#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include "../source/stdlib/_mem.h"

#define RUN_TEST(func)                                  \
    printf("---\tRUN TEST: %s\t---\n", #func);          \
    if (func()) {                                       \
        printf("[SUCCESS]\tTest %s is ok.\n\n", #func); \
    } else {                                            \
        fprintf(stderr, "[FAIL]\tTest %s failed.\n\n", #func);   \
        exit(EXIT_FAILURE);                             \
    }

// c between a and b
#define IN_RANGE(a, b, c, len) ((a > c && c > b) || ((a > c + len && c + len > b)))

bool test_malloc_basic_allocation()
{
    void* ptr = malloc(sizeof(int));

    if (ptr)
        free(ptr);

    return ptr;
}
bool test_malloc_zero_bytes()
{
    return malloc(0) == NULL;
}

bool test_malloc_multiple_allocations()
{
    void* ptr[512];

    for (int i = 1; i < sizeof(ptr) / sizeof(*ptr); i++) {
        ptr[i] = malloc(i);
        if (ptr[i] == NULL) {
            return false;
        }
    }
    for (int i = 1; i < sizeof(ptr) / sizeof(*ptr); i++) {
        for (int j = 1; j < sizeof(ptr) / sizeof(*ptr); j++) {
            if (i != j) {
                if (ptr[i] == ptr[j]) {
                    fprintf(stderr, "ptrs[%d] == ptrs[%d].\n", i, j);
                    return false;
                } else if (IN_RANGE(
                               (char*)GET_MEM_NODE_HEADER(ptr[i]) + GET_MEM_NODE_HEADER(ptr[i])->size,
                               (char*)GET_MEM_NODE_HEADER(ptr[i]),
                               (char*)GET_MEM_NODE_HEADER(ptr[j]),
                               GET_MEM_NODE_HEADER(ptr[j])->size)) {
                    fprintf(stderr, "node %p in node %p", GET_MEM_NODE_HEADER(ptr[i]), GET_MEM_NODE_HEADER(ptr[j]));
                    // additional info, may help with debug
                    fprintf(stderr, "node %p\n size:%p\n free:%p\n next: %p\n last: %p\n", GET_MEM_NODE_HEADER(ptr[i]), GET_MEM_NODE_HEADER(ptr[i])->size, GET_MEM_NODE_HEADER(ptr[i])->free, GET_MEM_NODE_HEADER(ptr[i])->next, GET_MEM_NODE_HEADER(ptr[i])->last);
                    fprintf(stderr, "node %p\n size:%p\n free:%p\n next: %p\n last: %p\n", GET_MEM_NODE_HEADER(ptr[j]), GET_MEM_NODE_HEADER(ptr[j])->size, GET_MEM_NODE_HEADER(ptr[j])->free, GET_MEM_NODE_HEADER(ptr[j])->next, GET_MEM_NODE_HEADER(ptr[j])->last);
                    exit(EXIT_FAILURE);
                }
            }
        }
    }

    for (int i = 1; i < sizeof(ptr) / sizeof(*ptr); i++) {
        free(ptr[i]);
    }

    return true;
}
bool test_malloc_data_integrity()
{
    const char* As = "AAA";
    const char* Cs = "CCC";

    char* A = (char*)malloc(10);
    char* B = (char*)malloc(10);
    char* C = (char*)malloc(10);

    if (!A || !B || !C) {
        printf("can't alloc\n");
        free(A);
        free(B);
        free(C);
        return false;
    }

    strcpy(A, As);
    strcpy(C, Cs);

    free(B);

    if (strcmp(A, As) != 0) {
        printf("A data is broken after free(B). A = '%s'\n", A);
        free(A);
        free(C);
        return false;
    }
    if (strcmp(C, Cs) != 0) {
        printf("C data is broken after free(B). C = '%s'\n", C);
        free(A);
        free(C);
        return false;
    }

    free(A);
    free(C);
    return true;
}
bool test_malloc_large_allocation()
{
    void* ptr = malloc(1024 * 1024 * 16); // alloc 16mb

    if (ptr)
        free(ptr);

    return ptr;
}
bool test_malloc_allocation_and_free()
{
    free(malloc(sizeof(int)));
    return true;
}

void fill_buffer(void* ptr, size_t size, unsigned char pattern)
{
    if (ptr) {
        memset(ptr, pattern, size);
    }
}

bool check_buffer(void* ptr, size_t size, unsigned char pattern)
{
    if (!ptr) {
        return false;
    }
    unsigned char* byte_ptr = (unsigned char*)ptr;
    for (size_t i = 0; i < size; ++i) {
        if (byte_ptr[i] != pattern) {
            fprintf(stderr, "Error: Byte %u does not match pattern. Expected %02X, got %02X\n",
                i, pattern, byte_ptr[i]);
            return false;
        }
    }
    return true;
}

bool test_realloc_basic_grow()
{
    size_t old_size = 10;
    size_t new_size = 20;
    int* ptr = (int*)malloc(old_size * sizeof(int));

    if (ptr == NULL) {
        return false;
    }
    fill_buffer(ptr, old_size * sizeof(int), 0xAA);

    int* new_ptr = (int*)realloc(ptr, new_size * sizeof(int));

    if (new_ptr == NULL) {
        free(ptr);
        return false;
    }

    if (!check_buffer(new_ptr, old_size * sizeof(int), 0xAA)) {
        free(new_ptr);
        return false;
    }

    fill_buffer(new_ptr + old_size, (new_size - old_size) * sizeof(int), 0xBB);
    if (!check_buffer(new_ptr + old_size, (new_size - old_size) * sizeof(int), 0xBB)) {
        free(new_ptr);
        return false;
    }

    free(new_ptr);
    return true;
}

bool test_realloc_basic_shrink()
{
    size_t old_size = 20;
    size_t new_size = 10;
    int* ptr = (int*)malloc(old_size * sizeof(int));

    if (ptr == NULL) {
        return false;
    }
    fill_buffer(ptr, old_size * sizeof(int), 0xCC);

    int* new_ptr = (int*)realloc(ptr, new_size * sizeof(int));

    if (new_ptr == NULL) {
        free(ptr);
        return false;
    }

    if (!check_buffer(new_ptr, new_size * sizeof(int), 0xCC)) {
        free(new_ptr);
        return false;
    }

    free(new_ptr);
    return true;
}

bool test_realloc_same_size()
{
    size_t size = 15;
    int* ptr = (int*)malloc(size * sizeof(int));

    if (ptr == NULL) {
        return false;
    }
    fill_buffer(ptr, size * sizeof(int), 0xDD);

    int* new_ptr = (int*)realloc(ptr, size * sizeof(int));

    if (new_ptr == NULL) {
        free(ptr);
        return false;
    }

    if (!check_buffer(new_ptr, size * sizeof(int), 0xDD)) {
        free(new_ptr);
        return false;
    }

    free(new_ptr);

    return true;
}

bool test_realloc_null_ptr()
{
    size_t size = 25;
    void* ptr = realloc(NULL, size);

    if (ptr == NULL) {
        return false;
    }

    fill_buffer(ptr, size, 0xEE);
    if (!check_buffer(ptr, size, 0xEE)) {
        free(ptr);
        return false;
    }

    free(ptr);

    return true;
}

bool test_realloc_to_zero_size()
{
    size_t old_size = 30;
    void* ptr = malloc(old_size);

    if (ptr == NULL) {
        return false;
    }
    fill_buffer(ptr, old_size, 0xFF);

    void* new_ptr = realloc(ptr, 0);

    if (new_ptr == NULL) {
        printf("realloc(ptr, 0) return NULL.\n");
        free(ptr);
    } else {
        printf("realloc(ptr, 0) return: %p.\n", new_ptr);
        free(new_ptr);
    }
    return true;
}

int main()
{
    RUN_TEST(test_malloc_basic_allocation);
    RUN_TEST(test_malloc_zero_bytes);
    RUN_TEST(test_malloc_multiple_allocations);
    RUN_TEST(test_malloc_data_integrity);
    RUN_TEST(test_malloc_large_allocation);
    RUN_TEST(test_malloc_basic_allocation);
    RUN_TEST(test_malloc_allocation_and_free);
    RUN_TEST(test_realloc_basic_grow);
    RUN_TEST(test_realloc_basic_shrink);
    RUN_TEST(test_realloc_same_size);
    RUN_TEST(test_realloc_null_ptr);
    RUN_TEST(test_realloc_to_zero_size);

    return 0;
}