#include <stdlib.h>
#include "unity/unity.h"
#include "stack.h"

void setUp(void) {}
void tearDown(void) {}

static StackNode *stack = NULL; // Für gemeinsame Benutzung in Tests

void test_push_and_top_should_return_last_integer(void) {
    int *v1 = malloc(sizeof(int));
    int *v2 = malloc(sizeof(int));
    int *v3 = malloc(sizeof(int));
    *v1 = 12; *v2 = 34; *v3 = 56;

    // Push Werte auf Stack
    stack = push(stack, v1);
    TEST_ASSERT_NOT_NULL(stack);
    TEST_ASSERT_EQUAL_INT(12, *(int *)top(stack));

    stack = push(stack, v2);
    TEST_ASSERT_EQUAL_INT(34, *(int *)top(stack));

    stack = push(stack, v3);
    TEST_ASSERT_EQUAL_INT(56, *(int *)top(stack));

    // Ressourcen werden in anderem Test wieder entfernt!
}

void test_pop_should_remove_and_free_integers(void) {
    // Gibt die gleichen Werte wie im vorherigen Push-Test frei
    int *val;
    
    val = top(stack);
    TEST_ASSERT_EQUAL_INT(56, *val);
    free(val);
    stack = pop(stack);

    val = top(stack);
    TEST_ASSERT_EQUAL_INT(34, *val);
    free(val);
    stack = pop(stack);

    val = top(stack);
    TEST_ASSERT_EQUAL_INT(12, *val);
    free(val);
    stack = pop(stack);

    TEST_ASSERT_NULL(stack);
}

void test_stack_empty_behavior(void) {
    // Nach allen pops/clear-Operationen sollte Stack NULL sein
    TEST_ASSERT_NULL(top(stack));
    StackNode *tmp = pop(stack);
    TEST_ASSERT_NULL(tmp);
    stack = clearStack(stack); // Sollte NULL bleiben
    TEST_ASSERT_NULL(stack);
}

int main(void) {
    UNITY_BEGIN();
    RUN_TEST(test_push_and_top_should_return_last_integer);
    RUN_TEST(test_pop_should_remove_and_free_integers);
    RUN_TEST(test_stack_empty_behavior);
    return UNITY_END();
}