;; lib/host/feed.sx — Feed domain endpoints on the host. The first real endpoint
;; migrated onto the SX host: the activity timeline, read straight from the feed
;; subsystem's public API (feed/all + the stream combinators) and serialised as
;; JSON. GET /feed returns recent-first activities; ?actor=<id> filters by actor
;; and ?limit=<n> caps the count. Depends on lib/feed/* + lib/host/handler.sx.

;; GET /feed -> recent-first activities as a JSON envelope.
;; Query: ?actor=<id> (filter) ?limit=<n> (cap, applied after filtering).
(define host/feed-timeline
  (fn (req)
    (let ((base (feed/recent (feed/all)))
          (actor (dream-query-param req "actor")))
      (let ((filtered (if actor (feed/by-actor base actor) base))
            (limit (dream-query-param req "limit")))
        (let ((capped
                (if limit (feed/take filtered (string->number limit)) filtered)))
          (host/ok (feed/items capped)))))))

;; Route group contributed by the feed domain.
(define host/feed-routes
  (list
    (dream-get "/feed" host/feed-timeline)))