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// This file is part of ICU4X. For terms of use, please see the file
// called LICENSE at the top level of the ICU4X source tree
//! This module contains types and implementations for the Ethiopian calendar.
//!
//! ```rust
//! use icu::calendar::{ethiopian::Ethiopian, Date, DateTime};
//!
//! // `Date` type
//! let date_iso = Date::try_new_iso_date(1970, 1, 2)
//! .expect("Failed to initialize ISO Date instance.");
//! let date_ethiopian = Date::new_from_iso(date_iso, Ethiopian::new());
//!
//! // `DateTime` type
//! let datetime_iso = DateTime::try_new_iso_datetime(1970, 1, 2, 13, 1, 0)
//! .expect("Failed to initialize ISO DateTime instance.");
//! let datetime_ethiopian =
//! DateTime::new_from_iso(datetime_iso, Ethiopian::new());
//!
//! // `Date` checks
//! assert_eq!(date_ethiopian.year().number, 1962);
//! assert_eq!(date_ethiopian.month().ordinal, 4);
//! assert_eq!(date_ethiopian.day_of_month().0, 24);
//!
//! // `DateTime` type
//! assert_eq!(datetime_ethiopian.date.year().number, 1962);
//! assert_eq!(datetime_ethiopian.date.month().ordinal, 4);
//! assert_eq!(datetime_ethiopian.date.day_of_month().0, 24);
//! assert_eq!(datetime_ethiopian.time.hour.number(), 13);
//! assert_eq!(datetime_ethiopian.time.minute.number(), 1);
//! assert_eq!(datetime_ethiopian.time.second.number(), 0);
//! ```
use crate::any_calendar::AnyCalendarKind;
use crate::calendar_arithmetic::{ArithmeticDate, CalendarArithmetic};
use crate::iso::Iso;
use crate::{types, Calendar, CalendarError, Date, DateDuration, DateDurationUnit, DateTime, Time};
use calendrical_calculations::helpers::I32CastError;
use calendrical_calculations::rata_die::RataDie;
use tinystr::tinystr;
/// The number of years the Amete Alem epoch precedes the Amete Mihret epoch
const AMETE_ALEM_OFFSET: i32 = 5500;
/// Which era style the ethiopian calendar uses
#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
#[non_exhaustive]
pub enum EthiopianEraStyle {
/// Use an era scheme of pre- and post- Incarnation eras,
/// anchored at the date of the Incarnation of Jesus in this calendar
AmeteMihret,
/// Use an era scheme of the Anno Mundi era, anchored at the date of Creation
/// in this calendar
AmeteAlem,
}
/// The [Ethiopian Calendar]
///
/// The [Ethiopian calendar] is a solar calendar used by the Coptic Orthodox Church, with twelve normal months
/// and a thirteenth small epagomenal month.
///
/// This type can be used with [`Date`] or [`DateTime`] to represent dates in this calendar.
///
/// It can be constructed in two modes: using the Amete Alem era scheme, or the Amete Mihret era scheme (the default),
/// see [`EthiopianEraStyle`] for more info.
///
///
/// # Era codes
///
/// This calendar supports three era codes, based on what mode it is in. In the Amete Mihret scheme it has
/// the `"incar"` and `"pre-incar"` eras, 1 Incarnation is 9 CE. In the Amete Alem scheme, it instead has a single era,
/// `"mundi`, where 1 Anno Mundi is 5493 BCE. Dates before that use negative year numbers.
///
/// # Month codes
///
/// This calendar supports 13 solar month codes (`"M01" - "M13"`), with `"M13"` being used for the short epagomenal month
/// at the end of the year.
// The bool specifies whether dates should be in the Amete Alem era scheme
#[derive(Copy, Clone, Debug, Hash, Default, Eq, PartialEq, PartialOrd, Ord)]
pub struct Ethiopian(pub(crate) bool);
/// The inner date type used for representing [`Date`]s of [`Ethiopian`]. See [`Date`] and [`Ethiopian`] for more details.
#[derive(Copy, Clone, Debug, Hash, Eq, PartialEq, PartialOrd, Ord)]
pub struct EthiopianDateInner(ArithmeticDate<Ethiopian>);
impl CalendarArithmetic for Ethiopian {
type YearInfo = ();
fn month_days(year: i32, month: u8, _data: ()) -> u8 {
if (1..=12).contains(&month) {
30
} else if month == 13 {
if Self::is_leap_year(year, ()) {
6
} else {
5
}
} else {
0
}
}
fn months_for_every_year(_: i32, _data: ()) -> u8 {
13
}
fn is_leap_year(year: i32, _data: ()) -> bool {
year.rem_euclid(4) == 3
}
fn last_month_day_in_year(year: i32, _data: ()) -> (u8, u8) {
if Self::is_leap_year(year, ()) {
(13, 6)
} else {
(13, 5)
}
}
fn days_in_provided_year(year: i32, _data: ()) -> u16 {
if Self::is_leap_year(year, ()) {
366
} else {
365
}
}
}
impl Calendar for Ethiopian {
type DateInner = EthiopianDateInner;
fn date_from_codes(
&self,
era: types::Era,
year: i32,
month_code: types::MonthCode,
day: u8,
) -> Result<Self::DateInner, CalendarError> {
let year = if era.0 == tinystr!(16, "incar") {
if year <= 0 {
return Err(CalendarError::OutOfRange);
}
year
} else if era.0 == tinystr!(16, "pre-incar") {
if year <= 0 {
return Err(CalendarError::OutOfRange);
}
1 - year
} else if era.0 == tinystr!(16, "mundi") {
year - AMETE_ALEM_OFFSET
} else {
return Err(CalendarError::UnknownEra(era.0, self.debug_name()));
};
ArithmeticDate::new_from_codes(self, year, month_code, day).map(EthiopianDateInner)
}
fn date_from_iso(&self, iso: Date<Iso>) -> EthiopianDateInner {
let fixed_iso = Iso::fixed_from_iso(*iso.inner());
Self::ethiopian_from_fixed(fixed_iso)
}
fn date_to_iso(&self, date: &Self::DateInner) -> Date<Iso> {
let fixed_ethiopian = Ethiopian::fixed_from_ethiopian(date.0);
Iso::iso_from_fixed(fixed_ethiopian)
}
fn months_in_year(&self, date: &Self::DateInner) -> u8 {
date.0.months_in_year()
}
fn days_in_year(&self, date: &Self::DateInner) -> u16 {
date.0.days_in_year()
}
fn days_in_month(&self, date: &Self::DateInner) -> u8 {
date.0.days_in_month()
}
fn day_of_week(&self, date: &Self::DateInner) -> types::IsoWeekday {
Iso.day_of_week(self.date_to_iso(date).inner())
}
fn offset_date(&self, date: &mut Self::DateInner, offset: DateDuration<Self>) {
date.0.offset_date(offset, &());
}
#[allow(clippy::field_reassign_with_default)]
fn until(
&self,
date1: &Self::DateInner,
date2: &Self::DateInner,
_calendar2: &Self,
_largest_unit: DateDurationUnit,
_smallest_unit: DateDurationUnit,
) -> DateDuration<Self> {
date1.0.until(date2.0, _largest_unit, _smallest_unit)
}
fn year(&self, date: &Self::DateInner) -> types::FormattableYear {
Self::year_as_ethiopian(date.0.year, self.0)
}
fn is_in_leap_year(&self, date: &Self::DateInner) -> bool {
Self::is_leap_year(date.0.year, ())
}
fn month(&self, date: &Self::DateInner) -> types::FormattableMonth {
date.0.month()
}
fn day_of_month(&self, date: &Self::DateInner) -> types::DayOfMonth {
date.0.day_of_month()
}
fn day_of_year_info(&self, date: &Self::DateInner) -> types::DayOfYearInfo {
let prev_year = date.0.year - 1;
let next_year = date.0.year + 1;
types::DayOfYearInfo {
day_of_year: date.0.day_of_year(),
days_in_year: date.0.days_in_year(),
prev_year: Self::year_as_ethiopian(prev_year, self.0),
days_in_prev_year: Ethiopian::days_in_year_direct(prev_year),
next_year: Self::year_as_ethiopian(next_year, self.0),
}
}
fn debug_name(&self) -> &'static str {
"Ethiopian"
}
fn any_calendar_kind(&self) -> Option<AnyCalendarKind> {
if self.0 {
Some(AnyCalendarKind::EthiopianAmeteAlem)
} else {
Some(AnyCalendarKind::Ethiopian)
}
}
}
impl Ethiopian {
/// Construct a new Ethiopian Calendar for the Amete Mihret era naming scheme
pub const fn new() -> Self {
Self(false)
}
/// Construct a new Ethiopian Calendar with a value specifying whether or not it is Amete Alem
pub const fn new_with_era_style(era_style: EthiopianEraStyle) -> Self {
Self(matches!(era_style, EthiopianEraStyle::AmeteAlem))
}
/// Set whether or not this uses the Amete Alem era scheme
pub fn set_era_style(&mut self, era_style: EthiopianEraStyle) {
self.0 = era_style == EthiopianEraStyle::AmeteAlem
}
/// Returns whether this has the Amete Alem era
pub fn era_style(&self) -> EthiopianEraStyle {
if self.0 {
EthiopianEraStyle::AmeteAlem
} else {
EthiopianEraStyle::AmeteMihret
}
}
fn fixed_from_ethiopian(date: ArithmeticDate<Ethiopian>) -> RataDie {
calendrical_calculations::ethiopian::fixed_from_ethiopian(date.year, date.month, date.day)
}
fn ethiopian_from_fixed(date: RataDie) -> EthiopianDateInner {
let (year, month, day) =
match calendrical_calculations::ethiopian::ethiopian_from_fixed(date) {
Err(I32CastError::BelowMin) => {
return EthiopianDateInner(ArithmeticDate::min_date())
}
Err(I32CastError::AboveMax) => {
return EthiopianDateInner(ArithmeticDate::max_date())
}
Ok(ymd) => ymd,
};
EthiopianDateInner(ArithmeticDate::new_unchecked(year, month, day))
}
fn days_in_year_direct(year: i32) -> u16 {
if Ethiopian::is_leap_year(year, ()) {
366
} else {
365
}
}
fn year_as_ethiopian(year: i32, amete_alem: bool) -> types::FormattableYear {
if amete_alem {
types::FormattableYear {
era: types::Era(tinystr!(16, "mundi")),
number: year + AMETE_ALEM_OFFSET,
cyclic: None,
related_iso: None,
}
} else if year > 0 {
types::FormattableYear {
era: types::Era(tinystr!(16, "incar")),
number: year,
cyclic: None,
related_iso: None,
}
} else {
types::FormattableYear {
era: types::Era(tinystr!(16, "pre-incar")),
number: 1 - year,
cyclic: None,
related_iso: None,
}
}
}
}
impl Date<Ethiopian> {
/// Construct new Ethiopian Date.
///
/// For the Amete Mihret era style, negative years work with
/// year 0 as 1 pre-Incarnation, year -1 as 2 pre-Incarnation,
/// and so on.
///
/// ```rust
/// use icu::calendar::ethiopian::EthiopianEraStyle;
/// use icu::calendar::Date;
///
/// let date_ethiopian = Date::try_new_ethiopian_date(
/// EthiopianEraStyle::AmeteMihret,
/// 2014,
/// 8,
/// 25,
/// )
/// .expect("Failed to initialize Ethopic Date instance.");
///
/// assert_eq!(date_ethiopian.year().number, 2014);
/// assert_eq!(date_ethiopian.month().ordinal, 8);
/// assert_eq!(date_ethiopian.day_of_month().0, 25);
/// ```
pub fn try_new_ethiopian_date(
era_style: EthiopianEraStyle,
mut year: i32,
month: u8,
day: u8,
) -> Result<Date<Ethiopian>, CalendarError> {
if era_style == EthiopianEraStyle::AmeteAlem {
year -= AMETE_ALEM_OFFSET;
}
ArithmeticDate::new_from_ordinals(year, month, day)
.map(EthiopianDateInner)
.map(|inner| Date::from_raw(inner, Ethiopian::new_with_era_style(era_style)))
}
}
impl DateTime<Ethiopian> {
/// Construct a new Ethiopian datetime from integers.
///
/// For the Amete Mihret era style, negative years work with
/// year 0 as 1 pre-Incarnation, year -1 as 2 pre-Incarnation,
/// and so on.
///
/// ```rust
/// use icu::calendar::ethiopian::EthiopianEraStyle;
/// use icu::calendar::DateTime;
///
/// let datetime_ethiopian = DateTime::try_new_ethiopian_datetime(
/// EthiopianEraStyle::AmeteMihret,
/// 2014,
/// 8,
/// 25,
/// 13,
/// 1,
/// 0,
/// )
/// .expect("Failed to initialize Ethiopian DateTime instance.");
///
/// assert_eq!(datetime_ethiopian.date.year().number, 2014);
/// assert_eq!(datetime_ethiopian.date.month().ordinal, 8);
/// assert_eq!(datetime_ethiopian.date.day_of_month().0, 25);
/// assert_eq!(datetime_ethiopian.time.hour.number(), 13);
/// assert_eq!(datetime_ethiopian.time.minute.number(), 1);
/// assert_eq!(datetime_ethiopian.time.second.number(), 0);
/// ```
pub fn try_new_ethiopian_datetime(
era_style: EthiopianEraStyle,
year: i32,
month: u8,
day: u8,
hour: u8,
minute: u8,
second: u8,
) -> Result<DateTime<Ethiopian>, CalendarError> {
Ok(DateTime {
date: Date::try_new_ethiopian_date(era_style, year, month, day)?,
time: Time::try_new(hour, minute, second, 0)?,
})
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_leap_year() {
// 11th September 2023 in gregorian is 6/13/2015 in ethiopian
let iso_date = Date::try_new_iso_date(2023, 9, 11).unwrap();
let ethiopian_date = Ethiopian::new().date_from_iso(iso_date);
assert_eq!(ethiopian_date.0.year, 2015);
assert_eq!(ethiopian_date.0.month, 13);
assert_eq!(ethiopian_date.0.day, 6);
}
#[test]
fn test_iso_to_ethiopian_conversion_and_back() {
let iso_date = Date::try_new_iso_date(1970, 1, 2).unwrap();
let date_ethiopian = Date::new_from_iso(iso_date, Ethiopian::new());
assert_eq!(date_ethiopian.inner.0.year, 1962);
assert_eq!(date_ethiopian.inner.0.month, 4);
assert_eq!(date_ethiopian.inner.0.day, 24);
assert_eq!(
date_ethiopian.to_iso(),
Date::try_new_iso_date(1970, 1, 2).unwrap()
);
}
#[test]
fn test_roundtrip_negative() {
let iso_date = Date::try_new_iso_date(-1000, 3, 3).unwrap();
let ethiopian = iso_date.to_calendar(Ethiopian::new());
let recovered_iso = ethiopian.to_iso();
assert_eq!(iso_date, recovered_iso);
}
}