(.module:
  [lux #*
   ["_" test (#+ Test)]
   [abstract
    [monad (#+ do)]]
   [control
    ["." try]
    ["." exception (#+ exception:)]
    [concurrency
     ["." promise (#+ Promise)]]
    [security
     ["!" capability]]]
   [data
    ["." maybe]
    ["." text ("#\." equivalence)
     ["%" format (#+ format)]]]
   [math
    ["." random]]
   [tool
    [compiler
     ["." version]
     ["." language #_
      ["#/." lux #_
       ["#" version]]]]]
   [world
    ["." console (#+ Console Simulation)]]]
  [///
   ["@." profile]]
  {#program
   ["." /]})

(exception: #export console_is_closed!)

(structure: simulation
  (Simulation [Bit Text])

  (def: (on_read [open? state])
    (if open?
      (try.from_maybe
       (do maybe.monad
         [head (text.nth 0 state)
          [_ tail] (text.split 1 state)]
         (wrap [[open? tail] head])))
      (exception.throw ..console_is_closed! [])))
  (def: (on_read_line [open? state])
    (if open?
      (try.from_maybe
       (do maybe.monad
         [[output state] (text.split_with text.new_line state)]
         (wrap [[open? state] output])))
      (exception.throw ..console_is_closed! [])))
  (def: (on_write input [open? state])
    (if open?
      (#try.Success [open? (format state input)])
      (exception.throw ..console_is_closed! [])))
  (def: (on_close [open? buffer])
    (if open?
      (#try.Success [false buffer])
      (exception.throw ..console_is_closed! []))))

(def: #export echo
  (-> Text (Console Promise))
  (|>> [true]
       (console.mock ..simulation)
       console.async))

(def: #export test
  Test
  (<| (_.covering /._)
      (do random.monad
        [profile @profile.random]
        (wrap (do promise.monad
                [#let [console (..echo "")]
                 verdict (do (try.with promise.monad)
                           [_ (/.do! console profile)
                            logging (!.use (\ console read_line) [])]
                           (wrap (text\= (version.format language/lux.version)
                                         logging)))]
                (_.cover' [/.do!]
                          (try.default false verdict)))))))