max / makenotwork

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1	//! Feed page: items from followed users, projects, and tags.
2
3	use axum::extract::{Query, State};
4	use axum::response::IntoResponse;
5	use serde::Deserialize;
6	use sqlx::PgPool;
7	use tower_sessions::Session;
8
9	use crate::{
10	auth::AuthUser, constants, db, error::Result, helpers::get_csrf_token, templates::FeedTemplate,
11	types::DiscoverItem,
12	};
13
14	/// Query parameters for the feed page.
15	#[derive(Debug, Deserialize)]
16	pub(super) struct FeedQuery {
17	pub page: Option<u32>,
18	}
19
20	/// GET /feed: paginated feed of items from followed users, projects, and tags.
21	#[tracing::instrument(skip_all, name = "feed::feed_page")]
22	pub(super) async fn feed_page(
23	State(db): State<PgPool>,
24	session: Session,
25	AuthUser(user): AuthUser,
26	Query(query): Query<FeedQuery>,
27	) -> Result<impl IntoResponse> {
28	let csrf_token = get_csrf_token(&session).await;
29	let session_user = Some(user.clone());
30
31	// Clamp the upper bound too (matches admin/git pagination); the i64 widening
32	// below already prevents the overflow panic, but an unbounded page is a
33	// pointless huge offset (Run #2 UX MINOR).
34	let page = query.page.unwrap_or(1).clamp(1, 1_000_000_000);
35	// Widen to i64 BEFORE multiplying, `(page - 1) * FEED_PAGE_SIZE` in u32
36	// overflows for a large `?page=` (garbage offset in release, panic in debug).
37	let offset = (page as i64 - 1) * constants::FEED_PAGE_SIZE as i64;
38
39	let total_items = db::follows::count_followed_feed_items(&db, user.id).await? as u32;
40	let total_pages =
41	(total_items + constants::FEED_PAGE_SIZE - 1) / constants::FEED_PAGE_SIZE.max(1);
42
43	let db_items = db::follows::get_followed_feed_items(
44	&db,
45	user.id,
46	constants::FEED_PAGE_SIZE as i64,
47	offset,
48	)
49	.await?;
50
51	let items: Vec<DiscoverItem> = db_items.into_iter().map(DiscoverItem::from).collect();
52
53	// Compute the "showing X–Y" labels in i64 (saturating) to avoid the u32
54	// overflow `offset as u32 + FEED_PAGE_SIZE` would hit for a large `?page=`.
55	let showing_start = if total_items == 0 {
56	0
57	} else {
58	offset.saturating_add(1).clamp(0, u32::MAX as i64) as u32
59	};
60	let showing_end = offset
61	.saturating_add(constants::FEED_PAGE_SIZE as i64)
62	.min(total_items as i64)
63	.clamp(0, u32::MAX as i64) as u32;
64	let pagination_range = super::pagination::build_pagination_range(page, total_pages);
65
66	Ok(FeedTemplate {
67	csrf_token,
68	session_user,
69	items,
70	total_items,
71	current_page: page,
72	total_pages,
73	pagination_range,
74	showing_start,
75	showing_end,
76	})
77	}
78