feat(android): wire up import/export settings to UI

android/src/main/kotlin/dev/msfjarvis/claw/android/ui/LobstersApp.kt

@@ -18,6 +18,7 @@ import androidx.compose.material.icons.filled.Favorite
 import androidx.compose.material.icons.filled.NewReleases
 import androidx.compose.material.icons.filled.Whatshot
 import androidx.compose.material.icons.outlined.FavoriteBorder
+import androidx.compose.material.icons.outlined.ImportExport
 import androidx.compose.material.icons.outlined.NavigateBefore
 import androidx.compose.material.icons.outlined.NewReleases
 import androidx.compose.material.icons.outlined.Whatshot
@@ -49,6 +50,7 @@ import androidx.navigation.navDeepLink
 import androidx.paging.compose.collectAsLazyPagingItems
 import com.deliveryhero.whetstone.compose.injectedViewModel
 import dev.msfjarvis.claw.android.R
+import dev.msfjarvis.claw.android.ui.datatransfer.DataTransferScreen
 import dev.msfjarvis.claw.android.ui.decorations.ClawNavigationBar
 import dev.msfjarvis.claw.android.ui.decorations.ClawNavigationRail
 import dev.msfjarvis.claw.android.ui.decorations.NavigationItem
@@ -149,6 +151,14 @@ fun LobstersApp(
               Text(text = stringResource(R.string.app_name), fontWeight = FontWeight.Bold)
             }
           },
+          actions = {
+            IconButton(onClick = { navController.navigate(Destinations.DataTransfer.route) }) {
+              Icon(
+                imageVector = Icons.Outlined.ImportExport,
+                contentDescription = "Data transfer options"
+              )
+            }
+          },
         )
       },
       bottomBar = {
@@ -237,6 +247,12 @@ fun LobstersApp(
               getProfile = viewModel::getUserProfile,
             )
           }
+          composable(route = Destinations.DataTransfer.route) {
+            DataTransferScreen(
+              context = context,
+              dataTransferRepository = viewModel.dataTransferRepository,
+            )
+          }
         }
       }
     }

android/src/main/kotlin/dev/msfjarvis/claw/android/ui/datatransfer/DataTransferScreen.kt

@@ -0,0 +1,116 @@
+/*
+ * Copyright © 2023 Harsh Shandilya.
+ * Use of this source code is governed by an MIT-style
+ * license that can be found in the LICENSE file or at
+ * https://opensource.org/licenses/MIT.
+ */
+package dev.msfjarvis.claw.android.ui.datatransfer
+
+import android.content.Context
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts.CreateDocument
+import androidx.activity.result.contract.ActivityResultContracts.GetContent
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.height
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.NorthEast
+import androidx.compose.material.icons.outlined.SouthWest
+import androidx.compose.material3.Icon
+import androidx.compose.material3.ListItem
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.unit.dp
+import dev.msfjarvis.claw.android.viewmodel.DataTransferRepository
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.launch
+
+private const val MIME_TYPE = "application/json"
+
+@Composable
+fun DataTransferScreen(
+  context: Context,
+  dataTransferRepository: DataTransferRepository,
+  modifier: Modifier = Modifier,
+) {
+  val coroutineScope = rememberCoroutineScope()
+  Column(modifier = modifier) {
+    ImportOption(context, coroutineScope, dataTransferRepository)
+    ExportOption(context, coroutineScope, dataTransferRepository)
+  }
+}
+
+@Composable
+private fun ImportOption(
+  context: Context,
+  coroutineScope: CoroutineScope,
+  dataTransferRepository: DataTransferRepository,
+) {
+  val importAction =
+    rememberLauncherForActivityResult(GetContent()) { uri ->
+      if (uri == null) return@rememberLauncherForActivityResult
+      coroutineScope.launch {
+        context.contentResolver.openInputStream(uri)?.use { stream ->
+          dataTransferRepository.importPosts(stream)
+        }
+      }
+    }
+  SettingsActionItem(
+    title = "Import saved posts",
+    description = "Import saved posts from a previously generated export",
+    icon = Icons.Outlined.SouthWest,
+  ) {
+    importAction.launch(MIME_TYPE)
+  }
+}
+
+@Composable
+private fun ExportOption(
+  context: Context,
+  coroutineScope: CoroutineScope,
+  dataTransferRepository: DataTransferRepository,
+) {
+  val exportAction =
+    rememberLauncherForActivityResult(CreateDocument(MIME_TYPE)) { uri ->
+      if (uri == null) return@rememberLauncherForActivityResult
+      coroutineScope.launch {
+        context.contentResolver.openOutputStream(uri)?.use { stream ->
+          dataTransferRepository.exportPosts(stream)
+        }
+      }
+    }
+  SettingsActionItem(
+    title = "Export posts to file",
+    description = "Write all saved posts into a JSON file that can be imported at a later date",
+    icon = Icons.Outlined.NorthEast,
+  ) {
+    exportAction.launch("claw-export.json")
+  }
+}
+
+@Composable
+private fun SettingsActionItem(
+  title: String,
+  modifier: Modifier = Modifier,
+  description: String? = null,
+  icon: ImageVector? = null,
+  onClick: (() -> Unit)? = null,
+) {
+  ListItem(
+    headlineContent = { Text(title) },
+    supportingContent = { description?.let { Text(it) } },
+    leadingContent = {
+      icon?.let {
+        Icon(
+          imageVector = icon,
+          contentDescription = null,
+          modifier = Modifier.height(32.dp),
+        )
+      }
+    },
+    modifier = modifier.clickable { onClick?.invoke() },
+  )
+}

android/src/main/kotlin/dev/msfjarvis/claw/android/ui/navigation/Destinations.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2021-2022 Harsh Shandilya.
+ * Copyright © 2021-2023 Harsh Shandilya.
  * Use of this source code is governed by an MIT-style
  * license that can be found in the LICENSE file or at
  * https://opensource.org/licenses/MIT.
@@ -31,6 +31,10 @@ sealed class Destinations {
     override val route = "user/$placeholder"
   }
 
+  object DataTransfer : Destinations() {
+    override val route: String = "datatransfer"
+  }
+
   companion object {
     val startDestination
       get() = Hottest

android/src/main/kotlin/dev/msfjarvis/claw/android/viewmodel/ClawViewModel.kt

@@ -41,6 +41,7 @@ constructor(
   private val savedPostsRepository: SavedPostsRepository,
   private val commentsRepository: CommentsRepository,
   private val linkMetadataRepository: LinkMetadataRepository,
+  val dataTransferRepository: DataTransferRepository,
   private val pagingSourceFactory: LobstersPagingSource.Factory,
   @IODispatcher private val ioDispatcher: CoroutineDispatcher,
 ) : ViewModel() {