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|
open Prelude
module Debit_credit = Ledger.Debit_credit
type tx_type =
| Interest_tx
| Online_banking_tx
| Recurrent_direct_tx
| Payment_terminal_tx
| Cash_payment_tx
| Atm_tx
| Auto_save_rounding_tx
| Batch_tx
| Direct_debit_tx
| Periodic_tx
[@@deriving compare, sexp]
type iban_tag = Account_tag | Counterparty_iban_tag [@@deriving compare, sexp]
type unit_tag = Filed_tag | Google_pay_tag | Auto_round_savings_tag
[@@deriving compare, sexp]
type string_tag =
| Desc_tag
| User_tag
| Counterparty_name_tag
| Reference_tag
| Mandate_id_tag
| Creditor_id_tag
| Other_party_tag
| Transaction_tag
| Terminal_tag
| Card_seq_no_tag
| Savings_account_tag
[@@deriving compare, sexp]
module Label = struct
type 'a t =
| Iban_label : iban_tag -> Iban.t t
| String_label : string_tag -> string t
| Timestamp_label : Time_ns.t t
| Tx_type_label : tx_type t
| Unit_label : unit_tag -> unit t
let int_to_cmp x : ('a, 'a) Dmap.cmp =
if x < 0 then Lt else if x > 0 then Gt else Eq
let compare (type a1 a2) (v1 : a1 t) (v2 : a2 t) : (a1, a2) Dmap.cmp =
match (v1, v2) with
| Iban_label t1, Iban_label t2 -> int_to_cmp @@ [%compare: iban_tag] t1 t2
| String_label t1, String_label t2 ->
int_to_cmp @@ [%compare: string_tag] t1 t2
| Timestamp_label, Timestamp_label -> Eq
| Tx_type_label, Tx_type_label -> Eq
| Unit_label t1, Unit_label t2 -> int_to_cmp @@ [%compare: unit_tag] t1 t2
| Iban_label _, _ -> Lt
| String_label _, Iban_label _ -> Gt
| String_label _, _ -> Lt
| Timestamp_label, Unit_label _ -> Lt
| Timestamp_label, Tx_type_label -> Lt
| Timestamp_label, _ -> Gt
| Tx_type_label, Unit_label _ -> Lt
| Tx_type_label, _ -> Gt
| Unit_label _, _ -> Gt
end
module Labels = struct
include Dmap.Make (Label)
let sexp_of_binding = function
| Binding (Iban_label tag, iban) ->
Sexp.List
[
Sexp.Atom "iban"; [%sexp_of: iban_tag] tag; [%sexp_of: Iban.t] iban;
]
| Binding (String_label tag, s) ->
Sexp.List
[ Sexp.Atom "string"; [%sexp_of: string_tag] tag; Sexp.Atom s ]
| Binding (Timestamp_label, ts) ->
Sexp.List [ Sexp.Atom "timestamp"; [%sexp_of: Time_ns_unix.t] ts ]
| Binding (Tx_type_label, type_) ->
Sexp.List [ Sexp.Atom "tx_type"; [%sexp_of: tx_type] type_ ]
| Binding (Unit_label tag, ()) ->
Sexp.List [ Sexp.Atom "unit"; [%sexp_of: unit_tag] tag ]
let binding_of_sexp sexp =
match sexp with
| Sexp.List [ Sexp.Atom "iban"; tag_sexp; iban_sexp ] ->
Binding
( Iban_label ([%of_sexp: iban_tag] tag_sexp),
[%of_sexp: Iban.t] iban_sexp )
| Sexp.List [ Sexp.Atom "string"; tag_sexp; Sexp.Atom s ] ->
Binding (String_label ([%of_sexp: string_tag] tag_sexp), s)
| Sexp.List [ Sexp.Atom "timestamp"; ts_sexp ] ->
Binding (Timestamp_label, [%of_sexp: Time_ns_unix.t] ts_sexp)
| Sexp.List [ Sexp.Atom "tx_type"; type_sexp ] ->
Binding (Tx_type_label, [%of_sexp: tx_type] type_sexp)
| Sexp.List [ Sexp.Atom "unit"; tag_sexp ] ->
Binding (Unit_label ([%of_sexp: unit_tag] tag_sexp), ())
| _ -> of_sexp_error "Labels.binding_of_sexp: invalid binding" sexp
let sexp_of_t m = Sexp.List (bindings m |> List.map ~f:sexp_of_binding)
let t_of_sexp sexp =
match sexp with
| Sexp.List labels ->
Sequence.(of_list labels >>| binding_of_sexp |> to_seq) |> of_seq
| Sexp.Atom _ -> of_sexp_error "Labels.t_of_sexp: list needed" sexp
end
module Money : sig
type t
val equal : t -> t -> bool
val compare : t -> t -> int
val of_z : Z.t -> t
val to_z : t -> Z.t
val ( + ) : t -> t -> t
val ( - ) : t -> t -> t
val ( = ) : t -> t -> bool
val ( ~$ ) : int -> t
val sexp_of_t : t -> Sexp.t
end = struct
type t = Z.t [@@deriving sexp_of]
let equal = Z.equal
let compare = Z.compare
let of_z = Fn.id
let to_z = Fn.id
let ( + ) x y = Z.(x + y)
let ( - ) x y = Z.(x - y)
let ( = ) = equal
let ( ~$ ) = Fn.compose of_z Z.of_int
end
(* TODO: make rate a decimal *)
type scalar =
| Amount of Money.t
| Rate of { in_primary_commodity : Money.t; rate : Z.t }
[@@deriving equal, compare, sexp_of]
type commodity_id = string
(* TODO: consider making this UUID *) [@@deriving sexp]
module Account_id = struct
type t = string list [@@deriving sexp, compare]
end
type account = {
id : Account_id.t;
description : string list;
commodity_id : commodity_id;
balance : Money.t;
}
[@@deriving sexp_of]
type bal_assert = {
account : Account_id.t;
amount : Money.t;
labels : Labels.t;
}
[@@deriving sexp_of]
module Account_id_map = Map.Make (Account_id)
module Tx : sig
(* Private because we only want to allow constructing balanced transactions. *)
type t = private {
cleared : Date.t option;
commodity_id : commodity_id;
entries : (Debit_credit.t * scalar * Money.t option) Account_id_map.t;
labels : Labels.t;
}
type error = Unbalanced
val make :
cleared:Date.t option ->
commodity_id:commodity_id ->
entries:(Debit_credit.t * scalar * Money.t option) Account_id_map.t ->
labels:Labels.t ->
(t, error) result
val sexp_of_t : t -> Sexp.t
end = struct
type t = {
cleared : Date.t option;
commodity_id : commodity_id;
entries : (Debit_credit.t * scalar * Money.t option) Account_id_map.t;
labels : Labels.t;
}
[@@deriving sexp_of]
type error = Unbalanced
let is_balanced entries =
Map.fold entries
~init:Money.(~$0, ~$0)
~f:(fun ~key:_ ~data:(type_, scalar, _oassert) (ds, cs) ->
let m =
match scalar with
| Amount m -> m
| Rate { in_primary_commodity = m; _ } -> m
in
match type_ with
| Debit_credit.Debit -> Money.(ds + m, cs)
| Debit_credit.Credit -> Money.(ds, cs + m))
|> fun (ds, cs) -> Money.(ds = cs)
let make ~cleared ~commodity_id ~entries ~labels =
if not (is_balanced entries) then Error Unbalanced
else Ok { cleared; commodity_id; entries; labels }
end
type item = Tx_item of Tx.t | Bal_assert_item of bal_assert
[@@deriving sexp_of]
type t = item list [@@deriving sexp_of]
|
