max / makenotwork

3.7 KB · 104 lines History Blame Raw

1	//! thread-tracking and read-position reads
2
3	use super::{DateTime, PgPool, Utc, Uuid};
4
5	/// Check if a user is tracking a specific thread.
6	#[tracing::instrument(skip_all)]
7	pub async fn is_thread_tracked(
8	pool: &PgPool,
9	user_id: Uuid,
10	thread_id: Uuid,
11	) -> Result<bool, sqlx::Error> {
12	sqlx::query_scalar!(
13	r#"SELECT EXISTS(SELECT 1 FROM tracked_threads WHERE user_id = $1 AND thread_id = $2) AS "exists!""#,
14	user_id,
15	thread_id,
16	)
17	.fetch_one(pool)
18	.await
19	}
20
21	#[derive(sqlx::FromRow)]
22	pub struct TrackedThreadRow {
23	pub thread_id: Uuid,
24	pub thread_title: String,
25	pub community_name: String,
26	pub community_slug: String,
27	pub category_slug: String,
28	pub unread_count: i64,
29	pub has_mention: bool,
30	pub tracked_at: DateTime<Utc>,
31	}
32
33	/// List a user's tracked threads with unread post counts, newest activity first.
34	///
35	/// Paginated (`limit`/`offset`) so a user tracking hundreds of threads doesn't
36	/// render (and recompute) an unbounded page. The last-read cutoff is resolved
37	/// with a single LEFT JOIN rather than a per-row nested subquery, and both the
38	/// unread count and the mention flag count only live posts (`p.is_active`,
39	/// migration 034), so neither badge can be inflated by removed content and both
40	/// can use the `idx_posts_active` index.
41	///
42	/// The two carry the same filter deliberately. Both point the reader at content,
43	/// so a badge that outlives the post it names sends them to a thread with
44	/// nothing to find.
45	#[tracing::instrument(skip_all)]
46	pub async fn list_tracked_threads(
47	pool: &PgPool,
48	user_id: Uuid,
49	limit: i64,
50	offset: i64,
51	) -> Result<Vec<TrackedThreadRow>, sqlx::Error> {
52	sqlx::query_as!(
53	TrackedThreadRow,
54	r#"SELECT tt.thread_id,
55	t.title AS thread_title,
56	co.name AS community_name,
57	co.slug AS community_slug,
58	cat.slug AS category_slug,
59	(SELECT COUNT(*) FROM posts p
60	WHERE p.thread_id = tt.thread_id
61	AND p.is_active
62	AND (lrp.created_at IS NULL OR p.created_at > lrp.created_at)
63	) AS "unread_count!",
64	EXISTS (
65	SELECT 1 FROM post_mentions pm
66	JOIN posts p ON p.id = pm.post_id
67	WHERE pm.mentioned_user_id = tt.user_id
68	AND p.thread_id = tt.thread_id
69	AND p.is_active
70	) AS "has_mention!",
71	tt.tracked_at AS "tracked_at: chrono::DateTime<chrono::Utc>"
72	FROM tracked_threads tt
73	JOIN threads t ON t.id = tt.thread_id
74	JOIN categories cat ON cat.id = t.category_id
75	JOIN communities co ON co.id = cat.community_id
76	LEFT JOIN posts lrp ON lrp.id = tt.last_read_post_id
77	WHERE tt.user_id = $1 AND t.deleted_at IS NULL AND co.suspended_at IS NULL
78	ORDER BY t.last_activity_at DESC
79	LIMIT $2 OFFSET $3"#,
80	user_id,
81	limit,
82	offset,
83	)
84	.fetch_all(pool)
85	.await
86	}
87
88	/// Count a user's visible tracked threads (for pagination). Mirrors the
89	/// visibility filters of `list_tracked_threads`.
90	#[tracing::instrument(skip_all)]
91	pub async fn count_tracked_threads(pool: &PgPool, user_id: Uuid) -> Result<i64, sqlx::Error> {
92	sqlx::query_scalar!(
93	r#"SELECT COUNT(*) AS "count!"
94	FROM tracked_threads tt
95	JOIN threads t ON t.id = tt.thread_id
96	JOIN categories cat ON cat.id = t.category_id
97	JOIN communities co ON co.id = cat.community_id
98	WHERE tt.user_id = $1 AND t.deleted_at IS NULL AND co.suspended_at IS NULL"#,
99	user_id,
100	)
101	.fetch_one(pool)
102	.await
103	}
104