appota_buyCards.go

func newOrderInfo(cardType string, value int64, quantity int) string {
        orderInfo := []map[string]interface{}{
                {
                        "type":    cardType,
                        "value":   strconv.FormatInt(value, 10),
                        "quantity": quantity,
                },
        }
        orderData, err := json.Marshal(orderInfo)
        if err != nil {
                panic(err) // Impossible to failed.
        }
        return string(orderData)
}

func (c *DealerClient) BuyCards(
        cardType string, value int64, quantity int,
) (*CardsResponse, error) {
        transID, err := newDeveloperTransID()
        if err != nil {
                log.WithError(err).Error("Could not generate developer transaction ID")
                return nil, err
        }

        orderInfo := newOrderInfo(cardType, value, quantity)

        payload := url.Values{}
        payload.Add("apiKey", c.apiKey)
        payload.Add("orderInfo", orderInfo)
        payload.Add("transID", transID)
        payload.Add("signature", crypto.SumSHA1(c.apiKey+transID+orderInfo+c.secretKey))

        resp, err := c.PostForm(c.buyCardsEndpoint(), payload)
        ...
}