fix(query): preserve chronological context after backfill

补导历史后按时间和 ID 选取相邻消息，保留分段边界并补充回归测试。
Select neighbors by timestamp and ID after backfill; preserve segment boundaries and add regressions.

packages/core/src/query/__tests__/message-query-functions.test.ts

@@ -7,6 +7,8 @@
 import assert from 'node:assert/strict'
 import { describe, it } from 'node:test'
 import Database from 'better-sqlite3'
+import { getMessageContext, getSearchMessageContext } from '../message-queries'
+import { SqliteTestAdapter } from './sqlite-test-adapter'
 
 import {
   fetchAllRecentMessages,
@@ -142,17 +144,28 @@ describe('message search and context', () => {
   it('loads chronological context instead of insertion order', async () => {
     const db = createBackfilledMessageDb()
     try {
-      const messages = await fetchMessageContext(createSqliteExecutor(db), 1, 2)
-      assert.deepEqual(
-        messages.map((message) => message.id),
-        [3, 4, 1, 2]
-      )
+      const adapter = new SqliteTestAdapter(db)
+      const executor = createSqliteExecutor(db)
+      for (const messages of [getMessageContext(adapter, [1], 2), await fetchMessageContext(executor, 1, 2)]) {
+        assert.deepEqual(
+          messages.map((message) => message.id),
+          [3, 4, 1, 2]
+        )
+      }
+      db.exec(`INSERT INTO message (id, sender_id, ts, type, content) VALUES
+        (5, 1, 300, 0, 'same-second backfill'), (6, 1, 300, 0, 'same-second later');`)
+      for (const messages of [getMessageContext(adapter, [5], 1), await fetchMessageContext(executor, 5, 1)]) {
+        assert.deepEqual(
+          messages.map((message) => message.id),
+          [1, 5, 6]
+        )
+      }
     } finally {
       db.close()
     }
   })
 
-  it('falls back to neighboring message ids without a message_context table', async () => {
+  it('falls back to chronological neighbors without a message_context table', async () => {
     const db = createMessageDb()
     try {
       const result = await fetchSearchMessageContext(createSqliteExecutor(db), [3], 1, 1)
@@ -164,6 +177,43 @@ describe('message search and context', () => {
       db.close()
     }
   })
+
+  for (const indexed of [false, true]) {
+    it(`loads backfilled search context in time order and respects segments (indexed=${indexed})`, async () => {
+      const db = createBackfilledMessageDb()
+      try {
+        db.exec(`INSERT INTO message (id, sender_id, ts, type, content) VALUES
+          (5, 1, 300, 0, 'same-second backfill'), (6, 1, 300, 0, 'same-second later'),
+          (7, 1, 5000, 0, 'another segment');`)
+        if (indexed) {
+          db.exec(`CREATE TABLE message_context (message_id INTEGER PRIMARY KEY, segment_id INTEGER);
+            INSERT INTO message_context SELECT id, CASE WHEN id = 7 THEN 2 ELSE 1 END FROM message;`)
+        }
+        const adapter = new SqliteTestAdapter(db)
+        const executor = createSqliteExecutor(db)
+        for (const { ids, before, after, expected } of [
+          { ids: [1], before: 1, after: 1, expected: [4, 1, 5] },
+          { ids: [5], before: 1, after: 1, expected: [1, 5, 6] },
+          { ids: [6], before: 1, after: 1, expected: [5, 6, 2] },
+          { ids: [2], before: 1, after: 1, expected: indexed ? [6, 2] : [6, 2, 7] },
+          { ids: [1, 5], before: 1, after: 1, expected: [4, 1, 5, 6] },
+          { ids: [1], before: 0, after: 1, expected: [1, 5] },
+        ]) {
+          for (const messages of [
+            getSearchMessageContext(adapter, ids, before, after),
+            await fetchSearchMessageContext(executor, ids, before, after),
+          ]) {
+            assert.deepEqual(
+              messages.map((message) => message.id),
+              expected
+            )
+          }
+        }
+      } finally {
+        db.close()
+      }
+    })
+  }
 })
 
 describe('recent messages', () => {

packages/core/src/query/message-queries.ts

@@ -592,14 +592,14 @@ function hydrateMessagesByIds(db: DatabaseAdapter, ids: number[]): MappedMessage
   if (ids.length === 0) return []
   const placeholders = ids.map(() => '?').join(', ')
   const rows = db
-    .prepare(`${FULL_MSG_SELECT} WHERE msg.id IN (${placeholders}) ORDER BY msg.id ASC`)
+    .prepare(`${FULL_MSG_SELECT} WHERE msg.id IN (${placeholders}) ORDER BY msg.ts ASC, msg.id ASC`)
     .all(...ids) as unknown as FullMessageRow[]
   return rows.map(mapMessageRow)
 }
 
 /**
  * Get surrounding context messages for given message IDs.
- * Uses simple id-based ordering (not session-aware).
+ * Uses chronological (timestamp, id) ordering (not session-aware).
  */
 export function getMessageContext(
   db: DatabaseAdapter,
@@ -614,12 +614,22 @@ export function getMessageContext(
     contextIds.add(messageId)
 
     const beforeRows = db
-      .prepare('SELECT id FROM message WHERE id < ? ORDER BY id DESC LIMIT ?')
+      .prepare(
+        `SELECT msg.id FROM message msg
+         JOIN message anchor ON anchor.id = ?
+         WHERE msg.ts < anchor.ts OR (msg.ts = anchor.ts AND msg.id < anchor.id)
+         ORDER BY msg.ts DESC, msg.id DESC LIMIT ?`
+      )
       .all(messageId, contextSize) as { id: number }[]
     beforeRows.forEach((r) => contextIds.add(r.id))
 
     const afterRows = db
-      .prepare('SELECT id FROM message WHERE id > ? ORDER BY id ASC LIMIT ?')
+      .prepare(
+        `SELECT msg.id FROM message msg
+         JOIN message anchor ON anchor.id = ?
+         WHERE msg.ts > anchor.ts OR (msg.ts = anchor.ts AND msg.id > anchor.id)
+         ORDER BY msg.ts ASC, msg.id ASC LIMIT ?`
+      )
       .all(messageId, contextSize) as { id: number }[]
     afterRows.forEach((r) => contextIds.add(r.id))
   }
@@ -629,7 +639,7 @@ export function getMessageContext(
 
 /**
  * Get context messages around search results.
- * Session-aware when message_context table is available, falls back to id-based ordering.
+ * Uses chronological neighbors within the indexed segment, or across the chat when unindexed.
  */
 export function getSearchMessageContext(
   db: DatabaseAdapter,
@@ -657,21 +667,25 @@ export function getSearchMessageContext(
         if (contextBefore > 0) {
           const rows = db
             .prepare(
-              `SELECT mc.message_id as id FROM message_context mc
-               WHERE mc.segment_id = ? AND mc.message_id < ?
-               ORDER BY mc.message_id DESC LIMIT ?`
+              `SELECT msg.id FROM message_context mc
+               JOIN message msg ON msg.id = mc.message_id
+               JOIN message anchor ON anchor.id = ?
+               WHERE mc.segment_id = ? AND (msg.ts < anchor.ts OR (msg.ts = anchor.ts AND msg.id < anchor.id))
+               ORDER BY msg.ts DESC, msg.id DESC LIMIT ?`
             )
-            .all(sessionRow.segment_id, messageId, contextBefore) as { id: number }[]
+            .all(messageId, sessionRow.segment_id, contextBefore) as { id: number }[]
           rows.forEach((r) => contextIds.add(r.id))
         }
         if (contextAfter > 0) {
           const rows = db
             .prepare(
-              `SELECT mc.message_id as id FROM message_context mc
-               WHERE mc.segment_id = ? AND mc.message_id > ?
-               ORDER BY mc.message_id ASC LIMIT ?`
+              `SELECT msg.id FROM message_context mc
+               JOIN message msg ON msg.id = mc.message_id
+               JOIN message anchor ON anchor.id = ?
+               WHERE mc.segment_id = ? AND (msg.ts > anchor.ts OR (msg.ts = anchor.ts AND msg.id > anchor.id))
+               ORDER BY msg.ts ASC, msg.id ASC LIMIT ?`
             )
-            .all(sessionRow.segment_id, messageId, contextAfter) as { id: number }[]
+            .all(messageId, sessionRow.segment_id, contextAfter) as { id: number }[]
           rows.forEach((r) => contextIds.add(r.id))
         }
         continue
@@ -680,13 +694,23 @@ export function getSearchMessageContext(
 
     if (contextBefore > 0) {
       const rows = db
-        .prepare('SELECT id FROM message WHERE id < ? ORDER BY id DESC LIMIT ?')
+        .prepare(
+          `SELECT msg.id FROM message msg
+           JOIN message anchor ON anchor.id = ?
+           WHERE msg.ts < anchor.ts OR (msg.ts = anchor.ts AND msg.id < anchor.id)
+           ORDER BY msg.ts DESC, msg.id DESC LIMIT ?`
+        )
         .all(messageId, contextBefore) as { id: number }[]
       rows.forEach((r) => contextIds.add(r.id))
     }
     if (contextAfter > 0) {
       const rows = db
-        .prepare('SELECT id FROM message WHERE id > ? ORDER BY id ASC LIMIT ?')
+        .prepare(
+          `SELECT msg.id FROM message msg
+           JOIN message anchor ON anchor.id = ?
+           WHERE msg.ts > anchor.ts OR (msg.ts = anchor.ts AND msg.id > anchor.id)
+           ORDER BY msg.ts ASC, msg.id ASC LIMIT ?`
+        )
         .all(messageId, contextAfter) as { id: number }[]
       rows.forEach((r) => contextIds.add(r.id))
     }

packages/core/src/query/message-query-functions.ts

@@ -177,7 +177,7 @@ export async function fetchMessageContext(
 
 /**
  * Get context messages around search results.
- * Session-aware when message_context table is available, falls back to id-based.
+ * Uses chronological neighbors within the indexed segment, or across the chat when unindexed.
  */
 export async function fetchSearchMessageContext(
   executor: AsyncSqlExecutor,
@@ -211,19 +211,23 @@ export async function fetchSearchMessageContext(
       if (sessionRow) {
         if (contextBefore > 0) {
           const rows = await executor.all<{ id: number }>(
-            `SELECT mc.message_id as id FROM message_context mc
-             WHERE mc.segment_id = ? AND mc.message_id < ?
-             ORDER BY mc.message_id DESC LIMIT ?`,
-            [sessionRow.segment_id, messageId, contextBefore]
+            `SELECT msg.id FROM message_context mc
+             JOIN message msg ON msg.id = mc.message_id
+             JOIN message anchor ON anchor.id = ?
+             WHERE mc.segment_id = ? AND (msg.ts < anchor.ts OR (msg.ts = anchor.ts AND msg.id < anchor.id))
+             ORDER BY msg.ts DESC, msg.id DESC LIMIT ?`,
+            [messageId, sessionRow.segment_id, contextBefore]
           )
           rows.forEach((r) => contextIds.add(r.id))
         }
         if (contextAfter > 0) {
           const rows = await executor.all<{ id: number }>(
-            `SELECT mc.message_id as id FROM message_context mc
-             WHERE mc.segment_id = ? AND mc.message_id > ?
-             ORDER BY mc.message_id ASC LIMIT ?`,
-            [sessionRow.segment_id, messageId, contextAfter]
+            `SELECT msg.id FROM message_context mc
+             JOIN message msg ON msg.id = mc.message_id
+             JOIN message anchor ON anchor.id = ?
+             WHERE mc.segment_id = ? AND (msg.ts > anchor.ts OR (msg.ts = anchor.ts AND msg.id > anchor.id))
+             ORDER BY msg.ts ASC, msg.id ASC LIMIT ?`,
+            [messageId, sessionRow.segment_id, contextAfter]
           )
           rows.forEach((r) => contextIds.add(r.id))
         }
@@ -232,17 +236,23 @@ export async function fetchSearchMessageContext(
     }
 
     if (contextBefore > 0) {
-      const rows = await executor.all<{ id: number }>('SELECT id FROM message WHERE id < ? ORDER BY id DESC LIMIT ?', [
-        messageId,
-        contextBefore,
-      ])
+      const rows = await executor.all<{ id: number }>(
+        `SELECT msg.id FROM message msg
+         JOIN message anchor ON anchor.id = ?
+         WHERE msg.ts < anchor.ts OR (msg.ts = anchor.ts AND msg.id < anchor.id)
+         ORDER BY msg.ts DESC, msg.id DESC LIMIT ?`,
+        [messageId, contextBefore]
+      )
       rows.forEach((r) => contextIds.add(r.id))
     }
     if (contextAfter > 0) {
-      const rows = await executor.all<{ id: number }>('SELECT id FROM message WHERE id > ? ORDER BY id ASC LIMIT ?', [
-        messageId,
-        contextAfter,
-      ])
+      const rows = await executor.all<{ id: number }>(
+        `SELECT msg.id FROM message msg
+         JOIN message anchor ON anchor.id = ?
+         WHERE msg.ts > anchor.ts OR (msg.ts = anchor.ts AND msg.id > anchor.id)
+         ORDER BY msg.ts ASC, msg.id ASC LIMIT ?`,
+        [messageId, contextAfter]
+      )
       rows.forEach((r) => contextIds.add(r.id))
     }
   }