#include "../tdkpin_random.h"

#include <assert.h>

uint32_t g_borland_random_seed;

static uint32_t expected_next(uint32_t seed)
{
    return seed * 0x08088405u + 1u;
}

int main(void)
{
    g_borland_random_seed = 0x12345678;
    uint32_t first = expected_next(g_borland_random_seed);
    assert(borland_next_random() == first);

    uint32_t second = expected_next(first);
    uint16_t expected_below = (uint16_t)(((uint64_t)second * 3800) >> 32);
    assert(borland_random_below(3800) == expected_below);

    uint32_t third = expected_next(second);
    int8_t expected_exponent = 0;
    if (third != 0) {
        expected_exponent = -128;
        while ((third & 0x80000000u) == 0) {
            third <<= 1;
            expected_exponent--;
        }
    }
    assert(borland_random_exponent() == expected_exponent);

    g_borland_random_seed = 7;
    (void)borland_random_below(0);
    assert(g_borland_random_seed == expected_next(7));

    g_borland_random_seed = 0xfedcba98;
    uint32_t unit_seed = expected_next(g_borland_random_seed);
    assert(borland_random_unit_interval() ==
           (double)unit_seed / 4294967296.0);
    assert(borland_random_unit_interval() >= 0.0 &&
           borland_random_unit_interval() < 1.0);

    win16_reset_segment_bindings();
    win16_set_dos_time_words(0x33441122);
    borland_seed_random_from_dos_time();
    assert(g_borland_random_seed == 0x33441122);
    return 0;
}