(* This file is part of the Catala compiler, a specification language for tax and social benefits
   computation rules. Copyright (C) 2020 Inria, contributor: Denis Merigoux
   <denis.merigoux@inria.fr>

   Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
   in compliance with the License. You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software distributed under the License
   is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
   or implied. See the License for the specific language governing permissions and limitations under
   the License. *)

[@@@ocaml.warning "-7-34"]

open Utils

module ScopeName : Uid.Id with type info = Uid.MarkedString.info = Uid.Make (Uid.MarkedString) ()

module StructName : Uid.Id with type info = Uid.MarkedString.info = Uid.Make (Uid.MarkedString) ()

module StructFieldName : Uid.Id with type info = Uid.MarkedString.info =
  Uid.Make (Uid.MarkedString) ()

module StructMap : Map.S with type key = StructName.t = Map.Make (StructName)

module EnumName : Uid.Id with type info = Uid.MarkedString.info = Uid.Make (Uid.MarkedString) ()

module EnumConstructor : Uid.Id with type info = Uid.MarkedString.info =
  Uid.Make (Uid.MarkedString) ()

module EnumMap : Map.S with type key = EnumName.t = Map.Make (EnumName)

type typ_lit = TBool | TUnit | TInt | TRat | TMoney | TDate | TDuration

type struct_name = StructName.t

type enum_name = EnumName.t

type typ =
  | TLit of typ_lit
  | TTuple of typ Pos.marked list * struct_name option
  | TEnum of typ Pos.marked list * enum_name
  | TArrow of typ Pos.marked * typ Pos.marked
  | TArray of typ Pos.marked
  | TAny

type date = Runtime.date

type duration = Runtime.duration

type integer = Runtime.integer

type decimal = Runtime.decimal

type money = Runtime.money

type lit =
  | LBool of bool
  | LEmptyError
  | LInt of integer
  | LRat of decimal
  | LMoney of money
  | LUnit
  | LDate of date
  | LDuration of duration

type op_kind = KInt | KRat | KMoney | KDate | KDuration

type ternop = Fold

type binop =
  | And
  | Or
  | Xor
  | Add of op_kind
  | Sub of op_kind
  | Mult of op_kind
  | Div of op_kind
  | Lt of op_kind
  | Lte of op_kind
  | Gt of op_kind
  | Gte of op_kind
  | Eq
  | Neq
  | Map
  | Concat
  | Filter

type log_entry = VarDef of typ | BeginCall | EndCall | PosRecordIfTrueBool

type unop =
  | Not
  | Minus of op_kind
  | Log of log_entry * (Utils.Uid.MarkedString.info list[@opaque])
  | Length
  | IntToRat
  | GetDay
  | GetMonth
  | GetYear

type operator = Ternop of ternop | Binop of binop | Unop of unop

type expr =
  | EVar of (expr Bindlib.var[@opaque]) Pos.marked
  | ETuple of expr Pos.marked list * struct_name option
  | ETupleAccess of expr Pos.marked * int * struct_name option * typ Pos.marked list
  | EInj of expr Pos.marked * int * enum_name * typ Pos.marked list
  | EMatch of expr Pos.marked * expr Pos.marked list * enum_name
  | EArray of expr Pos.marked list
  | ELit of lit
  | EAbs of (expr, expr Pos.marked) Bindlib.mbinder Pos.marked * typ Pos.marked list
  | EApp of expr Pos.marked * expr Pos.marked list
  | EAssert of expr Pos.marked
  | EOp of operator
  | EDefault of expr Pos.marked list * expr Pos.marked * expr Pos.marked
  | EIfThenElse of expr Pos.marked * expr Pos.marked * expr Pos.marked
  | ErrorOnEmpty of expr Pos.marked

type struct_ctx = (StructFieldName.t * typ Pos.marked) list StructMap.t

type enum_ctx = (EnumConstructor.t * typ Pos.marked) list EnumMap.t

type decl_ctx = { ctx_enums : enum_ctx; ctx_structs : struct_ctx }

type binder = (expr, expr Pos.marked) Bindlib.binder

type scope_let_kind =
  | DestructuringInputStruct
  | ScopeVarDefinition
  | SubScopeVarDefinition
  | CallingSubScope
  | Assertion
  | DestructuringSubScopeResults

type scope_let = {
  scope_let_var : expr Bindlib.var Pos.marked;
  scope_let_kind : scope_let_kind;
  scope_let_typ : typ Pos.marked;
  scope_let_expr : expr Pos.marked;
}

type scope_body = { scope_body_lets : scope_let list; scope_result : expr Pos.marked }

type program = { decl_ctx : decl_ctx; scopes : (ScopeName.t * expr Bindlib.var * scope_body) list }

module Var = struct
  type t = expr Bindlib.var

  let make (s : string Pos.marked) : t =
    Bindlib.new_var
      (fun (x : expr Bindlib.var) : expr -> EVar (x, Pos.get_position s))
      (Pos.unmark s)

  let compare x y = Bindlib.compare_vars x y
end

module VarMap = Map.Make (Var)

type vars = expr Bindlib.mvar

let make_var ((x, pos) : Var.t Pos.marked) : expr Pos.marked Bindlib.box =
  Bindlib.box_apply (fun x -> (x, pos)) (Bindlib.box_var x)

let make_abs (xs : vars) (e : expr Pos.marked Bindlib.box) (pos_binder : Pos.t)
    (taus : typ Pos.marked list) (pos : Pos.t) : expr Pos.marked Bindlib.box =
  Bindlib.box_apply (fun b -> (EAbs ((b, pos_binder), taus), pos)) (Bindlib.bind_mvar xs e)

let make_app (e : expr Pos.marked Bindlib.box) (u : expr Pos.marked Bindlib.box list) (pos : Pos.t)
    : expr Pos.marked Bindlib.box =
  Bindlib.box_apply2 (fun e u -> (EApp (e, u), pos)) e (Bindlib.box_list u)

let make_let_in (x : Var.t) (tau : typ Pos.marked) (e1 : expr Pos.marked Bindlib.box)
    (e2 : expr Pos.marked Bindlib.box) (pos : Pos.t) : expr Pos.marked Bindlib.box =
  make_app (make_abs (Array.of_list [ x ]) e2 pos [ tau ] pos) [ e1 ] pos

let make_multiple_let_in (xs : Var.t array) (taus : typ Pos.marked list)
    (e1 : expr Pos.marked Bindlib.box list) (e2 : expr Pos.marked Bindlib.box) (pos : Pos.t) :
    expr Pos.marked Bindlib.box =
  make_app (make_abs xs e2 pos taus pos) e1 pos