#include <linux/kernel.h>
#include <linux/tty.h> /* For the tty declarations */
#include <linux/slab.h>

#include "../include/utils.h"
#include "../include/message.h"

/**
 * create_message()
 *
 * @buff: pointer to buffer containing string.
 * @len: length to read from buffer
 * @user: flag to check if user land buffer
 * 
 * Populates a message struct with a given string
 */
message *create_message(const char *buff, size_t len, int user)
{
	message *m;
	int ret;

	m = kmalloc(sizeof(message), GFP_KERNEL);
	if (!m) {
		printk("%s - [ERROR]: Failed to initialize message\n", MODNAME);
		return NULL;
	}

	if (!buff) {
		kfree(m);
		return NULL;
	}

	m->data = kmalloc(len, GFP_KERNEL);

	if (user) {
		// buff comes from user space
		ret = strncpy_from_user(m->data, buff, len);
	} else {
		// buff comes from kernel space
		if (strncpy(m->data, buff, len) == NULL) {
			printk("%s - [ERROR]: Could not copy string for new message\n",
			       MODNAME);
			return 0;
		}
	}

	m->length = len;

	return m;
}

/**
 * create_message()
 *
 * @m: pointer to a message struct.
 *
 * Frees the memory associated with the message
 */
void destroy_message(message *m)
{
	if (!m) {
		return;
	}

	if (!m->data) {
		kfree(m);
		return;
	}

	kfree(m->data);
	kfree(m);

	return;
}