(**************************************************************************)
(*                                                                        *)
(*  Heptagon                                                              *)
(*                                                                        *)
(*  Author : Marc Pouzet                                                  *)
(*  Organization : Demons, LRI, University of Paris-Sud, Orsay            *)
(*                                                                        *)
(**************************************************************************)

(** An Obc.program is a Java.package,
       Obc.type_dec, Obc.class_def are Java.classs
       Obc.const_dec is defined in the special class CONSTANTES
       Obc.Lvar are Pvar
       Obc.Lmem are this.Pvar (Pfield)
       Obc.Oobj and Oarray are simply Pvar and Parray_elem
       Obc.Types_alias are dereferenced since no simple type alias is possible in Java *)

open Format
open Misc
open Names
open Modules
open Signature
open Obc
open Java


(** a [Module] becomes a [package] *)
let translate_qualname q = match q with
  | { qual = "Pervasives" } -> q
  | { qual = m } when m = g_env.current_mod -> q (* current module is not translated to keep track,
                                                    there is no issue since printed without the qualifier *)
  | { qual = m } when m = local_qualname -> q
  | _ -> { q with qual = String.lowercase q.qual }

(** a [Module.const] becomes a [module.CONSTANTES.CONST] *)
let translate_const_name q =
  let q = translate_qualname q in
  { qual = q.qual ^ ".CONSTANTES"; name = String.uppercase q.name }

(** a [Module.name] becomes a [module.Name]
    used for type_names, class_names, fun_names *)
let qualname_to_class_name q =
  let q = translate_qualname q in
  { q with name = String.capitalize q.name }

(** a [Module.Constr] of an [Module.enum] type becomes a [module.Enum.CONSTR] of the [module.Enum] class *)
let _translate_constructor_name q q_ty =
  let classe = qualname_to_class_name q_ty in
  let classe_name = classe.qual ^ "." ^ classe.name in
  let constr = { qual = classe_name; name = q |> shortname |> String.uppercase } in
  constr

let translate_constructor_name q =
  match Modules.find_constrs c with
    | Tid c_ty -> _translate_constructor_name q q_ty
    | _ -> assert false

(** a [name] becomes a [package.Name] *)
let name_to_classe_name n = n |> Modules.current_qual |> qualname_to_class_name

(** translate an ostatic_exp into an jexp *)
let rec static_exp param_env se = match se.Types.se_desc with
  | Types.Svar c ->
      if shortname c = local_qualname
      then let n = NamesEnv.find (shortname c) param_env in Svar (n |> Idents.name |> local_qn)
      else Svar (translate_const_name c)
  | Types.Sint i -> Sint i
  | Types.Sfloat f -> Sfloat f
  | Types.Sbool b -> Sbool b
  | Types.Sconstructor c -> let c = translate_constructor_name c in Sconstructor c
  | Types.Sfield f -> assert false;
  | Types.Stuple t -> assert false; (* TODO java ?? not too dificult if needed, return Tuplen<..>() *)
  | Types.Sarray_power _ -> assert false; (* TODO java array *)
  | Types.Sarray se_l -> Earray (List.map (static_exp param_env) se_l)
  | Types.Srecord _ -> assert false; (* TODO java *)
  | Types.Sop (f, se_l) -> Efun (qualname_to_class_name f, List.map (static_exp param_env) se_l)

and boxed_ty param_env t = match t with
  | Types.Tprod ty_l ->
      let ln = ty_l |> List.length |> Pervasives.char_of_int |> (String.make 1) in
      Tgeneric ({ qual = "heptagon"; name = "Tuple"^ln }, List.map (boxed_ty param_env) ty_l)
  | Types.Tid t when t = Initial.pbool -> Tclass (Names.local_qn "Boolean")
  | Types.Tid t when t = Initial.pint -> Tclass (Names.local_qn "Integer")
  | Types.Tid t when t = Initial.pfloat -> Tclass (Names.local_qn "Float")
  | Types.Tid t -> Tclass (qualname_to_class_name t)
  | Types.Tarray (t,size) -> Tarray (boxed_ty param_env t, static_exp param_env size)
  | Types.Tasync _ -> assert false; (* TODO async *)
  | Types.Tunit -> Tunit

and ty param_env t :Java.ty = match t with
  | Types.Tprod ty_l ->
      let ln = ty_l |> List.length |> Pervasives.char_of_int |> (String.make 1) in
      Tgeneric ({ qual = "heptagon"; name = "Tuple"^ln }, List.map (boxed_ty param_env) ty_l)
  | Types.Tid t when t = Initial.pbool -> Tbool
  | Types.Tid t when t = Initial.pint -> Tint
  | Types.Tid t when t = Initial.pfloat -> Tfloat
  | Types.Tid t -> Tclass (qualname_to_class_name t)
  | Types.Tarray (t,size) -> Tarray (ty param_env t, static_exp param_env size)
  | Types.Tasync _ -> assert false; (* TODO async *)
  | Types.Tunit -> Tunit


let var_dec_list param_env vd_l =
  let _vd vd = { vd_type = ty param_env vd.v_type; vd_ident = vd.v_ident } in
  List.map _vd vd_l

let act_list param_env act_l =
  let _act acts act = match act with
    | Obc.Aassgn (p,e) -> (Aassgn (pattern param_env p, exp param_env e))::acts
    | Obc.Acall ([], obj, Mstep, e_l) ->
        let acall = Amethod_call (obj_ref param_env obj, "step", exp_list param_env e_l) in
        acall::acts
    | Obc.Acall ([p], obj, Mstep, e_l) ->
        let ecall = Emethod_call (obj_ref param_env obj, "step", exp_list param_env e_l) in
        let assgn = Aassgn (pattern param_env p, call) in
        assgn::acts
    | Obc.Acall (p_l, obj, _, e_l) ->
        let return_ty = p_l |> pattern_list_to_type |> (ty param_env) in
        let return_id = Idents.gen_var "obc2java" "out" in
        let return_vd = { vd_type = return_ty; vd_ident = return_id } in
        let ecall = Emethod_call (obj_ref param_env obj, "step", exp_list param_env e_l) in
        let assgn = Anewvar (return_vd, ecall) in
        let copies = Misc.mapi (fun i p -> Aassgn (p, Eval (Pfield (return_id, "c"^(string_of_int i))))) p_l in
        assgn::(copies@acts)
    | Obc.Acall (_, obj, Mreset, _) ->
        let acall = Amethod_call (obj_ref param_env obj, "step", []) in
        acall::acts
    | Obc.Async_call _ -> assert false (* TODO java async *)
    | Obc.Acase (e, c_b_l) ->
        let _c_b (c,b) = translate_constructor_name
        Aswitch (exp param_env e,

let block param_env ?(locals=[]) ?(end_acts=[]) ob =
  let blocals = var_dec_list param_env ob.Obc.b_locals in
  let locals = locals @ blocals in
  let bacts = act_list param_env ob.Obc.b_body in
  let acts = end_acts @ bacts in
  { b_locals = locals; b_body = acts }

let class_def_list classes cd_l =
  let class_def classes cd =
    Idents.enter_node cd.cd_name;
    let class_name = qualname_to_class_name cd.cd_name in
     (* [param_env] is an env mapping local param name to ident *)
    let constructeur, param_env =
      let param_to_arg param_env p =
        let p_ident = Idents.gen_var "obc2java" p.Signature.p_name in
        let p_vd = { vd_ident = p_ident; vd_type = ty param_env p.Signature.p_type } in
        let param_env = NamesEnv.add p.Signature.p_name p_ident param_env in
        p_vd, param_env
      in
      let args, param_env = Misc.mapfold param_to_arg NamesEnv.empty cd.cd_params in
      let body =
        (* TODO java array : also initialize arrays with [ new int[3] ] *)
        let final_field_init_act arg = Aassgn (Pthis arg.vd_ident, Eval (Pvar arg.vd_ident)) in
        let obj_init_act acts od =
          let params = List.map (static_exp param_env) od.o_params in
          let act = match od.o_size with
            | None -> Aassgn (Pthis od.o_ident, Enew (Tclass od.o_class, params))
            | Some size -> assert false; (* TODO java :
                Aassgn (Pthis od.o_ident, Enew ( Tarray, Earray [Enew (Tclass, params)... ] ) ) cf node.java*)
          in
          act::acts
        in
        let acts = List.map final_field_init_act args in
        let acts = List.fold_left obj_init_act acts cd.cd_objs in
        { b_locals = []; b_body = acts }
      in
      mk_methode ~args:args body (shortname class_name), param_env
    in
    let fields =
      let mem_to_field fields vd = (mk_field ~protection:Pprotected (ty param_env vd.v_type) vd.v_ident) :: fields in
      let obj_to_field fields od = (* TODO [o_params] are treated in the [reset] code *)
        let jty = match od.o_size with
          | None -> Tclass (qualname_to_class_name od.o_class)
          | Some size -> Tarray (Tclass (qualname_to_class_name od.o_class), static_exp param_env size)
        in
        (mk_field ~protection:Pprotected jty od.o_ident) :: fields
      in
      let params_to_field fields p =
        let p_ident = NamesEnv.find p.p_name param_env in
        (mk_field ~protection:Pprotected ~final:true (ty param_env p.p_type) p_ident) :: fields
      in
      let fields = List.fold_left mem_to_field [] cd.cd_mems in
      let fields = List.fold_left obj_to_field fields cd.cd_objs in
      List.fold_left params_to_field fields cd.cd_params
    in
    let step =
      let ostep = find_step_method cd in
      let vd_output = var_dec_list param_env ostep.m_outputs in
      let return_ty = ostep.m_outputs |> vd_list_to_type |> (ty param_env) in
      let return_act = Areturn (match vd_output with
                                 | [] -> Evoid
                                 | [vd] -> Eval (Pvar vd.vd_ident)
                                 | vd_l -> Enew (return_ty, List.map (fun vd -> Eval (Pvar vd.vd_ident)) vd_l))
      in
      let body = block param_env ~locals:vd_output ~end_acts:[return_act] ostep.m_body in
      mk_methode ~args:(var_dec_list ostep.m_inputs) ~returns:jreturn_ty body "step"
    in
    let reset =
      let oreset = find_reset_method cd in
      let body = block param_env oreset.m_body in
      mk_methode body "reset"
    in
    let classe = mk_classe ~fields=fields ~constrs=[constructeur] ~methodes=[step;reset] class_name in
    classe::classes
  in
  List.fold_left classe_def classes cd_l


let type_dec_list classes td_l =
  let param_env = NamesEnv.empty in
  let _td classes td =
    let classe_name = td.t_name |> qualname_to_class_name |> Names.shortname in
    let classe, jty = match td.t_desc with
      | Type_abs -> eprintf "Abstract types not supported in Java backend"; assert false (* TODO java *)
      | Type_alias ot -> classes
      | Type_enum c_l ->
          let mk_constr_enum oc =
            let jc = _translate_constructor_name oc td.t_name in
            add_constr_name oc jc;
            jc
          in
          (mk_enum (List.map mk_constr_enum oc_l) classe_name) :: classes
      | Type_struct f_l ->
          let mk_field_jfield { f_name = oname; f_type = oty } =
            let jty = ty param_env oty in
            let name = oname |> Names.shortname |> String.lowercase in
            add_Field_name oname name;
            mk_field jty name
          in
          (mk_classe ~fields:(List.map mk_field_jfield f_l) classe_name) :: classes
    in
    add_type_name td.t_name jty;
    classes
  in
  List.fold_left classes _td


let const_dec_list cd_l =
  let param_env = NamesEnv.empty in
  let mk_const_field { Obc.c_name = oname ; Obc.c_value = ovalue; Obc.c_type = otype } =
    let name = oname |> translate_const_name |> shortname in
    let value = static_exp ovalue in
    let t = ty param_env otype in
    mk_field ~static:true ~final:true ~value:value t name
  in
  match cd_l with
    | [] -> []
    | _ ->
        let classe_name = "CONSTANTES" |> name_to_classe_name |> shortname in
        let fields = List.map mk_const_field cd_l in
        [mk_classe ~fields:fields classe_name]


let program p =
  let classes = const_dec_list p.p_consts in
  let classes = type_dec_list classes p.p_types in
  let p = class_def_list classes p.p_defs in
  p