From 58e02ad54c9a5fd5a8a09cf6151c06e9b7ecc798 Mon Sep 17 00:00:00 2001
From: Eduard Dlabal <eduard.dlabal@edcs.cz>
Date: Tue, 22 Apr 2025 20:51:06 +0200
Subject: [PATCH] Refactor user management functions and improve memory
 handling in addPersonToList

---
 .vscode/settings.json |  6 +++--
 include/users.h       | 39 ++++++++++++++++++++++-----
 src/users.c           | 63 ++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 99 insertions(+), 9 deletions(-)

diff --git a/.vscode/settings.json b/.vscode/settings.json
index 41e1322..3483249 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -4,6 +4,8 @@
         "ncurses.h": "c",
         "stdlib.h": "c",
         "errno.h": "c",
-        "rfid_handler.h": "c"
-    }
+        "rfid_handler.h": "c",
+        "fcntl.h": "c"
+    },
+    "C_Cpp.errorSquiggles": "enabled"
 }
\ No newline at end of file
diff --git a/include/users.h b/include/users.h
index bfe8431..54f0072 100644
--- a/include/users.h
+++ b/include/users.h
@@ -17,7 +17,7 @@ typedef struct person
     time_t last_time_event;
     uint32_t total;
 
-    pthread_mutex_t lock; 
+    pthread_mutex_t lock;
 } person_t;
 
 typedef struct node
@@ -26,14 +26,41 @@ typedef struct node
     struct node *next;
 } node_t;
 
-uint16_t generateUUID(node_t * _head);
+uint16_t generateUUID(node_t *_head);
 
-uint16_t searchUUIDByName(node_t * _head);
+uint16_t searchUUIDByName(node_t *_head);
 
-node_t * searchPersonByUUID(node_t * _head);
+node_t *searchPersonByUUID(node_t *_head);
 
-void addPersonToList(node_t * _head, char * _name, char * _surname, uint32_t _department);
+/**
+ * @brief Adds a new person to the linked list.
+ *
+ * This function creates a new person and appends it to the end of the linked list.
+ * It dynamically allocates memory for the new person and initializes their details.
+ * If memory allocation fails or the input parameters are invalid, the function returns an error.
+ *
+ * @param _head Pointer to the head of the linked list (node_t **).
+ * @param _name Pointer to a string containing the person's first name.
+ * @param _surname Pointer to a string containing the person's last name.
+ * @param _department The department number to which the person belongs.
+ * 
+ * @return int Returns 1 if the person was successfully added, otherwise 0 on failure.
+ *
+ * @note Memory for the name and surname is dynamically allocated. It is the caller's
+ *       responsibility to free the memory for the entire list to avoid memory leaks.
+ *
+ * @example
+ * ```c
+ * node_t *head = NULL;
+ * if (addPersonToList(&head, "John", "Doe", 101)) {
+ *     printf("Person successfully added.\n");
+ * } else {
+ *     printf("Error adding person.\n");
+ * }
+ * ```
+ */
+int addPersonToList(node_t **_head, char *_name, char *_surname, uint32_t _department);
 
-void addTimeEvent(node_t * _person);
+int addTimeEvent(node_t *_person);
 
 #endif
\ No newline at end of file
diff --git a/src/users.c b/src/users.c
index 06b11a5..3a384e6 100644
--- a/src/users.c
+++ b/src/users.c
@@ -1 +1,62 @@
-#include "users.h"
\ No newline at end of file
+#include "users.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <termios.h>
+#include <string.h>
+
+int addPersonToList(
+    node_t **_head,
+    char *_name,
+    char *_surname,
+    uint32_t _department)
+{
+    node_t *new_node = (node_t *)malloc(sizeof(node_t));
+    if (new_node == NULL)
+        return 0;
+
+    if (!strlen(_name) || !strlen(_surname))
+    {
+        free(new_node);
+        new_node = NULL;
+        return 0;
+    }
+
+    new_node->user.name = (char *)malloc(strlen(_name) + 1);
+    new_node->user.surname = (char *)malloc(strlen(_surname) + 1);
+
+    if (new_node->user.name == NULL || new_node->user.surname == NULL)
+    {
+        free(new_node->user.name);
+        free(new_node->user.surname);
+        free(new_node);
+        return 0;
+    }
+
+    strcpy(new_node->user.name, _name);
+    strcpy(new_node->user.surname, _surname);
+    new_node->user.department = _department;
+    new_node->user.last_time_event = -255;
+    new_node->user.total = 0;
+
+    new_node->next = NULL;
+
+    if (*_head == NULL)
+    {
+        *_head = new_node;
+        return;
+    }
+
+    node_t *current = *_head;
+    while (current->next != NULL)
+    {
+        current = current->next;
+    }
+    current->next = new_node;
+
+    return 0;
+}
\ No newline at end of file