upub/src/activitypub/user/following.rs

use axum::{extract::{Path, Query, State}, http::StatusCode};
use sea_orm::{ColumnTrait, Condition, EntityTrait, PaginatorTrait, QueryFilter, QuerySelect, SelectColumns};

use crate::{activitypub::{jsonld::LD, JsonLD, Pagination}, activitystream::{object::collection::{page::CollectionPageMut, CollectionMut, CollectionType}, BaseMut, Node}, model, server::Context, url};

pub async fn follow___<const out: bool>(
	State(ctx): State<Context>,
	Path(id): Path<String>,
	Query(page): Query<Pagination>,
) -> Result<JsonLD<serde_json::Value>, StatusCode> {
	let follow___ = if out { "following" } else { "followers" };
	let limit = page.batch.unwrap_or(20).min(50);
	let offset = page.offset.unwrap_or(0);
	if let Some(true) = page.page {

		use model::relation::Column::{Following, Follower};
		match model::relation::Entity::find()
			.filter(Condition::all().add(if out { Follower } else { Following }.eq(id.clone())))
			.select_column(if out { Following } else { Follower })
			.limit(limit)
			.offset(page.offset.unwrap_or(0))
			.all(ctx.db()).await
		{
			Err(e) => {
				tracing::error!("error queriying {follow___} for {id}: {e}");
				Err(StatusCode::INTERNAL_SERVER_ERROR)
			},
			Ok(following) => {
				Ok(JsonLD(
					serde_json::Value::new_object()
						.set_collection_type(Some(CollectionType::OrderedCollectionPage))
						.set_part_of(Node::link(url!(ctx, "/users/{id}/{follow___}")))
						.set_next(Node::link(url!(ctx, "/users/{id}/{follow___}?page=true&offset={}", offset+limit)))
						.set_ordered_items(Node::array(following.into_iter().map(|x| x.following).collect()))
						.ld_context()
				))
			},
		}

	} else {

		let count = model::relation::Entity::find()
			.filter(Condition::all().add(model::relation::Column::Follower.eq(id.clone())))
			.count(ctx.db()).await.unwrap_or_else(|e| {
				tracing::error!("failed counting {follow___} for {id}: {e}");
				0
			});
		Ok(JsonLD(
			serde_json::Value::new_object()
				.set_id(Some(&format!("{}/users/{id}/{follow___}", ctx.base())))
				.set_collection_type(Some(CollectionType::OrderedCollection))
				.set_total_items(Some(count))
				.set_first(Node::link(format!("{}/users/{id}/{follow___}?page=true", ctx.base())))
				.ld_context()
		))

	}
}