restructure project, add claudemd

go/validation/validation.go

@@ -0,0 +1,211 @@
+package validation
+
+import (
+	"errors"
+	"regexp"
+	"slices"
+	"strconv"
+	"strings"
+	"unicode/utf8"
+)
+
+func SanitizeEmail(input string) string {
+	input = strings.ToLower(strings.TrimSpace(input))
+
+	re := regexp.MustCompile(`[a-z0-9!#$%&'*+/=?^_` + "`" + `{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_` + "`" + `{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?`)
+	match := re.FindString(input)
+
+	return match
+}
+
+// Checks an email address against a first and last name and returns true if it matches one of the following patterns:
+// firstlast@domain.tld, flast@domain.tld, firstl@domain.tld, first.last@domain.tld, f.last@domain.tld,
+// first.l@domain.tld, first-last@domain.tld, f-last@domain.tld, first-l@domain.tld. Otherwise, false.
+// Also handles hyphenated and space-separated last names (e.g., Meyer-Ogren or Van Der Berg)
+func DoesNameMatchEmail(email string, firstName string, lastName string) bool {
+	// Validate inputs
+	if email == "" || firstName == "" || lastName == "" {
+		return true
+	}
+
+	email = strings.ToLower(email)
+	firstName = strings.ToLower(firstName)
+	lastName = strings.ToLower(lastName)
+
+	emailIdentifier := strings.Split(email, "@")[0]
+	firstInitial := string(firstName[0])
+
+	// Split hyphenated and space-separated last names
+	lastNameParts := []string{lastName}
+
+	// Also add concatenated version (removing hyphens/spaces)
+	lastNameNormalized := strings.ReplaceAll(lastName, "-", "")
+	lastNameNormalized = strings.ReplaceAll(lastNameNormalized, " ", "")
+	if lastNameNormalized != lastName {
+		lastNameParts = append(lastNameParts, lastNameNormalized)
+	}
+
+	// Add individual parts
+	if strings.Contains(lastName, "-") {
+		lastNameParts = append(lastNameParts, strings.Split(lastName, "-")...)
+	}
+	if strings.Contains(lastName, " ") {
+		lastNameParts = append(lastNameParts, strings.Split(lastName, " ")...)
+	}
+
+	separators := []string{"", ".", "-"}
+
+	// Check standalone first or last names
+	if emailIdentifier == firstName {
+		return true
+	}
+
+	// Check each part of the last name
+	for _, lastPart := range lastNameParts {
+		if lastPart == "" {
+			continue
+		}
+
+		if emailIdentifier == lastPart {
+			return true
+		}
+
+		lastPartInitial := string(lastPart[0])
+
+		// Check all separator combinations with each last name part
+		for _, separator := range separators {
+			switch emailIdentifier {
+			case strings.Join([]string{firstName, lastPart}, separator),
+				strings.Join([]string{firstInitial, lastPart}, separator),
+				strings.Join([]string{firstName, lastPartInitial}, separator):
+				return true
+			}
+		}
+	}
+
+	return false
+}
+
+func SanitizePhone(input string) string {
+	// Regular expression to match non-digit characters
+	re := regexp.MustCompile(`[^0-9]`)
+
+	// Replace non-digit characters with empty string
+	sanitized := re.ReplaceAllString(input, "")
+
+	return sanitized
+}
+
+func ValidatePhoneNumber(phoneNumber string) error {
+	isNumber, _ := regexp.MatchString(`^\d+$`, phoneNumber)
+	if !isNumber {
+		return errors.New("Phone number must only contain numbers.")
+	}
+
+	if len(phoneNumber) != 10 {
+		return errors.New("Invalid phone number length.")
+	}
+
+	areaCode, _ := strconv.Atoi(phoneNumber[:3])
+
+	// Lowest area code is 200, so less than (200) 000-0000
+	if areaCode < 200 {
+		return errors.New("Phone number has invalid area code.")
+	}
+
+	return nil
+}
+
+// Removes invalid UTF-8 sequences and replaces special characters
+func SanitizeString(s string) string {
+	// Replace non-breaking spaces (0xa0) with regular spaces
+	s = strings.ReplaceAll(s, "\u00a0", " ")
+
+	// Remove other common problematic characters
+	s = strings.ReplaceAll(s, "\r", "")
+
+	// Remove replacement character (<28>) that appears when invalid UTF-8 is encountered
+	s = strings.ReplaceAll(s, "\ufffd", "")
+
+	// Validate and fix UTF-8 encoding
+	if !utf8.ValidString(s) {
+		// Convert to valid UTF-8 by removing invalid bytes
+		v := make([]rune, 0, len(s))
+		for _, r := range s {
+			if r != utf8.RuneError {
+				v = append(v, r)
+			}
+		}
+		s = string(v)
+	}
+
+	// Trim whitespace
+	return strings.TrimSpace(s)
+}
+
+var stateCodes []string = []string{
+	"AL", "AK", "AZ", "AR", "AS", "CA", "CO", "CT", "DE", "DC", "FL", "GA",
+	"GU", "HI", "ID", "IL", "IN", "IA", "KS", "KY", "LA", "ME", "MD", "MA",
+	"MI", "MN", "MS", "MO", "MT", "NE", "NV", "NH", "NJ", "NM", "NY", "NC",
+	"ND", "MP", "OH", "OK", "OR", "PA", "PR", "RI", "SC", "SD", "TN", "TX",
+	"TT", "UT", "VT", "VA", "VI", "WA", "WV", "WI", "WY",
+}
+
+// Checks if the input string is a proper two-letter state code
+func ValidateStateCode(s string) error {
+	if slices.Contains(stateCodes, s) {
+		return nil
+	}
+
+	return errors.New("Invalid state code.")
+}
+
+func ValidateTaxId(id string) error {
+	isNumber, _ := regexp.MatchString(`^\d+$`, id)
+	if !isNumber {
+		return errors.New("Tax ID must only contain numbers.")
+	}
+
+	if len(id) != 9 {
+		return errors.New("Tax ID must be 9 digits long.")
+	}
+
+	idNum, _ := strconv.Atoi(id)
+	if idNum == 0 {
+		return errors.New("Tax ID cannot be 00-0000000.")
+	}
+
+	return nil
+}
+
+func ValidateZipCode(zip string) error {
+	isNumber, _ := regexp.MatchString(`^\d+$`, zip)
+	if !isNumber {
+		return errors.New("ZIP code must only contain numbers.")
+	}
+
+	if (len(zip) != 5) && (len(zip) != 9) {
+		return errors.New("Invalid length for ZIP code.")
+	}
+
+	zipCode, _ := strconv.Atoi(zip[:5])
+
+	// Lowest 5 digit ZIP code is 00501
+	if zipCode < 501 {
+		return errors.New("Invalid ZIP code.")
+	}
+
+	return nil
+}
+
+func ValidateUrl(url string) error {
+	err := errors.New("Invalid URL.")
+
+	valid, _ := regexp.MatchString(`[(http(s)?):\/\/(www\.)?a-zA-Z0-9@:%._\+~#=]{2,256}\.[a-z]{2,6}\b([-a-zA-Z0-9@:%_\+.~#?&//=]*)`, url)
+
+	if !valid {
+		return err
+	}
+
+	return nil
+}