/*
    Copyright (C) 2009 William Hart
    Copyright (C) 2010 Sebastian Pancratz

    This file is part of FLINT.

    FLINT 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/>.
*/

#include "test_helpers.h"
#include "ulong_extras.h"
#include "long_extras.h"
#include "fmpz.h"
#include "fmpq_poly.h"

TEST_FUNCTION_START(fmpq_poly_scalar_div_si, state)
{
    int i, result;
    ulong cflags = UWORD(0);

    /* Check aliasing of a and b */
    for (i = 0; i < 1000 * flint_test_multiplier(); i++)
    {
        fmpq_poly_t a, b;
        slong n;

        fmpq_poly_init(a);
        fmpq_poly_init(b);
        fmpq_poly_randtest(a, state, n_randint(state, 100), 200);
        n = z_randtest_not_zero(state);

        fmpq_poly_scalar_div_si(b, a, n);
        fmpq_poly_scalar_div_si(a, a, n);

        cflags |= fmpq_poly_is_canonical(a) ? 0 : 1;
        cflags |= fmpq_poly_is_canonical(b) ? 0 : 2;
        result = (fmpq_poly_equal(a, b) && !cflags);
        if (!result)
        {
            flint_printf("FAIL:\n");
            fmpq_poly_debug(a), flint_printf("\n\n");
            fmpq_poly_debug(b), flint_printf("\n\n");
            flint_printf("cflags = %wu\n\n", cflags);
            fflush(stdout);
            flint_abort();
        }

        fmpq_poly_clear(a);
        fmpq_poly_clear(b);
    }

    /* Compare with fmpq_poly_scalar_div_ui */
    for (i = 0; i < 1000 * flint_test_multiplier(); i++)
    {
        fmpq_poly_t a, b;
        ulong n;

        n = n_randtest_not_zero(state);
        if (n > WORD_MAX)
            n >>= 1;

        fmpq_poly_init(a);
        fmpq_poly_init(b);
        fmpq_poly_randtest(a, state, n_randint(state, 100), 200);

        fmpq_poly_scalar_div_ui(b, a, n);
        fmpq_poly_scalar_div_si(a, a, n);

        cflags |= fmpq_poly_is_canonical(a) ? 0 : 1;
        cflags |= fmpq_poly_is_canonical(b) ? 0 : 2;
        result = (fmpq_poly_equal(a, b) && !cflags);
        if (!result)
        {
            flint_printf("FAIL:\n");
            fmpq_poly_debug(a), flint_printf("\n\n");
            fmpq_poly_debug(b), flint_printf("\n\n");
            flint_printf("cflags = %wu\n\n", cflags);
            fflush(stdout);
            flint_abort();
        }

        fmpq_poly_clear(a);
        fmpq_poly_clear(b);
    }

    /* Check (a / n1) / n2 == a / (n1 * n2) */
    for (i = 0; i < 1000 * flint_test_multiplier(); i++)
    {
        fmpq_poly_t a, b, c;
        slong n1, n2;
        ulong m;

        while ((n1 = (slong) n_randbits(state, FLINT_BITS / 2)) == 0) ;
        while ((n2 = (slong) n_randbits(state, FLINT_BITS / 2 - 1)) == 0) ;

        m = n_randlimb(state);
        if (m & UWORD(1))
            n1 = -n1;
        if (m & UWORD(2))
            n2 = -n2;

        fmpq_poly_init(a);
        fmpq_poly_init(b);
        fmpq_poly_init(c);
        fmpq_poly_randtest(a, state, n_randint(state, 100), 200);

        fmpq_poly_scalar_div_si(b, a, n1);
        fmpq_poly_scalar_div_si(c, b, n2);
        fmpq_poly_scalar_div_si(b, a, n1 * n2);

        cflags |= fmpq_poly_is_canonical(b) ? 0 : 1;
        cflags |= fmpq_poly_is_canonical(c) ? 0 : 2;
        result = (fmpq_poly_equal(b, c) && !cflags);
        if (!result)
        {
            flint_printf("FAIL:\n\n");
            flint_printf("n1 = %wu, n2 = %wu:\n\n", n1, n2);
            fmpq_poly_debug(a), flint_printf("\n\n");
            fmpq_poly_debug(b), flint_printf("\n\n");
            fmpq_poly_debug(c), flint_printf("\n\n");
            flint_printf("cflags = %wu\n\n", cflags);
            fflush(stdout);
            flint_abort();
        }

        fmpq_poly_clear(a);
        fmpq_poly_clear(b);
        fmpq_poly_clear(c);
    }

    TEST_FUNCTION_END(state);
}
