feat: add cursor-based message queries

src/moderation/messageStore.ts

@@ -1,11 +1,43 @@
-import { and, asc, desc, eq, isNull, or } from "drizzle-orm";
+import { and, asc, desc, eq, isNull, or, sql } from "drizzle-orm";
 import { getDatabase } from "../database/drizzle";
 import { attachmentsTable, messagesTable } from "../database/schema";
 import { createChildLogger } from "../logger";
-import type { AttachmentRecord, MessageRecord } from "./types";
+import type {
+  AIStatus,
+  AttachmentRecord,
+  MessageQuery,
+  MessageRecord,
+  PageResult,
+} from "./types";
 
 const logger = createChildLogger("message-store");
 
+// Cursor helpers for pagination
+interface CursorData {
+  created_at: number;
+  id: string;
+}
+
+export function encodeCursor(data: CursorData): string {
+  return Buffer.from(JSON.stringify(data)).toString("base64");
+}
+
+export function decodeCursor(cursor?: string): CursorData | null {
+  if (!cursor) return null;
+  try {
+    const data = JSON.parse(Buffer.from(cursor, "base64").toString("utf-8"));
+    if (
+      typeof data.created_at === "number" &&
+      typeof data.id === "string"
+    ) {
+      return data;
+    }
+    return null;
+  } catch {
+    return null;
+  }
+}
+
 export async function insertMessage(message: MessageRecord): Promise<void> {
   try {
     const db = getDatabase() as any;
@@ -327,3 +359,103 @@ export async function getMessageById(
     throw error;
   }
 }
+
+export async function listMessages(
+  query: MessageQuery,
+): Promise<PageResult<MessageRecord>> {
+  try {
+    const db = getDatabase() as any;
+    const conditions: any[] = [];
+
+    // Apply filters
+    if (query.guildId) {
+      conditions.push(eq(messagesTable.guild_id, query.guildId));
+    }
+
+    if (query.channelId) {
+      conditions.push(
+        or(
+          eq(messagesTable.channel_id, query.channelId),
+          eq(messagesTable.thread_id, query.channelId),
+        ),
+      );
+    }
+
+    if (query.threadId) {
+      conditions.push(eq(messagesTable.thread_id, query.threadId));
+    }
+
+    if (query.userId) {
+      conditions.push(eq(messagesTable.user_id, query.userId));
+    }
+
+    if (query.status && query.status.length > 0) {
+      conditions.push(
+        or(...query.status.map((status) => eq(messagesTable.ai_status, status))),
+      );
+    }
+
+    // Text search
+    if (query.q) {
+      const pattern = `%${query.q.toLowerCase()}%`;
+      conditions.push(sql`lower(${messagesTable.content}) like ${pattern}`);
+    }
+
+    // Cursor-based pagination (newest first)
+    if (query.cursor) {
+      const cursorData = decodeCursor(query.cursor);
+      if (cursorData) {
+        conditions.push(
+          or(
+            sql`${messagesTable.created_at} < ${cursorData.created_at}`,
+            and(
+              eq(messagesTable.created_at, cursorData.created_at),
+              sql`${messagesTable.id} < ${cursorData.id}`,
+            ),
+          ),
+        );
+      }
+    }
+
+    // Fetch limit + 1 to determine if there's a next page
+    const fetchLimit = query.limit + 1;
+    const rows = await db
+      .select()
+      .from(messagesTable)
+      .where(conditions.length > 0 ? and(...conditions) : undefined)
+      .orderBy(desc(messagesTable.created_at), desc(messagesTable.id))
+      .limit(fetchLimit);
+
+    const hasMore = rows.length > query.limit;
+    const data = (rows.slice(0, query.limit) as MessageRecord[]);
+
+    let nextCursor: string | null = null;
+    if (hasMore && data.length > 0) {
+      const lastItem = data[data.length - 1];
+      nextCursor = encodeCursor({
+        created_at: lastItem.created_at,
+        id: lastItem.id,
+      });
+    }
+
+    return { data, nextCursor };
+  } catch (error) {
+    logger.error(
+      {
+        query,
+        error: error instanceof Error ? error.message : String(error),
+      },
+      "Failed to list messages",
+    );
+    throw error;
+  }
+}
+
+export async function listReviewMessages(
+  query: Omit<MessageQuery, "status">,
+): Promise<PageResult<MessageRecord>> {
+  return listMessages({
+    ...query,
+    status: ["warn", "flagged", "error"],
+  });
+}

tests/moderation/messageStoreQueries.test.ts

@@ -0,0 +1,13 @@
+import { describe, expect, it } from "vitest";
+import { decodeCursor, encodeCursor } from "../../src/moderation/messageStore";
+
+describe("message cursor helpers", () => {
+  it("round-trips created_at and id", () => {
+    const cursor = encodeCursor({ created_at: 1710000000000, id: "abc" });
+    expect(decodeCursor(cursor)).toEqual({ created_at: 1710000000000, id: "abc" });
+  });
+
+  it("returns null for invalid cursor", () => {
+    expect(decodeCursor("not-base64-json")).toBeNull();
+  });
+});