Refactor code structure for improved readability and maintainability

docs/DETAILED_OVERVIEW.MD

@@ -0,0 +1,84 @@
+# LightTAM: Detailed Overview
+
+LightTAM (Lightweight Time And Attendance Manager) is a terminal-based application for managing employee or student attendance using RFID cards. The system is modular, with each component responsible for a specific aspect of the program's functionality. Below is a detailed overview of how the program works, referencing the component UML diagram (`component_uml.png`).
+
+
+
+## Component Overview
+
+![Component UML Diagram](component_uml.png)
+
+### 1. **Main Application (`main.c`)**
+- **Role:** Entry point of the program. Initializes all subsystems, parses command-line arguments, loads the user database, and starts the main event loop.
+- **Responsibilities:**
+  - Initializes the logger, file/database handlers, and TUI.
+  - Loads user data from the specified file.
+  - Handles program shutdown and resource cleanup.
+
+### 2. **Terminal User Interface (TUI) (`tui.c`, `tui.h`)**
+- **Role:** Provides all user interaction via a terminal-based UI using ncurses.
+- **Responsibilities:**
+  - Displays menus (main, edit, search, user details, etc.).
+  - Handles keyboard input and navigation.
+  - Calls business logic functions based on user actions.
+  - Shows dialogs for success, warnings, and errors.
+  - Manages forms for adding/removing users and logging time events.
+
+### 3. **User Management (`users.c`, `users.h`)**
+- **Role:** Manages the in-memory linked list of users.
+- **Responsibilities:**
+  - Defines the `person_t`, `node_t`, and `list_t` structures.
+  - Provides functions to add, remove, search, and update users.
+  - Handles synchronization (mutex) for thread safety.
+  - Calculates presence times and manages user states.
+
+### 4. **File Handler (`file_handler.c`, `file_handler.h`)**
+- **Role:** Handles reading and writing user data to CSV files.
+- **Responsibilities:**
+  - Loads the user list from a CSV file at startup.
+  - Saves the user list to a CSV file on demand.
+  - Exports user or database information to external files.
+
+### 5. **RFID Handler (`rfid_handler.c`, `rfid_handler.h`)**
+- **Role:** Interfaces with the RFID reader hardware via a serial port.
+- **Responsibilities:**
+  - Opens and manages the serial port connection.
+  - Reads RFID card data and matches it to users.
+  - Triggers time event logging when a card is detected.
+
+### 6. **Logger (`logger.c`, `logger.h`)**
+- **Role:** Logs all actions, errors, and system events to a journal file.
+- **Responsibilities:**
+  - Provides logging functions for other modules.
+  - Records user actions, errors, and system messages for auditing.
+
+### 7. **Utilities (`utils.h`)**
+- **Role:** Provides helper functions used throughout the program.
+- **Responsibilities:**
+  - String manipulation, time formatting, and other common tasks.
+
+
+## Component Interactions
+
+- **TUI ↔ User Management:** TUI calls user management functions to modify or query the user list.
+- **TUI ↔ File Handler:** TUI triggers file operations for loading, saving, and exporting data.
+- **TUI ↔ RFID Handler:** TUI may display status or prompt for RFID actions.
+- **RFID Handler ↔ User Management:** When a card is read, the handler updates the user list.
+- **All Components ↔ Logger:** All modules log actions and errors via the logger.
+
+
+
+## Error Handling & Logging
+
+- All errors (file I/O, serial port, invalid input) are reported to the user via TUI dialogs and logged in the journal file.
+- The logger ensures traceability for all critical operations.
+
+
+
+## Extensibility
+
+- The modular design allows for easy extension, such as supporting new file formats, additional authentication methods, or a graphical UI.
+
+---
+
+For further details, see the [README.md](../README.md) and the code documentation in each header file.

src/file_handler.c

@@ -28,8 +28,10 @@ int loadListFromCSV(char *_filename, list_t *_list)
         }
         else
         {
-
+            logErrorEvent(logger_global, "Error loading person from CSV: %s", buffer);
-            exit(-1);
+            free(buffer);
+            fclose(f_in);
+            return 0;
         }
     }
     free(buffer);