add new bitcoin electrum SPV provider

providers/bitcoinElectrum/spv.go

@@ -0,0 +1,76 @@
+package bitcoinElectrum
+
+import (
+	"bufio"
+	"crypto/tls"
+	"encoding/json"
+	"fmt"
+	"net"
+	"time"
+
+	"github.com/btcsuite/btcd/btcutil"
+)
+
+// --- Electrum JSON-RPC Structures ---
+type ElectrumRequest struct {
+	ID     int           `json:"id"`
+	Method string        `json:"method"`
+	Params []interface{} `json:"params"`
+}
+
+type ElectrumBalanceResponse struct {
+	Result struct {
+		Confirmed   int64 `json:"confirmed"`
+		Unconfirmed int64 `json:"unconfirmed"`
+	} `json:"result"`
+	Error *struct {
+		Message string `json:"message"`
+	} `json:"error"`
+}
+
+// Connects to Electrum and queries the balance for a single address.
+func getAddressBalance(electrumServer string, address btcutil.Address) (*ElectrumBalanceResponse, error) {
+	scripthash, err := addressToScriptHash(address)
+	if err != nil {
+		return nil, fmt.Errorf("could not create scripthash: %w", err)
+	}
+
+	// Connect to the server with SSL/TLS
+	conf := &tls.Config{InsecureSkipVerify: true} // Use InsecureSkipVerify for public servers, but be aware of MITM risks
+	conn, err := tls.DialWithDialer(&net.Dialer{Timeout: 5 * time.Second}, "tcp", electrumServer, conf)
+	if err != nil {
+		return nil, fmt.Errorf("could not connect to electrum server: %w", err)
+	}
+	defer conn.Close()
+
+	// Prepare the JSON-RPC request
+	request := ElectrumRequest{
+		ID:     1,
+		Method: "blockchain.scripthash.get_balance",
+		Params: []interface{}{scripthash},
+	}
+	requestBytes, _ := json.Marshal(request)
+
+	// Send the request (with a newline delimiter)
+	_, err = fmt.Fprintf(conn, "%s\n", requestBytes)
+	if err != nil {
+		return nil, fmt.Errorf("failed to send request: %w", err)
+	}
+
+	// Read the response
+	reader := bufio.NewReader(conn)
+	responseLine, err := reader.ReadString('\n')
+	if err != nil {
+		return nil, fmt.Errorf("failed to read response: %w", err)
+	}
+
+	var response ElectrumBalanceResponse
+	if err := json.Unmarshal([]byte(responseLine), &response); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal response: %w", err)
+	}
+	if response.Error != nil {
+		return nil, fmt.Errorf("electrum server error: %s", response.Error.Message)
+	}
+
+	return &response, nil
+}