Support unread reminders

Co-authored-by: trevor-signal <131492920+trevor-signal@users.noreply.github.com>

ts/sql/server/unreadReminders.std.ts

@@ -0,0 +1,190 @@
+// Copyright 2026 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { ReadStatus } from '../../messages/MessageReadStatus.std.ts';
+import type { AciString } from '../../types/ServiceId.std.ts';
+import type { ReadableDB } from '../Interface.std.ts';
+import type { QueryFragment, QueryTemplate } from '../util.std.ts';
+import {
+  batchMultiVarQuery,
+  sql,
+  sqlConstant,
+  sqlFragment,
+  sqlJoin,
+} from '../util.std.ts';
+
+const MAX_SENDERS_TO_SHOW = 5;
+
+function storyIdPredicate(includeStoryReplies: boolean): QueryFragment {
+  return includeStoryReplies
+    ? sqlFragment`NULL IS NULL`
+    : sqlFragment`storyId IS NULL`;
+}
+
+export type UnreadReminderConversationCandidate = Readonly<{
+  conversationId: string;
+  lastRemindedAt: number | null;
+  includeStoryReplies: boolean;
+}>;
+
+export type UnreadMessageTimeRange = Readonly<{
+  conversationId: string;
+  oldestUnremindedReceivedAtMs: number;
+  newestUnreadReceivedAtMs: number;
+}>;
+
+function cutoffsCte(
+  batch: ReadonlyArray<UnreadReminderConversationCandidate>
+): QueryFragment {
+  return sqlJoin(
+    batch.map(
+      ({ conversationId, lastRemindedAt, includeStoryReplies }) =>
+        sqlFragment`(${conversationId}, ${lastRemindedAt}, ${includeStoryReplies ? 1 : 0})`
+    )
+  );
+}
+
+export function getUnremindedUnreadMessageTimeRangesQuery(
+  batch: ReadonlyArray<UnreadReminderConversationCandidate>
+): QueryTemplate {
+  return sql`
+    WITH cutoffs(conversationId, lastRemindedAt, includeStoryReplies) AS (
+      VALUES ${cutoffsCte(batch)}
+    )
+    SELECT
+      messages.conversationId AS conversationId,
+      MIN(messages.received_at_ms) AS oldestUnremindedReceivedAtMs,
+      MAX(messages.received_at_ms) AS newestUnreadReceivedAtMs
+    FROM messages
+    INNER JOIN cutoffs ON cutoffs.conversationId IS messages.conversationId
+    WHERE
+      messages.readStatus = ${sqlConstant(ReadStatus.Unread)} AND
+      messages.isStory IS 0 AND
+      (cutoffs.includeStoryReplies IS 1 OR messages.storyId IS NULL) AND
+      messages.received_at_ms > IFNULL(cutoffs.lastRemindedAt, 0)
+    GROUP BY messages.conversationId
+  `;
+}
+
+export function getUnremindedUnreadMessageTimeRanges(
+  db: ReadableDB,
+  conversations: ReadonlyArray<UnreadReminderConversationCandidate>
+): ReadonlyArray<UnreadMessageTimeRange> {
+  return batchMultiVarQuery(db, conversations, (batch, persistent) => {
+    const [query, params] = getUnremindedUnreadMessageTimeRangesQuery(batch);
+
+    return db
+      .prepare(query, { persistent })
+      .all<UnreadMessageTimeRange>(params);
+  });
+}
+
+export type UnreadReminderSummaryData = Readonly<{
+  unreadMessageCount: number;
+  mentionCount: number;
+  replyCount: number;
+  senders: ReadonlyArray<{ sourceServiceId: string }>;
+  mentioners: ReadonlyArray<{ sourceServiceId: string }>;
+  repliers: ReadonlyArray<{ sourceServiceId: string }>;
+}>;
+
+export type UnreadReminderSummaryOptions = Readonly<{
+  includeStoryReplies: boolean;
+  ourAci: AciString;
+}>;
+
+export type UnreadReminderFilter = 'all' | 'mentions' | 'replies';
+
+function unreadPredicate(
+  conversationId: string,
+  filter: UnreadReminderFilter,
+  { includeStoryReplies, ourAci }: UnreadReminderSummaryOptions
+): QueryFragment {
+  let filterPredicate: QueryFragment;
+  if (filter === 'mentions') {
+    filterPredicate = sqlFragment`mentionsMe IS 1`;
+  } else if (filter === 'replies') {
+    filterPredicate = sqlFragment`json ->> '$.quote.authorAci' IS ${ourAci}`;
+  } else {
+    filterPredicate = sqlFragment`TRUE`;
+  }
+
+  return sqlFragment`
+    conversationId = ${conversationId} AND
+    readStatus = ${sqlConstant(ReadStatus.Unread)} AND
+    isStory IS 0 AND
+    (${storyIdPredicate(includeStoryReplies)}) AND
+    (${filterPredicate})
+  `;
+}
+
+export function getUnreadReminderCountQuery(
+  conversationId: string,
+  filter: UnreadReminderFilter,
+  options: UnreadReminderSummaryOptions
+): QueryTemplate {
+  return sql`
+    SELECT count(1) FROM messages
+    WHERE ${unreadPredicate(conversationId, filter, options)}
+  `;
+}
+
+export function getUnreadReminderSendersQuery(
+  conversationId: string,
+  filter: UnreadReminderFilter,
+  options: UnreadReminderSummaryOptions
+): QueryTemplate {
+  return sql`
+    SELECT
+      sourceServiceId,
+      MAX(received_at_ms) AS latestReceivedAtMs
+    FROM messages
+    WHERE
+      sourceServiceId IS NOT NULL AND
+      ${unreadPredicate(conversationId, filter, options)}
+    GROUP BY sourceServiceId
+    ORDER BY latestReceivedAtMs DESC
+    LIMIT ${MAX_SENDERS_TO_SHOW}
+  `;
+}
+
+export function getUnreadReminderSummaryData(
+  db: ReadableDB,
+  conversationId: string,
+  options: UnreadReminderSummaryOptions
+): UnreadReminderSummaryData {
+  return db.transaction(() => {
+    const countUnread = (filter: UnreadReminderFilter) => {
+      const [query, params] = getUnreadReminderCountQuery(
+        conversationId,
+        filter,
+        options
+      );
+      return db.prepare(query, { pluck: true }).get<number>(params) ?? 0;
+    };
+
+    const getSenders = (filter: UnreadReminderFilter) => {
+      const [query, params] = getUnreadReminderSendersQuery(
+        conversationId,
+        filter,
+        options
+      );
+      return db.prepare(query).all<{
+        sourceServiceId: string;
+      }>(params);
+    };
+
+    const unreadMessageCount = countUnread('all');
+    const mentionCount = countUnread('mentions');
+    const replyCount = countUnread('replies');
+
+    return {
+      unreadMessageCount,
+      mentionCount,
+      replyCount,
+      senders: getSenders('all'),
+      mentioners: mentionCount > 0 ? getSenders('mentions') : [],
+      repliers: replyCount > 0 ? getSenders('replies') : [],
+    };
+  })();
+}