android: integrate database

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

@@ -15,6 +15,7 @@ import androidx.compose.runtime.SideEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Offset
@@ -35,6 +36,7 @@ import com.google.accompanist.systemuicontroller.rememberSystemUiController
 import dev.msfjarvis.claw.android.viewmodel.ClawViewModel
 import dev.msfjarvis.claw.common.theme.LobstersTheme
 import dev.msfjarvis.claw.common.urllauncher.UrlLauncher
+import kotlinx.coroutines.launch
 
 private const val ScrollDelta = 50
 
@@ -47,6 +49,7 @@ fun LobstersApp(
   val systemUiController = rememberSystemUiController()
   val scaffoldState = rememberScaffoldState()
   val listState = rememberLazyListState()
+  val coroutineScope = rememberCoroutineScope()
   var isFabVisible by remember { mutableStateOf(true) }
   val nestedScrollConnection = remember {
     object : NestedScrollConnection {
@@ -97,6 +100,8 @@ fun LobstersApp(
               items = items,
               launchUrl = urlLauncher::launch,
               listState = listState,
+              isSaved = viewModel::isPostSaved,
+              toggleSave = { coroutineScope.launch { viewModel.toggleSave(it) } },
               modifier = Modifier.padding(top = 16.dp).nestedScroll(nestedScrollConnection),
             )
           }

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

@@ -4,6 +4,11 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.LazyListState
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
 import androidx.paging.compose.LazyPagingItems
@@ -11,26 +16,34 @@ import androidx.paging.compose.items
 import dev.msfjarvis.claw.android.ext.toDbModel
 import dev.msfjarvis.claw.api.model.LobstersPost
 import dev.msfjarvis.claw.common.posts.LobstersCard
+import dev.msfjarvis.claw.database.local.SavedPost
+import kotlinx.coroutines.launch
 
 @Composable
 fun NetworkPosts(
   items: LazyPagingItems<LobstersPost>,
   listState: LazyListState,
   launchUrl: (String) -> Unit,
+  isSaved: suspend (SavedPost) -> Boolean,
+  toggleSave: (SavedPost) -> Unit,
   modifier: Modifier = Modifier,
 ) {
+  val coroutineScope = rememberCoroutineScope()
   LazyColumn(
     state = listState,
     modifier = Modifier.then(modifier),
   ) {
     items(items) { item ->
       if (item != null) {
+        val dbModel = item.toDbModel()
+        var saved by remember(dbModel) { mutableStateOf(false) }
+        coroutineScope.launch { saved = isSaved(dbModel) }
         LobstersCard(
-          post = item.toDbModel(),
-          isSaved = false,
+          post = dbModel,
+          isSaved = saved,
           viewPost = { launchUrl(item.url.ifEmpty { item.commentsUrl }) },
           viewComments = { launchUrl(item.commentsUrl) },
-          toggleSave = {},
+          toggleSave = { toggleSave(dbModel) },
           modifier = Modifier.padding(bottom = 16.dp, start = 16.dp, end = 16.dp),
         )
       }

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

@@ -6,15 +6,24 @@ import androidx.paging.PagingConfig
 import dagger.hilt.android.lifecycle.HiltViewModel
 import dev.msfjarvis.claw.android.paging.LobstersPagingSource
 import dev.msfjarvis.claw.api.LobstersApi
+import dev.msfjarvis.claw.database.local.SavedPost
 import javax.inject.Inject
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.last
+import kotlinx.coroutines.flow.mapLatest
 
+@OptIn(ExperimentalCoroutinesApi::class)
 @HiltViewModel
 class ClawViewModel
 @Inject
 constructor(
   api: LobstersApi,
+  private val repository: SavedPostsRepository,
 ) : ViewModel() {
   var lastPagingSource: LobstersPagingSource? = null
+  private val savedPosts = flow { repository.savedPosts.collect { emit(it) } }
   private val pager =
     Pager(PagingConfig(20)) {
       LobstersPagingSource(api::getHottestPosts).also { lastPagingSource = it }
@@ -23,6 +32,20 @@ constructor(
   val pagerFlow
     get() = pager.flow
 
+  suspend fun isPostSaved(post: SavedPost): Boolean {
+    return savedPosts.mapLatest { posts -> post in posts }.last()
+  }
+
+  suspend fun toggleSave(post: SavedPost) {
+    val saved = isPostSaved(post)
+    println("saved=$saved")
+    if (saved) {
+      repository.removePost(post)
+    } else {
+      repository.savePost(post)
+    }
+  }
+
   fun reloadPosts() {
     lastPagingSource?.invalidate()
   }

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

@@ -0,0 +1,28 @@
+package dev.msfjarvis.claw.android.viewmodel
+
+import com.squareup.sqldelight.runtime.coroutines.asFlow
+import com.squareup.sqldelight.runtime.coroutines.mapToList
+import dev.msfjarvis.claw.database.LobstersDatabase
+import dev.msfjarvis.claw.database.local.SavedPost
+import javax.inject.Inject
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+
+class SavedPostsRepository
+@Inject
+constructor(
+  database: LobstersDatabase,
+) {
+  private val savedPostQueries = database.savedPostQueries
+  val savedPosts = savedPostQueries.selectAllPosts().asFlow().mapToList()
+
+  suspend fun savePost(post: SavedPost) {
+    println("Saving post: ${post.shortId}")
+    withContext(Dispatchers.IO) { savedPostQueries.insertOrReplacePost(post) }
+  }
+
+  suspend fun removePost(post: SavedPost) {
+    println("Removing post: ${post.shortId}")
+    withContext(Dispatchers.IO) { savedPostQueries.deletePost(post.shortId) }
+  }
+}