(.using
  [library
   [lux {"-" Type}
    ["[0]" ffi {"+" import: do_to}]
    [control
     ["[0]" function]]
    [data
     ["[0]" product]
     ["[0]" text
      ["%" format {"+" format}]]
     [collection
      ["[0]" array {"+" Array}]
      ["[0]" list ("[1]@[0]" functor)]]]
    [math
     [number
      ["i" int]]]
    [target
     [jvm
      [encoding
       ["[0]" name]]
      ["[0]" type {"+" Type Constraint}
       [category {"+" Class Value Method}]
       ["[0]" signature]
       ["[0]" descriptor]]]]]]
  ["[0]" //])

(def: signature (|>> type.signature signature.signature))
(def: descriptor (|>> type.descriptor descriptor.descriptor))
(def: class_name (|>> type.descriptor descriptor.class_name name.read))

(import: java/lang/Object)
(import: java/lang/String)

(import: org/objectweb/asm/Opcodes
  ["[1]::[0]"
   ("static" ACC_PUBLIC int)
   ("static" ACC_PROTECTED int)
   ("static" ACC_PRIVATE int)

   ("static" ACC_TRANSIENT int)
   ("static" ACC_VOLATILE int)

   ("static" ACC_ABSTRACT int)
   ("static" ACC_FINAL int)
   ("static" ACC_STATIC int)
   ("static" ACC_SYNCHRONIZED int)
   ("static" ACC_STRICT int)

   ("static" ACC_SUPER int)
   ("static" ACC_INTERFACE int)

   ("static" V1_1 int)
   ("static" V1_2 int)
   ("static" V1_3 int)
   ("static" V1_4 int)
   ("static" V1_5 int)
   ("static" V1_6 int)
   ("static" V1_7 int)
   ("static" V1_8 int)])

(import: org/objectweb/asm/FieldVisitor
  ["[1]::[0]"
   (visitEnd [] void)])

(import: org/objectweb/asm/MethodVisitor
  ["[1]::[0]"
   (visitCode [] void)
   (visitMaxs [int int] void)
   (visitEnd [] void)])

(import: org/objectweb/asm/ClassWriter
  ["[1]::[0]"
   ("static" COMPUTE_MAXS int)
   ("static" COMPUTE_FRAMES int)
   (new [int])
   (visit [int int java/lang/String java/lang/String java/lang/String [java/lang/String]] void)
   (visitEnd [] void)
   (visitField [int java/lang/String java/lang/String java/lang/String java/lang/Object] org/objectweb/asm/FieldVisitor)
   (visitMethod [int java/lang/String java/lang/String java/lang/String [java/lang/String]] org/objectweb/asm/MethodVisitor)
   (toByteArray [] [byte])])

(def: (string_array values)
  (-> (List Text) (Array Text))
  (let [output (ffi.array java/lang/String (list.size values))]
    (exec (list@each (function (_ [idx value])
                       (ffi.write! idx value output))
                     (list.enumeration values))
      output)))

(def: (version_flag version)
  (-> //.Version Int)
  (case version
    {//.#V1_1} (org/objectweb/asm/Opcodes::V1_1)
    {//.#V1_2} (org/objectweb/asm/Opcodes::V1_2)
    {//.#V1_3} (org/objectweb/asm/Opcodes::V1_3)
    {//.#V1_4} (org/objectweb/asm/Opcodes::V1_4)
    {//.#V1_5} (org/objectweb/asm/Opcodes::V1_5)
    {//.#V1_6} (org/objectweb/asm/Opcodes::V1_6)
    {//.#V1_7} (org/objectweb/asm/Opcodes::V1_7)
    {//.#V1_8} (org/objectweb/asm/Opcodes::V1_8)))

(def: (visibility_flag visibility)
  (-> //.Visibility Int)
  (case visibility
    {//.#Public}    (org/objectweb/asm/Opcodes::ACC_PUBLIC)
    {//.#Protected} (org/objectweb/asm/Opcodes::ACC_PROTECTED)
    {//.#Private}   (org/objectweb/asm/Opcodes::ACC_PRIVATE)
    {//.#Default}   +0))

(def: (class_flags config)
  (-> //.Class_Config Int)
  ($_ i.+
      (if (value@ //.#finalC config) (org/objectweb/asm/Opcodes::ACC_FINAL) +0)))

(def: (method_flags config)
  (-> //.Method_Config Int)
  ($_ i.+
      (if (value@ //.#staticM config) (org/objectweb/asm/Opcodes::ACC_STATIC) +0)
      (if (value@ //.#finalM config) (org/objectweb/asm/Opcodes::ACC_FINAL) +0)
      (if (value@ //.#synchronizedM config) (org/objectweb/asm/Opcodes::ACC_SYNCHRONIZED) +0)
      (if (value@ //.#strictM config) (org/objectweb/asm/Opcodes::ACC_STRICT) +0)))

(def: (field_flags config)
  (-> //.Field_Config Int)
  ($_ i.+
      (if (value@ //.#staticF config) (org/objectweb/asm/Opcodes::ACC_STATIC) +0)
      (if (value@ //.#finalF config) (org/objectweb/asm/Opcodes::ACC_FINAL) +0)
      (if (value@ //.#transientF config) (org/objectweb/asm/Opcodes::ACC_TRANSIENT) +0)
      (if (value@ //.#volatileF config) (org/objectweb/asm/Opcodes::ACC_VOLATILE) +0)))

(def: param_signature
  (-> (Type Class) Text)
  (|>> ..signature (format ":")))

(def: (formal_param [name super interfaces])
  (-> Constraint Text)
  (format name
          (param_signature super)
          (|> interfaces
              (list@each param_signature)
              (text.interposed ""))))

(def: (constraints_signature constraints super interfaces)
  (-> (List Constraint) (Type Class) (List (Type Class))
      Text)
  (let [formal_params (if (list.empty? constraints)
                        ""
                        (format "<"
                                (|> constraints
                                    (list@each formal_param)
                                    (text.interposed ""))
                                ">"))]
    (format formal_params
            (..signature super)
            (|> interfaces
                (list@each ..signature)
                (text.interposed "")))))

(def: class_computes
  Int
  ($_ i.+
      (org/objectweb/asm/ClassWriter::COMPUTE_MAXS)
      ... (org/objectweb/asm/ClassWriter::COMPUTE_FRAMES)
      ))

(def: binary_name (|>> name.internal name.read))

(template [<name> <flag>]
  [(def: .public (<name> version visibility config name constraints super interfaces
                         definitions)
     (-> //.Version //.Visibility //.Class_Config Text (List Constraint) (Type Class) (List (Type Class)) //.Def
         (ffi.type [byte]))
     (let [writer (|> (do_to (org/objectweb/asm/ClassWriter::new class_computes)
                        (org/objectweb/asm/ClassWriter::visit (version_flag version)
                                                              ($_ i.+
                                                                  (org/objectweb/asm/Opcodes::ACC_SUPER)
                                                                  <flag>
                                                                  (visibility_flag visibility)
                                                                  (class_flags config))
                                                              (..binary_name name)
                                                              (constraints_signature constraints super interfaces)
                                                              (..class_name super)
                                                              (|> interfaces
                                                                  (list@each ..class_name)
                                                                  string_array)))
                      definitions)
           _ (org/objectweb/asm/ClassWriter::visitEnd writer)]
       (org/objectweb/asm/ClassWriter::toByteArray writer)))]

  [class    +0]
  [abstract (org/objectweb/asm/Opcodes::ACC_ABSTRACT)]
  )

(def: $Object
  (Type Class)
  (type.class "java.lang.Object" (list)))

(def: .public (interface version visibility config name constraints interfaces
                         definitions)
  (-> //.Version //.Visibility //.Class_Config Text (List Constraint) (List (Type Class)) //.Def
      (ffi.type [byte]))
  (let [writer (|> (do_to (org/objectweb/asm/ClassWriter::new class_computes)
                     (org/objectweb/asm/ClassWriter::visit (version_flag version)
                                                           ($_ i.+
                                                               (org/objectweb/asm/Opcodes::ACC_ABSTRACT)
                                                               (org/objectweb/asm/Opcodes::ACC_INTERFACE)
                                                               (visibility_flag visibility)
                                                               (class_flags config))
                                                           (..binary_name name)
                                                           (constraints_signature constraints $Object interfaces)
                                                           (..class_name $Object)
                                                           (|> interfaces
                                                               (list@each ..class_name)
                                                               string_array)))
                   definitions)
        _ (org/objectweb/asm/ClassWriter::visitEnd writer)]
    (org/objectweb/asm/ClassWriter::toByteArray writer)))

(def: .public (method visibility config name type then)
  (-> //.Visibility //.Method_Config Text (Type Method) //.Inst
      //.Def)
  (function (_ writer)
    (let [=method (org/objectweb/asm/ClassWriter::visitMethod ($_ i.+
                                                                  (visibility_flag visibility)
                                                                  (method_flags config))
                                                              (..binary_name name)
                                                              (..descriptor type)
                                                              (..signature type)
                                                              (string_array (list))
                                                              writer)
          _ (org/objectweb/asm/MethodVisitor::visitCode =method)
          _ (then =method)
          _ (org/objectweb/asm/MethodVisitor::visitMaxs +0 +0 =method)
          _ (org/objectweb/asm/MethodVisitor::visitEnd =method)]
      writer)))

(def: .public (abstract_method visibility config name type)
  (-> //.Visibility //.Method_Config Text (Type Method)
      //.Def)
  (function (_ writer)
    (let [=method (org/objectweb/asm/ClassWriter::visitMethod ($_ i.+
                                                                  (visibility_flag visibility)
                                                                  (method_flags config)
                                                                  (org/objectweb/asm/Opcodes::ACC_ABSTRACT))
                                                              (..binary_name name)
                                                              (..descriptor type)
                                                              (..signature type)
                                                              (string_array (list))
                                                              writer)
          _ (org/objectweb/asm/MethodVisitor::visitEnd =method)]
      writer)))

(def: .public (field visibility config name type)
  (-> //.Visibility //.Field_Config Text (Type Value) //.Def)
  (function (_ writer)
    (let [=field (do_to (org/objectweb/asm/ClassWriter::visitField ($_ i.+
                                                                       (visibility_flag visibility)
                                                                       (field_flags config))
                                                                   (..binary_name name)
                                                                   (..descriptor type)
                                                                   (..signature type)
                                                                   (ffi.null)
                                                                   writer)
                   (org/objectweb/asm/FieldVisitor::visitEnd))]
      writer)))

(template [<name> <lux_type> <jvm_type> <prepare>]
  [(def: .public (<name> visibility config name value)
     (-> //.Visibility //.Field_Config Text <lux_type> //.Def)
     (function (_ writer)
       (let [=field (do_to (org/objectweb/asm/ClassWriter::visitField ($_ i.+
                                                                          (visibility_flag visibility)
                                                                          (field_flags config))
                                                                      (..binary_name name)
                                                                      (..descriptor <jvm_type>)
                                                                      (..signature <jvm_type>)
                                                                      (<prepare> value)
                                                                      writer)
                      (org/objectweb/asm/FieldVisitor::visitEnd))]
         writer)))]

  [boolean_field Bit  type.boolean                           function.identity]
  [byte_field    Int  type.byte                              ffi.long_to_byte]
  [short_field   Int  type.short                             ffi.long_to_short]
  [int_field     Int  type.int                               ffi.long_to_int]
  [long_field    Int  type.long                              function.identity]
  [float_field   Frac type.float                             ffi.double_to_float]
  [double_field  Frac type.double                            function.identity]
  [char_field    Nat  type.char                              (|>> .int ffi.long_to_int ffi.int_to_char)]
  [string_field  Text (type.class "java.lang.String" (list)) function.identity]
  )

(def: .public (fuse defs)
  (-> (List //.Def) //.Def)
  (case defs
    {.#End}
    function.identity

    {.#Item singleton {.#End}}
    singleton

    {.#Item head tail}
    (function.composite (fuse tail) head)))