all: implement API for online transfer inquiry

The RtolInquiry method get the information of the name of the account
owner of the transfer destination.

After getting this information, customers can determine whether the
purpose of such a transfer is in accordance with the intended or not.
If appropriate, the customer can proceed to the transfer process.

Ref: https://docs.duitku.com/disbursement/en/#transfer-online

1 files changed, 46 insertions, 0 deletions

diff --git a/rtol_inquiry.go b/rtol_inquiry.go
new file mode 100644
index 0000000..33ab55d
--- /dev/null
+++ b/rtol_inquiry.go
@@ -0,0 +1,46 @@
+package duitku
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+)
+
+// RtolInquiry contains request to initiate transfer from merchant to
+// customer's bank account using [Online Transfer].
+//
+// The signature formula is SHA256(email + timestamp + bankCode +
+// bankAccount + amountTransfer + purpose + apiKey).
+//
+// [Online Transfer]: https://docs.duitku.com/disbursement/en/#online-transfer-inquiry-request
+type RtolInquiry struct {
+	// Destination Bank Code.
+	BankCode string `json:"bankCode"`
+
+	// Destination account number.
+	BankAccount string `json:"bankAccount"`
+
+	// Description of transfer purpose.
+	Purpose string `json:"purpose"`
+
+	// Customer name provided by merchant.
+	SenderName string `json:"senderName"`
+
+	request
+
+	// Customer ID provided by merchant.
+	SenderID int64 `json:"senderID"`
+
+	// Disbursement transfer amount.
+	Amount int64 `json:"amountTransfer"`
+}
+
+func (inq *RtolInquiry) sign(apiKey string) {
+	var (
+		plain = fmt.Sprintf(`%s%d%s%s%d%s%s`, inq.Email,
+			inq.Timestamp, inq.BankCode, inq.BankAccount,
+			inq.Amount, inq.Purpose, apiKey)
+		plainHash [sha256.Size]byte = sha256.Sum256([]byte(plain))
+	)
+	inq.Signature = hex.EncodeToString(plainHash[:])
+}