package validation

import (
	"regexp"
	"strings"
)

var emailRe = regexp.MustCompile(`^[a-zA-Z0-9._%+\-]+@[a-zA-Z0-9.\-]+\.[a-zA-Z]{2,}$`)

// SanitizeEmail trims, lowercases, and validates email format. Returns empty if invalid.
func SanitizeEmail(input string) string {
	s := strings.TrimSpace(strings.ToLower(input))
	if s == "" || !emailRe.MatchString(s) || len(s) > 254 {
		return ""
	}
	return s
}

// SanitizePhone normalizes to E.164-like format: + followed by 10-15 digits.
// Accepts (555) 123-4567, +1 555 123 4567, etc.
func SanitizePhone(input string) string {
	var digits strings.Builder
	hasPlus := false
	for _, r := range input {
		if r == '+' {
			hasPlus = true
		} else if r >= '0' && r <= '9' {
			digits.WriteRune(r)
		}
	}
	d := digits.String()
	if len(d) < 10 || len(d) > 15 {
		return ""
	}
	if hasPlus {
		return "+" + d
	}
	return "+" + d
}