/*
    Copyright (C) 2010 William Hart

    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 "fmpz.h"
#include "fmpz_poly.h"
#include "ulong_extras.h"

TEST_FUNCTION_START(fmpz_poly_mullow_classical, state)
{
    int i, result;

    /* Check aliasing of a and b */
    for (i = 0; i < 200 * flint_test_multiplier(); i++)
    {
        fmpz_poly_t a, b, c;
        slong len, trunc;

        fmpz_poly_init(a);
        fmpz_poly_init(b);
        fmpz_poly_init(c);
        fmpz_poly_randtest(b, state, n_randint(state, 50), 200);
        fmpz_poly_randtest(c, state, n_randint(state, 50), 200);

        len = b->length + c->length - 1;
        trunc = (len <= 0) ? 0 : n_randint(state, b->length + c->length);

        fmpz_poly_mullow_classical(a, b, c, trunc);
        fmpz_poly_mullow_classical(b, b, c, trunc);

        result = (fmpz_poly_equal(a, b));
        if (!result)
        {
            flint_printf("FAIL:\n");
            fmpz_poly_print(a), flint_printf("\n\n");
            fmpz_poly_print(b), flint_printf("\n\n");
            fflush(stdout);
            flint_abort();
        }

        fmpz_poly_clear(a);
        fmpz_poly_clear(b);
        fmpz_poly_clear(c);
    }

    /* Check aliasing of a and c */
    for (i = 0; i < 200 * flint_test_multiplier(); i++)
    {
        fmpz_poly_t a, b, c;
        slong len;
        ulong trunc;

        fmpz_poly_init(a);
        fmpz_poly_init(b);
        fmpz_poly_init(c);
        fmpz_poly_randtest(b, state, n_randint(state, 50), 200);
        fmpz_poly_randtest(c, state, n_randint(state, 50), 200);

        len = b->length + c->length - 1;
        trunc = (len <= 0) ? 0 : n_randint(state, b->length + c->length - 1);

        fmpz_poly_mullow_classical(a, b, c, trunc);
        fmpz_poly_mullow_classical(c, b, c, trunc);

        result = (fmpz_poly_equal(a, c));
        if (!result)
        {
            flint_printf("FAIL:\n");
            fmpz_poly_print(a), flint_printf("\n\n");
            fmpz_poly_print(c), flint_printf("\n\n");
            fflush(stdout);
            flint_abort();
        }

        fmpz_poly_clear(a);
        fmpz_poly_clear(b);
        fmpz_poly_clear(c);
    }

    /* Compare with mul_basecase */
    for (i = 0; i < 200 * flint_test_multiplier(); i++)
    {
        fmpz_poly_t a, b, c, d;
        slong len, trunc;

        fmpz_poly_init(a);
        fmpz_poly_init(b);
        fmpz_poly_init(c);
        fmpz_poly_init(d);
        fmpz_poly_randtest(b, state, n_randint(state, 50), 200);
        fmpz_poly_randtest(c, state, n_randint(state, 50), 200);

        len = b->length + c->length - 1;
        trunc = (len <= 0) ? 0 : n_randint(state, b->length + c->length - 1);

        fmpz_poly_mul_classical(a, b, c);
        fmpz_poly_truncate(a, trunc);
        fmpz_poly_mullow_classical(d, b, c, trunc);

        result = (fmpz_poly_equal(a, d));
        if (!result)
        {
            flint_printf("FAIL:\n");
            fmpz_poly_print(a), flint_printf("\n\n");
            fmpz_poly_print(d), flint_printf("\n\n");
            fflush(stdout);
            flint_abort();
        }

        fmpz_poly_clear(a);
        fmpz_poly_clear(b);
        fmpz_poly_clear(c);
        fmpz_poly_clear(d);
    }

    TEST_FUNCTION_END(state);
}
