Add standardized documentation headers

<UserStory> INV004: Check Availability Status </UserStory>

<Changes>
    1. Updated Controller to delegate getInventoryItem calls to InventoryManagementService.
    2. Implemented InventoryManagementService::getInventoryItem to fetch items from datastore by ID.
    3. Enhanced AdminMenu with checkStockAvailability function:
       - Accepts part ID as input.
       - Retrieves item details from Controller.
       - Displays item information (ID, part name, quantity) if found and active.
       - Handles inactive or missing items gracefully.
</Changes>

<Test>

  Precondition:
  1. Admin user is logged into the system.
  2. Inventory contains multiple items with unique IDs.
  3. DataStore is initialized and accessible.

  Steps:
  1. Navigate to Admin Menu and select "Check Stock Availability".
    - Verify that the system prompts for an Item ID.
  2. Enter a valid Item ID for an active item.
    - Verify that the system displays the item’s details including current quantity.
  3. Enter an Item ID that does not exist.
    - Verify that the system displays “Item not found”.
  4. Enter an Item ID for an inactive item.
    - Verify that the system does not display details and indicates the item is inactive.
</Test>

<Review>
Sreeja Reghukumar
</Review>

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/controllers/Controller.cpp

@@ -1,5 +1,20 @@
+/*
+File: Controller.cpp
+Description: Implementation file containing the method definitions
+             of the Controller class, which manages user authentication,
+             inventory, services, bookings, and notifications.
+Author: Trenser
+Date:19-May-2026
+*/
 #include "Controller.h"
 
+/*
+Function: login
+Description: Authenticates a user based on provided credentials.
+Parameter: const std::string& username - the username of the user
+           const std::string& password - the password of the user
+Return type: bool
+*/
 bool Controller::login(const std::string& username, const std::string& password)
 {
     return false;
@@ -48,22 +63,70 @@ void Controller::purchaseComboPackage(const std::string& comboPackageID, const s
 {
 }
 
+/*
+Function: getInventoryItems
+Description: Retrieves all inventory items from the inventory management service
+             and constructs a read-only map for external use.
+Parameter: None
+Return type: util::Map<std::string, const InventoryItem*>
+*/
 util::Map<std::string, const InventoryItem*> Controller::getInventoryItems()
 {
-    return util::Map<std::string, const InventoryItem*>();
+    auto inventoryIems = m_inventoryManagementService.getInventoryItems();
+    util::Map<std::string, const InventoryItem*> readOnlyInventoryItems;
+    int inventoryItemsMapSize = inventoryIems.getSize();
+    for (int index = 0; index < inventoryItemsMapSize; index++)
+    {
+        readOnlyInventoryItems.insert(inventoryIems.getKeyAt(index), inventoryIems.getValueAt(index));
+    }
+    return readOnlyInventoryItems;
 }
 
+/*
+Function: getInventoryItem
+Description: Retrieves a specific inventory item by its ID from the inventory management service.
+Parameter: const std::string& inventoryItemID - ID of the inventory item
+Return type: const InventoryItem*
+*/
 const InventoryItem* Controller::getInventoryItem(const std::string& inventoryItemID)
 {
-    return nullptr;
+    return m_inventoryManagementService.getInventoryItem(inventoryItemID);
 }
 
+/*
+Function: addInventoryItem
+Description: Adds a new inventory item with specified details to the inventory management service.
+Parameter: const std::string& partName - name of the part
+           int quantity - quantity of the part
+           double price - price of the part
+Return type: void
+*/
 void Controller::addInventoryItem(const std::string& partName, int quantity, double price)
 {
+    m_inventoryManagementService.addInventoryItem(partName, quantity, price);
 }
 
+/*
+Function: removeInventoryItem
+Description: Removes an inventory item from the inventory management service by its ID.
+Parameter: const std::string& inventoryItemID - ID of the inventory item
+Return type: void
+*/
 void Controller::removeInventoryItem(const std::string& inventoryItemID)
 {
+    m_inventoryManagementService.removeInventoryItem(inventoryItemID);
+}
+
+/*
+Function: addInventoryItemStock
+Description: Adds stock to an existing inventory item in the inventory management service.
+Parameter: const std::string& selectedItemId - ID of the inventory item
+           int quantity - quantity to add
+Return type: void
+*/
+void Controller::addInventoryItemStock(const std::string& selectedItemId, int quantity)
+{
+    m_inventoryManagementService.addInventoryItemStock(selectedItemId, quantity);
 }
 
 util::Map<std::string, const ServiceBooking*> Controller::getServiceBookings()

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/controllers/Controller.h

@@ -1,7 +1,16 @@
+/*
+File: Controller.h
+Description: Header file declaring the Controller class, which manages
+             user authentication, inventory, services, bookings, job cards,
+             invoices, and notifications in the system.
+Author: Trenser
+Date:19-May-2026
+*/
 #pragma once
 #include "Map.h"
 #include <string>
 #include "Enums.h"
+#include "InventoryManagementService.h";
 
 class Service;
 class ComboPackage;
@@ -14,6 +23,8 @@ class Notification;
 
 class Controller
 {
+private:
+    InventoryManagementService m_inventoryManagementService;
 public:
     bool login(const std::string& username, const std::string& password);
     void logout();
@@ -47,5 +58,6 @@ public:
     util::Vector<const Notification*> getNotifications();
     void deleteNotification(const std::string& notificationID);
     void configureNotifications(const std::string& userID, bool paymentNotifications, bool serviceNotifications);
+    void addInventoryItemStock(const std::string& selectedItemId, int quantity);
     void runSystemChecks();
 };

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/InventoryManagementService.cpp

@@ -1 +1,93 @@
+/*
+File: InventoryManagementService.cpp
+Description: Implementation file containing the method definitions of the
+             InventoryManagementService class, including inventory operations
+             and notification handling.
+Author: Trenser
+Date:19-May-2026
+*/
 #include "InventoryManagementService.h"
+#include "InventoryItem.h"
+#include "Factory.h"
+
+/*
+Function: addInventoryItem
+Description: Creates a new inventory item using the Factory and inserts it
+             into the DataStore.
+Parameter: const std::string& partName - name of the part
+           int quantity - initial quantity of the part
+           double price - price of the part
+Return type: void
+*/
+void InventoryManagementService::addInventoryItem(const std::string& partName, int quantity, double price)
+{
+    InventoryItem* newItem = Factory::getObject<InventoryItem>(partName, quantity, price);
+    m_dataStore.getInventoryItems().insert(newItem->getId(), newItem);
+}
+
+/*
+Function: addInventoryItemStock
+Description: Increases the stock quantity of an existing inventory item.
+Parameter: const std::string& selectedItemId - ID of the inventory item
+           int quantity - quantity to add
+Return type: void
+*/
+void InventoryManagementService::addInventoryItemStock(const std::string& selectedItemId, int quantity)
+{
+    int index = m_dataStore.getInventoryItems().find(selectedItemId);
+    if (index != -1)
+    {
+        InventoryItem* item = m_dataStore.getInventoryItems().getValueAt(index);
+        if (item != nullptr)
+        {
+            int totalQuantity = item->getQuantity() + quantity;
+            item->setQuantity(totalQuantity);
+        }
+    }
+}
+
+/*
+Function: getInventoryItems
+Description: Retrieves all inventory items stored in the DataStore.
+Parameter: None
+Return type: util::Map<std::string, InventoryItem*>
+*/
+util::Map<std::string, InventoryItem*> InventoryManagementService::getInventoryItems()
+{
+	return m_dataStore.getInventoryItems();
+}
+
+/*
+Function: removeInventoryItem
+Description: Marks an inventory item as inactive instead of deleting it.
+Parameter: const std::string& inventoryItemID - ID of the inventory item
+Return type: void
+*/
+void InventoryManagementService::removeInventoryItem(const std::string& inventoryItemID)
+{
+    int index = m_dataStore.getInventoryItems().find(inventoryItemID);
+    if (index != -1)
+    {
+        InventoryItem* item = m_dataStore.getInventoryItems().getValueAt(index);
+        if (item != nullptr)
+        {
+            item->setState(util::State::INACTIVE);
+        }
+    }
+}
+
+/*
+Function: getInventoryItem
+Description: Retrieves a specific inventory item by its ID from the DataStore.
+Parameter: const std::string& inventoryItemID - ID of the inventory item
+Return type: InventoryItem*
+*/
+InventoryItem* InventoryManagementService::getInventoryItem(const std::string& inventoryItemID)
+{
+    int index = m_dataStore.getInventoryItems().find(inventoryItemID);
+    if (index != -1)
+    {
+        return m_dataStore.getInventoryItems().getValueAt(index);
+    }
+    return nullptr;
+}

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/services/InventoryManagementService.h

@@ -1,3 +1,11 @@
+/*
+File: InventoryManagementService.h
+Description: Header file declaring the InventoryManagementService class,
+             which manages inventory items, stock updates, and notifications
+             related to low stock alerts. Inherits from NotificationManagementService.
+Author: Trenser
+Date:19-May-2026
+*/
 #pragma once
 #include <string>
 #include "Map.h"
@@ -17,6 +25,7 @@ public:
     InventoryItem* getInventoryItem(const std::string& inventoryItemID);
     void addInventoryItem(const std::string& partName, int quantity, double price);
     void removeInventoryItem(const std::string& inventoryItemID);
+    void addInventoryItemStock(const std::string& selectedItemId, int quantity);
     void sendLowStockAlerts();
     void sendNotification(User* user, const std::string& title, const std::string& message) override;
     void attach(User* user) override;

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/AdminMenu.cpp

@@ -1,7 +1,23 @@
+/*
+File: AdminMenu.cpp
+Description: Implementation file containing the method definitions of the
+             AdminMenu class, including menu handling, inventory operations,
+             and stock management functions.
+Author: Trenser
+Date:19-May-2026
+*/
+#include <iomanip>
 #include "AdminMenu.h"
+#include "InventoryItem.h"
 #include "InputHelper.h"
 #include "OutputHelper.h"
 
+/*
+Function: showMenu
+Description: Displays the admin menu and handles user input until the menu is exited.
+Parameter: None
+Return type: void
+*/
 void AdminMenu::showMenu()
 {
 	bool isMenuActive = true;
@@ -40,20 +56,252 @@ void AdminMenu::changePassword()
 {
 }
 
+/*
+Function: viewStockLevels
+Description: Displays all active inventory items with their details
+             including ID, part name, quantity, and price.
+Parameter: None
+Return type: void
+*/
 void AdminMenu::viewStockLevels()
 {
+	auto inventoryItems = m_controller.getInventoryItems();
+	std::cout << std::left << std::setw(15) << "Item ID"
+		<< std::setw(25) << "Part Name"
+		<< std::setw(10) << "Quantity"
+		<< std::setw(10) << "Price"
+		<< std::endl;
+	for (int iterator = 0; iterator < inventoryItems.getSize(); ++iterator)
+	{
+		const InventoryItem* item = inventoryItems.getValueAt(iterator);
+		if (item != nullptr)
+		{
+			if (item->getState() != util::State::INACTIVE)
+			{
+				std::cout << std::left << std::setw(15) << item->getId()
+					<< std::setw(25) << item->getPartName()
+					<< std::setw(10) << item->getQuantity()
+					<< std::setw(10) << item->getPrice()
+					<< std::endl;
+			}
+		}
+	}
 }
 
+/*
+Function: filterActiveItems
+Description: Filters out inactive inventory items and returns a map
+             containing only active items.
+Parameter: const util::Map<std::string, const InventoryItem*>& inventoryItems -
+           map of all inventory items
+Return type: util::Map<std::string, const InventoryItem*>
+*/
+static util::Map<std::string, const InventoryItem*>
+filterActiveItems(const util::Map<std::string, const InventoryItem*>& inventoryItems)
+{
+    util::Map<std::string, const InventoryItem*> activeItems;
+    int inventorySize = inventoryItems.getSize();
+    for (int index = 0; index < inventorySize; index++)
+    {
+        const InventoryItem* item = inventoryItems.getValueAt(index);
+        if (item != nullptr && item->getState() != util::State::INACTIVE)
+        {
+            activeItems.insert(item->getId(), item);
+        }
+    }
+    return activeItems;
+}
+
+/*
+Function: displayInventoryWithItems
+Description: Displays inventory items in a tabular format with index, ID,
+             part name, quantity, and price.
+Parameter: util::Map<std::string, const InventoryItem*>& inventoryItems -
+           map of inventory items to display
+Return type: void
+*/
+static void displayInventoryWithItems(util::Map<std::string, const InventoryItem*>& inventoryItems)
+{
+    int inventorySize = inventoryItems.getSize();
+    std::cout << std::left << std::setw(10) << "Index"
+        << std::setw(15) << "Item ID"
+        << std::setw(25) << "Part Name"
+        << std::setw(10) << "Quantity"
+        << std::setw(10) << "Price"
+        << std::endl;
+    for (int iterator = 0; iterator < inventorySize; iterator++)
+    {
+        const InventoryItem* item = inventoryItems.getValueAt(iterator);
+        if (item != nullptr)
+        {
+            std::cout << std::left << std::setw(10) << (iterator + 1)
+                << std::setw(15) << item->getId()
+                << std::setw(25) << item->getPartName()
+                << std::setw(10) << item->getQuantity()
+                << std::setw(10) << item->getPrice()
+                << std::endl;
+        }
+    }
+}
+
+/*
+Function: addQuantityToItem
+Description: Allows the admin to select an active inventory item and
+             increase its stock quantity.
+Parameter: util::Map<std::string, const InventoryItem*>& inventoryItems -
+           map of inventory items
+           Controller& m_controller - controller instance to update stock
+Return type: void
+*/
+static void addQuantityToItem(util::Map<std::string, const InventoryItem*>& inventoryItems, Controller& m_controller)
+{
+    int itemIndex;
+    int quantity;
+    auto activeItems = filterActiveItems(inventoryItems);
+    int activeSize = activeItems.getSize();
+    if (activeSize == 0)
+    {
+        std::cout << "No active items available in Inventory" << std::endl;
+        return;
+    }
+    displayInventoryWithItems(activeItems);
+    std::cout << "Enter the index of the item to update: ";
+    util::read(itemIndex);
+    if (itemIndex < 1 || itemIndex > activeSize)
+    {
+        std::cout << "Invalid index selected." << std::endl;
+        return;
+    }
+    std::cout << "Enter quantity to add: ";
+    util::read(quantity);
+    if (quantity < 0)
+    {
+        std::cout << "The quantity should be Greater than 0." << std::endl;
+        return;
+    }
+    const InventoryItem* selectedItem = activeItems.getValueAt(itemIndex - 1);
+    if (selectedItem != nullptr)
+    {
+        std::string selectedItemId = selectedItem->getId();
+        m_controller.addInventoryItemStock(selectedItemId, quantity);
+        std::cout << "Updated " << selectedItem->getPartName()
+            << " stock. New quantity: " << selectedItem->getQuantity()
+            << std::endl;
+    }
+    else
+    {
+        std::cout << "Error: Selected item could not be found." << std::endl;
+    }
+}
+
+/*
+Function: addInventoryItem
+Description: Allows the admin to either add a new inventory item
+             or increase the quantity of an existing item.
+Parameter: None
+Return type: void
+*/
 void AdminMenu::addInventoryItem()
 {
+	util::clear();
+	int choice, quantity;
+	double price;
+	std::string partName;
+	std::cout << "1. Add new item \n2. Add Quantity\nEnter your choice : ";
+	util::read(choice);
+	switch (choice)
+	{
+	case 1: 
+	{
+		std::cout << "--------Enter Item Details----------\n";
+		std::cout << "Part Name : ";
+		util::read(partName);
+		std::cout << "Quantity : ";
+		util::read(quantity);
+		std::cout << "Price : ";
+		util::read(price);
+		m_controller.addInventoryItem(partName, quantity, price);
+		std::cout << "New Item " << partName << " added to the Inventory.\n";
+		break;
+	}
+	case 2:
+	{
+		auto inventoryItems = m_controller.getInventoryItems();
+		addQuantityToItem(inventoryItems, m_controller);
+		break;
+	}
+	}
+	util::pressEnter();
 }
 
+/*
+Function: removeInventoryItem
+Description: Removes an active inventory item by marking it inactive
+             after user selection.
+Parameter: None
+Return type: void
+*/
 void AdminMenu::removeInventoryItem()
 {
+    util::clear();
+    auto inventoryItems = m_controller.getInventoryItems();
+    auto activeItems = filterActiveItems(inventoryItems);
+    int activeItemsSize = activeItems.getSize();
+    if (activeItemsSize == 0)
+    {
+        std::cout << "No items available in Inventory." << std::endl;
+        util::pressEnter();
+        return;
+    }
+    displayInventoryWithItems(activeItems);
+    int itemIndex;
+    std::cout << "Enter the index of the item to remove: ";
+    util::read(itemIndex);
+    if (itemIndex < 1 || itemIndex > activeItemsSize)
+    {
+        std::cout << "Invalid index selected." << std::endl;
+        util::pressEnter();
+        return;
+    }
+    const InventoryItem* selectedItem = inventoryItems.getValueAt(itemIndex - 1);
+    if (selectedItem != nullptr)
+    {
+        if(selectedItem->getState() != util::State::INACTIVE)
+        {
+            std::string selectedItemId = selectedItem->getId();
+            m_controller.removeInventoryItem(selectedItemId);
+            std::cout << "Item " << selectedItem->getPartName() << " removed successfully." << std::endl;
+        }
+    }
+    util::pressEnter();
 }
 
+/*
+Function: checkStockAvailability
+Description: Checks if a specific inventory item is available
+             and displays its details if active.
+Parameter: None
+Return type: void
+*/
 void AdminMenu::checkStockAvailability()
 {
+	util::clear();
+	std::string itemId;
+	std::cout << "Enter the Item Id : ";
+	util::read(itemId);
+	const InventoryItem* selectedItem = m_controller.getInventoryItem(itemId);
+	if (selectedItem != nullptr)
+	{
+		if (selectedItem->getState() != util::State::INACTIVE)
+		{
+			std::cout << "Item Details\n";
+			std::cout << "---------------------------------------------\n";
+			std::cout << "Item ID      : " << selectedItem->getId() << "\n";
+			std::cout << "Part Name    : " << selectedItem->getPartName() << "\n";
+			std::cout << "Quantity     : " << selectedItem->getQuantity() << "\n";
+		}
+	}
+	util::pressEnter();
 }
 
 void AdminMenu::assignJob()

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/AdminMenu.h

@@ -1,3 +1,11 @@
+/*
+File: AdminMenu.h
+Description: Header file declaring the AdminMenu class, which provides
+             administrative operations such as inventory management,
+             user management, service configuration, and notifications.
+Author: Trenser
+Date:19-May-2026
+*/
 #pragma once
 #include "Controller.h"