(.module:
  [library
   [lux {"-" [Type]}
    ["[0]" ffi {"+" [import:]}]
    [abstract
     ["[0]" monad {"+" [do]}]]
    [control
     ["[0]" exception {"+" [exception:]}]]
    [data
     [text
      ["%" format {"+" [format]}]]
     [collection
      ["[0]" list]]]
    [math
     [number
      ["n" nat]
      ["i" int]]]
    [target
     [jvm
      ["[0]" type {"+" [Type]}
       ["[0]" category {"+" [Void Value Return Primitive Object Class Array Var Parameter Method]}]
       ["[0]" descriptor {"+" [Descriptor]}]
       ["[0]" signature {"+" [Signature]}]]]]
    [tool
     [compiler
      ["[0]" phase]
      [meta
       [archive {"+" [Archive]}]]
      [language
       [lux
        [synthesis {"+" [Synthesis]}]]]]]]]
  [luxc
   [lang
    [host
     [jvm {"+" [Inst Operation Phase Generator]}
      ["_" inst]]]]]
  ["[0]" //
   ["[1][0]" runtime]])

(exception: .public (not_a_tuple [size Nat])
  (exception.report
   ["Expected size" ">= 2"]
   ["Actual size" (%.nat size)]))

(def: .public (tuple generate archive members)
  (Generator (List Synthesis))
  (do [@ phase.monad]
    [.let [size (list.size members)]
     _ (phase.assertion ..not_a_tuple size
                        (n.>= 2 size))
     membersI (|> members
                  list.enumeration
                  (monad.each @ (function (_ [idx member])
                                  (do @
                                    [memberI (generate archive member)]
                                    (in (|>> _.DUP
                                             (_.int (.int idx))
                                             memberI
                                             _.AASTORE)))))
                  (\ @ each _.fuse))]
    (in (|>> (_.int (.int size))
             (_.array //runtime.$Value)
             membersI))))

(import: java/lang/Byte
  ["[1]::[0]"
   ("static" MAX_VALUE byte)
   ("static" MIN_VALUE byte)])

(import: java/lang/Short
  ["[1]::[0]"
   ("static" MAX_VALUE short)
   ("static" MIN_VALUE short)])

(def: .public (tagI lefts right?)
  (-> Nat Bit Inst)
  (case lefts
    0 _.ICONST_0
    1 _.ICONST_1
    2 _.ICONST_2
    3 _.ICONST_3
    4 _.ICONST_4
    5 _.ICONST_5
    tag (let [tag (.int tag)]
          (cond (and (i.>= (java/lang/Byte::MIN_VALUE) tag)
                     (i.<= (java/lang/Byte::MAX_VALUE) tag))
                (_.BIPUSH tag)
                
                (and (i.>= (java/lang/Short::MIN_VALUE) tag)
                     (i.<= (java/lang/Short::MAX_VALUE) tag))
                (_.SIPUSH tag)

                ... else
                (_.int tag)))))

(def: .public leftI _.NULL)
(def: .public rightI (_.string ""))

(def: .public (flagI right?)
  (-> Bit Inst)
  (if right?
    ..rightI
    ..leftI))

(def: .public (variant generate archive [lefts right? member])
  (Generator [Nat Bit Synthesis])
  (do phase.monad
    [memberI (generate archive member)
     .let [tagI (..tagI lefts right?)]]
    (in (|>> tagI
             (flagI right?)
             memberI
             (_.INVOKESTATIC //.$Runtime
                             "variant_make"
                             (type.method [(list)
                                           (list //runtime.$Lefts //runtime.$Right? //runtime.$Value)
                                           //.$Variant
                                           (list)]))))))