add debit logic

1 files changed, 25 insertions, 7 deletions

diff --git a/lib/handler.ml b/lib/handler.ml
index a4d8cae..fb075ff 100644
--- a/lib/handler.ml
+++ b/lib/handler.ml
@@ -1,5 +1,10 @@
 open Piaf
 
+let valid_debit value limit balance =
+  let balance_after_op = balance - value in
+  not (balance_after_op <= limit * -1)
+;;
+
 let create_transaction client_id (db_pool : Query.pool) (request : Request.t) =
   Caqti_eio.Pool.use
     (fun conn ->
@@ -7,22 +12,35 @@ let create_transaction client_id (db_pool : Query.pool) (request : Request.t) =
         Option.join @@ Result.to_option @@ Query.find_client client_id conn
       in
       match client_opt with
-      | Some _client ->
+      | Some client ->
         let insert_result =
           let body = Result.to_option @@ Body.to_string request.body in
-          let json = Option.map Yojson.Safe.from_string body in
+          let json =
+            Option.map
+              (fun str ->
+                try Yojson.Safe.from_string str with
+                | _ -> `Null)
+              body
+          in
           let decoded_op = Option.bind json (Utils.Decoder.decode Operation.decoder) in
           match decoded_op with
-          | Some op ->
-            (match Query.execute_operation ~client_id ~op conn with
+          | Some (`Credit { value = _value; description = _desc } as op) ->
+            (match Query.execute_transaction ~client_id ~op conn with
              | Ok _ as ok -> ok
              | Error e -> Error (`DB e))
+          | Some (`Debit { value; description = _desc } as op) ->
+            if valid_debit value client.mov_limit client.balance
+            then (
+              match Query.execute_transaction ~client_id ~op conn with
+              | Ok _ as ok -> ok
+              | Error e -> Error (`DB e))
+            else Error `InvalidValue
           | None -> Error (`Decoder "Invalid operation")
         in
         (match insert_result with
          | Ok () ->
            let json : Yojson.Safe.t =
-             `Assoc [ "limite", `Int 100000; "saldo", `Int (-9098) ]
+             `Assoc [ "limite", `Int client.mov_limit; "saldo", `Int client.balance ]
            in
            Ok (Response.of_string ~body:(Yojson.Safe.to_string json) `OK)
          | Error _ -> Ok (Response.create (`Code 422)))
@@ -39,7 +57,7 @@ let get_balance client_id (db_pool : Query.pool) (_request : Request.t) =
         Option.join @@ Result.to_option @@ Query.find_client client_id conn
       in
       match client_opt with
-      | Some _client ->
+      | Some client ->
         let client_balance_opt =
           Option.join @@ Result.to_option @@ Query.balance client_id conn
         in
@@ -52,7 +70,7 @@ let get_balance client_id (db_pool : Query.pool) (_request : Request.t) =
                  `String
                    (Format.asprintf "%a" (Ptime.pp_rfc3339 ~tz_offset_s:(-10800) ()) time)
                in
-               let limit = `Int 100000 in
+               let limit = `Int client.mov_limit in
                `Assoc [ "total", total; "data_extrato", date; "limite", limit ]
              in
              let last_transactions = `List [] in