add vendoring

vendor/gitlab.com/etke.cc/go/validator/validator.go

@@ -0,0 +1,73 @@
+package validator
+
+import (
+	"regexp"
+	"strings"
+)
+
+// V is a validator implementation
+type V struct {
+	spamlist []*regexp.Regexp
+	enforce  Enforce
+	from     string
+	log      Logger
+}
+
+// Enforce checks
+type Enforce struct {
+	// Email enforces email check and rejects empty emails
+	Email bool
+	// Domain enforces domain check and rejects empty domains
+	Domain bool
+	// SMTP enforces SMTP check (email actually exists on mail server) and rejects non-existing emails
+	SMTP bool
+	// MX enforces MX records check on email's mail server
+	MX bool
+}
+
+type Logger interface {
+	Info(string, ...interface{})
+	Error(string, ...interface{})
+}
+
+// New Validator, accepts spamlist with wildcards
+func New(spamlist []string, enforce Enforce, smtpFrom string, log Logger) *V {
+	spamregexes, err := parseSpamlist(spamlist)
+	if err != nil {
+		log.Error("cannot parse spamlist: %v", err)
+	}
+
+	return &V{
+		spamlist: spamregexes,
+		enforce:  enforce,
+		from:     smtpFrom,
+		log:      log,
+	}
+}
+
+func parseSpamlist(patterns []string) ([]*regexp.Regexp, error) {
+	regexes := []*regexp.Regexp{}
+	for _, pattern := range patterns {
+		rule, err := regexp.Compile("^" + parsePattern(pattern) + "$")
+		if err != nil {
+			return regexes, err
+		}
+
+		regexes = append(regexes, rule)
+	}
+
+	return regexes, nil
+}
+
+func parsePattern(pattern string) string {
+	var regexpattern strings.Builder
+	for _, runeItem := range pattern {
+		if runeItem == '*' {
+			regexpattern.WriteString("(.*)")
+			continue
+		}
+		regexpattern.WriteString(regexp.QuoteMeta(string(runeItem)))
+	}
+
+	return regexpattern.String()
+}