add debit logic

5 files changed, 63 insertions, 45 deletions

diff --git a/docker-compose.yml b/docker-compose.yml
index ccf1661..eb90487 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -35,7 +35,6 @@ services:
 
   db:
     image: postgres:latest
-    hostname: db
     environment:
       - POSTGRES_PASSWORD=123
       - POSTGRES_USER=admin
@@ -49,14 +48,3 @@ services:
         limits:
           cpus: "0.63"
           memory: "140MB"
-
-  pgadmin:
-    image: dpage/pgadmin4
-    environment:
-      PGADMIN_DEFAULT_EMAIL: admin@admin.com
-      PGADMIN_DEFAULT_PASSWORD: admin
-      PGADMIN_LISTEN_PORT: 5050
-    ports:
-      - 5050:5050
-    depends_on:
-      - db
diff --git a/lib/client.ml b/lib/client.ml
index 80a11b7..8be4644 100644
--- a/lib/client.ml
+++ b/lib/client.ml
@@ -1,4 +1,5 @@
 type t =
   { id : int
   ; mov_limit : int
+  ; balance : int
   }
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
diff --git a/lib/operation.ml b/lib/operation.ml
index 1fb1dd5..3c8df2a 100644
--- a/lib/operation.ml
+++ b/lib/operation.ml
@@ -1,29 +1,34 @@
 module TransactionType = struct
   type t =
-    | Credit
-    | Debit
+    [ `Credit
+    | `Debit
+    ]
 
   let t =
     let encode = function
-      | Credit -> "credit"
-      | Debit -> "debit"
+      | `Credit -> "credit"
+      | `Debit -> "debit"
     in
     let decode = function
-      | "credit" -> Ok Credit
-      | "debit" -> Ok Debit
+      | "credit" -> Ok `Credit
+      | "debit" -> Ok `Debit
       | _ -> Error "Invalid transaction type"
     in
     Caqti_type.(enum ~encode ~decode "transaction_type")
   ;;
 end
 
-type t =
-  | Transaction of
-      { transaction_type : TransactionType.t
-      ; value : int
-      ; description : string
-      }
-  | Balance of { client_id : int }
+type transaction_payload =
+  { value : int
+  ; description : string
+  }
+
+type transaction_op =
+  [ `Credit of transaction_payload
+  | `Debit of transaction_payload
+  ]
+
+type t = Balance of { client_id : int }
 
 type transaction =
   { id : int
@@ -34,15 +39,14 @@ type transaction =
   ; created_at : Ptime.t
   }
 
-let decoder =
+let decoder : transaction_op Utils.Decoder.decoder =
   let open Utils.Decoder in
   let open Syntax in
   let transaction_type_decoder =
-    literal "c" *> return TransactionType.Credit
-    <|> literal "d" *> return TransactionType.Debit
+    literal "c" *> return (fun p -> `Credit p)
+    <|> literal "d" *> return (fun p -> `Debit p)
   in
-  (fun value transaction_type description ->
-    Transaction { value; description; transaction_type })
+  (fun value transaction_type description -> transaction_type { value; description })
   <$> ("valor" <: int)
   <*> ("tipo" <: transaction_type_decoder)
   <*> ("descricao" <: string)
diff --git a/lib/query.ml b/lib/query.ml
index 85f91f0..6e359ce 100644
--- a/lib/query.ml
+++ b/lib/query.ml
@@ -31,7 +31,9 @@ module Q = struct
     [%rapper
       get_opt
         {sql|
-          SELECT @int{id}, @int{mov_limit} FROM clients WHERE id = %int{id}
+          SELECT clients.id as @int{id}, @int{mov_limit}, value as @int{balance} FROM clients
+          JOIN balances ON balances.client_id = %int{id}
+          WHERE clients.id = %int{id}
         |sql}
         record_out]
   ;;
@@ -47,14 +49,19 @@ end
 
 let ( let* ) = Result.bind
 
-let execute_operation ~client_id ~(op : Operation.t) conn =
+(* TODO: Separar em duas funções *)
+let execute_transaction ~client_id ~(op : Operation.transaction_op) conn =
   match op with
-  | Transaction { value; description; transaction_type } ->
-    let* () = Q.transaction ~client_id ~value ~description conn ~transaction_type in
-    (match transaction_type with
-     | Credit -> Q.credit ~value ~client_id conn
-     | Debit -> Q.debit ~value ~client_id conn)
-  | _ -> failwith "TODO"
+  | `Credit { value; description } ->
+    let* () =
+      Q.transaction ~client_id ~value ~description conn ~transaction_type:`Credit
+    in
+    Q.credit ~value ~client_id conn
+  | `Debit { value; description } ->
+    let* () =
+      Q.transaction ~client_id ~value ~description conn ~transaction_type:`Debit
+    in
+    Q.debit ~value ~client_id conn
 ;;
 
 let find_client id conn = Q.client ~id conn