feat(lifelog/chat): lifelog 模式 RAG 问答 + 会话状态持久化 + 键盘修复

- LifelogRetriever：「lifelog 模式」开关下，发送前本地检索纪要 + 转写拼成 system context 注入（本地 2B/4B 和 Hermes 通用，不落库）。中文用 bigram + 重叠打分召回（FTS4 unicode61 对中文短语不命中），命中多者优先、抑制单 bigram 噪声 - Daos：加 timelineList / searchTextLike / summaries.recentList 三个 suspend 检索方法 - ChatViewModel：会话状态搬进 VM（随 Activity 存活）。修复切 tab 回来：流式请求被取消(viewModelScope 不取消) / 变成新会话 / lifelog 开关重置—— currentConvId / selectedTargetId / lifelogMode 均持久化到 prefs，重启也记住 - 键盘 inset：Activity setDecorFitsSystemWindows(false) + manifest adjustResize + Scaffold imePadding，键盘弹出时整个界面（含底部 tab）抬到键盘上方、可见 Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

feat(lifelog/chat): lifelog 模式 RAG 问答 + 会话状态持久化 + 键盘修复
- LifelogRetriever：「lifelog 模式」开关下，发送前本地检索纪要 + 转写拼成 system context 注入（本地 2B/4B 和 Hermes 通用，不落库）。中文用 bigram + 重叠打分召回（FTS4 unicode61 对中文短语不命中），命中多者优先、抑制单 bigram 噪声 - Daos：加 timelineList / searchTextLike / summaries.recentList 三个 suspend 检索方法 - ChatViewModel：会话状态搬进 VM（随 Activity 存活）。修复切 tab 回来：流式请求被取消(viewModelScope 不取消) / 变成新会话 / lifelog 开关重置—— currentConvId / selectedTargetId / lifelogMode 均持久化到 prefs，重启也记住 - 键盘 inset：Activity setDecorFitsSystemWindows(false) + manifest adjustResize + Scaffold imePadding，键盘弹出时整个界面（含底部 tab）抬到键盘上方、可见 Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
yibo
1 parent faf5436b
Showing 5 changed files with 379 additions and 118 deletions
lifelog-recorder/app/src/main/AndroidManifest.xml
lifelog-recorder/app/src/main/kotlin/com/lemon/lifelog/ChatScreen.kt
lifelog-recorder/app/src/main/kotlin/com/lemon/lifelog/chat/ChatViewModel.kt
lifelog-recorder/app/src/main/kotlin/com/lemon/lifelog/chat/LifelogRetriever.kt
lifelog-recorder/app/src/main/kotlin/com/lemon/lifelog/data/Daos.kt
@@ -25,6 +25,7 @@
             android:name=".MainActivity"
             android:exported="true"
             android:label="Lifelog"
+            android:windowSoftInputMode="adjustResize"
             android:theme="@style/Theme.Lifelog">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
@@ -22,6 +22,7 @@ import androidx.compose.material3.DropdownMenu
 import androidx.compose.material3.DropdownMenuItem
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.FilledTonalButton
+import androidx.compose.material3.FilterChip
 import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.Icon
 import androidx.compose.material3.IconButton
@@ -54,119 +55,43 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
-import com.lemon.lifelog.chat.ChatClient
 import com.lemon.lifelog.chat.ChatConfig
 import com.lemon.lifelog.chat.ChatTarget
-import com.lemon.lifelog.data.ChatConversation
-import com.lemon.lifelog.data.ChatMessage
+import com.lemon.lifelog.chat.ChatViewModel
 import com.lemon.lifelog.data.Repository
-import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
-import kotlinx.coroutines.withContext
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 internal fun ChatTab(repo: Repository) {
     val ctx = LocalContext.current
     val scope = rememberCoroutineScope()
-    val client = remember { ChatClient() }
+    // 会话状态都在 ViewModel 里（随 Activity 存活），切 tab 回来不丢、流式不被取消。
+    val vm: ChatViewModel = androidx.lifecycle.viewmodel.compose.viewModel()
-    // 配置刷新计数器：改完端点设置后 bump 一下重新读 targets。
-    var configRev by remember { mutableStateOf(0) }
-    val targets = remember(configRev) { ChatConfig.targets(ctx) }
+    val targets = remember(vm.configRev) { ChatConfig.targets(ctx) }
+    val selectedTarget = remember(vm.selectedTargetId, vm.configRev) { ChatConfig.targetById(ctx, vm.selectedTargetId) }
-    val conversations by repo.chats.observeConversations().collectAsState(initial = emptyList())
-
-    var currentConvId by remember { mutableStateOf<Long?>(null) }
-    var selectedTargetId by remember { mutableStateOf(targets.first().id) }
-    val selectedTarget = remember(selectedTargetId, configRev) { ChatConfig.targetById(ctx, selectedTargetId) }
+    val conversations by vm.repo.chats.observeConversations().collectAsState(initial = emptyList())
     // 当前会话的消息流。
-    val messages by remember(currentConvId) {
-        val cid = currentConvId
+    val messages by remember(vm.currentConvId) {
+        val cid = vm.currentConvId
         if (cid == null) kotlinx.coroutines.flow.flowOf(emptyList())
-        else repo.chats.observeMessages(cid)
+        else vm.repo.chats.observeMessages(cid)
     }.collectAsState(initial = emptyList())
-    // 流式中的 assistant 回复（还没落库）。
-    var streaming by remember { mutableStateOf(false) }
-    var streamingText by remember { mutableStateOf("") }
-
     var showSettings by remember { mutableStateOf(false) }
-    var input by remember { mutableStateOf("") }
     val drawerState = rememberDrawerState(DrawerValue.Closed)
     val listState = rememberLazyListState()
     // 新消息 / 流式更新时滚到底。
-    androidx.compose.runtime.LaunchedEffect(messages.size, streamingText) {
-        val total = messages.size + if (streaming) 1 else 0
+    androidx.compose.runtime.LaunchedEffect(messages.size, vm.streamingText) {
+        val total = messages.size + if (vm.streaming) 1 else 0
         if (total > 0) listState.animateScrollToItem(total - 1)
     }
-    fun send() {
-        val text = input.trim()
-        if (text.isEmpty() || streaming) return
-        input = ""
-        val target = selectedTarget
-        scope.launch {
-            val now = System.currentTimeMillis()
-            var convId = currentConvId
-            if (convId == null) {
-                convId = withContext(Dispatchers.IO) {
-                    repo.chats.insertConversation(
-                        ChatConversation(
-                            title = text.take(20),
-                            targetId = target.id,
-                            createdAt = now,
-                            updatedAt = now,
-                        ),
-                    )
-                }
-                currentConvId = convId
-            }
-            withContext(Dispatchers.IO) {
-                repo.chats.insertMessage(ChatMessage(conversationId = convId!!, role = "user", content = text, createdAt = now))
-                repo.chats.touch(convId!!, now)
-            }
-            val history = withContext(Dispatchers.IO) { repo.chats.messagesOf(convId!!) }
-                .map { it.role to it.content }
-
-            streaming = true
-            streamingText = ""
-            try {
-                val full = client.stream(target, history) { delta -> streamingText += delta }
-                withContext(Dispatchers.IO) {
-                    repo.chats.insertMessage(
-                        ChatMessage(
-                            conversationId = convId!!,
-                            role = "assistant",
-                            content = full.ifBlank { "(空回复)" },
-                            model = target.model,
-                            createdAt = System.currentTimeMillis(),
-                        ),
-                    )
-                    repo.chats.touch(convId!!, System.currentTimeMillis())
-                }
-            } catch (t: Throwable) {
-                withContext(Dispatchers.IO) {
-                    repo.chats.insertMessage(
-                        ChatMessage(
-                            conversationId = convId!!,
-                            role = "assistant",
-                            content = "⚠ 出错：${t.message ?: t.toString()}",
-                            model = target.model,
-                            createdAt = System.currentTimeMillis(),
-                        ),
-                    )
-                }
-            } finally {
-                streaming = false
-                streamingText = ""
-            }
-        }
-    }
-
     ModalNavigationDrawer(
         drawerState = drawerState,
         drawerContent = {
@@ -175,8 +100,7 @@ internal fun ChatTab(repo: Repository) {
                     Text("对话历史", style = MaterialTheme.typography.titleMedium, modifier = Modifier.padding(8.dp))
                     FilledTonalButton(
                         onClick = {
-                            currentConvId = null
-                            streamingText = ""
+                            vm.newConversation()
                             scope.launch { drawerState.close() }
                         },
                         modifier = Modifier.fillMaxWidth(),
@@ -197,23 +121,15 @@ internal fun ChatTab(repo: Repository) {
                                         overflow = TextOverflow.Ellipsis,
                                     )
                                 },
-                                selected = conv.id == currentConvId,
+                                selected = conv.id == vm.currentConvId,
                                 onClick = {
-                                    currentConvId = conv.id
-                                    selectedTargetId = conv.targetId
-                                    streamingText = ""
+                                    vm.openConversation(conv.id, conv.targetId)
                                     scope.launch { drawerState.close() }
                                 },
                                 badge = {
-                                    IconButton(onClick = {
-                                        scope.launch {
-                                            withContext(Dispatchers.IO) {
-                                                repo.chats.deleteMessages(conv.id)
-                                                repo.chats.deleteConversation(conv.id)
-                                            }
-                                            if (currentConvId == conv.id) currentConvId = null
-                                        }
-                                    }) { Icon(Icons.Filled.Delete, contentDescription = "删除") }
+                                    IconButton(onClick = { vm.deleteConversation(conv.id) }) {
+                                        Icon(Icons.Filled.Delete, contentDescription = "删除")
+                                    }
                                 },
                             )
                         }
@@ -226,13 +142,7 @@ internal fun ChatTab(repo: Repository) {
             // 顶栏：菜单 + 聊天对象选择 + 设置。
             TopAppBar(
                 title = { TargetSelector(targets = targets, selected = selectedTarget) { picked ->
-                    selectedTargetId = picked.id
-                    val cid = currentConvId
-                    if (cid != null) {
-                        scope.launch {
-                            withContext(Dispatchers.IO) { repo.chats.updateTarget(cid, picked.id, System.currentTimeMillis()) }
-                        }
-                    }
+                    vm.selectTarget(picked.id)
                 } },
                 navigationIcon = {
                     IconButton(onClick = { scope.launch { drawerState.open() } }) {
@@ -240,7 +150,7 @@ internal fun ChatTab(repo: Repository) {
                     }
                 },
                 actions = {
-                    IconButton(onClick = { currentConvId = null; streamingText = "" }) {
+                    IconButton(onClick = { vm.newConversation() }) {
                         Icon(Icons.Filled.Add, contentDescription = "新对话")
                     }
                     IconButton(onClick = { showSettings = true }) {
@@ -251,7 +161,7 @@ internal fun ChatTab(repo: Repository) {
             // 消息列表。
             Box(modifier = Modifier.weight(1f).fillMaxWidth()) {
-                if (messages.isEmpty() && !streaming) {
+                if (messages.isEmpty() && !vm.streaming) {
                     Column(
                         modifier = Modifier.fillMaxSize().padding(24.dp),
                         verticalArrangement = Arrangement.Center,
@@ -273,15 +183,32 @@ internal fun ChatTab(repo: Repository) {
                         verticalArrangement = Arrangement.spacedBy(8.dp),
                     ) {
                         items(messages, key = { it.id }) { m -> MessageBubble(m.role, m.content) }
-                        if (streaming) {
+                        if (vm.streaming) {
                             item(key = "streaming") {
-                                MessageBubble("assistant", streamingText.ifEmpty { "…" }, inProgress = true)
+                                MessageBubble("assistant", vm.streamingText.ifEmpty { "…" }, inProgress = true)
                             }
                         }
                     }
                 }
             }
+            // lifelog 模式开关。
+            Row(
+                modifier = Modifier.fillMaxWidth().padding(horizontal = 12.dp),
+                verticalAlignment = Alignment.CenterVertically,
+                horizontalArrangement = Arrangement.spacedBy(8.dp),
+            ) {
+                FilterChip(
+                    selected = vm.lifelogMode,
+                    onClick = { vm.setLifelog(!vm.lifelogMode) },
+                    label = { Text("🧠 lifelog 模式") },
+                )
+                Text(
+                    if (vm.lifelogMode) "回答会带上你的纪要/转写检索" else "纯聊天，不读 lifelog",
+                    style = MaterialTheme.typography.labelSmall,
+                )
+            }
+
             HorizontalDivider()
             // 输入区。
@@ -291,14 +218,14 @@ internal fun ChatTab(repo: Repository) {
                 horizontalArrangement = Arrangement.spacedBy(8.dp),
             ) {
                 OutlinedTextField(
-                    value = input,
-                    onValueChange = { input = it },
+                    value = vm.input,
+                    onValueChange = { vm.input = it },
                     modifier = Modifier.weight(1f),
                     placeholder = { Text("发消息给 ${selectedTarget.label}…") },
                     maxLines = 5,
                 )
-                IconButton(onClick = { send() }, enabled = input.isNotBlank() && !streaming) {
-                    if (streaming) {
+                IconButton(onClick = { vm.send() }, enabled = vm.input.isNotBlank() && !vm.streaming) {
+                    if (vm.streaming) {
                         CircularProgressIndicator(modifier = Modifier.height(22.dp), strokeWidth = 2.dp)
                     } else {
                         Icon(Icons.AutoMirrored.Filled.Send, contentDescription = "发送")
@@ -316,7 +243,7 @@ internal fun ChatTab(repo: Repository) {
             onDismiss = { showSettings = false },
             onSave = { base, m2, m4 ->
                 ChatConfig.save(ctx, base, m2, m4)
-                configRev++
+                vm.bumpConfig()
                 showSettings = false
             },
         )
+package com.lemon.lifelog.chat
+
+import android.app.Application
+import android.content.Context
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import androidx.lifecycle.AndroidViewModel
+import androidx.lifecycle.viewModelScope
+import com.lemon.lifelog.data.ChatConversation
+import com.lemon.lifelog.data.ChatMessage
+import com.lemon.lifelog.data.Repository
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+
+/**
+ * 聊天会话状态 + 发送逻辑的宿主。放在 ViewModel 里（随 Activity 存活）而不是 ChatTab
+ * composable 里，是为了：切到别的 tab 再回来时——
+ *  1. 正在跑的流式请求不被取消（viewModelScope，不随 ChatTab 离开 composition 而 cancel）；
+ *  2. 当前会话 / 选中模型 / lifelog 开关不丢（且持久化到 prefs，连重启都记住）。
+ */
+class ChatViewModel(app: Application) : AndroidViewModel(app) {
+    val repo = Repository(app)
+    private val client = ChatClient()
+    private val prefs = app.getSharedPreferences(ChatConfig.PREFS, Context.MODE_PRIVATE)
+
+    var currentConvId by mutableStateOf(prefs.getLong(K_CONV, -1L).takeIf { it > 0 })
+        private set
+    var selectedTargetId by mutableStateOf(
+        prefs.getString(K_TARGET, null) ?: ChatConfig.targets(app).first().id,
+    )
+        private set
+    var lifelogMode by mutableStateOf(prefs.getBoolean(K_LIFELOG, false))
+        private set
+
+    var input by mutableStateOf("")
+    var streaming by mutableStateOf(false)
+        private set
+    var streamingText by mutableStateOf("")
+        private set
+    var configRev by mutableStateOf(0)
+        private set
+
+    fun setLifelog(on: Boolean) {
+        lifelogMode = on
+        prefs.edit().putBoolean(K_LIFELOG, on).apply()
+    }
+
+    fun selectTarget(id: String) {
+        selectedTargetId = id
+        prefs.edit().putString(K_TARGET, id).apply()
+        val cid = currentConvId
+        if (cid != null) viewModelScope.launch {
+            withContext(Dispatchers.IO) { repo.chats.updateTarget(cid, id, System.currentTimeMillis()) }
+        }
+    }
+
+    fun openConversation(id: Long, targetId: String) {
+        currentConvId = id
+        prefs.edit().putLong(K_CONV, id).apply()
+        selectedTargetId = targetId
+        prefs.edit().putString(K_TARGET, targetId).apply()
+        streamingText = ""
+    }
+
+    fun newConversation() {
+        currentConvId = null
+        prefs.edit().remove(K_CONV).apply()
+        streamingText = ""
+    }
+
+    fun bumpConfig() {
+        configRev++
+    }
+
+    fun deleteConversation(id: Long) {
+        viewModelScope.launch {
+            withContext(Dispatchers.IO) {
+                repo.chats.deleteMessages(id)
+                repo.chats.deleteConversation(id)
+            }
+            if (currentConvId == id) newConversation()
+        }
+    }
+
+    fun send() {
+        val text = input.trim()
+        if (text.isEmpty() || streaming) return
+        input = ""
+        val app = getApplication<Application>()
+        val target = ChatConfig.targetById(app, selectedTargetId)
+        val useLifelog = lifelogMode
+        viewModelScope.launch {
+            val now = System.currentTimeMillis()
+            var convId = currentConvId
+            if (convId == null) {
+                convId = withContext(Dispatchers.IO) {
+                    repo.chats.insertConversation(
+                        ChatConversation(title = text.take(20), targetId = target.id, createdAt = now, updatedAt = now),
+                    )
+                }
+                currentConvId = convId
+                prefs.edit().putLong(K_CONV, convId!!).apply()
+            }
+            val cid = convId!!
+            withContext(Dispatchers.IO) {
+                repo.chats.insertMessage(ChatMessage(conversationId = cid, role = "user", content = text, createdAt = now))
+                repo.chats.touch(cid, now)
+            }
+            val history = withContext(Dispatchers.IO) { repo.chats.messagesOf(cid) }.map { it.role to it.content }
+
+            streaming = true
+            streamingText = ""
+            try {
+                val messagesToSend = if (useLifelog) {
+                    val c = LifelogRetriever.buildContext(repo, text)
+                    if (c != null) listOf("system" to c) + history else history
+                } else {
+                    history
+                }
+                val full = client.stream(target, messagesToSend) { delta -> streamingText += delta }
+                withContext(Dispatchers.IO) {
+                    repo.chats.insertMessage(
+                        ChatMessage(
+                            conversationId = cid, role = "assistant",
+                            content = full.ifBlank { "(空回复)" }, model = target.model,
+                            createdAt = System.currentTimeMillis(),
+                        ),
+                    )
+                    repo.chats.touch(cid, System.currentTimeMillis())
+                }
+            } catch (t: Throwable) {
+                withContext(Dispatchers.IO) {
+                    repo.chats.insertMessage(
+                        ChatMessage(
+                            conversationId = cid, role = "assistant",
+                            content = "⚠ 出错：${t.message ?: t.toString()}", model = target.model,
+                            createdAt = System.currentTimeMillis(),
+                        ),
+                    )
+                }
+            } finally {
+                streaming = false
+                streamingText = ""
+            }
+        }
+    }
+
+    companion object {
+        private const val K_LIFELOG = "lifelog_mode"
+        private const val K_TARGET = "selected_target"
+        private const val K_CONV = "current_conv"
+    }
+}
+package com.lemon.lifelog.chat
+
+import android.util.Log
+import com.lemon.lifelog.data.Repository
+import com.lemon.lifelog.data.SegmentRow
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+
+/**
+ * 「lifelog 模式」的本地检索（RAG）。聊天时把跟用户问题相关的 lifelog 内容
+ * 拼成一段 system context 注入到模型请求里——本地 2B/4B 和 Hermes 通用。
+ *
+ * 检索三路（高信号优先）：
+ *  1. 会话纪要（已 LLM 压缩，覆盖面广、最省 token）——backbone。
+ *  2. 关键词子串命中的转写片段（LIKE，对中文可靠）——精确细节。
+ *  3. 最近时间轴片段——兜底「最近/今天」类问题。
+ */
+object LifelogRetriever {
+    private val FMT = SimpleDateFormat("MM-dd HH:mm", Locale.US)
+    private val TS_FMT = SimpleDateFormat("MM-dd HH:mm:ss", Locale.US)
+
+    /** 注入 context 的字符上限（≈3–4k 中文 token，兼顾本地 4B 的上下文窗口）。 */
+    private const val MAX_CHARS = 6000
+    private const val SUMMARY_LIMIT = 20
+    private const val SUMMARY_EACH_CHARS = 400
+    private const val HITS_PER_TERM = 12
+    private const val HITS_TOTAL = 30
+    private const val RECENT_LIMIT = 20
+    private const val MAX_TERMS = 16
+
+    // 纯虚词/高频功能 bigram：命中无意义、只会污染候选，检索时丢掉。
+    private val STOP_BIGRAMS = setOf(
+        "什么", "怎么", "这个", "那个", "一下", "这样", "那样", "可以", "就是", "然后",
+        "因为", "所以", "但是", "如果", "的话", "我们", "你们", "他们", "今天", "昨天",
+        "最近", "这周", "本周", "上周", "有没", "没有", "知道", "觉得", "可能",
+    )
+
+    /** 给定用户问题，返回要注入的 system context；无任何数据返回 null。 */
+    suspend fun buildContext(repo: Repository, question: String): String? = withContext(Dispatchers.IO) {
+        val summaries = repo.summaries.recentList(SUMMARY_LIMIT)
+        val terms = searchTerms(question)
+
+        // bigram 召回 + 重叠打分：一段转写命中越多 query bigram 越相关，
+        // 单 bigram 噪声（如某段只含"内容"）被排到尾部丢掉。
+        val cand = LinkedHashMap<Long, SegmentRow>()
+        for (t in terms) {
+            repo.segments.searchTextLike(t, HITS_PER_TERM).forEach { row ->
+                if (row.text != null) cand.putIfAbsent(row.id, row)
+            }
+        }
+        val scored = cand.values
+            .map { row -> row to terms.count { row.text!!.contains(it) } }
+            .filter { it.second > 0 }
+        // 有 ≥2 命中的强匹配时，丢掉只命中 1 个 bigram 的弱噪声。
+        val minScore = if (scored.any { it.second >= 2 }) 2 else 1
+        val hits = scored
+            .filter { it.second >= minScore }
+            .sortedWith(compareByDescending<Pair<SegmentRow, Int>> { it.second }.thenByDescending { it.first.startTs })
+            .take(HITS_TOTAL)
+            .map { it.first }
+        val recent = repo.segments.timelineList(RECENT_LIMIT).filter { it.text != null }
+
+        if (summaries.isEmpty() && hits.isEmpty() && recent.isEmpty()) return@withContext null
+
+        val sb = StringBuilder()
+        sb.appendLine(
+            "你是用户的私人 lifelog 助手。lifelog 是用户 24/7 录音转写出来的个人记忆库。" +
+                "下面是从中检索出的相关内容，请**只依据这些内容**回答用户的问题；" +
+                "若不足以回答，明确说「我的 lifelog 里没找到相关内容」，不要编造。" +
+                "引用具体事实时可带上 [时间戳]。",
+        )
+        sb.appendLine()
+
+        if (summaries.isNotEmpty()) {
+            sb.appendLine("【会话纪要】（共 ${summaries.size} 篇，时间倒序）")
+            summaries.forEach { s ->
+                val range = "${FMT.format(Date(s.windowStartTs))}–${FMT.format(Date(s.windowEndTs))}"
+                val body = s.markdown.trim().replace("\n", " ").take(SUMMARY_EACH_CHARS)
+                sb.appendLine("- [$range] $body")
+            }
+            sb.appendLine()
+        }
+
+        if (hits.isNotEmpty()) {
+            sb.appendLine("【相关转写片段】（按问题关键词命中，相关度优先）")
+            hits.forEach { sb.appendLine(formatSeg(it)) }
+            sb.appendLine()
+        }
+
+        if (recent.isNotEmpty()) {
+            sb.appendLine("【最近转写】（最近 ${recent.size} 段，供「最近/今天」类问题参考）")
+            recent.forEach { sb.appendLine(formatSeg(it)) }
+        }
+
+        var ctx = sb.toString()
+        if (ctx.length > MAX_CHARS) ctx = ctx.take(MAX_CHARS) + "\n…（上下文已截断）"
+        Log.i(
+            "LifelogRAG",
+            "q=\"${question.take(40)}\" terms=$terms " +
+                "纪要=${summaries.size} 命中=${hits.size} 最近=${recent.size} chars=${ctx.length}",
+        )
+        ctx
+    }
+
+    private fun formatSeg(r: SegmentRow): String {
+        val who = r.speakerName ?: "未知"
+        return "[${TS_FMT.format(Date(r.startTs))}] $who：${r.text?.trim().orEmpty()}"
+    }
+
+    /**
+     * 把问题切成检索词：英文/数字整词保留；中文按**重叠 bigram**切。
+     * 当前 FTS4 unicode61 对中文把整段 CJK 当一个 token、短语检索不命中；
+     * bigram + LIKE 才能让"黑神话悟空"这种被真正召回（黑神/神话/悟空…多 bigram 命中）。
+     */
+    private fun searchTerms(question: String): List<String> {
+        val cleaned = question.lowercase()
+            .replace(Regex("[\\p{Punct}，。！？、；：“”‘’（）《》【】…—～·\\s]+"), " ")
+        val terms = LinkedHashSet<String>()
+        for (tok in cleaned.split(" ")) {
+            if (tok.isBlank()) continue
+            if (tok.all { it.code < 128 }) {
+                if (tok.length >= 2) terms += tok            // 英文/数字整词
+            } else {
+                val s = tok.filter { !it.isWhitespace() }
+                for (i in 0 until s.length - 1) {
+                    val bg = s.substring(i, i + 2)           // CJK 重叠 bigram
+                    if (bg !in STOP_BIGRAMS) terms += bg
+                }
+            }
+            if (terms.size >= MAX_TERMS) break
+        }
+        return terms.take(MAX_TERMS).toList()
+    }
+}
@@ -101,6 +101,43 @@ interface SegmentDao {
     )
     fun observeTimeline(limit: Int = 100): Flow<List<SegmentRow>>
+    /** 一次性取最近时间轴（RAG 检索用，非 Flow）。 */
+    @Query(
+        """
+        SELECT s.id AS id, s.startTs AS startTs, s.durationMs AS durationMs,
+               t.text AS text, s.audioPath AS audioPath,
+               s.speakerId AS speakerId, s.speakerSim AS speakerSim,
+               sp.name AS speakerName
+        FROM segments s
+        LEFT JOIN transcripts t ON t.segmentId = s.id
+        LEFT JOIN speaker_profiles sp ON sp.id = s.speakerId
+        ORDER BY s.startTs DESC
+        LIMIT :limit
+        """,
+    )
+    suspend fun timelineList(limit: Int): List<SegmentRow>
+
+    /**
+     * 中文子串检索（RAG 用）：LIKE '%kw%'。
+     * 当前 FTS4 是 unicode61，对中文把整段 CJK 当一个 token、短语检索几乎不命中；
+     * 个人库行数少，直接 LIKE 子串扫最稳。
+     */
+    @Query(
+        """
+        SELECT s.id AS id, s.startTs AS startTs, s.durationMs AS durationMs,
+               t.text AS text, s.audioPath AS audioPath,
+               s.speakerId AS speakerId, s.speakerSim AS speakerSim,
+               sp.name AS speakerName
+        FROM segments s
+        INNER JOIN transcripts t ON t.segmentId = s.id
+        LEFT JOIN speaker_profiles sp ON sp.id = s.speakerId
+        WHERE t.text LIKE '%' || :kw || '%'
+        ORDER BY s.startTs DESC
+        LIMIT :limit
+        """,
+    )
+    suspend fun searchTextLike(kw: String, limit: Int): List<SegmentRow>
+
     /** Full-text search via FTS4 virtual table. Falls back to LIKE if MATCH query is empty. */
     @Query(
         """
@@ -144,6 +181,10 @@ interface SummaryDao {
     @Query("SELECT * FROM summaries ORDER BY windowStartTs DESC LIMIT :n")
     fun recent(n: Int): Flow<List<Summary>>
+    /** 一次性取最近 n 篇纪要（RAG 检索用，非 Flow）。 */
+    @Query("SELECT * FROM summaries ORDER BY windowStartTs DESC LIMIT :n")
+    suspend fun recentList(n: Int): List<Summary>
+
     @Query("SELECT * FROM summaries ORDER BY windowStartTs DESC")
     suspend fun all(): List<Summary>