feat(android): add the ability to export posts as browser bookmarks

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

@@ -16,6 +16,7 @@ import androidx.compose.foundation.layout.height
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Download
 import androidx.compose.material.icons.filled.Upload
+import androidx.compose.material.icons.filled.WebStories
 import androidx.compose.material3.Icon
 import androidx.compose.material3.ListItem
 import androidx.compose.material3.SnackbarHostState
@@ -30,25 +31,28 @@ import java.io.OutputStream
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.launch
 
-private const val MIME_TYPE = "application/json"
+private const val JSON_MIME_TYPE = "application/json"
+private const val HTML_MIME_TYPE = "application/html"
 
 @Composable
 fun DataTransferScreen(
   context: Context,
   importPosts: suspend (InputStream) -> Unit,
   exportPosts: suspend (OutputStream) -> Unit,
+  exportPostsAsHtml: suspend (OutputStream) -> Unit,
   snackbarHostState: SnackbarHostState,
   modifier: Modifier = Modifier,
 ) {
   val coroutineScope = rememberCoroutineScope()
   Column(modifier = modifier) {
-    ImportOption(context, coroutineScope, importPosts, snackbarHostState)
-    ExportOption(context, coroutineScope, exportPosts, snackbarHostState)
+    JsonImportOption(context, coroutineScope, importPosts, snackbarHostState)
+    JsonExportOption(context, coroutineScope, exportPosts, snackbarHostState)
+    HtmlExportOption(context, coroutineScope, exportPostsAsHtml, snackbarHostState)
   }
 }
 
 @Composable
-private fun ImportOption(
+private fun JsonImportOption(
   context: Context,
   coroutineScope: CoroutineScope,
   importPosts: suspend (InputStream) -> Unit,
@@ -72,19 +76,64 @@ private fun ImportOption(
     description = "Import saved posts from a previously generated export",
     icon = Icons.Filled.Download,
   ) {
-    importAction.launch(MIME_TYPE)
+    importAction.launch(JSON_MIME_TYPE)
   }
 }
 
 @Composable
-private fun ExportOption(
+private fun JsonExportOption(
+  context: Context,
+  coroutineScope: CoroutineScope,
+  exportPosts: suspend (OutputStream) -> Unit,
+  snackbarHostState: SnackbarHostState,
+) {
+  GenericExportOption(
+    title = "Export posts to file",
+    description = "Write all saved posts into a JSON file that can be imported at a later date",
+    icon = Icons.Filled.Upload,
+    fileName = "claw-export.json",
+    mimeType = JSON_MIME_TYPE,
+    context = context,
+    coroutineScope = coroutineScope,
+    exportPosts = exportPosts,
+    snackbarHostState = snackbarHostState,
+  )
+}
+
+@Composable
+private fun HtmlExportOption(
+  context: Context,
+  coroutineScope: CoroutineScope,
+  exportPosts: suspend (OutputStream) -> Unit,
+  snackbarHostState: SnackbarHostState,
+) {
+  GenericExportOption(
+    title = "Export posts as bookmarks",
+    description = "Write all saved posts into a HTML file that can be imported by web browsers",
+    icon = Icons.Filled.WebStories,
+    fileName = "claw-export.html",
+    mimeType = HTML_MIME_TYPE,
+    context = context,
+    coroutineScope = coroutineScope,
+    exportPosts = exportPosts,
+    snackbarHostState = snackbarHostState,
+  )
+}
+
+@Composable
+private fun GenericExportOption(
+  title: String,
+  description: String,
+  icon: ImageVector,
+  fileName: String,
+  mimeType: String,
   context: Context,
   coroutineScope: CoroutineScope,
   exportPosts: suspend (OutputStream) -> Unit,
   snackbarHostState: SnackbarHostState,
 ) {
   val exportAction =
-    rememberLauncherForActivityResult(CreateDocument(MIME_TYPE)) { uri ->
+    rememberLauncherForActivityResult(CreateDocument(mimeType)) { uri ->
       if (uri == null) {
         coroutineScope.launch { snackbarHostState.showSnackbarDismissing("No file selected") }
         return@rememberLauncherForActivityResult
@@ -97,11 +146,11 @@ private fun ExportOption(
       }
     }
   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.Filled.Upload,
+    title = title,
+    description = description,
+    icon = icon,
   ) {
-    exportAction.launch("claw-export.json")
+    exportAction.launch(fileName)
   }
 }
 

android/src/main/kotlin/dev/msfjarvis/claw/android/ui/screens/LobstersPostsScreen.kt

@@ -322,6 +322,7 @@ fun LobstersPostsScreen(
             context = context,
             importPosts = viewModel::importPosts,
             exportPosts = viewModel::exportPosts,
+            exportPostsAsHtml = viewModel::exportPostsAsHtml,
             snackbarHostState = snackbarHostState,
           )
         }

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

@@ -179,6 +179,9 @@ constructor(
 
   suspend fun exportPosts(output: OutputStream) = dataTransferRepository.exportPosts(output)
 
+  suspend fun exportPostsAsHtml(output: OutputStream) =
+    dataTransferRepository.exportPostsAsHTML(output)
+
   fun markPostAsRead(postId: String) {
     viewModelScope.launch { readPostsRepository.markRead(postId) }
   }

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

@@ -13,6 +13,8 @@ import dev.msfjarvis.claw.database.local.SavedPost
 import dev.msfjarvis.claw.database.local.SavedPostQueries
 import java.io.InputStream
 import java.io.OutputStream
+import java.time.Instant
+import java.time.format.DateTimeFormatter
 import javax.inject.Inject
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.withContext
@@ -50,4 +52,53 @@ constructor(
     val posts = withContext(dbDispatcher) { savedPostQueries.selectAllPosts().executeAsList() }
     withContext(ioDispatcher) { json.encodeToStream(serializer, posts, output) }
   }
+
+  suspend fun exportPostsAsHTML(output: OutputStream) {
+    fun computeTimestamp(post: SavedPost): Long {
+      val temporal = DateTimeFormatter.ISO_OFFSET_DATE_TIME.parse(post.createdAt)
+      val instant = Instant.from(temporal)
+      return instant.toEpochMilli()
+    }
+
+    val posts = withContext(dbDispatcher) { savedPostQueries.selectAllPosts().executeAsList() }
+    val header =
+      """
+      <!DOCTYPE NETSCAPE-Bookmark-file-1>
+      <!-- This is an automatically generated file.
+           It will be read and overwritten.
+           DO NOT EDIT! -->
+      <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=UTF-8">
+      <TITLE>Bookmarks</TITLE>
+      <H1>Bookmarks</H1>
+    """
+        .trimIndent()
+    val html = buildString {
+      append(header)
+      append("<DD><p>\n")
+      for (post in posts) {
+        append(
+          """
+          <DT><A HREF="${post.url.ifEmpty { post.commentsUrl }}" ADD_DATE="${computeTimestamp(post)}" PRIVATE="0" TAGS="${post.tags.joinToString(",")}">${post.title}</A>
+          <DD>${post.title}
+
+        """
+            .trimIndent()
+        )
+      }
+      append(
+        """
+        <DT><A HREF="https://example.com/" ADD_DATE="0" PRIVATE="0" TAGS="delete,me,pls">Padding post</A>
+        <DD>Linkding ignores the last entry so this pads the difference for imports
+
+      """
+          .trimIndent()
+      )
+      append("</DD></p>\n")
+    }
+    withContext(ioDispatcher) {
+      val writer = output.bufferedWriter()
+      writer.write(html)
+      writer.flush()
+    }
+  }
 }