feat: add full-text search with debounce, history, and highlighted results

app/src/main/java/com/swoosh/microblog/data/api/GhostApiService.kt

@@ -15,7 +15,8 @@ interface GhostApiService {
         @Query("page") page: Int = 1,
         @Query("include") include: String = "authors",
         @Query("formats") formats: String = "html,plaintext,mobiledoc",
-        @Query("order") order: String = "created_at desc"
+        @Query("order") order: String = "created_at desc",
+        @Query("filter") filter: String? = null
     ): Response<PostsResponse>
 
     @POST("ghost/api/admin/posts/")

app/src/main/java/com/swoosh/microblog/data/db/LocalPostDao.kt

@@ -31,6 +31,9 @@ interface LocalPostDao {
     @Delete
     suspend fun deletePost(post: LocalPost)
 
+    @Query("SELECT * FROM local_posts WHERE content LIKE '%' || :query || '%' OR title LIKE '%' || :query || '%' ORDER BY createdAt DESC")
+    suspend fun searchPosts(query: String): List<LocalPost>
+
     @Query("DELETE FROM local_posts WHERE localId = :localId")
     suspend fun deleteById(localId: Long)
 

app/src/main/java/com/swoosh/microblog/data/repository/PostRepository.kt

@@ -120,6 +120,76 @@ class PostRepository(private val context: Context) {
         return tempFile
     }
 
+    // --- Search operations ---
+
+    suspend fun searchLocalPosts(query: String): List<LocalPost> =
+        withContext(Dispatchers.IO) {
+            dao.searchPosts(query)
+        }
+
+    suspend fun searchRemotePosts(query: String): Result<List<GhostPost>> =
+        withContext(Dispatchers.IO) {
+            try {
+                // Ghost Admin API supports plaintext filter
+                val response = getApi().getPosts(
+                    limit = 50,
+                    filter = "plaintext:~'$query'"
+                )
+                if (response.isSuccessful) {
+                    Result.success(response.body()!!.posts)
+                } else {
+                    // Fallback: fetch posts and filter client-side
+                    searchRemoteClientSide(query)
+                }
+            } catch (e: Exception) {
+                // Fallback: fetch posts and filter client-side
+                try {
+                    searchRemoteClientSide(query)
+                } catch (e2: Exception) {
+                    Result.failure(e2)
+                }
+            }
+        }
+
+    private suspend fun searchRemoteClientSide(query: String): Result<List<GhostPost>> {
+        val allPosts = mutableListOf<GhostPost>()
+        var page = 1
+        var hasMore = true
+
+        while (hasMore && page <= 5) { // Limit to 5 pages for search
+            val response = getApi().getPosts(limit = 50, page = page)
+            if (response.isSuccessful) {
+                val body = response.body()!!
+                allPosts.addAll(body.posts)
+                hasMore = body.meta?.pagination?.next != null
+                page++
+            } else {
+                return Result.failure(Exception("API error ${response.code()}"))
+            }
+        }
+
+        val queryLower = query.lowercase()
+        val filtered = allPosts.filter { post ->
+            (post.title?.lowercase()?.contains(queryLower) == true) ||
+            (post.plaintext?.lowercase()?.contains(queryLower) == true) ||
+            (post.html?.lowercase()?.contains(queryLower) == true)
+        }
+        return Result.success(filtered)
+    }
+
+    suspend fun searchPosts(query: String): Result<List<Pair<List<LocalPost>, List<GhostPost>>>> =
+        withContext(Dispatchers.IO) {
+            val localResults = searchLocalPosts(query)
+            val remoteResult = try {
+                searchRemotePosts(query)
+            } catch (e: Exception) {
+                Result.failure(e)
+            }
+
+            val remotePosts = remoteResult.getOrDefault(emptyList())
+            Result.success(listOf(localResults to remotePosts))
+        }
+
     // --- Local operations ---
 
     fun getLocalPosts(): Flow<List<LocalPost>> = dao.getAllPosts()

app/src/main/java/com/swoosh/microblog/ui/feed/FeedScreen.kt

@@ -1,5 +1,8 @@
 package com.swoosh.microblog.ui.feed
 
+import androidx.compose.animation.AnimatedVisibility
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.*
 import androidx.compose.foundation.lazy.LazyColumn
@@ -7,10 +10,8 @@ import androidx.compose.foundation.lazy.items
 import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.material.ExperimentalMaterialApi
 import androidx.compose.material.icons.Icons
-import androidx.compose.material.icons.filled.Add
-import androidx.compose.material.icons.filled.Refresh
-import androidx.compose.material.icons.filled.Settings
-import androidx.compose.material.icons.filled.WifiOff
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material.icons.filled.*
 import androidx.compose.material.pullrefresh.PullRefreshIndicator
 import androidx.compose.material.pullrefresh.pullRefresh
 import androidx.compose.material.pullrefresh.rememberPullRefreshState
@@ -19,9 +20,15 @@ import androidx.compose.runtime.*
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
+import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.focus.focusRequester
 import androidx.compose.ui.layout.ContentScale
+import androidx.compose.ui.text.SpanStyle
+import androidx.compose.ui.text.buildAnnotatedString
+import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.text.withStyle
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
@@ -38,6 +45,12 @@ fun FeedScreen(
     viewModel: FeedViewModel = viewModel()
 ) {
     val state by viewModel.uiState.collectAsStateWithLifecycle()
+    val searchQuery by viewModel.searchQuery.collectAsStateWithLifecycle()
+    val searchResults by viewModel.searchResults.collectAsStateWithLifecycle()
+    val isSearchActive by viewModel.isSearchActive.collectAsStateWithLifecycle()
+    val isSearching by viewModel.isSearching.collectAsStateWithLifecycle()
+    val searchResultCount by viewModel.searchResultCount.collectAsStateWithLifecycle()
+    val recentSearches by viewModel.recentSearches.collectAsStateWithLifecycle()
     val listState = rememberLazyListState()
 
     // Pull-to-refresh
@@ -55,28 +68,46 @@ fun FeedScreen(
     }
 
     LaunchedEffect(shouldLoadMore) {
-        if (shouldLoadMore && state.posts.isNotEmpty()) {
+        if (shouldLoadMore && state.posts.isNotEmpty() && !isSearchActive) {
             viewModel.loadMore()
         }
     }
 
+    val displayPosts = if (isSearchActive && searchQuery.isNotBlank()) searchResults else state.posts
+    val focusRequester = remember { FocusRequester() }
+
     Scaffold(
         topBar = {
-            TopAppBar(
-                title = { Text("Swoosh") },
-                actions = {
-                    IconButton(onClick = { viewModel.refresh() }) {
-                        Icon(Icons.Default.Refresh, contentDescription = "Refresh")
+            if (isSearchActive) {
+                SearchTopBar(
+                    query = searchQuery,
+                    onQueryChange = viewModel::onSearchQueryChange,
+                    onClose = viewModel::deactivateSearch,
+                    onClear = viewModel::clearSearchQuery,
+                    focusRequester = focusRequester
+                )
+            } else {
+                TopAppBar(
+                    title = { Text("Swoosh") },
+                    actions = {
+                        IconButton(onClick = { viewModel.activateSearch() }) {
+                            Icon(Icons.Default.Search, contentDescription = "Search")
+                        }
+                        IconButton(onClick = { viewModel.refresh() }) {
+                            Icon(Icons.Default.Refresh, contentDescription = "Refresh")
+                        }
+                        IconButton(onClick = onSettingsClick) {
+                            Icon(Icons.Default.Settings, contentDescription = "Settings")
+                        }
                     }
-                    IconButton(onClick = onSettingsClick) {
-                        Icon(Icons.Default.Settings, contentDescription = "Settings")
-                    }
-                }
-            )
+                )
+            }
         },
         floatingActionButton = {
-            FloatingActionButton(onClick = onCompose) {
-                Icon(Icons.Default.Add, contentDescription = "New post")
+            if (!isSearchActive) {
+                FloatingActionButton(onClick = onCompose) {
+                    Icon(Icons.Default.Add, contentDescription = "New post")
+                }
             }
         }
     ) { padding ->
@@ -84,9 +115,63 @@ fun FeedScreen(
             modifier = Modifier
                 .fillMaxSize()
                 .padding(padding)
-                .pullRefresh(pullRefreshState)
+                .then(if (!isSearchActive) Modifier.pullRefresh(pullRefreshState) else Modifier)
         ) {
-            if (state.posts.isEmpty() && !state.isRefreshing) {
+            // Show recent searches when search is active but query is empty
+            if (isSearchActive && searchQuery.isBlank() && recentSearches.isNotEmpty()) {
+                RecentSearchesList(
+                    recentSearches = recentSearches,
+                    onSearchTap = viewModel::onRecentSearchTap,
+                    onRemove = viewModel::removeRecentSearch
+                )
+            } else if (isSearchActive && searchQuery.isNotBlank() && isSearching) {
+                // Searching indicator
+                Box(
+                    modifier = Modifier.fillMaxSize(),
+                    contentAlignment = Alignment.Center
+                ) {
+                    Column(horizontalAlignment = Alignment.CenterHorizontally) {
+                        CircularProgressIndicator(modifier = Modifier.size(32.dp))
+                        Spacer(modifier = Modifier.height(12.dp))
+                        Text(
+                            text = "Searching...",
+                            style = MaterialTheme.typography.bodyMedium,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant
+                        )
+                    }
+                }
+            } else if (isSearchActive && searchQuery.isNotBlank() && searchResults.isEmpty() && !isSearching) {
+                // No results empty state
+                Box(
+                    modifier = Modifier.fillMaxSize(),
+                    contentAlignment = Alignment.Center
+                ) {
+                    Column(
+                        horizontalAlignment = Alignment.CenterHorizontally,
+                        modifier = Modifier.padding(horizontal = 32.dp)
+                    ) {
+                        Icon(
+                            imageVector = Icons.Default.SearchOff,
+                            contentDescription = null,
+                            modifier = Modifier.size(48.dp),
+                            tint = MaterialTheme.colorScheme.onSurfaceVariant
+                        )
+                        Spacer(modifier = Modifier.height(16.dp))
+                        Text(
+                            text = "No results found",
+                            style = MaterialTheme.typography.titleMedium,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant
+                        )
+                        Spacer(modifier = Modifier.height(8.dp))
+                        Text(
+                            text = "No posts matching \"$searchQuery\"",
+                            style = MaterialTheme.typography.bodyMedium,
+                            color = MaterialTheme.colorScheme.onSurfaceVariant,
+                            textAlign = TextAlign.Center
+                        )
+                    }
+                }
+            } else if (!isSearchActive && displayPosts.isEmpty() && !state.isRefreshing) {
                 if (state.isConnectionError && state.error != null) {
                     // Connection error empty state
                     Column(
@@ -140,43 +225,65 @@ fun FeedScreen(
                         )
                     }
                 }
-            }
+            } else {
+                LazyColumn(
+                    state = listState,
+                    modifier = Modifier.fillMaxSize(),
+                    contentPadding = PaddingValues(vertical = 8.dp)
+                ) {
+                    // Show result count badge when searching
+                    if (isSearchActive && searchQuery.isNotBlank() && !isSearching && searchResults.isNotEmpty()) {
+                        item {
+                            SearchResultsHeader(count = searchResultCount, query = searchQuery)
+                        }
+                    }
 
-            LazyColumn(
-                state = listState,
-                modifier = Modifier.fillMaxSize(),
-                contentPadding = PaddingValues(vertical = 8.dp)
-            ) {
-                items(state.posts, key = { it.ghostId ?: "local_${it.localId}" }) { post ->
-                    PostCard(
-                        post = post,
-                        onClick = { onPostClick(post) },
-                        onCancelQueue = { viewModel.cancelQueuedPost(post) }
-                    )
-                }
+                    items(displayPosts, key = { it.ghostId ?: "local_${it.localId}" }) { post ->
+                        if (isSearchActive && searchQuery.isNotBlank()) {
+                            PostCard(
+                                post = post,
+                                onClick = { onPostClick(post) },
+                                onCancelQueue = { viewModel.cancelQueuedPost(post) },
+                                highlightQuery = searchQuery
+                            )
+                        } else {
+                            PostCard(
+                                post = post,
+                                onClick = { onPostClick(post) },
+                                onCancelQueue = { viewModel.cancelQueuedPost(post) }
+                            )
+                        }
+                    }
 
-                if (state.isLoadingMore) {
-                    item {
-                        Box(
-                            modifier = Modifier.fillMaxWidth().padding(16.dp),
-                            contentAlignment = Alignment.Center
-                        ) {
-                            CircularProgressIndicator(modifier = Modifier.size(24.dp))
+                    if (!isSearchActive && state.isLoadingMore) {
+                        item {
+                            Box(
+                                modifier = Modifier
+                                    .fillMaxWidth()
+                                    .padding(16.dp),
+                                contentAlignment = Alignment.Center
+                            ) {
+                                CircularProgressIndicator(modifier = Modifier.size(24.dp))
+                            }
                         }
                     }
                 }
             }
 
-            PullRefreshIndicator(
-                refreshing = state.isRefreshing,
-                state = pullRefreshState,
-                modifier = Modifier.align(Alignment.TopCenter)
-            )
+            if (!isSearchActive) {
+                PullRefreshIndicator(
+                    refreshing = state.isRefreshing,
+                    state = pullRefreshState,
+                    modifier = Modifier.align(Alignment.TopCenter)
+                )
+            }
 
             // Show non-connection errors as snackbar (when posts are visible)
-            if (state.error != null && (!state.isConnectionError || state.posts.isNotEmpty())) {
+            if (!isSearchActive && state.error != null && (!state.isConnectionError || state.posts.isNotEmpty())) {
                 Snackbar(
-                    modifier = Modifier.align(Alignment.BottomCenter).padding(16.dp),
+                    modifier = Modifier
+                        .align(Alignment.BottomCenter)
+                        .padding(16.dp),
                     action = {
                         TextButton(onClick = { viewModel.refresh() }) { Text("Retry") }
                     },
@@ -191,11 +298,128 @@ fun FeedScreen(
     }
 }
 
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun SearchTopBar(
+    query: String,
+    onQueryChange: (String) -> Unit,
+    onClose: () -> Unit,
+    onClear: () -> Unit,
+    focusRequester: FocusRequester
+) {
+    TopAppBar(
+        title = {
+            TextField(
+                value = query,
+                onValueChange = onQueryChange,
+                placeholder = { Text("Search posts...") },
+                singleLine = true,
+                colors = TextFieldDefaults.colors(
+                    focusedContainerColor = MaterialTheme.colorScheme.surface,
+                    unfocusedContainerColor = MaterialTheme.colorScheme.surface,
+                    focusedIndicatorColor = MaterialTheme.colorScheme.primary,
+                    unfocusedIndicatorColor = MaterialTheme.colorScheme.surfaceVariant
+                ),
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .focusRequester(focusRequester),
+                trailingIcon = {
+                    if (query.isNotEmpty()) {
+                        IconButton(onClick = onClear) {
+                            Icon(Icons.Default.Close, contentDescription = "Clear search")
+                        }
+                    }
+                }
+            )
+        },
+        navigationIcon = {
+            IconButton(onClick = onClose) {
+                Icon(Icons.AutoMirrored.Filled.ArrowBack, contentDescription = "Close search")
+            }
+        }
+    )
+
+    LaunchedEffect(Unit) {
+        focusRequester.requestFocus()
+    }
+}
+
+@Composable
+fun SearchResultsHeader(count: Int, query: String) {
+    Row(
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(horizontal = 16.dp, vertical = 8.dp),
+        verticalAlignment = Alignment.CenterVertically
+    ) {
+        Surface(
+            shape = MaterialTheme.shapes.small,
+            color = MaterialTheme.colorScheme.primaryContainer
+        ) {
+            Text(
+                text = "$count",
+                style = MaterialTheme.typography.labelMedium,
+                color = MaterialTheme.colorScheme.onPrimaryContainer,
+                modifier = Modifier.padding(horizontal = 8.dp, vertical = 4.dp)
+            )
+        }
+        Spacer(modifier = Modifier.width(8.dp))
+        Text(
+            text = if (count == 1) "result for \"$query\"" else "results for \"$query\"",
+            style = MaterialTheme.typography.bodySmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant
+        )
+    }
+}
+
+@Composable
+fun RecentSearchesList(
+    recentSearches: List<String>,
+    onSearchTap: (String) -> Unit,
+    onRemove: (String) -> Unit
+) {
+    Column(
+        modifier = Modifier
+            .fillMaxWidth()
+            .padding(top = 8.dp)
+    ) {
+        Text(
+            text = "Recent searches",
+            style = MaterialTheme.typography.titleSmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            modifier = Modifier.padding(horizontal = 16.dp, vertical = 8.dp)
+        )
+        recentSearches.forEach { query ->
+            ListItem(
+                headlineContent = { Text(query) },
+                leadingContent = {
+                    Icon(
+                        Icons.Default.History,
+                        contentDescription = null,
+                        tint = MaterialTheme.colorScheme.onSurfaceVariant
+                    )
+                },
+                trailingContent = {
+                    IconButton(onClick = { onRemove(query) }) {
+                        Icon(
+                            Icons.Default.Close,
+                            contentDescription = "Remove",
+                            modifier = Modifier.size(18.dp)
+                        )
+                    }
+                },
+                modifier = Modifier.clickable { onSearchTap(query) }
+            )
+        }
+    }
+}
+
 @Composable
 fun PostCard(
     post: FeedPost,
     onClick: () -> Unit,
-    onCancelQueue: () -> Unit
+    onCancelQueue: () -> Unit,
+    highlightQuery: String? = null
 ) {
     var expanded by remember { mutableStateOf(false) }
     val displayText = if (expanded || post.textContent.length <= 280) {
@@ -231,13 +455,21 @@ fun PostCard(
 
             Spacer(modifier = Modifier.height(8.dp))
 
-            // Content
-            Text(
-                text = displayText,
-                style = MaterialTheme.typography.bodyMedium,
-                maxLines = if (expanded) Int.MAX_VALUE else 8,
-                overflow = TextOverflow.Ellipsis
-            )
+            // Content with optional highlighting
+            if (highlightQuery != null && highlightQuery.isNotBlank()) {
+                HighlightedText(
+                    text = displayText,
+                    query = highlightQuery,
+                    maxLines = if (expanded) Int.MAX_VALUE else 8
+                )
+            } else {
+                Text(
+                    text = displayText,
+                    style = MaterialTheme.typography.bodyMedium,
+                    maxLines = if (expanded) Int.MAX_VALUE else 8,
+                    overflow = TextOverflow.Ellipsis
+                )
+            }
 
             if (!expanded && post.textContent.length > 280) {
                 TextButton(
@@ -324,6 +556,63 @@ fun PostCard(
     }
 }
 
+/**
+ * Displays text with matching substrings highlighted in bold.
+ * Case-insensitive matching.
+ */
+@Composable
+fun HighlightedText(
+    text: String,
+    query: String,
+    maxLines: Int = Int.MAX_VALUE
+) {
+    val annotatedString = buildHighlightedString(text, query)
+    Text(
+        text = annotatedString,
+        style = MaterialTheme.typography.bodyMedium,
+        maxLines = maxLines,
+        overflow = TextOverflow.Ellipsis
+    )
+}
+
+/**
+ * Builds an AnnotatedString with all case-insensitive occurrences of [query] in [text]
+ * highlighted with bold + primary color styling.
+ */
+fun buildHighlightedString(
+    text: String,
+    query: String
+) = buildAnnotatedString {
+    if (query.isBlank()) {
+        append(text)
+        return@buildAnnotatedString
+    }
+
+    val textLower = text.lowercase()
+    val queryLower = query.lowercase()
+    var currentIndex = 0
+
+    while (currentIndex < text.length) {
+        val matchIndex = textLower.indexOf(queryLower, currentIndex)
+        if (matchIndex == -1) {
+            append(text.substring(currentIndex))
+            break
+        }
+
+        // Add text before match
+        if (matchIndex > currentIndex) {
+            append(text.substring(currentIndex, matchIndex))
+        }
+
+        // Add highlighted match
+        withStyle(SpanStyle(fontWeight = FontWeight.Bold)) {
+            append(text.substring(matchIndex, matchIndex + query.length))
+        }
+
+        currentIndex = matchIndex + query.length
+    }
+}
+
 @Composable
 fun StatusBadge(post: FeedPost) {
     val (label, color) = when {

app/src/main/java/com/swoosh/microblog/ui/feed/FeedViewModel.kt

@@ -1,10 +1,14 @@
 package com.swoosh.microblog.ui.feed
 
 import android.app.Application
+import android.content.Context
+import android.content.SharedPreferences
 import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.viewModelScope
 import com.swoosh.microblog.data.model.*
 import com.swoosh.microblog.data.repository.PostRepository
+import kotlinx.coroutines.FlowPreview
+import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.*
 import kotlinx.coroutines.launch
 import java.net.ConnectException
@@ -19,17 +23,57 @@ import javax.net.ssl.SSLException
 class FeedViewModel(application: Application) : AndroidViewModel(application) {
 
     private val repository = PostRepository(application)
+    private val searchHistoryManager = SearchHistoryManager(application)
 
     private val _uiState = MutableStateFlow(FeedUiState())
     val uiState: StateFlow<FeedUiState> = _uiState.asStateFlow()
 
+    private val _searchQuery = MutableStateFlow("")
+    val searchQuery: StateFlow<String> = _searchQuery.asStateFlow()
+
+    private val _searchResults = MutableStateFlow<List<FeedPost>>(emptyList())
+    val searchResults: StateFlow<List<FeedPost>> = _searchResults.asStateFlow()
+
+    private val _isSearchActive = MutableStateFlow(false)
+    val isSearchActive: StateFlow<Boolean> = _isSearchActive.asStateFlow()
+
+    private val _isSearching = MutableStateFlow(false)
+    val isSearching: StateFlow<Boolean> = _isSearching.asStateFlow()
+
+    private val _searchResultCount = MutableStateFlow(0)
+    val searchResultCount: StateFlow<Int> = _searchResultCount.asStateFlow()
+
+    private val _recentSearches = MutableStateFlow<List<String>>(emptyList())
+    val recentSearches: StateFlow<List<String>> = _recentSearches.asStateFlow()
+
     private var currentPage = 1
     private var hasMorePages = true
     private var remotePosts = listOf<FeedPost>()
+    private var searchJob: Job? = null
 
     init {
         observeLocalPosts()
+        observeSearchQuery()
         refresh()
+        _recentSearches.value = searchHistoryManager.getRecentSearches()
+    }
+
+    @OptIn(FlowPreview::class)
+    private fun observeSearchQuery() {
+        viewModelScope.launch {
+            _searchQuery
+                .debounce(300)
+                .distinctUntilChanged()
+                .collect { query ->
+                    if (query.isBlank()) {
+                        _searchResults.value = emptyList()
+                        _searchResultCount.value = 0
+                        _isSearching.value = false
+                    } else {
+                        performSearch(query)
+                    }
+                }
+        }
     }
 
     private fun observeLocalPosts() {
@@ -43,6 +87,76 @@ class FeedViewModel(application: Application) : AndroidViewModel(application) {
         }
     }
 
+    fun onSearchQueryChange(query: String) {
+        _searchQuery.value = query
+    }
+
+    fun activateSearch() {
+        _isSearchActive.value = true
+        _recentSearches.value = searchHistoryManager.getRecentSearches()
+    }
+
+    fun deactivateSearch() {
+        _isSearchActive.value = false
+        _searchQuery.value = ""
+        _searchResults.value = emptyList()
+        _searchResultCount.value = 0
+        _isSearching.value = false
+    }
+
+    fun clearSearchQuery() {
+        _searchQuery.value = ""
+        _searchResults.value = emptyList()
+        _searchResultCount.value = 0
+        _isSearching.value = false
+    }
+
+    fun onRecentSearchTap(query: String) {
+        _searchQuery.value = query
+    }
+
+    fun removeRecentSearch(query: String) {
+        searchHistoryManager.removeSearch(query)
+        _recentSearches.value = searchHistoryManager.getRecentSearches()
+    }
+
+    private fun performSearch(query: String) {
+        searchJob?.cancel()
+        searchJob = viewModelScope.launch {
+            _isSearching.value = true
+
+            try {
+                // Search local posts
+                val localResults = repository.searchLocalPosts(query)
+                    .map { it.toFeedPost() }
+
+                // Search remote posts
+                val remoteResults = try {
+                    repository.searchRemotePosts(query)
+                        .getOrDefault(emptyList())
+                        .map { it.toFeedPost() }
+                } catch (e: Exception) {
+                    emptyList()
+                }
+
+                // Deduplicate: prefer remote version when ghostId matches
+                val deduplicatedResults = deduplicateResults(localResults, remoteResults)
+
+                _searchResults.value = deduplicatedResults
+                _searchResultCount.value = deduplicatedResults.size
+                _isSearching.value = false
+
+                // Save to recent searches
+                searchHistoryManager.addSearch(query)
+                _recentSearches.value = searchHistoryManager.getRecentSearches()
+            } catch (e: Exception) {
+                _isSearching.value = false
+                _searchResults.value = emptyList()
+                _searchResultCount.value = 0
+            }
+        }
+    }
+
     fun refresh() {
         viewModelScope.launch {
             _uiState.update { it.copy(isRefreshing = true, error = null, isConnectionError = false) }
@@ -173,6 +287,29 @@ class FeedViewModel(application: Application) : AndroidViewModel(application) {
         isLocal = true,
         queueStatus = queueStatus
     )
+
+    companion object {
+        /**
+         * Deduplicates local and remote search results.
+         * When a local post has a ghostId matching a remote post, the remote version is preferred.
+         * Local-only posts (no ghostId) are always included.
+         */
+        fun deduplicateResults(
+            localResults: List<FeedPost>,
+            remoteResults: List<FeedPost>
+        ): List<FeedPost> {
+            val remoteGhostIds = remoteResults.mapNotNull { it.ghostId }.toSet()
+
+            // Include local posts that don't have a matching remote post
+            val uniqueLocalPosts = localResults.filter { localPost ->
+                localPost.ghostId == null || localPost.ghostId !in remoteGhostIds
+            }
+
+            return (uniqueLocalPosts + remoteResults).sortedByDescending { post ->
+                post.publishedAt ?: post.createdAt ?: ""
+            }
+        }
+    }
 }
 
 data class FeedUiState(
@@ -183,6 +320,52 @@ data class FeedUiState(
     val isConnectionError: Boolean = false
 )
 
+/**
+ * Manages recent search history stored in SharedPreferences.
+ * Stores up to 5 most recent search queries.
+ */
+class SearchHistoryManager(context: Context) {
+
+    private val prefs: SharedPreferences = context.getSharedPreferences(
+        PREFS_NAME, Context.MODE_PRIVATE
+    )
+
+    fun getRecentSearches(): List<String> {
+        val raw = prefs.getString(KEY_RECENT_SEARCHES, null) ?: return emptyList()
+        return raw.split(SEPARATOR).filter { it.isNotBlank() }
+    }
+
+    fun addSearch(query: String) {
+        val trimmed = query.trim()
+        if (trimmed.isBlank()) return
+
+        val current = getRecentSearches().toMutableList()
+        current.remove(trimmed) // Remove if already exists
+        current.add(0, trimmed) // Add to front
+
+        // Keep only last MAX_HISTORY items
+        val limited = current.take(MAX_HISTORY)
+        prefs.edit().putString(KEY_RECENT_SEARCHES, limited.joinToString(SEPARATOR)).apply()
+    }
+
+    fun removeSearch(query: String) {
+        val current = getRecentSearches().toMutableList()
+        current.remove(query.trim())
+        prefs.edit().putString(KEY_RECENT_SEARCHES, current.joinToString(SEPARATOR)).apply()
+    }
+
+    fun clearAll() {
+        prefs.edit().remove(KEY_RECENT_SEARCHES).apply()
+    }
+
+    companion object {
+        const val PREFS_NAME = "swoosh_search_history"
+        const val KEY_RECENT_SEARCHES = "recent_searches"
+        const val SEPARATOR = "\u001F" // Unit separator character
+        const val MAX_HISTORY = 5
+    }
+}
+
 fun formatRelativeTime(isoString: String?): String {
     if (isoString == null) return ""
     return try {

app/src/test/java/com/swoosh/microblog/ui/feed/SearchTest.kt

@@ -0,0 +1,415 @@
+package com.swoosh.microblog.ui.feed
+
+import com.swoosh.microblog.data.model.FeedPost
+import com.swoosh.microblog.data.model.QueueStatus
+import org.junit.Assert.*
+import org.junit.Test
+
+/**
+ * Pure unit tests for search deduplication logic and text highlighting.
+ * No Android framework dependencies needed.
+ */
+class SearchDeduplicationTest {
+
+    @Test
+    fun `deduplicateResults returns all posts when no overlap`() {
+        val local = listOf(
+            createFeedPost(localId = 1, ghostId = null, title = "Local Draft")
+        )
+        val remote = listOf(
+            createFeedPost(ghostId = "ghost-1", title = "Remote Post")
+        )
+
+        val result = FeedViewModel.deduplicateResults(local, remote)
+
+        assertEquals(2, result.size)
+    }
+
+    @Test
+    fun `deduplicateResults prefers remote when ghostId matches`() {
+        val local = listOf(
+            createFeedPost(localId = 1, ghostId = "ghost-1", title = "Local Version", textContent = "old content")
+        )
+        val remote = listOf(
+            createFeedPost(ghostId = "ghost-1", title = "Remote Version", textContent = "new content")
+        )
+
+        val result = FeedViewModel.deduplicateResults(local, remote)
+
+        assertEquals(1, result.size)
+        assertEquals("Remote Version", result[0].title)
+        assertEquals("new content", result[0].textContent)
+    }
+
+    @Test
+    fun `deduplicateResults keeps local posts without ghostId`() {
+        val local = listOf(
+            createFeedPost(localId = 1, ghostId = null, title = "Draft 1"),
+            createFeedPost(localId = 2, ghostId = null, title = "Draft 2")
+        )
+        val remote = listOf(
+            createFeedPost(ghostId = "ghost-1", title = "Published Post")
+        )
+
+        val result = FeedViewModel.deduplicateResults(local, remote)
+
+        assertEquals(3, result.size)
+    }
+
+    @Test
+    fun `deduplicateResults with empty local returns only remote`() {
+        val local = emptyList<FeedPost>()
+        val remote = listOf(
+            createFeedPost(ghostId = "ghost-1", title = "Remote 1"),
+            createFeedPost(ghostId = "ghost-2", title = "Remote 2")
+        )
+
+        val result = FeedViewModel.deduplicateResults(local, remote)
+
+        assertEquals(2, result.size)
+    }
+
+    @Test
+    fun `deduplicateResults with empty remote returns only local`() {
+        val local = listOf(
+            createFeedPost(localId = 1, ghostId = null, title = "Draft 1")
+        )
+        val remote = emptyList<FeedPost>()
+
+        val result = FeedViewModel.deduplicateResults(local, remote)
+
+        assertEquals(1, result.size)
+        assertEquals("Draft 1", result[0].title)
+    }
+
+    @Test
+    fun `deduplicateResults with both empty returns empty list`() {
+        val result = FeedViewModel.deduplicateResults(emptyList(), emptyList())
+        assertTrue(result.isEmpty())
+    }
+
+    @Test
+    fun `deduplicateResults removes multiple local duplicates of same ghostId`() {
+        val local = listOf(
+            createFeedPost(localId = 1, ghostId = "ghost-1", title = "Local V1"),
+            createFeedPost(localId = 2, ghostId = "ghost-1", title = "Local V2")
+        )
+        val remote = listOf(
+            createFeedPost(ghostId = "ghost-1", title = "Remote Version")
+        )
+
+        val result = FeedViewModel.deduplicateResults(local, remote)
+
+        assertEquals(1, result.size)
+        assertEquals("Remote Version", result[0].title)
+    }
+
+    @Test
+    fun `deduplicateResults handles mixed local with and without ghostIds`() {
+        val local = listOf(
+            createFeedPost(localId = 1, ghostId = null, title = "Draft"),
+            createFeedPost(localId = 2, ghostId = "ghost-1", title = "Local Synced")
+        )
+        val remote = listOf(
+            createFeedPost(ghostId = "ghost-1", title = "Remote Synced"),
+            createFeedPost(ghostId = "ghost-2", title = "Remote Only")
+        )
+
+        val result = FeedViewModel.deduplicateResults(local, remote)
+
+        assertEquals(3, result.size)
+        val titles = result.map { it.title }
+        assertTrue(titles.contains("Draft"))
+        assertTrue(titles.contains("Remote Synced"))
+        assertTrue(titles.contains("Remote Only"))
+        assertFalse(titles.contains("Local Synced"))
+    }
+
+    private fun createFeedPost(
+        localId: Long? = null,
+        ghostId: String? = null,
+        title: String = "",
+        textContent: String = "",
+        status: String = "draft",
+        publishedAt: String? = null,
+        createdAt: String? = null
+    ) = FeedPost(
+        localId = localId,
+        ghostId = ghostId,
+        title = title,
+        textContent = textContent,
+        htmlContent = null,
+        imageUrl = null,
+        linkUrl = null,
+        linkTitle = null,
+        linkDescription = null,
+        linkImageUrl = null,
+        status = status,
+        publishedAt = publishedAt,
+        createdAt = createdAt,
+        updatedAt = null,
+        isLocal = localId != null,
+        queueStatus = QueueStatus.NONE
+    )
+}
+
+/**
+ * Tests for text highlighting logic used in search results.
+ * Pure unit tests, no Android dependencies.
+ */
+class SearchHighlightTest {
+
+    @Test
+    fun `buildHighlightedString with no match returns plain text`() {
+        val result = buildHighlightedString("Hello World", "xyz")
+
+        assertEquals("Hello World", result.text)
+        assertEquals(0, result.spanStyles.size)
+    }
+
+    @Test
+    fun `buildHighlightedString highlights single match`() {
+        val result = buildHighlightedString("Hello World", "World")
+
+        assertEquals("Hello World", result.text)
+        assertEquals(1, result.spanStyles.size)
+        assertEquals(6, result.spanStyles[0].start)
+        assertEquals(11, result.spanStyles[0].end)
+    }
+
+    @Test
+    fun `buildHighlightedString highlights multiple matches`() {
+        val result = buildHighlightedString("cat and cat and cat", "cat")
+
+        assertEquals("cat and cat and cat", result.text)
+        assertEquals(3, result.spanStyles.size)
+    }
+
+    @Test
+    fun `buildHighlightedString is case insensitive`() {
+        val result = buildHighlightedString("Hello HELLO hello", "hello")
+
+        assertEquals("Hello HELLO hello", result.text)
+        assertEquals(3, result.spanStyles.size)
+    }
+
+    @Test
+    fun `buildHighlightedString with empty query returns plain text`() {
+        val result = buildHighlightedString("Hello World", "")
+
+        assertEquals("Hello World", result.text)
+        assertEquals(0, result.spanStyles.size)
+    }
+
+    @Test
+    fun `buildHighlightedString with blank query returns plain text`() {
+        val result = buildHighlightedString("Hello World", "   ")
+
+        assertEquals("Hello World", result.text)
+        assertEquals(0, result.spanStyles.size)
+    }
+
+    @Test
+    fun `buildHighlightedString with query at start of text`() {
+        val result = buildHighlightedString("Hello World", "Hello")
+
+        assertEquals("Hello World", result.text)
+        assertEquals(1, result.spanStyles.size)
+        assertEquals(0, result.spanStyles[0].start)
+        assertEquals(5, result.spanStyles[0].end)
+    }
+
+    @Test
+    fun `buildHighlightedString with query at end of text`() {
+        val result = buildHighlightedString("Hello World", "World")
+
+        assertEquals("Hello World", result.text)
+        assertEquals(1, result.spanStyles.size)
+        assertEquals(6, result.spanStyles[0].start)
+        assertEquals(11, result.spanStyles[0].end)
+    }
+
+    @Test
+    fun `buildHighlightedString with entire text matching`() {
+        val result = buildHighlightedString("hello", "hello")
+
+        assertEquals("hello", result.text)
+        assertEquals(1, result.spanStyles.size)
+        assertEquals(0, result.spanStyles[0].start)
+        assertEquals(5, result.spanStyles[0].end)
+    }
+
+    @Test
+    fun `buildHighlightedString preserves original case`() {
+        val result = buildHighlightedString("Hello WORLD", "hello")
+
+        assertEquals("Hello WORLD", result.text)
+    }
+
+    @Test
+    fun `buildHighlightedString with overlapping potential matches`() {
+        val result = buildHighlightedString("aaa", "aa")
+
+        assertEquals("aaa", result.text)
+        // Should find first match at 0-2, then next search starts at 2
+        assertEquals(1, result.spanStyles.size)
+        assertEquals(0, result.spanStyles[0].start)
+        assertEquals(2, result.spanStyles[0].end)
+    }
+
+    @Test
+    fun `buildHighlightedString with single character query`() {
+        val result = buildHighlightedString("banana", "a")
+
+        assertEquals("banana", result.text)
+        assertEquals(3, result.spanStyles.size)
+    }
+}
+
+/**
+ * Tests for SearchHistoryManager.
+ * Uses Robolectric for SharedPreferences access.
+ */
+@org.junit.runner.RunWith(org.robolectric.RobolectricTestRunner::class)
+@org.robolectric.annotation.Config(
+    sdk = [28],
+    manifest = org.robolectric.annotation.Config.NONE,
+    application = android.app.Application::class
+)
+class SearchHistoryManagerTest {
+
+    private lateinit var searchHistoryManager: SearchHistoryManager
+
+    @org.junit.Before
+    fun setup() {
+        val context = org.robolectric.RuntimeEnvironment.getApplication()
+        context.getSharedPreferences(SearchHistoryManager.PREFS_NAME, android.content.Context.MODE_PRIVATE)
+            .edit().clear().apply()
+        searchHistoryManager = SearchHistoryManager(context)
+    }
+
+    @Test
+    fun `getRecentSearches returns empty list initially`() {
+        val result = searchHistoryManager.getRecentSearches()
+        assertTrue(result.isEmpty())
+    }
+
+    @Test
+    fun `addSearch adds query to history`() {
+        searchHistoryManager.addSearch("test query")
+
+        val result = searchHistoryManager.getRecentSearches()
+        assertEquals(1, result.size)
+        assertEquals("test query", result[0])
+    }
+
+    @Test
+    fun `addSearch adds newest first`() {
+        searchHistoryManager.addSearch("first")
+        searchHistoryManager.addSearch("second")
+
+        val result = searchHistoryManager.getRecentSearches()
+        assertEquals("second", result[0])
+        assertEquals("first", result[1])
+    }
+
+    @Test
+    fun `addSearch limits to MAX_HISTORY items`() {
+        repeat(7) { i ->
+            searchHistoryManager.addSearch("query $i")
+        }
+
+        val result = searchHistoryManager.getRecentSearches()
+        assertEquals(SearchHistoryManager.MAX_HISTORY, result.size)
+    }
+
+    @Test
+    fun `addSearch deduplicates same query`() {
+        searchHistoryManager.addSearch("test")
+        searchHistoryManager.addSearch("other")
+        searchHistoryManager.addSearch("test") // Duplicate
+
+        val result = searchHistoryManager.getRecentSearches()
+        assertEquals(2, result.size)
+        assertEquals("test", result[0]) // Most recent
+        assertEquals("other", result[1])
+    }
+
+    @Test
+    fun `addSearch trims whitespace`() {
+        searchHistoryManager.addSearch("  test  ")
+
+        val result = searchHistoryManager.getRecentSearches()
+        assertEquals(1, result.size)
+        assertEquals("test", result[0])
+    }
+
+    @Test
+    fun `addSearch ignores blank queries`() {
+        searchHistoryManager.addSearch("")
+        searchHistoryManager.addSearch("   ")
+
+        val result = searchHistoryManager.getRecentSearches()
+        assertTrue(result.isEmpty())
+    }
+
+    @Test
+    fun `removeSearch removes specific query`() {
+        searchHistoryManager.addSearch("first")
+        searchHistoryManager.addSearch("second")
+        searchHistoryManager.addSearch("third")
+
+        searchHistoryManager.removeSearch("second")
+
+        val result = searchHistoryManager.getRecentSearches()
+        assertEquals(2, result.size)
+        assertFalse(result.contains("second"))
+    }
+
+    @Test
+    fun `removeSearch does nothing for nonexistent query`() {
+        searchHistoryManager.addSearch("first")
+
+        searchHistoryManager.removeSearch("nonexistent")
+
+        val result = searchHistoryManager.getRecentSearches()
+        assertEquals(1, result.size)
+    }
+
+    @Test
+    fun `clearAll removes all searches`() {
+        searchHistoryManager.addSearch("first")
+        searchHistoryManager.addSearch("second")
+
+        searchHistoryManager.clearAll()
+
+        val result = searchHistoryManager.getRecentSearches()
+        assertTrue(result.isEmpty())
+    }
+
+    @Test
+    fun `search history persists across instances`() {
+        searchHistoryManager.addSearch("persistent query")
+
+        val context = org.robolectric.RuntimeEnvironment.getApplication()
+        val newManager = SearchHistoryManager(context)
+        val result = newManager.getRecentSearches()
+
+        assertEquals(1, result.size)
+        assertEquals("persistent query", result[0])
+    }
+
+    @Test
+    fun `addSearch moves existing query to front`() {
+        searchHistoryManager.addSearch("first")
+        searchHistoryManager.addSearch("second")
+        searchHistoryManager.addSearch("third")
+        searchHistoryManager.addSearch("first") // Re-add
+
+        val result = searchHistoryManager.getRecentSearches()
+        assertEquals(3, result.size)
+        assertEquals("first", result[0])
+        assertEquals("third", result[1])
+        assertEquals("second", result[2])
+    }
+}