(;module:
  lux
  (lux [io]
       (concurrency ["A" atom])
       (data ["R" result]
             (coll ["d" dict])
             text/format)
       [macro #+ Monad<Lux>]
       [host #+ jvm-import do-to]))

## [Host]
(jvm-import org.objectweb.asm.Opcodes
  (#static V1_6 int)
  (#static CHECKCAST int)
  (#static INVOKESTATIC int)
  (#static INVOKEVIRTUAL int))

(jvm-import org.objectweb.asm.MethodVisitor
  (visitLdcInsn [Object] void)
  (visitTypeInsn [int String] void)
  (visitMethodInsn [int String String String boolean] void))

(jvm-import java.lang.Object
  (toString [] String))

(jvm-import (java.lang.Class a))

(jvm-import java.lang.ClassLoader
  (loadClass [String] (Class Object)))

## [Types]
(type: #export Bytecode host;Byte-Array)

(type: #export Class-Store (A;Atom (d;Dict Text Bytecode)))

(type: #export Host
  {#visitor (Maybe MethodVisitor)
   #loader ClassLoader
   #store Class-Store})

(def: #export unit Text "\u0000")

(def: (visitor::get compiler)
  (-> Compiler (Maybe MethodVisitor))
  (|> (get@ #;host compiler)
      (:! Host)
      (get@ #visitor)))

(def: (visitor::put ?visitor compiler)
  (-> (Maybe MethodVisitor) Compiler Compiler)
  (update@ #;host
           (function [host]
             (|> host
                 (:! Host)
                 (set@ #visitor ?visitor)
                 (:! Void)))
           compiler))

(def: #export get-visitor
  (Lux MethodVisitor)
  (function [compiler]
    (case (visitor::get compiler)
      #;None
      (#R;Error "No visitor has been set.")

      (#;Some visitor)
      (#R;Success [compiler visitor]))))

(def: #export (with-visitor visitor body)
  (All [a] (-> MethodVisitor (Lux a) (Lux a)))
  (function [compiler]
    (case (macro;run' (visitor::put (#;Some visitor) compiler) body)
      (#R;Error error)
      (#R;Error error)

      (#R;Success [compiler' output])
      (#R;Success [(visitor::put (visitor::get compiler) compiler')
                   output]))))

(def: #export (store-class name byte-code)
  (-> Text Bytecode (Lux Unit))
  (function [compiler]
    (let [store (|> (get@ #;host compiler)
                    (:! Host)
                    (get@ #store))]
      (if (d;contains? name (|> store A;get io;run))
        (#R;Error (format "Cannot store class that already exists: " name))
        (#R;Success [compiler (io;run (A;update (d;put name byte-code) store))])
        ))))

(def: #export (load-class name)
  (-> Text (Lux (Class Object)))
  (function [compiler]
    (let [host (:! Host (get@ #;host compiler))
          store (|> host (get@ #store) A;get io;run)]
      (if (d;contains? name store)
        (#R;Success [compiler (ClassLoader.loadClass [name] (get@ #loader host))])
        (#R;Error (format "Unknown class: " name))))))


(do-template [<wrap> <unwrap> <class> <unwrap-method> <prim> <dup>]
  [(def: #export (<wrap> writer)
     (-> MethodVisitor MethodVisitor)
     (do-to writer
       (MethodVisitor.visitMethodInsn [Opcodes.INVOKESTATIC
                                       <class> "valueOf" (format "(" <prim> ")" "L" <class> ";")
                                       false])))
   (def: #export (<unwrap> writer)
     (-> MethodVisitor MethodVisitor)
     (do-to writer
       (MethodVisitor.visitTypeInsn [Opcodes.CHECKCAST <class>])
       (MethodVisitor.visitMethodInsn [Opcodes.INVOKEVIRTUAL
                                       <class> <unwrap-method> (format "()" <prim>)
                                       false])))]

  [wrap-boolean unwrap-boolean "java/lang/Boolean"   "booleanValue" "Z" Opcodes.DUP_X1]
  [wrap-byte    unwrap-byte    "java/lang/Byte"      "byteValue"    "B" Opcodes.DUP_X1]
  [wrap-short   unwrap-short   "java/lang/Short"     "shortValue"   "S" Opcodes.DUP_X1]
  [wrap-int     unwrap-int     "java/lang/Integer"   "intValue"     "I" Opcodes.DUP_X1]
  [wrap-long    unwrap-long    "java/lang/Long"      "longValue"    "J" Opcodes.DUP_X2]
  [wrap-float   unwrap-float   "java/lang/Float"     "floatValue"   "F" Opcodes.DUP_X1]
  [wrap-double  unwrap-double  "java/lang/Double"    "doubleValue"  "D" Opcodes.DUP_X2]
  [wrap-char    unwrap-char    "java/lang/Character" "charValue"    "C" Opcodes.DUP_X1]
  )

(type: #export Flags Int)
(type: #export Descriptor Text)

(def: #export bytecode-version Flags Opcodes.V1_6)
(def: #export runtime-class-name Text "LuxRT")