; Forward direction — artdag job as a feed "post object" (per the host loop).
; A job projects to a content-addressed, self-verifying object suitable as a feed
; activity :object; a peer decodes, verifies and runs it to the same result.

(define po-runner (artdag/op-table-runner {:blur (fn (params inputs) (+ (first inputs) (get params :radius))) :src (fn (params inputs) 0) :over (fn (params inputs) (+ (nth inputs 0) (nth inputs 1)))}))

(define
  po-job
  (artdag/build
    (list
      (list "s" "src" (list) {})
      (list "b" "blur" (list "s") {:radius 2})
      (list "c" "blur" (list "s") {:radius 3})
      (list "out" "over" (list "b" "c") {} true))))
(define po-out-id (artdag/dag-id po-job "out"))
(define po-post (artdag/job->post-object po-job "out"))

(artdag-test
  "post: is a well-formed post object"
  (artdag/post-object? po-post)
  true)

(artdag-test "post: type tag is artdag/job" (get po-post :type) "artdag/job")

(artdag-test
  "post: post id is the output node's content-id"
  (artdag/post-object-id po-post)
  po-out-id)

(artdag-test
  "post: payload is the whole dag (one record per node)"
  (len (artdag/post-object-wire po-post))
  (artdag/node-count po-job))

(artdag-test
  "post: verifies (ids intact, output present)"
  (artdag/post-object-verify po-post)
  true)

; ---- round-trip: decode reconstructs the job by content-id ----

(define po-job2 (artdag/post-object->job po-post))

(artdag-test
  "post: decoded job contains the output node by content-id"
  (artdag/member? po-out-id (keys (artdag/dag-nodes po-job2)))
  true)

(artdag-test
  "post: decoded job has the same node count"
  (artdag/node-count po-job2)
  (artdag/node-count po-job))

; ---- string transport (feed activity / SXTP body) ----

(define po-str (artdag/job->post-string po-job "out"))
(define po-post2 (artdag/post-string->object po-str))

(artdag-test
  "post: survives string transport (id preserved)"
  (artdag/post-object-id po-post2)
  po-out-id)

(artdag-test
  "post: transported post still verifies"
  (artdag/post-object-verify po-post2)
  true)

; ---- a peer runs the received post to the same result ----

(define
  po-local-result
  (artdag/result-of (artdag/run po-job po-runner (persist/open)) po-out-id))
(define po-peer-result (artdag/post-run po-post2 po-runner (persist/open)))

(artdag-test
  "post: peer runs the received job to the same result"
  (= po-peer-result po-local-result)
  true)

; ---- tamper detection: mutate a param under a stale id ----

(define
  po-tampered
  (assoc
    po-post
    :wire (map
      (fn
        (rec)
        (if
          (= (nth rec 1) "blur")
          (list
            (nth rec 0)
            (nth rec 1)
            (nth rec 2)
            {:radius 99}
            (nth rec 4))
          rec))
      (artdag/post-object-wire po-post))))

(artdag-test
  "post: tampered payload fails verification"
  (artdag/post-object-verify po-tampered)
  false)

; ---- an id not produced by the job fails verification ----

(artdag-test
  "post: post id absent from payload fails verification"
  (artdag/post-object-verify (assoc po-post :id "node:bogus"))
  false)