(.module:
  [lux #*
   ["_" test (#+ Test)]
   [abstract
    [monad (#+ do)]]
   [control
    [io (#+ io)]
    [parser
     [cli (#+ program:)]]]
   [data
    ["." bit ("#\." equivalence)]
    ["." maybe ("#\." functor)]
    ["." text]
    [number
     ["n" nat ("#\." interval)]]
    [collection
     ["." list ("#\." functor)]]]
   [math
    ["." random (#+ Random)]]]
  {#program
   [/
    ["." license (#+ Identification
                     Termination
                     Liability
                     Distribution
                     Commercial
                     Extension
                     Entity Black-List
                     URL Attribution
                     Addendum
                     License)
     ["." time (#+ Period)]
     ["." copyright]
     ["." notice]
     ["." definition]
     ["." grant]
     ["." limitation]
     ["." submission]
     ["." liability]
     ["." distribution]
     ["." commercial]
     ["." extension]
     ["." miscellaneous]
     ["." black-list]
     ["." addendum]]
    ["." output]]})

(def: period
  (Random (Period Nat))
  (do {! random.monad}
    [start (random.filter (|>> (n.= n\top) not)
                          random.nat)
     #let [wiggle-room (n.- start n\top)]
     end (\ ! map
            (|>> (n.% wiggle-room) (n.max 1))
            random.nat)]
    (wrap {#time.start start
           #time.end end})))

(def: copyright-holder
  (Random copyright.Holder)
  ($_ random.and
      (random.ascii 10)
      ..period))

(def: identification
  (Random Identification)
  ($_ random.and
      (random.ascii 10)
      (random.ascii 10)))

(def: termination
  (Random Termination)
  ($_ random.and
      random.bit
      random.nat
      random.nat))

(def: liability
  (Random Liability)
  ($_ random.and
      random.bit
      random.bit))

(def: distribution
  (Random Distribution)
  ($_ random.and
      random.bit
      random.bit))

(def: commercial
  (Random Commercial)
  ($_ random.and
      random.bit
      random.bit
      random.bit))

(def: extension
  (Random Extension)
  ($_ random.and
      random.bit
      random.bit
      (random.maybe ..period)
      random.bit))

(def: entity
  (Random Entity)
  (random.ascii 10))

(def: (variable-list max-size gen-element)
  (All [a] (-> Nat (Random a) (Random (List a))))
  (do {! random.monad}
    [amount (\ ! map (n.% (n.max 1 max-size))
               random.nat)]
    (random.list amount gen-element)))

(def: black-list
  (Random Black-List)
  ($_ random.and
      (random.maybe (random.ascii 10))
      (variable-list 10 ..entity)))

(def: url
  (Random URL)
  (random.ascii 10))

(def: attribution
  (Random Attribution)
  ($_ random.and
      (random.ascii 10)
      (random.maybe (random.ascii 10))
      ..url
      (random.maybe ..url)))

(def: addendum
  (Random Addendum)
  ($_ random.and
      random.bit
      ))

(def: license
  (Random License)
  ($_ random.and
      (random.list 2 ..copyright-holder)
      (random.maybe ..identification)
      ..termination
      ..liability
      ..distribution
      ..commercial
      ..extension
      (variable-list 3 ..black-list)
      (random.maybe attribution)
      ..addendum
      ))

(type: (Concern a)
  (-> (-> Text Bit) a Test))

(def: (about-grant present? termination)
  (Concern Termination)
  ($_ _.and
      (_.test "Copyright grant is present."
              (present? grant.copyright))
      (_.test "Patent grant is present."
              (present? (grant.patent (get@ #license.patent-retaliation? termination))))
      (_.test "Effective date for the grants is present."
              (present? grant.date))
      (_.test "Patent grant is present."
              (present? (grant.termination (get@ #license.termination-period termination)
                                           (get@ #license.grace-period termination))))
      (_.test "The termination period is accurately conveyed."
              (present? (grant.grant-restoration-clause (get@ #license.termination-period termination))))
      (_.test "The grace period is accurately conveyed."
              (present? (grant.grace-period-clause (get@ #license.grace-period termination))))
      (_.test "The grants are not retro-actively terminated."
              (present? grant.no-retroactive-termination))
      ))

(def: (about-liability present? liability)
  (Concern Liability)
  ($_ _.and
      (_.test "Warranty liability disclaimer is present."
              (present? liability.warranty))
      (_.test "Limitation of liability is present."
              (present? liability.limitation))
      (_.test "Litigation conditions are present."
              (present? liability.litigation))
      (_.test "Liability acceptance conditions may be present."
              (bit\= (get@ #license.can-accept? liability)
                     (present? liability.can-accept)))
      (_.test "Liability acceptance conditions may be present."
              (bit\= (get@ #license.disclaim-high-risk? liability)
                     (present? liability.disclaim-high-risk)))
      ))

(def: (about-distribution present? distribution)
  (Concern Distribution)
  ($_ _.and
      (_.test "Conditions for source-code distribution are present."
              (present? distribution.source-code-form))
      (_.test "Conditions for object-code distribution are present."
              (present? distribution.object-form))
      (_.test "Conditions for extension distribution are present."
              (present? (distribution.extension distribution)))
      ))

(def: (about-commercial present? commercial)
  (Concern Commercial)
  ($_ _.and
      (_.test "Non-commercial clause is present."
              (bit\= (not (get@ #license.can-sell? commercial))
                     (present? commercial.cannot-sell)))
      (_.test "Contributor credit condition is present."
              (bit\= (get@ #license.require-contributor-credit? commercial)
                     (present? commercial.require-contributor-attribution)))
      (_.test "Anti-endorsement condition is present."
              (bit\= (not (get@ #license.allow-contributor-endorsement? commercial))
                     (present? commercial.disallow-contributor-endorsement)))
      ))

(def: (about-extension present? extension)
  (Concern Extension)
  ($_ _.and
      (_.test "The license is viral."
              (bit\= (get@ #license.same-license? extension)
                     (and (list.every? present? extension.sharing-requirement)
                          (list.every? present? extension.license-conflict-resolution))))
      (_.test "Extensions must be distinguishable from the original work."
              (bit\= (get@ #license.must-be-distinguishable? extension)
                     (present? extension.distinctness-requirement)))
      (_.test "The community must be notified of new extensions."
              (case (get@ #license.notification-period extension)
                (#.Some period)
                (present? (extension.notification-requirement period))

                #.None
                true))
      (_.test "Must describe modifications."
              (bit\= (get@ #license.must-describe-modifications? extension)
                     (present? extension.description-requirement)))
      ))

(def: (about-attribution present? attribution)
  (Concern Attribution)
  ($_ _.and
      (_.test "The attribution copyright notice is present."
              (present? (get@ #license.copyright-notice attribution)))
      (_.test "The attribution phrase is present."
              (|> attribution
                  (get@ #license.phrase)
                  (maybe\map present?)
                  (maybe.default true)))
      (_.test "The attribution URL is present."
              (present? (get@ #license.url attribution)))
      (_.test "The attribution image is present."
              (|> attribution
                  (get@ #license.image)
                  (maybe\map present?)
                  (maybe.default true)))
      ))

(def: (about-miscellaneous present?)
  (-> (-> Text Bit) Test)
  ($_ _.and
      (_.test "License constitutes the entire agreement."
              (present? miscellaneous.entire-agreement))
      (_.test "Disclaims relationship of parties."
              (present? miscellaneous.relationship-of-parties))
      (_.test "Explicitly allows independent development."
              (present? miscellaneous.independent-development))
      (_.test "Clarifies consent to breach does not waiver."
              (present? miscellaneous.not-waiver))
      (_.test "Provides severability."
              (present? miscellaneous.severability))
      (_.test "Covers export restrictions."
              (present? miscellaneous.export-restrictions))
      ))

(def: (about-addendum present? value)
  (Concern Addendum)
  ($_ _.and
      (_.test "Commons clause"
              (bit\= (get@ #license.commons-clause? value)
                     (present? addendum.commons-clause)))
      ))

(def: test
  Test
  (do random.monad
    [license ..license
     #let [writ (output.license license)
           present? (: (-> Text Bit)
                       (function (_ snippet)
                         (text.contains? snippet writ)))]]
    ($_ _.and
        (_.test "Copyright notices are present."
                (list.every? (|>> notice.copyright-holder present?)
                             (get@ #license.copyright-holders license)))
        
        (_.test "Identification is present (if the license is identified)."
                (case (get@ #license.identification license)
                  (#.Some identification)
                  (and (present? (output.identification identification))
                       (present? miscellaneous.new-versions))

                  #.None
                  (not (present? miscellaneous.new-versions))))

        (_.test "Black-lists (if wanted by licensor) are explicitly enumerated and justified."
                (list.every? (function (_ black-list)
                               (let [black-list-is-justified? (case (get@ #license.justification black-list)
                                                                (#.Some justification)
                                                                (present? justification)

                                                                #.None
                                                                yes)
                                     every-entity-is-mentioned? (|> black-list
                                                                    (get@ #license.entities)
                                                                    (list\map black-list.entity)
                                                                    (list.every? present?))]
                                 (and black-list-is-justified?
                                      every-entity-is-mentioned?)))
                             (get@ #license.black-lists license)))
        
        (_.test "All definitions are present."
                (list.every? (|>> output.definition present?)
                             definition.all))

        (_.test "Acceptance of the license is demanded."
                (present? limitation.acceptance))
        
        (..about-grant present? (get@ #license.termination license))
        
        (_.test "All limitations are present."
                (present? output.limitation))
        
        (_.test "All assurances are present."
                (present? output.assurance))
        
        (_.test "The terms of submission are present."
                (present? submission.contribution))
        
        (..about-liability present? (get@ #license.liability license))

        (..about-distribution present? (get@ #license.distribution license))

        (..about-commercial present? (get@ #license.commercial license))

        (..about-extension present? (get@ #license.extension license))

        (case (get@ #license.attribution license)
          (#.Some attribution)
          (..about-attribution present? attribution)

          #.None
          (_.test "Attribution is missing."
                  yes))

        (..about-miscellaneous present?)

        (..about-addendum present? (get@ #license.addendum license))

        (_.test "License ending footer is present."
                (present? notice.end-of-license))
        )))

(program: args
  (io (_.run! (<| (_.times 100)
                  ..test))))