feat: add topic alias resolution APIs

src/queries/topics.ts

@@ -1,7 +1,7 @@
 import type { Kysely, Transaction } from 'kysely';
 
 import type { IdentityDatabaseSchema } from '../types/database';
-import type { TopicRecord } from '../types/domain';
+import type { TopicAliasRecord, TopicRecord } from '../types/domain';
 
 export type DatabaseExecutor = Kysely<IdentityDatabaseSchema> | Transaction<IdentityDatabaseSchema>;
 
@@ -20,14 +20,48 @@ export async function findTopicRowByNormalizedName(
     .executeTakeFirst();
 }
 
+export async function findTopicRowByNormalizedAlias(
+  executor: DatabaseExecutor,
+  normalizedAlias: string,
+): Promise<TopicRecord | undefined> {
+  return executor
+    .selectFrom('topic_aliases')
+    .innerJoin('topics', 'topics.id', 'topic_aliases.topic_id')
+    .selectAll('topics')
+    .where('topic_aliases.normalized_alias', '=', normalizedAlias)
+    .executeTakeFirst();
+}
+
+export async function findTopicRowByNameOrAlias(
+  executor: DatabaseExecutor,
+  normalizedName: string,
+): Promise<TopicRecord | undefined> {
+  const directMatch = await findTopicRowByNormalizedName(executor, normalizedName);
+  if (directMatch) {
+    return directMatch;
+  }
+
+  return findTopicRowByNormalizedAlias(executor, normalizedName);
+}
+
+export async function listTopicAliasRowsForTopicId(
+  executor: DatabaseExecutor,
+  topicId: string,
+): Promise<TopicAliasRecord[]> {
+  return executor
+    .selectFrom('topic_aliases')
+    .selectAll()
+    .where('topic_id', '=', topicId)
+    .orderBy('is_primary', 'desc')
+    .orderBy('normalized_alias', 'asc')
+    .execute();
+}
+
 export async function listTopicRows(
   executor: DatabaseExecutor,
   limit?: number,
 ): Promise<TopicRecord[]> {
-  let query = executor
-    .selectFrom('topics')
-    .selectAll()
-    .orderBy('normalized_name', 'asc');
+  let query = executor.selectFrom('topics').selectAll().orderBy('normalized_name', 'asc');
 
   if (limit !== undefined) {
     query = query.limit(limit);