use std::{fmt, ops::Add, str::FromStr};
use chrono::{Datelike, Month, NaiveDate};
use strum::EnumString;
use crate::syntax::bibtex::Value;
use super::text::TextFieldData;
#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Copy, Hash, EnumString)]
#[strum(ascii_case_insensitive)]
pub enum DateField {
Date,
EventDate,
Month,
UrlDate,
Year,
}
impl DateField {
pub fn parse(input: &str) -> Option<Self> {
Self::from_str(input).ok()
}
}
#[derive(Debug, PartialEq, Eq, Clone, Hash)]
pub enum DateFieldData {
Date(NaiveDate),
Year(i32),
Month(Month),
Other(String),
}
impl Add for DateFieldData {
type Output = Self;
fn add(self, rhs: Self) -> Self::Output {
match (self, rhs) {
(date @ Self::Year(_), Self::Year(_))
| (date @ Self::Month(_), Self::Month(_))
| (date @ Self::Date(_), Self::Date(_))
| (Self::Other(_), date)
| (date, Self::Other(_)) => date,
(Self::Year(year), Self::Month(month)) | (Self::Month(month), Self::Year(year)) => {
let new_date = NaiveDate::from_ymd_opt(year, month.number_from_month(), 1).unwrap();
Self::Date(new_date)
}
(Self::Year(year), Self::Date(date)) | (Self::Date(date), Self::Year(year)) => {
let new_date = date.with_year(year).unwrap_or(date);
Self::Date(new_date)
}
(Self::Date(date), Self::Month(month)) | (Self::Month(month), Self::Date(date)) => {
let new_date = date.with_month(month.number_from_month()).unwrap_or(date);
Self::Date(new_date)
}
}
}
}
impl fmt::Display for DateFieldData {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Self::Year(year) => write!(f, "{}", year),
Self::Date(date) => write!(f, "{}", date.format("%b. %Y")),
Self::Month(month) => write!(f, "{}", month.name()),
Self::Other(text) => write!(f, "{}", text),
}
}
}
impl DateFieldData {
pub fn parse(value: &Value) -> Option<Self> {
let TextFieldData { text } = TextFieldData::parse(value)?;
NaiveDate::from_str(&text)
.ok()
.map(Self::Date)
.or_else(|| text.parse().ok().map(Self::Year))
.or_else(|| text.parse().ok().map(Self::Month))
.or(Some(Self::Other(text)))
}
}