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use idna::domain_to_ascii;
use once_cell::sync::Lazy;
use regex::Regex;
use std::{
convert::{TryFrom, TryInto},
error::Error,
ffi::OsStr,
fmt::{Display, Formatter, Result as FmtResult},
net::IpAddr,
str::FromStr,
};
#[derive(Debug, Clone, PartialOrd, Ord, PartialEq, Eq, Hash)]
pub struct Address {
serialized: String,
at_start: usize,
}
static USER_RE: Lazy<Regex> =
Lazy::new(|| Regex::new(r"^(?i)[a-z0-9.!#$%&'*+/=?^_`{|}~-]+\z").unwrap());
static DOMAIN_RE: Lazy<Regex> = Lazy::new(|| {
Regex::new(
r"(?i)^[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?(?:.[a-z0-9](?:[a-z0-9-]{0,61}[a-z0-9])?)*$",
)
.unwrap()
});
static LITERAL_RE: Lazy<Regex> = Lazy::new(|| Regex::new(r"(?i)\[([A-f0-9:\.]+)\]\z").unwrap());
impl Address {
pub fn new<U: AsRef<str>, D: AsRef<str>>(user: U, domain: D) -> Result<Self, AddressError> {
(user, domain).try_into()
}
pub fn user(&self) -> &str {
&self.serialized[..self.at_start]
}
pub fn domain(&self) -> &str {
&self.serialized[self.at_start + 1..]
}
pub(super) fn check_user(user: &str) -> Result<(), AddressError> {
if USER_RE.is_match(user) {
Ok(())
} else {
Err(AddressError::InvalidUser)
}
}
pub(super) fn check_domain(domain: &str) -> Result<(), AddressError> {
Address::check_domain_ascii(domain).or_else(|_| {
domain_to_ascii(domain)
.map_err(|_| AddressError::InvalidDomain)
.and_then(|domain| Address::check_domain_ascii(&domain))
})
}
fn check_domain_ascii(domain: &str) -> Result<(), AddressError> {
if DOMAIN_RE.is_match(domain) {
return Ok(());
}
if let Some(caps) = LITERAL_RE.captures(domain) {
if let Some(cap) = caps.get(1) {
if cap.as_str().parse::<IpAddr>().is_ok() {
return Ok(());
}
}
}
Err(AddressError::InvalidDomain)
}
#[cfg(feature = "smtp-transport")]
pub(super) fn is_ascii(&self) -> bool {
self.serialized.is_ascii()
}
}
impl Display for Address {
fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
f.write_str(&self.serialized)
}
}
impl FromStr for Address {
type Err = AddressError;
fn from_str(val: &str) -> Result<Self, AddressError> {
let mut parts = val.rsplitn(2, '@');
let domain = parts.next().ok_or(AddressError::MissingParts)?;
let user = parts.next().ok_or(AddressError::MissingParts)?;
Address::check_user(user)?;
Address::check_domain(domain)?;
Ok(Address {
serialized: val.into(),
at_start: user.len(),
})
}
}
impl<U, D> TryFrom<(U, D)> for Address
where
U: AsRef<str>,
D: AsRef<str>,
{
type Error = AddressError;
fn try_from((user, domain): (U, D)) -> Result<Self, Self::Error> {
let user = user.as_ref();
Address::check_user(user)?;
let domain = domain.as_ref();
Address::check_domain(domain)?;
let serialized = format!("{}@{}", user, domain);
Ok(Address {
serialized,
at_start: user.len(),
})
}
}
impl AsRef<str> for Address {
fn as_ref(&self) -> &str {
&self.serialized
}
}
impl AsRef<OsStr> for Address {
fn as_ref(&self) -> &OsStr {
self.serialized.as_ref()
}
}
#[derive(Debug, PartialEq, Clone, Copy)]
pub enum AddressError {
MissingParts,
Unbalanced,
InvalidUser,
InvalidDomain,
}
impl Error for AddressError {}
impl Display for AddressError {
fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
match self {
AddressError::MissingParts => f.write_str("Missing domain or user"),
AddressError::Unbalanced => f.write_str("Unbalanced angle bracket"),
AddressError::InvalidUser => f.write_str("Invalid email user"),
AddressError::InvalidDomain => f.write_str("Invalid email domain"),
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn parse_address() {
let addr_str = "something@example.com";
let addr = Address::from_str(addr_str).unwrap();
let addr2 = Address::new("something", "example.com").unwrap();
assert_eq!(addr, addr2);
assert_eq!(addr.user(), "something");
assert_eq!(addr.domain(), "example.com");
assert_eq!(addr2.user(), "something");
assert_eq!(addr2.domain(), "example.com");
}
}