#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <mach/mach.h>
#include <sys/resource.h>

typedef struct {
    char* arr;
    size_t size;
    size_t capacity;
} Vec8_t;

Vec8_t create(const Vec8_t* input) {
    Vec8_t vec = { .arr = NULL, .size = 0, .capacity = 4 };
    if (input == NULL) {
        vec.arr = calloc(vec.capacity, sizeof(char));
        return vec;
    }
    if (input->size > 0) {
        vec.size = input->size + 1;
    }
    if (input->capacity >= vec.capacity) {
        vec.capacity = 2 * input->capacity;
    }
    vec.arr = calloc(vec.capacity, sizeof(char));
    return vec;
}

void delete(Vec8_t* vec) {
    if (vec->arr != NULL) {
        free(vec->arr);
        vec->arr = NULL;
    }
    vec->size = 0;
    vec->capacity = 0;
}

Vec8_t add_back(Vec8_t* vec, const char val) {
    if (vec->size < vec->capacity) {
        vec->arr[vec->size] = val;
        vec->size++;
        return *vec;
    }
    if (vec->size >= vec->capacity) {
        Vec8_t nvec = create(vec);
        if (nvec.arr == NULL) {
            return *vec;
        }
        memcpy(&nvec.arr[0], &vec->arr[0], vec->size * sizeof(char));
        if (nvec.arr && (nvec.size > 0 || nvec.size > vec->size)) {
            nvec.arr[vec->size] = val;
        }
        free(vec->arr);
        return nvec;
    }
    Vec8_t ret = { .arr = NULL, .capacity = 0, .size = 0 };
    return ret;
}

vm_size_t get_physical_mem() {
    struct task_basic_info info;
    mach_msg_type_number_t count = TASK_BASIC_INFO_COUNT;
    task_info(mach_task_self(), TASK_BASIC_INFO, (task_info_t)&info, &count);
    return info.resident_size;
}

int main() {
    printf("=== PHYSICAL MEMORY LEAK TEST ===\n\n");
    
    printf("Initial physical: %.2f MB\n", get_physical_mem() / 1024.0 / 1024.0);
    
    printf("\n--- Creating large vector ---\n");
    Vec8_t big = create(NULL);
    
    printf("Adding elements...\n");
    for (size_t i = 0; i < 100000000; i++) {
        big = add_back(&big, 'x');
        if (i % 10000000 == 0) {
            printf("  %zu elements: %.2f MB\n", i+1, get_physical_mem() / 1024.0 / 1024.0);
        }
    }
    
    printf("  Final: %zu elements, %.2f MB\n", big.size, get_physical_mem() / 1024.0 / 1024.0);
    
    printf("\n--- BEFORE delete: %.2f MB ---\n", get_physical_mem() / 1024.0 / 1024.0);
    
    delete(&big);
    
    printf("--- AFTER delete: %.2f MB ---\n", get_physical_mem() / 1024.0 / 1024.0);
    
    printf("\n--- Create 1000 vectors then delete ---\n");
    printf("Before: %.2f MB\n", get_physical_mem() / 1024.0 / 1024.0);
    
    for (int c = 0; c < 1000; c++) {
        Vec8_t v = create(NULL);
        for (int i = 0; i < 100000; i++) {
            v = add_back(&v, 'x');
        }
        delete(&v);
    }
    
    printf("After cycles: %.2f MB\n", get_physical_mem() / 1024.0 / 1024.0);
    
    printf("\n--- RESULT ---\n");
    printf("Physical memory used: %.2f MB\n", get_physical_mem() / 1024.0 / 1024.0);
    
    return 0;
}