inertia-core 0.4.0

/*
 *  Copyright (C) 2021 William Youmans
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

mod ops;
mod conv;

use crate::*;
use flint_sys::{fmpz, fmpz_mod, fmpz_mod_poly};
use std::fmt;
use std::hash::{Hash, Hasher};
use std::mem::{ManuallyDrop, MaybeUninit};


#[derive(Debug)]
pub struct IntModPoly {
    inner: fmpz_mod_poly::fmpz_mod_poly_struct,
    ctx: IntModCtx,
}

impl AsRef<IntModPoly> for IntModPoly {
    #[inline]
    fn as_ref(&self) -> &IntModPoly {
        self
    }
}

impl Clone for IntModPoly {
    #[inline]
    fn clone(&self) -> Self {
        let mut res = IntModPoly::zero(self.context());
        unsafe {
            fmpz_mod_poly::fmpz_mod_poly_set(
                res.as_mut_ptr(), 
                self.as_ptr(), 
                self.ctx_as_ptr()
            );
        }
        res
    }
}

impl fmt::Display for IntModPoly {
    #[inline]
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{}", IntPoly::from(self))
    }
}

impl Drop for IntModPoly {
    #[inline]
    fn drop(&mut self) {
        unsafe { 
            fmpz_mod_poly::fmpz_mod_poly_clear(self.as_mut_ptr(), self.ctx_as_ptr())
        }
    }
}

// TODO: avoid IntPoly allocation
impl Hash for IntModPoly {
    #[inline]
    fn hash<H: Hasher>(&self, state: &mut H) {
        self.context().hash(state);
        IntPoly::from(self).hash(state);
    }
}

impl<T: Into<IntPoly>> NewCtx<T, IntModCtx> for IntModPoly {
    fn new(src: T, ctx: &IntModCtx) -> Self {
        let mut z = MaybeUninit::uninit();
        unsafe {
            fmpz_mod_poly::fmpz_mod_poly_init(z.as_mut_ptr(), ctx.as_ptr());
            fmpz_mod_poly::fmpz_mod_poly_set_fmpz_poly(
                z.as_mut_ptr(), 
                src.into().as_ptr(),
                ctx.as_ptr()
            );
            IntModPoly::from_raw(z.assume_init(), ctx.clone())
        }
    }
}

impl IntModPoly {
    pub fn with_capacity(capacity: usize, ctx: &IntModCtx) -> Self {
        let mut z = MaybeUninit::uninit();
        unsafe {
            fmpz_mod_poly::fmpz_mod_poly_init2(
                z.as_mut_ptr(),
                capacity.try_into().expect("Cannot convert input to a signed long."),
                ctx.as_ptr()
            );
            IntModPoly::from_raw(z.assume_init(), ctx.clone())
        }
    }
    
    #[inline]
    pub fn zero(ctx: &IntModCtx) -> IntModPoly {
        let mut z = MaybeUninit::uninit();
        unsafe {
            fmpz_mod_poly::fmpz_mod_poly_init(z.as_mut_ptr(), ctx.as_ptr());
            IntModPoly::from_raw(z.assume_init(), ctx.clone())
        }
    }

    #[inline]
    pub fn one(ctx: &IntModCtx) -> IntModPoly {
        let mut res = IntModPoly::zero(ctx);
        unsafe{ fmpz_mod_poly::fmpz_mod_poly_one(res.as_mut_ptr(), ctx.as_ptr()); }
        res
    }
    
    #[inline]
    pub const fn as_ptr(&self) -> *const fmpz_mod_poly::fmpz_mod_poly_struct {
        &self.inner
    }

    #[inline]
    pub fn as_mut_ptr(&mut self) -> *mut fmpz_mod_poly::fmpz_mod_poly_struct {
        &mut self.inner
    }

    #[inline]
    pub fn ctx_as_ptr(&self) -> *const fmpz_mod::fmpz_mod_ctx_struct {
        self.context().as_ptr()
    }
    
    #[inline]
    pub fn modulus_as_ptr(&self) -> *const fmpz::fmpz {
        self.context().modulus_as_ptr()
    }

    /*
    // TODO: safety?
    #[inline]
    pub unsafe fn as_slice<'a>(&'a self) -> &'a [fmpz::fmpz] {
        std::slice::from_raw_parts((*self.as_ptr()).coeffs, self.len())
    }
    
    // TODO: safety?
    #[inline]
    pub unsafe fn as_mut_slice<'a>(&'a mut self) -> &'a mut [fmpz::fmpz] {
        std::slice::from_raw_parts_mut((*self.as_ptr()).coeffs, self.len())
    }*/

    #[inline]
    pub const unsafe fn from_raw(
        inner: fmpz_mod_poly::fmpz_mod_poly_struct, 
        ctx: IntModCtx
    ) -> Self {
        IntModPoly { inner, ctx }
    }
    
    #[inline]
    pub const fn into_raw(self) -> fmpz_mod_poly::fmpz_mod_poly_struct {
        let inner = self.inner;
        let _ = ManuallyDrop::new(self);
        inner
    }
    
    #[inline]
    pub fn context(&self) -> &IntModCtx {
        &self.ctx
    }
    
    #[inline]
    pub fn modulus(&self) -> Integer {
        self.context().modulus()
    }

    #[inline]
    pub fn is_zero(&self) -> bool {
        unsafe { 
            fmpz_mod_poly::fmpz_mod_poly_is_zero(
                self.as_ptr(), 
                self.ctx_as_ptr()
            ) == 1
        }
    }

    #[inline]
    pub fn is_one(&self) -> bool {
        unsafe { 
            fmpz_mod_poly::fmpz_mod_poly_is_one(
                self.as_ptr(), 
                self.ctx_as_ptr()
            ) == 1
        }
    }

    #[inline]
    pub fn is_gen(&self) -> bool {
        unsafe { 
            fmpz_mod_poly::fmpz_mod_poly_is_gen(
                self.as_ptr(), 
                self.ctx_as_ptr()
            ) == 1
        }
    }

    
    #[inline]
    pub fn len(&self) -> usize {
        unsafe { 
            fmpz_mod_poly::fmpz_mod_poly_length(
                self.as_ptr(), 
                self.ctx_as_ptr()
            ).try_into().unwrap()
        }
    }

    #[inline]
    pub fn degree(&self) -> i64 {
        unsafe { 
            fmpz_mod_poly::fmpz_mod_poly_degree(self.as_ptr(), self.ctx_as_ptr()) 
        }
    }
    
    pub fn get_coeff(&self, i: usize) -> IntMod {
        let ctx = self.context();
        let mut res = IntMod::zero(&ctx);
        unsafe { 
            fmpz_mod_poly::fmpz_mod_poly_get_coeff_fmpz(
                res.as_mut_ptr(), 
                self.as_ptr(), 
                i.try_into().expect("Cannot convert index to a signed long."),
                ctx.as_ptr()
            )
        }
        res
    }
    
    pub fn set_coeff<T: AsRef<IntMod>>(&mut self, i: usize, coeff: T) {
        unsafe {
            fmpz_mod_poly::fmpz_mod_poly_set_coeff_fmpz(
                self.as_mut_ptr(),                                 
                i.try_into().expect("Cannot convert index to a signed long."), 
                coeff.as_ref().as_ptr(),
                self.ctx_as_ptr()
            );
        }
    }
    
    // TODO: anything better?
    #[inline]
    pub fn get_coeffs(&self) -> Vec<IntMod> {
        let mut res = Vec::with_capacity(self.len());
        for i in 0..self.len() {
            res.push(self.get_coeff(i))
        }
        res
    }
}