#lang syndicate

(require racket/set)

(spawn #:name 'queryer
       (define/query-value as-value 'absent `(item ,$a ,$b) (list a b))
       (define/query-set as-set `(item ,$a ,$b) (list a b)
         #:on-add (log-info "as-set adding ~v/~v" a b)
         #:on-remove (log-info "as-set removing ~v/~v" a b))
       (define/query-hash as-hash `(item ,$a ,$b) a b)
       (define/query-hash-set as-hash-set `(item ,$a ,$b) a b)

       (field [as-value-notification-counter 0])

       (begin/dataflow
         (log-info "Notification counter: ~v" (as-value-notification-counter))
         (local-require (only-in racket/base sleep))
         (sleep 1))

       (let ((shadow-counter 0))
         (begin/dataflow
           (log-info "as-value is now: ~v" (as-value))
           (set! shadow-counter (+ shadow-counter 1))
           (as-value-notification-counter shadow-counter)))

       (on (message 'dump)
           (printf "----------------------------------------\n")
           (printf "Queried as-value: ~v\n" (as-value))
           (newline)
           (printf "Queried as-set:\n")
           (for [(item (as-set))]
             (match-define (list a b) item)
             (printf "  ~v -> ~v\n" a b))
           (newline)
           (printf "Queried as-hash:\n")
           (for [((k v) (in-hash (as-hash)))]
             (printf "  ~v -> ~v\n" k v))
           (newline)
           (printf "Queried as-hash-set:\n")
           (for [((k vs) (in-hash (as-hash-set)))]
             (printf "  ~v -> ~v\n" k vs))
           (printf "----------------------------------------\n")
           (flush-output)))

(spawn* #:name 'mutator
        (until (asserted 'observer-in-ds-ready))
        (assert! `(item a 1))
        (assert! `(item b 2))
        (assert! `(item b 3))
        (send! 'dump)
        (retract! `(item b ,?))
        (send! 'dump)
        (assert! `(item c 1))
        (assert! `(item c 4))
        (send! 'dump)
        (forever))

(let ((anchor (level-anchor)))
  (dataspace (define LEVEL (level-anchor->meta-level anchor))
             (log-info "Outer level anchor: ~a" anchor)
             (log-info "Inner level anchor: ~a" (level-anchor))
             (log-info "Computed meta-level: ~v" LEVEL)
             (spawn #:name 'observer-in-ds
                    (assert (outbound* LEVEL 'observer-in-ds-ready))
                    (on-start (log-info "observer-in-ds: STARTING"))
                    (define/query-set items (inbound* LEVEL `(item ,$a ,$b)) (list a b))
                    (on (message (inbound* LEVEL 'dump))
                        (log-info "observer-in-ds: ~v" (items))))
             (forever)))