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// Copyright © 2026 Mikhail Hogrefe
//
// This file is part of Malachite.
//
// Malachite is free software: you can redistribute it and/or modify it under the terms of the GNU
// Lesser General Public License (LGPL) as published by the Free Software Foundation; either version
// 3 of the License, or (at your option) any later version. See <https://www.gnu.org/licenses/>.
use crate::Rational;
use core::mem::swap;
use malachite_base::num::arithmetic::traits::{Ceiling, CeilingAssign, DivRound, DivRoundAssign};
use malachite_base::num::basic::traits::One;
use malachite_base::rounding_modes::RoundingMode::*;
use malachite_nz::integer::Integer;
use malachite_nz::natural::Natural;
impl Ceiling for Rational {
type Output = Integer;
/// Finds the ceiling of a [`Rational`], taking the [`Rational`] by value.
///
/// $$
/// f(x) = \lceil x \rceil.
/// $$
///
/// # Worst-case complexity
/// $T(n) = O(n \log n \log\log n)$
///
/// $M(n) = O(n \log n)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `max(self.significant_bits(),
/// other.significant_bits())`.
///
/// # Examples
/// ```
/// use malachite_base::num::arithmetic::traits::Ceiling;
/// use malachite_base::num::basic::traits::Zero;
/// use malachite_q::Rational;
///
/// assert_eq!(Rational::ZERO.ceiling(), 0);
/// assert_eq!(Rational::from_signeds(22, 7).ceiling(), 4);
/// assert_eq!(Rational::from_signeds(-22, 7).ceiling(), -3);
/// ```
fn ceiling(self) -> Integer {
if self.sign {
Integer::from(self.numerator.div_round(self.denominator, Ceiling).0)
} else {
Integer::from_sign_and_abs(false, self.numerator / self.denominator)
}
}
}
impl Ceiling for &Rational {
type Output = Integer;
/// Finds the ceiling of a [`Rational`], taking the [`Rational`] by reference.
///
/// $$
/// f(x) = \lceil x \rceil.
/// $$
///
/// # Worst-case complexity
/// $T(n) = O(n \log n \log\log n)$
///
/// $M(n) = O(n \log n)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `max(self.significant_bits(),
/// other.significant_bits())`.
///
/// # Examples
/// ```
/// use malachite_base::num::arithmetic::traits::Ceiling;
/// use malachite_base::num::basic::traits::Zero;
/// use malachite_q::Rational;
///
/// assert_eq!((&Rational::ZERO).ceiling(), 0);
/// assert_eq!((&Rational::from_signeds(22, 7)).ceiling(), 4);
/// assert_eq!((&Rational::from_signeds(-22, 7)).ceiling(), -3);
/// ```
fn ceiling(self) -> Integer {
if self.sign {
Integer::from((&self.numerator).div_round(&self.denominator, Ceiling).0)
} else {
Integer::from_sign_and_abs(false, &self.numerator / &self.denominator)
}
}
}
impl CeilingAssign for Rational {
/// Replaces a [`Rational`] with its ceiling.
///
/// $$
/// x \gets \lceil x \rceil.
/// $$
///
/// # Worst-case complexity
/// $T(n) = O(n \log n \log\log n)$
///
/// $M(n) = O(n \log n)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `max(self.significant_bits(),
/// other.significant_bits())`.
///
/// # Examples
/// ```
/// use malachite_base::num::arithmetic::traits::CeilingAssign;
/// use malachite_base::num::basic::traits::Zero;
/// use malachite_q::Rational;
///
/// let mut x = Rational::ZERO;
/// x.ceiling_assign();
/// assert_eq!(x, 0);
///
/// let mut x = Rational::from_signeds(22, 7);
/// x.ceiling_assign();
/// assert_eq!(x, 4);
///
/// let mut x = Rational::from_signeds(-22, 7);
/// x.ceiling_assign();
/// assert_eq!(x, -3);
/// ```
fn ceiling_assign(&mut self) {
let mut d = Natural::ONE;
swap(&mut self.denominator, &mut d);
if self.sign {
self.numerator.div_round_assign(d, Ceiling);
} else {
self.numerator /= d;
if !self.sign && self.numerator == 0 {
self.sign = true;
}
}
}
}