#include <stdlib.h>
#include <time.h>

#include "unity/unity.h"
#include "numbers.h"

void setUp(void)
{
}

void tearDown(void)
{
}

static unsigned int countOccurrences(const unsigned int *numbers,
                                     unsigned int len,
                                     unsigned int value)
{
    unsigned int count = 0;
    for (unsigned int i = 0; i < len; ++i) {
        if (numbers[i] == value) {
            count++;
        }
    }
    return count;
}

void test_createNumbers_returns_non_null(void)
{
    unsigned int len = 20;
    unsigned int *numbers = createNumbers(len);

    TEST_ASSERT_NOT_NULL(numbers);

    free(numbers);
}

void test_createNumbers_value_range(void)
{
    unsigned int len = 30;
    unsigned int *numbers = createNumbers(len);

    TEST_ASSERT_NOT_NULL(numbers);

    for (unsigned int i = 0; i < len; ++i) {
        TEST_ASSERT_TRUE(numbers[i] >= 1);
        TEST_ASSERT_TRUE(numbers[i] <= 2 * len);
    }

    free(numbers);
}

void test_getDuplicate_finds_exactly_one_duplicate(void)
{
    unsigned int len = 25;
    unsigned int *numbers = createNumbers(len);

    TEST_ASSERT_NOT_NULL(numbers);

    unsigned int duplicate = getDuplicate(numbers, len);
    TEST_ASSERT_NOT_EQUAL_UINT(0, duplicate);

    unsigned int occurrences =
        countOccurrences(numbers, len, duplicate);

    TEST_ASSERT_EQUAL_UINT(2, occurrences);

    free(numbers);
}

void test_error_cases(void)
{
    TEST_ASSERT_NULL(createNumbers(0));
    TEST_ASSERT_NULL(createNumbers(1));

    TEST_ASSERT_EQUAL_UINT(0, getDuplicate(NULL, 10));

    unsigned int oneElement[1] = { 42 };
    TEST_ASSERT_EQUAL_UINT(0, getDuplicate(oneElement, 1));
}

int main(void)
{
    srand((unsigned int) time(NULL));

    UNITY_BEGIN();

    RUN_TEST(test_createNumbers_returns_non_null);
    RUN_TEST(test_createNumbers_value_range);
    RUN_TEST(test_getDuplicate_finds_exactly_one_duplicate);
    RUN_TEST(test_error_cases);

    return UNITY_END();
}