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|
module Q = struct
let transaction =
[%rapper
execute
{sql|
INSERT INTO transactions (client_id, value, type, description)
VALUES (%int{client_id}, %int{value}, %Operation.TransactionType{transaction_type}, %string{description})
|sql}]
;;
let debit =
[%rapper
execute
{sql|
UPDATE balances SET value = value - %int{value} WHERE client_id = %int{client_id}
|sql}]
;;
let credit =
[%rapper
execute
{sql|
UPDATE balances SET value = value + %int{value} WHERE client_id = %int{client_id}
|sql}]
;;
let client =
let open Operation in
[%rapper
get_opt
{sql|
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]
;;
let balance =
[%rapper
get_opt
{sql|
SELECT @int{value}, @ptime{now()} as time FROM balances WHERE client_id = %int{client_id}
|sql}]
;;
let transactions =
let open Operation in
[%rapper
get_many
{sql|
SELECT @int{id}, @int{client_id}, @int{value}, type as @Operation.TransactionType{transaction_type}, @string{description}, @ptime{created_at} FROM transactions
WHERE transactions.client_id = %int{client_id}
ORDER BY created_at DESC
LIMIT 10
|sql}
record_out]
;;
let lock =
[%rapper
execute {sql|
SELECT pg_advisory_xact_lock(%int{client_id})
|sql}]
;;
end
let ( let* ) = Result.bind
(* TODO: Separar em duas funções *)
let execute_transaction ~client_id ~(op : Operation.transaction_op) conn =
match op with
| `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
let balance client_id conn = Q.balance ~client_id conn
let transactions client_id conn = Q.transactions ~client_id conn
let lock client_id conn = Q.lock ~client_id conn
|
