#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "unity.h"
#include "numbers.h"


// -------------------------------------------------------------
// Hilfsfunktion: zählt, wie oft ein Wert im Array vorkommt
// -------------------------------------------------------------
static unsigned int countOccurrences(const unsigned int *arr, unsigned int len, unsigned int value)
{
    unsigned int count = 0;
    for (unsigned int i = 0; i < len; i++)
        if (arr[i] == value)
            count++;
    return count;
}



// -------------------------------------------------------------
// Test 1: Array wird korrekt erzeugt (nicht NULL)
// -------------------------------------------------------------
void test_createNumbersReturnsNotNull(void)
{
    unsigned int len = 20;
    unsigned int *numbers = createNumbers(len);

    TEST_ASSERT_NOT_NULL(numbers);

    free(numbers);
}



// -------------------------------------------------------------
// Test 2: Alle Zahlen liegen im erlaubten Bereich (1..2*len)
// -------------------------------------------------------------
void test_numbersAreInCorrectRange(void)
{
    unsigned int len = 50;
    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);
}



// -------------------------------------------------------------
// Test 3: Es gibt GENAU EIN Duplikat
// -------------------------------------------------------------
void test_exactlyOneDuplicateExists(void)
{
    unsigned int len = 80;
    unsigned int *numbers = createNumbers(len);

    TEST_ASSERT_NOT_NULL(numbers);

    unsigned int duplicatesFound = 0;

    for (unsigned int i = 0; i < len; i++)
    {
        unsigned int occurrences = countOccurrences(numbers, len, numbers[i]);
        if (occurrences == 2)
            duplicatesFound++;
    }

    // Da das Duplikat an zwei Positionen vorkommt,
    // erwarten wir duplicatesFound == 2
    TEST_ASSERT_EQUAL_UINT(2, duplicatesFound);

    free(numbers);
}



// -------------------------------------------------------------
// Test 4: getDuplicate() findet die richtige doppelte Zahl
// -------------------------------------------------------------
void test_getDuplicateFindsCorrectValue(void)
{
    unsigned int len = 100;
    unsigned int *numbers = createNumbers(len);

    TEST_ASSERT_NOT_NULL(numbers);

    unsigned int duplicate = getDuplicate(numbers, len);

    TEST_ASSERT_TRUE(duplicate >= 1);
    TEST_ASSERT_TRUE(duplicate <= 2 * len);

    TEST_ASSERT_EQUAL_UINT(2, countOccurrences(numbers, len, duplicate));

    free(numbers);
}



// -------------------------------------------------------------
// Test 5: createNumbers() erzeugt len Elemente
// -------------------------------------------------------------
void test_arrayLengthIsCorrect(void)
{
    unsigned int len = 30;
    unsigned int *numbers = createNumbers(len);

    TEST_ASSERT_NOT_NULL(numbers);

    // Unity-Funktion prüft nicht direkt Länge, aber wir können checken,
    // ob Zugriff auf alle Elemente möglich ist (Segfault würde Test crashen).
    for (unsigned int i = 0; i < len; i++)
        TEST_ASSERT_TRUE(numbers[i] >= 1);

    free(numbers);
}



// -------------------------------------------------------------
// Leere setUp/tearDown 
// -------------------------------------------------------------
void setUp(void) {}
void tearDown(void) {}



// -------------------------------------------------------------
// Hauptprogramm für Unity-Tests
// -------------------------------------------------------------
int main(void)
{
    UNITY_BEGIN();

    printf("\n============================\nNumbers tests\n============================\n");

    RUN_TEST(test_createNumbersReturnsNotNull);
    RUN_TEST(test_numbersAreInCorrectRange);
    RUN_TEST(test_exactlyOneDuplicateExists);
    RUN_TEST(test_getDuplicateFindsCorrectValue);
    RUN_TEST(test_arrayLengthIsCorrect);

    return UNITY_END();
}