support get token transfers by level (#7)

* support get token transfers by level

token.go

@@ -59,6 +59,8 @@ type TokenTransfer struct {
 	TransactionID uint64    `json:"transactionId"`
 	From          *Account  `json:"from"`
 	To            Account   `json:"to"`
+	Amount        *string   `json:"amount"`
+	Token         *Token    `json:"token"`
 }
 
 type TokenOwner struct {
@@ -240,6 +242,38 @@ func (c *TZKT) GetTokenTransfers(contract, tokenID string, limit int) ([]TokenTr
 	return transfers, nil
 }
 
+func (c *TZKT) GetTokenTransfersByLevel(level string, limit int) ([]TokenTransfer, error) {
+	if limit == 0 {
+		limit = 100
+	}
+
+	v := url.Values{
+		"level.ge": []string{level},
+		"sort":     []string{"level"},
+		"limit":    []string{fmt.Sprint(limit)},
+	}
+
+	u := url.URL{
+		Scheme:   "https",
+		Host:     c.endpoint,
+		Path:     "/v1/tokens/transfers",
+		RawQuery: v.Encode(),
+	}
+
+	var transfers []TokenTransfer
+
+	req, err := http.NewRequest("GET", u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := c.request(req, &transfers); err != nil {
+		return nil, err
+	}
+
+	return transfers, nil
+}
+
 func (c *TZKT) GetTokenTransfersCount(contract, tokenID string) (int, error) {
 	v := url.Values{
 		"token.contract": []string{contract},