use crate::error::{Error, ErrorKind};
use serde::{Deserialize, Serialize, de};
use std::{
fmt::{self, Display},
str::FromStr,
};
pub(crate) const YEAR_MIN: u32 = 2000;
pub(crate) const YEAR_MAX: u32 = YEAR_MIN + 100;
#[derive(Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord, Serialize)]
pub struct Date(String);
impl Date {
pub fn year(&self) -> u32 {
self.component(0).expect("has year")
}
pub fn month(&self) -> u32 {
self.component(1).expect("has month")
}
pub fn day(&self) -> u32 {
self.component(2).expect("has day")
}
pub fn as_str(&self) -> &str {
self.0.as_ref()
}
fn component(&self, index: usize) -> Option<u32> {
self.0
.split('-')
.nth(index)
.map(|cmp| cmp.parse().expect("numerical date components"))
}
}
impl AsRef<str> for Date {
fn as_ref(&self) -> &str {
self.as_str()
}
}
impl Display for Date {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_str(self.as_str())
}
}
impl FromStr for Date {
type Err = Error;
fn from_str(rfc3339_date: &str) -> Result<Self, Error> {
validate_date(rfc3339_date)?;
Ok(Date(rfc3339_date.into()))
}
}
impl<'de> Deserialize<'de> for Date {
fn deserialize<D: de::Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
use de::Error;
String::deserialize(deserializer)?
.parse()
.map_err(D::Error::custom)
}
}
macro_rules! check_date_part {
($name:expr, $string:expr, $parts:expr, $len:expr, $min:expr, $max:expr) => {
let part = $parts
.next()
.ok_or_else(|| Error::new(ErrorKind::Parse, format!("invalid date: {}", $string)))?;
if part.len() != $len {
fail!(ErrorKind::Parse, "malformed {}: {}", $name, $string);
}
match part.parse::<u32>() {
Ok($min..=$max) => (),
_ => fail!(ErrorKind::Parse, "malformed {}: {}", $name, $string),
}
};
}
fn validate_date(string: &str) -> Result<(), Error> {
let mut parts = string.split('-');
check_date_part!("year", string, parts, 4, YEAR_MIN, YEAR_MAX);
check_date_part!("month", string, parts, 2, 1, 12);
check_date_part!("day", string, parts, 2, 1, 31);
if parts.next().is_some() {
fail!(ErrorKind::Parse, "invalid date: {}", string)
}
Ok(())
}
#[cfg(test)]
mod tests {
use super::Date;
use std::str::FromStr;
#[test]
fn from_str_test() {
assert!(Date::from_str("2000-01-01").is_ok());
assert!(Date::from_str("2017-01-01").is_ok());
assert!(Date::from_str("2099-12-31").is_ok());
assert!(Date::from_str("derp").is_err());
assert!(Date::from_str("1999-12-31").is_err());
assert!(Date::from_str("02017-01-01").is_err());
assert!(Date::from_str("2017-00-01").is_err());
assert!(Date::from_str("2017-01-00").is_err());
assert!(Date::from_str("2017-13-01").is_err());
assert!(Date::from_str("2017-01-32").is_err());
assert!(Date::from_str("2017-01-").is_err());
assert!(Date::from_str("2017-01-01-01").is_err());
}
#[test]
fn date_components_test() {
let date = Date::from_str("2000-01-02").unwrap();
assert_eq!(date.year(), 2000);
assert_eq!(date.month(), 1);
assert_eq!(date.day(), 2);
}
}