added helper functions to validate aliases, addresses and phone numbers

common/recipient.go

@@ -0,0 +1,48 @@
+package common
+
+import (
+	"fmt"
+	"regexp"
+)
+
+// Define the regex patterns as constants
+const (
+	phoneRegex   = `^(?:\+254|254|0)?((?:7[0-9]{8})|(?:1[01][0-9]{7}))$`
+	addressRegex = `^0x[a-fA-F0-9]{40}$`
+	aliasRegex   = `^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+$`
+)
+
+// IsValidPhoneNumber checks if the given number is a valid phone number
+func IsValidPhoneNumber(phonenumber string) bool {
+	match, _ := regexp.MatchString(phoneRegex, phonenumber)
+	return match
+}
+
+// IsValidAddress checks if the given address is a valid Ethereum address
+func IsValidAddress(address string) bool {
+	match, _ := regexp.MatchString(addressRegex, address)
+	return match
+}
+
+// IsValidAlias checks if the alias is a valid alias format
+func IsValidAlias(alias string) bool {
+	match, _ := regexp.MatchString(aliasRegex, alias)
+	return match
+}
+
+// CheckRecipient validates the recipient format based on the criteria
+func CheckRecipient(recipient string) (string, error) {
+	if IsValidPhoneNumber(recipient) {
+		return "phone number", nil
+	}
+
+	if IsValidAddress(recipient) {
+		return "address", nil
+	}
+
+	if IsValidAlias(recipient) {
+		return "alias", nil
+	}
+
+	return "", fmt.Errorf("invalid recipient: must be a phone number, address or alias")
+}