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// Copyright © 2026 Mikhail Hogrefe
//
// Uses code adopted from the FLINT Library.
//
// Copyright © 2011 Fredrik Johansson
//
// 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::cmp::max;
use malachite_base::num::logic::traits::SignificantBits;
use malachite_nz::natural::Natural;
impl Rational {
/// Returns the height of a [`Rational`]: the larger of the absolute value of its numerator and
/// its denominator, taking the [`Rational`] by reference and cloning.
///
/// The height is the measure in which Diophantine approximation bounds are usually stated.
///
/// $$
/// f(p/q) = H(p/q) = \max(|p|, q).
/// $$
///
/// # Worst-case complexity
/// $T(n) = O(n)$
///
/// $M(n) = O(n)$
///
/// where $T$ is time, $M$ is additional memory, and $n$ is `self.significant_bits()`.
///
/// # Examples
/// ```
/// use malachite_q::Rational;
/// use std::str::FromStr;
///
/// assert_eq!(Rational::from_str("22/7").unwrap().to_height(), 22);
/// assert_eq!(Rational::from_str("-1/101").unwrap().to_height(), 101);
/// assert_eq!(Rational::from_str("0").unwrap().to_height(), 1);
/// ```
///
/// This is fmpq_height from fmpq/height.c, FLINT 3.6.0, where the components are already
/// magnitudes, so no absolute values need to be taken.
#[inline]
pub fn to_height(&self) -> Natural {
max(&self.numerator, &self.denominator).clone()
}
/// Returns the height of a [`Rational`]: the larger of the absolute value of its numerator and
/// its denominator, taking the [`Rational`] by value.
///
/// The height is the measure in which Diophantine approximation bounds are usually stated.
///
/// $$
/// f(p/q) = H(p/q) = \max(|p|, q).
/// $$
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// ```
/// use malachite_q::Rational;
/// use std::str::FromStr;
///
/// assert_eq!(Rational::from_str("22/7").unwrap().into_height(), 22);
/// assert_eq!(Rational::from_str("-1/101").unwrap().into_height(), 101);
/// assert_eq!(Rational::from_str("0").unwrap().into_height(), 1);
/// ```
///
/// This is fmpq_height from fmpq/height.c, FLINT 3.6.0, where the components are already
/// magnitudes, so no absolute values need to be taken.
#[inline]
pub fn into_height(self) -> Natural {
max(self.numerator, self.denominator)
}
/// Returns the number of significant bits of the height of a [`Rational`]: the larger of the
/// numbers of significant bits of its numerator and its denominator.
///
/// Since bit length is monotone, this is `self.to_height().significant_bits()`, without
/// materializing the height.
///
/// $$
/// f(p/q) = \lfloor \log_2 \max(|p|, q) \rfloor + 1.
/// $$
///
/// # Worst-case complexity
/// Constant time and additional memory.
///
/// # Examples
/// ```
/// use malachite_q::Rational;
/// use std::str::FromStr;
///
/// assert_eq!(
/// Rational::from_str("22/7")
/// .unwrap()
/// .height_significant_bits(),
/// 5
/// );
/// assert_eq!(
/// Rational::from_str("-1/101")
/// .unwrap()
/// .height_significant_bits(),
/// 7
/// );
/// assert_eq!(
/// Rational::from_str("0").unwrap().height_significant_bits(),
/// 1
/// );
/// ```
///
/// This is fmpq_height_bits from fmpq/height_bits.c, FLINT 3.6.0.
#[inline]
pub fn height_significant_bits(&self) -> u64 {
max(
self.numerator.significant_bits(),
self.denominator.significant_bits(),
)
}
}