(PasswordRepository.getRepositoryDirectory(applicationContext))
+        val sourcePassDir = DocumentFile.fromFile(repositoryDirectory)
+
+        d { "Copying ${repositoryDirectory.path} to $targetDirectory" }
+
+        val dateString = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            LocalDateTime
+                .now()
+                .format(DateTimeFormatter.ISO_DATE_TIME)
+        } else {
+            String.format("%tFT%<tRZ", Calendar.getInstance(TimeZone.getTimeZone("Z")))
+        }
+
+        val passDir = targetDirectory.createDirectory("password_store_$dateString")
+
+        if (passDir != null) {
+            copyDirToDir(sourcePassDir, passDir)
+        }
+    }
+
+    /**
+     * Copies a password file to a given directory.
+     *
+     * Note: this does not preserve last modified time.
+     *
+     * @param passwordFile password file to copy.
+     * @param targetDirectory target directory to copy password.
+     */
+    private fun copyFileToDir(passwordFile: DocumentFile, targetDirectory: DocumentFile) {
+        val sourceInputStream = contentResolver.openInputStream(passwordFile.uri)
+        val name = passwordFile.name
+        val targetPasswordFile = targetDirectory.createFile("application/octet-stream", name!!)
+        if (targetPasswordFile?.exists() == true) {
+            val destOutputStream = contentResolver.openOutputStream(targetPasswordFile.uri)
+
+            if (destOutputStream != null && sourceInputStream != null) {
+                sourceInputStream.copyTo(destOutputStream, 1024)
+
+                sourceInputStream.close()
+                destOutputStream.close()
+            }
+        }
+    }
+
+    /**
+     * Recursively copies a directory to a destination.
+     *
+     *  @param sourceDirectory directory to copy from.
+     *  @param targetDirectory directory to copy to.
+     */
+    private fun copyDirToDir(sourceDirectory: DocumentFile, targetDirectory: DocumentFile) {
+        sourceDirectory.listFiles().forEach { file ->
+            if (file.isDirectory) {
+                // Create new directory and recurse
+                val newDir = targetDirectory.createDirectory(file.name!!)
+                copyDirToDir(file, newDir!!)
+            } else {
+                copyFileToDir(file, targetDirectory)
+            }
+        }
+    }
+
+    private fun createNotification() {
+        createNotificationChannel()
+
+        val notification = NotificationCompat.Builder(this, CHANNEL_ID)
+            .setContentTitle(getString(R.string.app_name))
+            .setContentText(getString(R.string.exporting_passwords))
+            .setSmallIcon(R.drawable.ic_round_import_export)
+            .setPriority(NotificationCompat.PRIORITY_LOW)
+            .build()
+
+        startForeground(2, notification)
+    }
+
+    private fun createNotificationChannel() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            val serviceChannel = NotificationChannel(
+                CHANNEL_ID,
+                getString(R.string.app_name),
+                NotificationManager.IMPORTANCE_LOW
+            )
+            val manager = getSystemService<NotificationManager>()
+            if (manager != null) {
+                manager.createNotificationChannel(serviceChannel)
+            } else {
+                d { "Failed to create notification channel" }
+            }
+        }
+    }
+
+    companion object {
+
+        const val ACTION_EXPORT_PASSWORD = "ACTION_EXPORT_PASSWORD"
+        private const val CHANNEL_ID = "NotificationService"
+    }
+}
diff --git a/app/src/main/java/com/zeapo/pwdstore/UserPreference.kt b/app/src/main/java/com/zeapo/pwdstore/UserPreference.kt
index 9f444d45..950b6523 100644
--- a/app/src/main/java/com/zeapo/pwdstore/UserPreference.kt
+++ b/app/src/main/java/com/zeapo/pwdstore/UserPreference.kt
@@ -59,11 +59,7 @@ import com.zeapo.pwdstore.utils.autofillManager
 import com.zeapo.pwdstore.utils.getEncryptedPrefs
 import java.io.File
 import java.io.IOException
-import java.time.LocalDateTime
-import java.time.format.DateTimeFormatter
-import java.util.Calendar
 import java.util.HashSet
-import java.util.TimeZone
 import me.msfjarvis.openpgpktx.util.OpenPgpUtils
 
 typealias ClickListener = Preference.OnPreferenceClickListener
@@ -643,6 +639,13 @@ class UserPreference : AppCompatActivity() {
      * Exports the passwords
      */
     private fun exportPasswords() {
+        val intent = Intent(Intent.ACTION_OPEN_DOCUMENT_TREE).apply {
+            flags = Intent.FLAG_GRANT_READ_URI_PERMISSION or
+                Intent.FLAG_GRANT_WRITE_URI_PERMISSION or
+                Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION or
+                Intent.FLAG_GRANT_PREFIX_URI_PERMISSION
+        }
+
         registerForActivityResult(StartActivityForResult()) { result ->
             if (!validateResult(result)) return@registerForActivityResult
             val uri = result.data?.data
@@ -651,10 +654,19 @@ class UserPreference : AppCompatActivity() {
                 val targetDirectory = DocumentFile.fromTreeUri(applicationContext, uri)
 
                 if (targetDirectory != null) {
-                    exportPasswords(targetDirectory)
+                    val service = Intent(applicationContext, PasswordExportService::class.java).apply {
+                        action = PasswordExportService.ACTION_EXPORT_PASSWORD
+                        putExtra("uri", uri)
+                    }
+
+                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                        startForegroundService(service)
+                    } else {
+                        startService(service)
+                    }
                 }
             }
-        }.launch(Intent(Intent.ACTION_OPEN_DOCUMENT_TREE))
+        }.launch(intent)
     }
 
     /**
@@ -772,77 +784,6 @@ class UserPreference : AppCompatActivity() {
             return autofillManager?.hasEnabledAutofillServices() == true
         }
 
-    /**
-     * Exports passwords to the given directory.
-     *
-     * Recursively copies the existing password store to an external directory.
-     *
-     * @param targetDirectory directory to copy password directory to.
-     */
-    private fun exportPasswords(targetDirectory: DocumentFile) {
-
-        val repositoryDirectory = requireNotNull(PasswordRepository.getRepositoryDirectory(applicationContext))
-        val sourcePassDir = DocumentFile.fromFile(repositoryDirectory)
-
-        tag(TAG).d { "Copying ${repositoryDirectory.path} to $targetDirectory" }
-
-        val dateString = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
-            LocalDateTime
-                .now()
-                .format(DateTimeFormatter.ISO_DATE_TIME)
-        } else {
-            String.format("%tFT%<tRZ", Calendar.getInstance(TimeZone.getTimeZone("Z")))
-        }
-
-        val passDir = targetDirectory.createDirectory("password_store_$dateString")
-
-        if (passDir != null) {
-            copyDirToDir(sourcePassDir, passDir)
-        }
-    }
-
-    /**
-     * Copies a password file to a given directory.
-     *
-     * Note: this does not preserve last modified time.
-     *
-     * @param passwordFile password file to copy.
-     * @param targetDirectory target directory to copy password.
-     */
-    private fun copyFileToDir(passwordFile: DocumentFile, targetDirectory: DocumentFile) {
-        val sourceInputStream = contentResolver.openInputStream(passwordFile.uri)
-        val name = passwordFile.name
-        val targetPasswordFile = targetDirectory.createFile("application/octet-stream", name!!)
-        if (targetPasswordFile?.exists() == true) {
-            val destOutputStream = contentResolver.openOutputStream(targetPasswordFile.uri)
-
-            if (destOutputStream != null && sourceInputStream != null) {
-                sourceInputStream.copyTo(destOutputStream, 1024)
-
-                sourceInputStream.close()
-                destOutputStream.close()
-            }
-        }
-    }
-
-    /**
-     * Recursively copies a directory to a destination.
-     *
-     *  @param sourceDirectory directory to copy from.
-     *  @param sourceDirectory directory to copy to.
-     */
-    private fun copyDirToDir(sourceDirectory: DocumentFile, targetDirectory: DocumentFile) {
-        sourceDirectory.listFiles().forEach { file ->
-            if (file.isDirectory) {
-                // Create new directory and recurse
-                val newDir = targetDirectory.createDirectory(file.name!!)
-                copyDirToDir(file, newDir!!)
-            } else {
-                copyFileToDir(file, targetDirectory)
-            }
-        }
-    }
-
     companion object {
 
         private const val TAG = "UserPreference"
diff --git a/app/src/main/res/drawable/ic_round_import_export.xml b/app/src/main/res/drawable/ic_round_import_export.xml
new file mode 100644
index 00000000..d732ca2f
--- /dev/null
+++ b/app/src/main/res/drawable/ic_round_import_export.xml
@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M8.65,3.35L5.86,6.14c-0.32,0.31 -0.1,0.85 0.35,0.85H8V13c0,0.55 0.45,1 1,1s1,-0.45 1,-1V6.99h1.79c0.45,0 0.67,-0.54 0.35,-0.85L9.35,3.35c-0.19,-0.19 -0.51,-0.19 -0.7,0zM16,17.01V11c0,-0.55 -0.45,-1 -1,-1s-1,0.45 -1,1v6.01h-1.79c-0.45,0 -0.67,0.54 -0.35,0.85l2.79,2.78c0.2,0.19 0.51,0.19 0.71,0l2.79,-2.78c0.32,-0.31 0.09,-0.85 -0.35,-0.85H16z"/>
+</vector>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 01b63579..625cf440 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -400,4 +400,5 @@
     <string name="otp_import_failure">Failed to import TOTP configuration</string>
     <string name="oreo_autofill_chrome_compat_fix_preference_title">Improve reliability in Chrome</string>
     <string name="oreo_autofill_chrome_compat_fix_preference_summary">Requires activating an accessibility service and may affect overall Chrome performance</string>
+    <string name="exporting_passwords">Exporting passwords…</string>
 </resources>