INVENTORY MANAGEMENT SYSTEM

Table of Contents

Introduction

The Inventory Management System is a comprehensive web-based solution designed to help businesses efficiently track, manage, and control their inventory. This system provides real-time visibility into stock levels, automates reordering processes, manages supplier relationships, handles multiple warehouses, and generates detailed reports. With both admin and staff interfaces, it streamlines inventory operations, reduces manual errors, and optimizes stock management.

Project Features

Admin Features:

Dashboard with Key Metrics
Product Management (Add, Edit, Delete, Import/Export)
Category Management
Supplier Management
Purchase Order Management
Sales Order Management
Stock Adjustment Management
Multiple Warehouse Support
User Management (Staff Accounts)
Role-Based Access Control
Report Generation (Stock, Sales, Purchase, Profit/Loss)
Low Stock Alerts
Expiry Date Tracking
Barcode Generation
Audit Logs
System Settings

Staff Features:

View Products
Process Sales
Check Stock Levels
Create Purchase Requests
Receive Stock
Transfer Stock Between Warehouses
View Reports (Limited Access)
Profile Management

General Features:

Real-time Stock Updates
Search and Filter Products
Pagination for Large Datasets
Responsive Design
Export to Excel/PDF
Print Invoices
Email Notifications
Dark/Light Mode Toggle

Project File Structure

inventory-management-system/
│
├── assets/
│   ├── css/
│   │   ├── style.css
│   │   ├── admin-style.css
│   │   └── responsive.css
│   ├── js/
│   │   ├── main.js
│   │   ├── dashboard.js
│   │   ├── products.js
│   │   ├── sales.js
│   │   └── charts.js
│   ├── images/
│   │   ├── products/
│   │   └── avatars/
│   └── vendor/
│       ├── bootstrap/
│       ├── font-awesome/
│       └── datatables/
│
├── database/
│   └── inventory_db.sql
│
├── includes/
│   ├── config.php
│   ├── db_connection.php
│   ├── functions.php
│   ├── session.php
│   ├── auth.php
│   └── validation.php
│
├── admin/
│   ├── index.php (Dashboard)
│   ├── login.php
│   ├── logout.php
│   ├── profile.php
│   ├── products/
│   │   ├── index.php
│   │   ├── add.php
│   │   ├── edit.php
│   │   ├── view.php
│   │   ├── delete.php
│   │   ├── import.php
│   │   ├── export.php
│   │   └── barcode.php
│   ├── categories/
│   │   ├── index.php
│   │   ├── add.php
│   │   ├── edit.php
│   │   └── delete.php
│   ├── suppliers/
│   │   ├── index.php
│   │   ├── add.php
│   │   ├── edit.php
│   │   ├── view.php
│   │   └── delete.php
│   ├── purchases/
│   │   ├── index.php
│   │   ├── create.php
│   │   ├── edit.php
│   │   ├── receive.php
│   │   └── view.php
│   ├── sales/
│   │   ├── index.php
│   │   ├── create.php
│   │   ├── invoice.php
│   │   └── return.php
│   ├── warehouses/
│   │   ├── index.php
│   │   ├── add.php
│   │   ├── edit.php
│   │   └── stock.php
│   ├── transfers/
│   │   ├── index.php
│   │   ├── create.php
│   │   └── receive.php
│   ├── adjustments/
│   │   ├── index.php
│   │   ├── create.php
│   │   └── history.php
│   ├── reports/
│   │   ├── index.php
│   │   ├── stock-report.php
│   │   ├── sales-report.php
│   │   ├── purchase-report.php
│   │   ├── profit-loss.php
│   │   └── low-stock.php
│   ├── users/
│   │   ├── index.php
│   │   ├── add.php
│   │   ├── edit.php
│   │   └── permissions.php
│   └── settings/
│       ├── index.php
│       ├── general.php
│       └── backup.php
│
├── staff/
│   ├── index.php (Dashboard)
│   ├── login.php
│   ├── logout.php
│   ├── profile.php
│   ├── products/
│   │   ├── index.php
│   │   └── search.php
│   ├── sales/
│   │   ├── create.php
│   │   └── history.php
│   ├── purchases/
│   │   ├── requests.php
│   │   └── receive.php
│   └── reports/
│       └── stock.php
│
├── api/
│   ├── get-products.php
│   ├── update-stock.php
│   ├── process-sale.php
│   ├── generate-report.php
│   └── search-suppliers.php
│
├── uploads/
│   ├── products/
│   └── imports/
│
├── exports/
│   └── reports/
│
├── index.php (Landing/Login Redirect)
├── .htaccess
└── README.md

Database Schema (inventory_db.sql)

-- Create Database
CREATE DATABASE IF NOT EXISTS inventory_db;
USE inventory_db;
-- Table: users
CREATE TABLE users (
user_id INT PRIMARY KEY AUTO_INCREMENT,
username VARCHAR(50) UNIQUE NOT NULL,
email VARCHAR(100) UNIQUE NOT NULL,
password VARCHAR(255) NOT NULL,
full_name VARCHAR(100) NOT NULL,
phone VARCHAR(20),
avatar VARCHAR(255),
role ENUM('admin', 'manager', 'staff') DEFAULT 'staff',
warehouse_id INT NULL,
is_active BOOLEAN DEFAULT TRUE,
last_login DATETIME,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);
-- Insert default admin
INSERT INTO users (username, email, password, full_name, role) VALUES 
('admin', '[email protected]', MD5('Admin@123'), 'System Administrator', 'admin'),
('manager', '[email protected]', MD5('Manager@123'), 'Store Manager', 'manager'),
('staff', '[email protected]', MD5('Staff@123'), 'Staff Member', 'staff');
-- Table: warehouses
CREATE TABLE warehouses (
warehouse_id INT PRIMARY KEY AUTO_INCREMENT,
warehouse_name VARCHAR(100) NOT NULL,
location VARCHAR(255),
address TEXT,
phone VARCHAR(20),
email VARCHAR(100),
manager_id INT,
is_active BOOLEAN DEFAULT TRUE,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
FOREIGN KEY (manager_id) REFERENCES users(user_id) ON DELETE SET NULL
);
-- Insert default warehouse
INSERT INTO warehouses (warehouse_name, location) VALUES ('Main Warehouse', 'Downtown');
-- Update users with warehouse
UPDATE users SET warehouse_id = 1 WHERE role IN ('manager', 'staff');
-- Table: categories
CREATE TABLE categories (
category_id INT PRIMARY KEY AUTO_INCREMENT,
category_name VARCHAR(100) NOT NULL,
category_code VARCHAR(50) UNIQUE,
description TEXT,
parent_category_id INT NULL,
is_active BOOLEAN DEFAULT TRUE,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
FOREIGN KEY (parent_category_id) REFERENCES categories(category_id) ON DELETE CASCADE
);
-- Insert sample categories
INSERT INTO categories (category_name, category_code, description) VALUES
('Electronics', 'ELEC', 'Electronic items and gadgets'),
('Clothing', 'CLTH', 'Apparel and fashion items'),
('Food & Beverages', 'FOOD', 'Food products and beverages'),
('Furniture', 'FURN', 'Home and office furniture'),
('Stationery', 'STAT', 'Office and school supplies');
-- Table: suppliers
CREATE TABLE suppliers (
supplier_id INT PRIMARY KEY AUTO_INCREMENT,
supplier_name VARCHAR(100) NOT NULL,
supplier_code VARCHAR(50) UNIQUE,
contact_person VARCHAR(100),
email VARCHAR(100),
phone VARCHAR(20),
mobile VARCHAR(20),
address TEXT,
city VARCHAR(50),
state VARCHAR(50),
postal_code VARCHAR(20),
country VARCHAR(50),
tax_id VARCHAR(50),
payment_terms VARCHAR(50),
is_active BOOLEAN DEFAULT TRUE,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);
-- Insert sample suppliers
INSERT INTO suppliers (supplier_name, supplier_code, contact_person, email, phone) VALUES
('ABC Electronics', 'SUP001', 'John Smith', '[email protected]', '123-456-7890'),
('XYZ Clothing', 'SUP002', 'Jane Doe', '[email protected]', '098-765-4321'),
('Global Foods', 'SUP003', 'Bob Wilson', '[email protected]', '555-123-4567');
-- Table: products
CREATE TABLE products (
product_id INT PRIMARY KEY AUTO_INCREMENT,
product_code VARCHAR(50) UNIQUE NOT NULL,
product_name VARCHAR(255) NOT NULL,
category_id INT,
supplier_id INT,
description TEXT,
unit VARCHAR(20) DEFAULT 'pcs',
purchase_price DECIMAL(10,2) NOT NULL,
selling_price DECIMAL(10,2) NOT NULL,
wholesale_price DECIMAL(10,2),
tax_rate DECIMAL(5,2) DEFAULT 0.00,
min_stock_level INT DEFAULT 5,
max_stock_level INT DEFAULT 100,
reorder_level INT DEFAULT 10,
barcode VARCHAR(100),
has_expiry BOOLEAN DEFAULT FALSE,
is_active BOOLEAN DEFAULT TRUE,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
FOREIGN KEY (category_id) REFERENCES categories(category_id) ON DELETE SET NULL,
FOREIGN KEY (supplier_id) REFERENCES suppliers(supplier_id) ON DELETE SET NULL,
INDEX idx_product_code (product_code),
INDEX idx_product_name (product_name)
);
-- Insert sample products
INSERT INTO products (product_code, product_name, category_id, supplier_id, unit, purchase_price, selling_price, min_stock_level, reorder_level) VALUES
('PRD001', 'Smartphone X', 1, 1, 'pcs', 500.00, 699.99, 5, 10),
('PRD002', 'Laptop Pro', 1, 1, 'pcs', 800.00, 1099.99, 3, 5),
('PRD003', 'T-Shirt Cotton', 2, 2, 'pcs', 10.00, 19.99, 20, 30),
('PRD004', 'Jeans Slim Fit', 2, 2, 'pcs', 25.00, 49.99, 15, 20),
('PRD005', 'Rice 5kg', 3, 3, 'bag', 8.00, 12.99, 50, 30),
('PRD006', 'Cooking Oil 1L', 3, 3, 'bottle', 3.00, 5.99, 40, 25);
-- Table: product_images
CREATE TABLE product_images (
image_id INT PRIMARY KEY AUTO_INCREMENT,
product_id INT NOT NULL,
image_path VARCHAR(255) NOT NULL,
is_primary BOOLEAN DEFAULT FALSE,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
FOREIGN KEY (product_id) REFERENCES products(product_id) ON DELETE CASCADE
);
-- Table: stock
CREATE TABLE stock (
stock_id INT PRIMARY KEY AUTO_INCREMENT,
product_id INT NOT NULL,
warehouse_id INT NOT NULL,
quantity INT DEFAULT 0,
reserved_quantity INT DEFAULT 0,
available_quantity INT GENERATED ALWAYS AS (quantity - reserved_quantity) STORED,
location_aisle VARCHAR(50),
location_rack VARCHAR(50),
location_bin VARCHAR(50),
last_updated TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
FOREIGN KEY (product_id) REFERENCES products(product_id) ON DELETE CASCADE,
FOREIGN KEY (warehouse_id) REFERENCES warehouses(warehouse_id) ON DELETE CASCADE,
UNIQUE KEY unique_product_warehouse (product_id, warehouse_id)
);
-- Initialize stock for main warehouse
INSERT INTO stock (product_id, warehouse_id, quantity) VALUES
(1, 1, 50),
(2, 1, 30),
(3, 1, 100),
(4, 1, 80),
(5, 1, 200),
(6, 1, 150);
-- Table: purchase_orders
CREATE TABLE purchase_orders (
po_id INT PRIMARY KEY AUTO_INCREMENT,
po_number VARCHAR(50) UNIQUE NOT NULL,
supplier_id INT NOT NULL,
warehouse_id INT NOT NULL,
order_date DATE NOT NULL,
expected_delivery DATE,
status ENUM('draft', 'pending', 'approved', 'ordered', 'received', 'cancelled') DEFAULT 'draft',
payment_status ENUM('unpaid', 'partial', 'paid') DEFAULT 'unpaid',
payment_method VARCHAR(50),
subtotal DECIMAL(10,2),
tax_amount DECIMAL(10,2),
discount_amount DECIMAL(10,2),
shipping_cost DECIMAL(10,2) DEFAULT 0.00,
total_amount DECIMAL(10,2),
notes TEXT,
created_by INT,
approved_by INT,
received_by INT,
received_date DATETIME,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
FOREIGN KEY (supplier_id) REFERENCES suppliers(supplier_id),
FOREIGN KEY (warehouse_id) REFERENCES warehouses(warehouse_id),
FOREIGN KEY (created_by) REFERENCES users(user_id),
FOREIGN KEY (approved_by) REFERENCES users(user_id),
FOREIGN KEY (received_by) REFERENCES users(user_id)
);
-- Table: purchase_order_items
CREATE TABLE purchase_order_items (
po_item_id INT PRIMARY KEY AUTO_INCREMENT,
po_id INT NOT NULL,
product_id INT NOT NULL,
quantity INT NOT NULL,
received_quantity INT DEFAULT 0,
unit_price DECIMAL(10,2) NOT NULL,
total_price DECIMAL(10,2) GENERATED ALWAYS AS (quantity * unit_price) STORED,
FOREIGN KEY (po_id) REFERENCES purchase_orders(po_id) ON DELETE CASCADE,
FOREIGN KEY (product_id) REFERENCES products(product_id)
);
-- Table: sales_orders
CREATE TABLE sales_orders (
so_id INT PRIMARY KEY AUTO_INCREMENT,
so_number VARCHAR(50) UNIQUE NOT NULL,
customer_name VARCHAR(100),
customer_email VARCHAR(100),
customer_phone VARCHAR(20),
customer_address TEXT,
warehouse_id INT NOT NULL,
user_id INT,
order_date DATETIME DEFAULT CURRENT_TIMESTAMP,
status ENUM('pending', 'processing', 'completed', 'cancelled', 'refunded') DEFAULT 'pending',
payment_status ENUM('unpaid', 'partial', 'paid') DEFAULT 'unpaid',
payment_method VARCHAR(50),
subtotal DECIMAL(10,2),
tax_amount DECIMAL(10,2),
discount_amount DECIMAL(10,2),
shipping_cost DECIMAL(10,2) DEFAULT 0.00,
total_amount DECIMAL(10,2),
notes TEXT,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
FOREIGN KEY (warehouse_id) REFERENCES warehouses(warehouse_id),
FOREIGN KEY (user_id) REFERENCES users(user_id)
);
-- Table: sales_order_items
CREATE TABLE sales_order_items (
so_item_id INT PRIMARY KEY AUTO_INCREMENT,
so_id INT NOT NULL,
product_id INT NOT NULL,
quantity INT NOT NULL,
unit_price DECIMAL(10,2) NOT NULL,
total_price DECIMAL(10,2) GENERATED ALWAYS AS (quantity * unit_price) STORED,
FOREIGN KEY (so_id) REFERENCES sales_orders(so_id) ON DELETE CASCADE,
FOREIGN KEY (product_id) REFERENCES products(product_id)
);
-- Table: stock_movements
CREATE TABLE stock_movements (
movement_id INT PRIMARY KEY AUTO_INCREMENT,
product_id INT NOT NULL,
from_warehouse_id INT,
to_warehouse_id INT,
quantity INT NOT NULL,
movement_type ENUM('purchase', 'sale', 'transfer', 'adjustment', 'return') NOT NULL,
reference_type VARCHAR(50),
reference_id INT,
notes TEXT,
created_by INT,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
FOREIGN KEY (product_id) REFERENCES products(product_id),
FOREIGN KEY (from_warehouse_id) REFERENCES warehouses(warehouse_id),
FOREIGN KEY (to_warehouse_id) REFERENCES warehouses(warehouse_id),
FOREIGN KEY (created_by) REFERENCES users(user_id)
);
-- Table: stock_adjustments
CREATE TABLE stock_adjustments (
adjustment_id INT PRIMARY KEY AUTO_INCREMENT,
product_id INT NOT NULL,
warehouse_id INT NOT NULL,
previous_quantity INT NOT NULL,
new_quantity INT NOT NULL,
adjustment_type ENUM('add', 'remove', 'damage', 'expired', 'found', 'lost') NOT NULL,
reason TEXT,
created_by INT,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
FOREIGN KEY (product_id) REFERENCES products(product_id),
FOREIGN KEY (warehouse_id) REFERENCES warehouses(warehouse_id),
FOREIGN KEY (created_by) REFERENCES users(user_id)
);
-- Table: stock_transfers
CREATE TABLE stock_transfers (
transfer_id INT PRIMARY KEY AUTO_INCREMENT,
transfer_number VARCHAR(50) UNIQUE NOT NULL,
from_warehouse_id INT NOT NULL,
to_warehouse_id INT NOT NULL,
status ENUM('pending', 'in_transit', 'completed', 'cancelled') DEFAULT 'pending',
request_date DATETIME DEFAULT CURRENT_TIMESTAMP,
completed_date DATETIME,
notes TEXT,
requested_by INT,
approved_by INT,
received_by INT,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
FOREIGN KEY (from_warehouse_id) REFERENCES warehouses(warehouse_id),
FOREIGN KEY (to_warehouse_id) REFERENCES warehouses(warehouse_id),
FOREIGN KEY (requested_by) REFERENCES users(user_id),
FOREIGN KEY (approved_by) REFERENCES users(user_id),
FOREIGN KEY (received_by) REFERENCES users(user_id)
);
-- Table: transfer_items
CREATE TABLE transfer_items (
transfer_item_id INT PRIMARY KEY AUTO_INCREMENT,
transfer_id INT NOT NULL,
product_id INT NOT NULL,
quantity INT NOT NULL,
received_quantity INT DEFAULT 0,
FOREIGN KEY (transfer_id) REFERENCES stock_transfers(transfer_id) ON DELETE CASCADE,
FOREIGN KEY (product_id) REFERENCES products(product_id)
);
-- Table: product_batches (for expiry tracking)
CREATE TABLE product_batches (
batch_id INT PRIMARY KEY AUTO_INCREMENT,
product_id INT NOT NULL,
batch_number VARCHAR(100),
supplier_id INT,
purchase_price DECIMAL(10,2),
quantity INT NOT NULL,
remaining_quantity INT NOT NULL,
manufacture_date DATE,
expiry_date DATE,
received_date DATE,
is_active BOOLEAN DEFAULT TRUE,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
FOREIGN KEY (product_id) REFERENCES products(product_id),
FOREIGN KEY (supplier_id) REFERENCES suppliers(supplier_id)
);
-- Table: activity_logs
CREATE TABLE activity_logs (
log_id INT PRIMARY KEY AUTO_INCREMENT,
user_id INT,
action VARCHAR(100) NOT NULL,
entity_type VARCHAR(50),
entity_id INT,
details TEXT,
ip_address VARCHAR(45),
user_agent TEXT,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
FOREIGN KEY (user_id) REFERENCES users(user_id) ON DELETE SET NULL
);
-- Table: system_settings
CREATE TABLE system_settings (
setting_id INT PRIMARY KEY AUTO_INCREMENT,
setting_key VARCHAR(100) UNIQUE NOT NULL,
setting_value TEXT,
setting_description TEXT,
updated_by INT,
updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);
-- Insert default settings
INSERT INTO system_settings (setting_key, setting_value, setting_description) VALUES
('company_name', 'Inventory Management System', 'Company name'),
('company_address', '123 Business Street, City, Country', 'Company address'),
('company_phone', '+1 234 567 890', 'Company phone'),
('company_email', '[email protected]', 'Company email'),
('company_tax_id', 'TAX123456', 'Company tax ID'),
('currency', 'USD', 'Default currency'),
('currency_symbol', '$', 'Currency symbol'),
('tax_rate', '10.00', 'Default tax rate'),
('low_stock_threshold', '10', 'Low stock alert threshold'),
('enable_barcode', '1', 'Enable barcode scanning'),
('date_format', 'Y-m-d', 'Date format'),
('time_format', 'H:i:s', 'Time format'),
('items_per_page', '25', 'Items per page in tables'),
('backup_path', '/backups/', 'Database backup path');
-- Table: customer (optional for CRM)
CREATE TABLE customers (
customer_id INT PRIMARY KEY AUTO_INCREMENT,
customer_code VARCHAR(50) UNIQUE,
customer_name VARCHAR(100) NOT NULL,
customer_type ENUM('regular', 'wholesale', 'vip') DEFAULT 'regular',
email VARCHAR(100),
phone VARCHAR(20),
mobile VARCHAR(20),
address TEXT,
city VARCHAR(50),
state VARCHAR(50),
postal_code VARCHAR(20),
country VARCHAR(50),
tax_id VARCHAR(50),
credit_limit DECIMAL(10,2) DEFAULT 0.00,
payment_terms VARCHAR(50),
is_active BOOLEAN DEFAULT TRUE,
created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);
-- Create indexes for performance
CREATE INDEX idx_product_category ON products(category_id);
CREATE INDEX idx_product_supplier ON products(supplier_id);
CREATE INDEX idx_stock_product ON stock(product_id);
CREATE INDEX idx_stock_warehouse ON stock(warehouse_id);
CREATE INDEX idx_movement_product ON stock_movements(product_id);
CREATE INDEX idx_movement_date ON stock_movements(created_at);
CREATE INDEX idx_po_supplier ON purchase_orders(supplier_id);
CREATE INDEX idx_po_status ON purchase_orders(status);
CREATE INDEX idx_so_customer ON sales_orders(customer_name);
CREATE INDEX idx_so_date ON sales_orders(order_date);
CREATE INDEX idx_logs_user ON activity_logs(user_id);
CREATE INDEX idx_logs_date ON activity_logs(created_at);

Core PHP Files

1. includes/config.php

<?php
// Database configuration
define('DB_HOST', 'localhost');
define('DB_USER', 'root');
define('DB_PASS', '');
define('DB_NAME', 'inventory_db');
// Application configuration
define('SITE_NAME', 'Inventory Management System');
define('SITE_URL', 'http://localhost/inventory-management-system/');
define('ADMIN_URL', SITE_URL . 'admin/');
define('STAFF_URL', SITE_URL . 'staff/');
// Paths
define('ROOT_PATH', $_SERVER['DOCUMENT_ROOT'] . '/inventory-management-system/');
define('INCLUDES_PATH', ROOT_PATH . 'includes/');
define('UPLOAD_PATH', ROOT_PATH . 'uploads/');
define('EXPORT_PATH', ROOT_PATH . 'exports/');
define('PRODUCT_IMG_PATH', UPLOAD_PATH . 'products/');
// File upload settings
define('MAX_FILE_SIZE', 5242880); // 5MB
define('ALLOWED_IMAGE_TYPES', 'jpg,jpeg,png,gif');
define('ALLOWED_DOC_TYPES', 'pdf,doc,docx,xls,xlsx');
// Pagination settings
define('ITEMS_PER_PAGE', 25);
define('MAX_PAGE_LINKS', 5);
// Tax settings
define('DEFAULT_TAX_RATE', 10.00);
define('CURRENCY', '$');
define('CURRENCY_CODE', 'USD');
// Low stock alert threshold
define('LOW_STOCK_THRESHOLD', 10);
// Session timeout (30 minutes)
define('SESSION_TIMEOUT', 1800);
// Start session if not started
if (session_status() == PHP_SESSION_NONE) {
session_start();
}
// Error reporting (disable in production)
error_reporting(E_ALL);
ini_set('display_errors', 1);
// Timezone setting
date_default_timezone_set('UTC');
?>

2. includes/db_connection.php

<?php
require_once 'config.php';
class Database {
private $connection;
private static $instance = null;
private $transaction_count = 0;
private function __construct() {
$this->connect();
}
public static function getInstance() {
if (self::$instance === null) {
self::$instance = new Database();
}
return self::$instance;
}
private function connect() {
$this->connection = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME);
if ($this->connection->connect_error) {
die("Connection failed: " . $this->connection->connect_error);
}
$this->connection->set_charset("utf8mb4");
$this->connection->query("SET time_zone = '+00:00'");
}
public function getConnection() {
return $this->connection;
}
public function escapeString($string) {
return $this->connection->real_escape_string(trim($string));
}
public function prepare($sql) {
return $this->connection->prepare($sql);
}
public function query($sql) {
return $this->connection->query($sql);
}
public function getLastInsertId() {
return $this->connection->insert_id;
}
public function affectedRows() {
return $this->connection->affected_rows;
}
public function beginTransaction() {
if ($this->transaction_count === 0) {
$this->connection->begin_transaction();
}
$this->transaction_count++;
}
public function commit() {
if ($this->transaction_count === 1) {
$this->connection->commit();
}
$this->transaction_count = max(0, $this->transaction_count - 1);
}
public function rollback() {
if ($this->transaction_count === 1) {
$this->connection->rollback();
}
$this->transaction_count = max(0, $this->transaction_count - 1);
}
public function inTransaction() {
return $this->transaction_count > 0;
}
public function __destruct() {
if ($this->connection) {
$this->connection->close();
}
}
}
// Global database instance
$db = Database::getInstance();
$conn = $db->getConnection();
?>

3. includes/functions.php

<?php
require_once 'db_connection.php';
// Redirect to specified page
function redirect($url) {
header("Location: $url");
exit();
}
// Check if user is logged in
function isLoggedIn() {
return isset($_SESSION['user_id']) && !empty($_SESSION['user_id']);
}
// Check if user is admin
function isAdmin() {
return isset($_SESSION['user_role']) && $_SESSION['user_role'] === 'admin';
}
// Check if user is manager
function isManager() {
return isset($_SESSION['user_role']) && $_SESSION['user_role'] === 'manager';
}
// Check if user is staff
function isStaff() {
return isset($_SESSION['user_role']) && $_SESSION['user_role'] === 'staff';
}
// Get current user ID
function getCurrentUserId() {
return $_SESSION['user_id'] ?? 0;
}
// Get current user role
function getCurrentUserRole() {
return $_SESSION['user_role'] ?? '';
}
// Get current user warehouse
function getCurrentUserWarehouse() {
return $_SESSION['warehouse_id'] ?? null;
}
// Format currency
function formatCurrency($amount) {
return CURRENCY . ' ' . number_format($amount, 2);
}
// Format date
function formatDate($date, $format = null) {
if (!$date) return '';
$format = $format ?? getSetting('date_format', 'Y-m-d');
return date($format, strtotime($date));
}
// Format datetime
function formatDateTime($datetime) {
$date_format = getSetting('date_format', 'Y-m-d');
$time_format = getSetting('time_format', 'H:i:s');
return date($date_format . ' ' . $time_format, strtotime($datetime));
}
// Generate unique code
function generateCode($prefix, $length = 8) {
$unique_id = uniqid();
$random = substr(str_shuffle('0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'), 0, $length);
return $prefix . '-' . date('Ymd') . '-' . $random;
}
// Generate barcode
function generateBarcode($product_id) {
$prefix = '20'; // Product identifier
$unique = str_pad($product_id, 6, '0', STR_PAD_LEFT);
$check_digit = calculateCheckDigit($prefix . $unique);
return $prefix . $unique . $check_digit;
}
// Calculate check digit for barcode
function calculateCheckDigit($number) {
$sum = 0;
for ($i = 0; $i < strlen($number); $i++) {
$digit = intval($number[$i]);
if ($i % 2 == 0) {
$sum += $digit;
} else {
$sum += $digit * 3;
}
}
$check = (10 - ($sum % 10)) % 10;
return $check;
}
// Get product stock
function getProductStock($product_id, $warehouse_id = null) {
global $conn;
if ($warehouse_id) {
$sql = "SELECT quantity, available_quantity FROM stock 
WHERE product_id = ? AND warehouse_id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("ii", $product_id, $warehouse_id);
} else {
$sql = "SELECT SUM(quantity) as total_quantity FROM stock WHERE product_id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("i", $product_id);
}
$stmt->execute();
$result = $stmt->get_result();
$row = $result->fetch_assoc();
return $row;
}
// Update stock after sale
function updateStockAfterSale($product_id, $warehouse_id, $quantity) {
global $conn;
$sql = "UPDATE stock SET quantity = quantity - ? 
WHERE product_id = ? AND warehouse_id = ? AND quantity >= ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("iiii", $quantity, $product_id, $warehouse_id, $quantity);
if ($stmt->execute() && $stmt->affected_rows > 0) {
// Log stock movement
logStockMovement($product_id, $warehouse_id, null, $quantity, 'sale');
return true;
}
return false;
}
// Update stock after purchase
function updateStockAfterPurchase($product_id, $warehouse_id, $quantity) {
global $conn;
// Check if stock record exists
$sql = "SELECT stock_id FROM stock WHERE product_id = ? AND warehouse_id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("ii", $product_id, $warehouse_id);
$stmt->execute();
$result = $stmt->get_result();
if ($result->num_rows > 0) {
$sql = "UPDATE stock SET quantity = quantity + ? 
WHERE product_id = ? AND warehouse_id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("iii", $quantity, $product_id, $warehouse_id);
} else {
$sql = "INSERT INTO stock (product_id, warehouse_id, quantity) VALUES (?, ?, ?)";
$stmt = $conn->prepare($sql);
$stmt->bind_param("iii", $product_id, $warehouse_id, $quantity);
}
if ($stmt->execute()) {
logStockMovement($product_id, null, $warehouse_id, $quantity, 'purchase');
return true;
}
return false;
}
// Transfer stock between warehouses
function transferStock($product_id, $from_warehouse, $to_warehouse, $quantity) {
global $conn;
$conn->begin_transaction();
try {
// Reduce from source warehouse
$sql = "UPDATE stock SET quantity = quantity - ? 
WHERE product_id = ? AND warehouse_id = ? AND quantity >= ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("iiii", $quantity, $product_id, $from_warehouse, $quantity);
$stmt->execute();
if ($stmt->affected_rows === 0) {
throw new Exception("Insufficient stock in source warehouse");
}
// Add to destination warehouse
$sql = "INSERT INTO stock (product_id, warehouse_id, quantity) 
VALUES (?, ?, ?) 
ON DUPLICATE KEY UPDATE quantity = quantity + ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("iiii", $product_id, $to_warehouse, $quantity, $quantity);
$stmt->execute();
// Log movement
logStockMovement($product_id, $from_warehouse, $to_warehouse, $quantity, 'transfer');
$conn->commit();
return true;
} catch (Exception $e) {
$conn->rollback();
return false;
}
}
// Log stock movement
function logStockMovement($product_id, $from_warehouse, $to_warehouse, $quantity, $type, $reference_type = null, $reference_id = null) {
global $conn;
$sql = "INSERT INTO stock_movements (product_id, from_warehouse_id, to_warehouse_id, quantity, movement_type, reference_type, reference_id, created_by) 
VALUES (?, ?, ?, ?, ?, ?, ?, ?)";
$stmt = $conn->prepare($sql);
$user_id = getCurrentUserId();
$stmt->bind_param("iiiissii", $product_id, $from_warehouse, $to_warehouse, $quantity, $type, $reference_type, $reference_id, $user_id);
return $stmt->execute();
}
// Log user activity
function logActivity($action, $entity_type = null, $entity_id = null, $details = null) {
global $conn;
$user_id = getCurrentUserId();
$ip_address = $_SERVER['REMOTE_ADDR'] ?? '';
$user_agent = $_SERVER['HTTP_USER_AGENT'] ?? '';
$sql = "INSERT INTO activity_logs (user_id, action, entity_type, entity_id, details, ip_address, user_agent) 
VALUES (?, ?, ?, ?, ?, ?, ?)";
$stmt = $conn->prepare($sql);
$stmt->bind_param("ississs", $user_id, $action, $entity_type, $entity_id, $details, $ip_address, $user_agent);
return $stmt->execute();
}
// Get low stock products
function getLowStockProducts($warehouse_id = null) {
global $conn;
$sql = "SELECT p.*, s.quantity, s.available_quantity, w.warehouse_name 
FROM products p 
JOIN stock s ON p.product_id = s.product_id 
JOIN warehouses w ON s.warehouse_id = w.warehouse_id 
WHERE s.quantity <= p.reorder_level AND p.is_active = 1";
if ($warehouse_id) {
$sql .= " AND s.warehouse_id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("i", $warehouse_id);
} else {
$stmt = $conn->prepare($sql);
}
$stmt->execute();
return $stmt->get_result()->fetch_all(MYSQLI_ASSOC);
}
// Get expiring products
function getExpiringProducts($days = 30) {
global $conn;
$expiry_date = date('Y-m-d', strtotime("+$days days"));
$sql = "SELECT pb.*, p.product_name, p.product_code 
FROM product_batches pb 
JOIN products p ON pb.product_id = p.product_id 
WHERE pb.expiry_date <= ? AND pb.expiry_date >= CURDATE() AND pb.remaining_quantity > 0 
ORDER BY pb.expiry_date ASC";
$stmt = $conn->prepare($sql);
$stmt->bind_param("s", $expiry_date);
$stmt->execute();
return $stmt->get_result()->fetch_all(MYSQLI_ASSOC);
}
// Generate sales report
function generateSalesReport($start_date, $end_date, $warehouse_id = null) {
global $conn;
$sql = "SELECT DATE(order_date) as sale_date, 
COUNT(*) as order_count, 
SUM(total_amount) as total_sales,
SUM(tax_amount) as total_tax,
SUM(shipping_cost) as total_shipping
FROM sales_orders 
WHERE status = 'completed' 
AND DATE(order_date) BETWEEN ? AND ?";
$params = [$start_date, $end_date];
$types = "ss";
if ($warehouse_id) {
$sql .= " AND warehouse_id = ?";
$params[] = $warehouse_id;
$types .= "i";
}
$sql .= " GROUP BY DATE(order_date) ORDER BY sale_date DESC";
$stmt = $conn->prepare($sql);
$stmt->bind_param($types, ...$params);
$stmt->execute();
return $stmt->get_result()->fetch_all(MYSQLI_ASSOC);
}
// Generate purchase report
function generatePurchaseReport($start_date, $end_date, $supplier_id = null) {
global $conn;
$sql = "SELECT DATE(order_date) as purchase_date, 
COUNT(*) as order_count, 
SUM(total_amount) as total_purchases
FROM purchase_orders 
WHERE status = 'received' 
AND DATE(order_date) BETWEEN ? AND ?";
$params = [$start_date, $end_date];
$types = "ss";
if ($supplier_id) {
$sql .= " AND supplier_id = ?";
$params[] = $supplier_id;
$types .= "i";
}
$sql .= " GROUP BY DATE(order_date) ORDER BY purchase_date DESC";
$stmt = $conn->prepare($sql);
$stmt->bind_param($types, ...$params);
$stmt->execute();
return $stmt->get_result()->fetch_all(MYSQLI_ASSOC);
}
// Get dashboard statistics
function getDashboardStats($warehouse_id = null) {
global $conn;
$stats = [];
// Total products
$sql = "SELECT COUNT(*) as total FROM products WHERE is_active = 1";
$result = $conn->query($sql);
$stats['total_products'] = $result->fetch_assoc()['total'];
// Low stock products
if ($warehouse_id) {
$sql = "SELECT COUNT(*) as total FROM stock s 
JOIN products p ON s.product_id = p.product_id 
WHERE s.warehouse_id = ? AND s.quantity <= p.reorder_level";
$stmt = $conn->prepare($sql);
$stmt->bind_param("i", $warehouse_id);
$stmt->execute();
$result = $stmt->get_result();
} else {
$sql = "SELECT COUNT(DISTINCT s.product_id) as total FROM stock s 
JOIN products p ON s.product_id = p.product_id 
WHERE s.quantity <= p.reorder_level";
$result = $conn->query($sql);
}
$stats['low_stock'] = $result->fetch_assoc()['total'];
// Today's sales
$today = date('Y-m-d');
$sql = "SELECT COUNT(*) as count, COALESCE(SUM(total_amount), 0) as total 
FROM sales_orders WHERE DATE(order_date) = ? AND status = 'completed'";
if ($warehouse_id) {
$sql .= " AND warehouse_id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("si", $today, $warehouse_id);
} else {
$stmt = $conn->prepare($sql);
$stmt->bind_param("s", $today);
}
$stmt->execute();
$result = $stmt->get_result();
$row = $result->fetch_assoc();
$stats['today_sales_count'] = $row['count'];
$stats['today_sales_total'] = $row['total'];
// Pending orders
$sql = "SELECT COUNT(*) as count FROM purchase_orders WHERE status = 'ordered'";
if ($warehouse_id) {
$sql .= " AND warehouse_id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("i", $warehouse_id);
$stmt->execute();
$result = $stmt->get_result();
} else {
$result = $conn->query($sql);
}
$stats['pending_orders'] = $result->fetch_assoc()['count'];
return $stats;
}
// Get system setting
function getSetting($key, $default = null) {
global $conn;
$sql = "SELECT setting_value FROM system_settings WHERE setting_key = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("s", $key);
$stmt->execute();
$result = $stmt->get_result();
if ($row = $result->fetch_assoc()) {
return $row['setting_value'];
}
return $default;
}
// Update system setting
function updateSetting($key, $value) {
global $conn;
$sql = "UPDATE system_settings SET setting_value = ?, updated_by = ? WHERE setting_key = ?";
$stmt = $conn->prepare($sql);
$user_id = getCurrentUserId();
$stmt->bind_param("sis", $value, $user_id, $key);
return $stmt->execute();
}
// Generate CSRF token
function generateCSRFToken() {
if (!isset($_SESSION['csrf_token'])) {
$_SESSION['csrf_token'] = bin2hex(random_bytes(32));
}
return $_SESSION['csrf_token'];
}
// Verify CSRF token
function verifyCSRFToken($token) {
return isset($_SESSION['csrf_token']) && hash_equals($_SESSION['csrf_token'], $token);
}
// Upload file
function uploadFile($file, $target_dir, $allowed_types = null) {
$allowed_types = $allowed_types ?? explode(',', ALLOWED_IMAGE_TYPES);
if ($file['error'] !== UPLOAD_ERR_OK) {
return ['success' => false, 'message' => 'Upload error'];
}
$extension = strtolower(pathinfo($file['name'], PATHINFO_EXTENSION));
if (!in_array($extension, $allowed_types)) {
return ['success' => false, 'message' => 'File type not allowed'];
}
if ($file['size'] > MAX_FILE_SIZE) {
return ['success' => false, 'message' => 'File too large'];
}
if (!file_exists($target_dir)) {
mkdir($target_dir, 0755, true);
}
$filename = uniqid() . '_' . time() . '.' . $extension;
$target_path = $target_dir . $filename;
if (move_uploaded_file($file['tmp_name'], $target_path)) {
return ['success' => true, 'filename' => $filename];
}
return ['success' => false, 'message' => 'Failed to save file'];
}
// Export to CSV
function exportToCSV($data, $filename, $headers = null) {
header('Content-Type: text/csv');
header('Content-Disposition: attachment; filename="' . $filename . '"');
$output = fopen('php://output', 'w');
if ($headers) {
fputcsv($output, $headers);
}
foreach ($data as $row) {
fputcsv($output, $row);
}
fclose($output);
exit();
}
// Export to PDF (requires TCPDF or similar library)
function exportToPDF($html, $filename) {
// This would require a PDF library
// For now, just redirect to a PDF generation script
$_SESSION['pdf_html'] = $html;
redirect(SITE_URL . 'api/generate-pdf.php?file=' . $filename);
}
// Pagination helper
function paginate($current_page, $total_pages, $url_pattern) {
$html = '<nav><ul class="pagination">';
// Previous button
if ($current_page > 1) {
$html .= '<li class="page-item"><a class="page-link" href="' . str_replace('{page}', $current_page - 1, $url_pattern) . '">Previous</a></li>';
} else {
$html .= '<li class="page-item disabled"><span class="page-link">Previous</span></li>';
}
// Page numbers
$start = max(1, $current_page - floor(MAX_PAGE_LINKS / 2));
$end = min($total_pages, $start + MAX_PAGE_LINKS - 1);
for ($i = $start; $i <= $end; $i++) {
if ($i == $current_page) {
$html .= '<li class="page-item active"><span class="page-link">' . $i . '</span></li>';
} else {
$html .= '<li class="page-item"><a class="page-link" href="' . str_replace('{page}', $i, $url_pattern) . '">' . $i . '</a></li>';
}
}
// Next button
if ($current_page < $total_pages) {
$html .= '<li class="page-item"><a class="page-link" href="' . str_replace('{page}', $current_page + 1, $url_pattern) . '">Next</a></li>';
} else {
$html .= '<li class="page-item disabled"><span class="page-link">Next</span></li>';
}
$html .= '</ul></nav>';
return $html;
}
?>

4. admin/index.php (Dashboard)

<?php
require_once '../includes/config.php';
require_once '../includes/functions.php';
require_once '../includes/auth.php';
// Check if user is logged in and is admin/manager
if (!isLoggedIn() || !(isAdmin() || isManager())) {
redirect('login.php');
}
$user_id = $_SESSION['user_id'];
$user_role = $_SESSION['user_role'];
$warehouse_id = isManager() ? $_SESSION['warehouse_id'] : null;
// Get dashboard statistics
$stats = getDashboardStats($warehouse_id);
// Get recent sales
$sql = "SELECT so.*, u.full_name as processed_by 
FROM sales_orders so 
LEFT JOIN users u ON so.user_id = u.user_id 
WHERE so.status = 'completed'";
if ($warehouse_id) {
$sql .= " AND so.warehouse_id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("i", $warehouse_id);
} else {
$stmt = $conn->prepare($sql);
}
$sql .= " ORDER BY so.order_date DESC LIMIT 10";
$stmt->execute();
$recent_sales = $stmt->get_result()->fetch_all(MYSQLI_ASSOC);
// Get low stock alerts
$low_stock = getLowStockProducts($warehouse_id);
// Get expiring products
$expiring = getExpiringProducts(30);
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Dashboard - <?php echo SITE_NAME; ?></title>
<link rel="stylesheet" href="../assets/css/admin-style.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.0.0/css/all.min.css">
<script src="https://cdn.jsdelivr.net/npm/chart.js"></script>
</head>
<body>
<div class="admin-container">
<!-- Sidebar -->
<?php include 'includes/sidebar.php'; ?>
<!-- Main Content -->
<div class="main-content">
<!-- Top Navigation -->
<?php include 'includes/topnav.php'; ?>
<!-- Dashboard Content -->
<div class="content-wrapper">
<div class="page-header">
<h1>Dashboard</h1>
<div class="date-range">
<select id="dateRange" class="form-select">
<option value="today">Today</option>
<option value="yesterday">Yesterday</option>
<option value="week" selected>This Week</option>
<option value="month">This Month</option>
<option value="year">This Year</option>
<option value="custom">Custom Range</option>
</select>
<button class="btn btn-primary" onclick="refreshDashboard()">
<i class="fas fa-sync-alt"></i> Refresh
</button>
</div>
</div>
<!-- Statistics Cards -->
<div class="stats-grid">
<div class="stat-card">
<div class="stat-icon bg-primary">
<i class="fas fa-boxes"></i>
</div>
<div class="stat-details">
<h3><?php echo $stats['total_products']; ?></h3>
<p>Total Products</p>
<small class="text-muted">Active in inventory</small>
</div>
</div>
<div class="stat-card">
<div class="stat-icon bg-warning">
<i class="fas fa-exclamation-triangle"></i>
</div>
<div class="stat-details">
<h3><?php echo $stats['low_stock']; ?></h3>
<p>Low Stock Items</p>
<small class="text-muted">Need reordering</small>
</div>
</div>
<div class="stat-card">
<div class="stat-icon bg-success">
<i class="fas fa-shopping-cart"></i>
</div>
<div class="stat-details">
<h3><?php echo $stats['today_sales_count']; ?></h3>
<p>Today's Sales</p>
<h4><?php echo formatCurrency($stats['today_sales_total']); ?></h4>
</div>
</div>
<div class="stat-card">
<div class="stat-icon bg-info">
<i class="fas fa-truck"></i>
</div>
<div class="stat-details">
<h3><?php echo $stats['pending_orders']; ?></h3>
<p>Pending Orders</p>
<small class="text-muted">Awaiting delivery</small>
</div>
</div>
</div>
<!-- Charts Row -->
<div class="charts-row">
<div class="chart-container">
<h3>Sales Overview</h3>
<canvas id="salesChart"></canvas>
</div>
<div class="chart-container">
<h3>Stock Distribution</h3>
<canvas id="stockChart"></canvas>
</div>
</div>
<!-- Alerts Section -->
<?php if (!empty($low_stock) || !empty($expiring)): ?>
<div class="alerts-section">
<h3>Alerts & Notifications</h3>
<div class="alerts-grid">
<?php if (!empty($low_stock)): ?>
<div class="alert-card alert-warning">
<div class="alert-icon">
<i class="fas fa-exclamation-triangle"></i>
</div>
<div class="alert-content">
<h4>Low Stock Alert (<?php echo count($low_stock); ?> items)</h4>
<ul>
<?php foreach (array_slice($low_stock, 0, 5) as $item): ?>
<li>
<?php echo htmlspecialchars($item['product_name']); ?> 
- Only <?php echo $item['quantity']; ?> left 
(Min: <?php echo $item['reorder_level']; ?>)
</li>
<?php endforeach; ?>
</ul>
<a href="reports/low-stock.php" class="btn-link">View All <i class="fas fa-arrow-right"></i></a>
</div>
</div>
<?php endif; ?>
<?php if (!empty($expiring)): ?>
<div class="alert-card alert-danger">
<div class="alert-icon">
<i class="fas fa-calendar-times"></i>
</div>
<div class="alert-content">
<h4>Expiring Soon (<?php echo count($expiring); ?> items)</h4>
<ul>
<?php foreach (array_slice($expiring, 0, 5) as $item): ?>
<li>
<?php echo htmlspecialchars($item['product_name']); ?> 
- Expires: <?php echo formatDate($item['expiry_date']); ?>
</li>
<?php endforeach; ?>
</ul>
<a href="reports/expiring.php" class="btn-link">View All <i class="fas fa-arrow-right"></i></a>
</div>
</div>
<?php endif; ?>
</div>
</div>
<?php endif; ?>
<!-- Recent Sales -->
<div class="recent-sales">
<div class="section-header">
<h3>Recent Sales</h3>
<a href="sales/index.php" class="btn-link">View All Sales <i class="fas fa-arrow-right"></i></a>
</div>
<div class="table-responsive">
<table class="table">
<thead>
<tr>
<th>Order #</th>
<th>Customer</th>
<th>Amount</th>
<th>Payment Status</th>
<th>Date</th>
<th>Processed By</th>
<th>Actions</th>
</tr>
</thead>
<tbody>
<?php foreach ($recent_sales as $sale): ?>
<tr>
<td>
<a href="sales/view.php?id=<?php echo $sale['so_id']; ?>">
<?php echo htmlspecialchars($sale['so_number']); ?>
</a>
</td>
<td><?php echo htmlspecialchars($sale['customer_name'] ?: 'Walk-in Customer'); ?></td>
<td><?php echo formatCurrency($sale['total_amount']); ?></td>
<td>
<span class="badge badge-<?php echo $sale['payment_status']; ?>">
<?php echo ucfirst($sale['payment_status']); ?>
</span>
</td>
<td><?php echo formatDateTime($sale['order_date']); ?></td>
<td><?php echo htmlspecialchars($sale['processed_by'] ?: 'N/A'); ?></td>
<td>
<a href="sales/invoice.php?id=<?php echo $sale['so_id']; ?>" class="btn-icon" title="Print Invoice">
<i class="fas fa-print"></i>
</a>
<a href="sales/view.php?id=<?php echo $sale['so_id']; ?>" class="btn-icon" title="View">
<i class="fas fa-eye"></i>
</a>
</td>
</tr>
<?php endforeach; ?>
<?php if (empty($recent_sales)): ?>
<tr>
<td colspan="7" class="text-center">No sales yet</td>
</tr>
<?php endif; ?>
</tbody>
</table>
</div>
</div>
<!-- Quick Actions -->
<div class="quick-actions">
<h3>Quick Actions</h3>
<div class="actions-grid">
<a href="products/add.php" class="action-card">
<i class="fas fa-plus-circle"></i>
<span>Add Product</span>
</a>
<a href="sales/create.php" class="action-card">
<i class="fas fa-shopping-cart"></i>
<span>New Sale</span>
</a>
<a href="purchases/create.php" class="action-card">
<i class="fas fa-truck"></i>
<span>Purchase Order</span>
</a>
<a href="transfers/create.php" class="action-card">
<i class="fas fa-exchange-alt"></i>
<span>Transfer Stock</span>
</a>
<a href="reports/stock-report.php" class="action-card">
<i class="fas fa-file-alt"></i>
<span>Stock Report</span>
</a>
<a href="adjustments/create.php" class="action-card">
<i class="fas fa-balance-scale"></i>
<span>Stock Adjustment</span>
</a>
</div>
</div>
</div>
</div>
</div>
<script>
// Sales Chart
const salesCtx = document.getElementById('salesChart').getContext('2d');
new Chart(salesCtx, {
type: 'line',
data: {
labels: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'],
datasets: [{
label: 'Sales',
data: [1200, 1900, 1500, 2100, 1800, 2400, 2000],
borderColor: '#4361ee',
backgroundColor: 'rgba(67, 97, 238, 0.1)',
tension: 0.4,
fill: true
}]
},
options: {
responsive: true,
maintainAspectRatio: false,
plugins: {
legend: {
display: false
}
},
scales: {
y: {
beginAtZero: true,
ticks: {
callback: function(value) {
return '$' + value;
}
}
}
}
}
});
// Stock Distribution Chart
const stockCtx = document.getElementById('stockChart').getContext('2d');
new Chart(stockCtx, {
type: 'doughnut',
data: {
labels: ['In Stock', 'Low Stock', 'Out of Stock'],
datasets: [{
data: [70, 20, 10],
backgroundColor: ['#4cc9f0', '#f8961e', '#f72585'],
borderWidth: 0
}]
},
options: {
responsive: true,
maintainAspectRatio: false,
plugins: {
legend: {
position: 'bottom'
}
}
}
});
function refreshDashboard() {
// Refresh dashboard data via AJAX
location.reload();
}
</script>
</body>
</html>

5. admin/products/index.php

<?php
require_once '../../includes/config.php';
require_once '../../includes/functions.php';
require_once '../../includes/auth.php';
// Check permissions
if (!isLoggedIn() || !(isAdmin() || isManager())) {
redirect('../login.php');
}
$page = isset($_GET['page']) ? (int)$_GET['page'] : 1;
$search = isset($_GET['search']) ? trim($_GET['search']) : '';
$category = isset($_GET['category']) ? (int)$_GET['category'] : 0;
$warehouse = isset($_GET['warehouse']) ? (int)$_GET['warehouse'] : 0;
$offset = ($page - 1) * ITEMS_PER_PAGE;
// Build query
$sql = "SELECT p.*, c.category_name, 
(SELECT SUM(quantity) FROM stock WHERE product_id = p.product_id) as total_stock 
FROM products p 
LEFT JOIN categories c ON p.category_id = c.category_id 
WHERE 1=1";
$count_sql = "SELECT COUNT(*) as total FROM products p WHERE 1=1";
$params = [];
$types = "";
if (!empty($search)) {
$sql .= " AND (p.product_name LIKE ? OR p.product_code LIKE ? OR p.description LIKE ?)";
$count_sql .= " AND (p.product_name LIKE ? OR p.product_code LIKE ? OR p.description LIKE ?)";
$search_term = "%$search%";
$params = array_merge($params, [$search_term, $search_term, $search_term]);
$types .= "sss";
}
if ($category > 0) {
$sql .= " AND p.category_id = ?";
$count_sql .= " AND p.category_id = ?";
$params[] = $category;
$types .= "i";
}
// Get total count
$stmt = $conn->prepare($count_sql);
if (!empty($params)) {
$stmt->bind_param($types, ...$params);
}
$stmt->execute();
$total_items = $stmt->get_result()->fetch_assoc()['total'];
$total_pages = ceil($total_items / ITEMS_PER_PAGE);
// Get products
$sql .= " ORDER BY p.created_at DESC LIMIT ? OFFSET ?";
$params[] = ITEMS_PER_PAGE;
$params[] = $offset;
$types .= "ii";
$stmt = $conn->prepare($sql);
if (!empty($params)) {
$stmt->bind_param($types, ...$params);
}
$stmt->execute();
$products = $stmt->get_result()->fetch_all(MYSQLI_ASSOC);
// Get categories for filter
$categories = $conn->query("SELECT * FROM categories WHERE is_active = 1 ORDER BY category_name")->fetch_all(MYSQLI_ASSOC);
// Get warehouses for filter
$warehouses = $conn->query("SELECT * FROM warehouses WHERE is_active = 1 ORDER BY warehouse_name")->fetch_all(MYSQLI_ASSOC);
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Products - <?php echo SITE_NAME; ?></title>
<link rel="stylesheet" href="../../assets/css/admin-style.css">
<link rel="stylesheet" href="https://cdn.datatables.net/1.11.5/css/dataTables.bootstrap5.min.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.0.0/css/all.min.css">
</head>
<body>
<div class="admin-container">
<!-- Sidebar -->
<?php include '../includes/sidebar.php'; ?>
<!-- Main Content -->
<div class="main-content">
<!-- Top Navigation -->
<?php include '../includes/topnav.php'; ?>
<!-- Content -->
<div class="content-wrapper">
<div class="page-header">
<h1>Products</h1>
<div class="header-actions">
<a href="add.php" class="btn btn-primary">
<i class="fas fa-plus"></i> Add Product
</a>
<a href="import.php" class="btn btn-secondary">
<i class="fas fa-upload"></i> Import
</a>
<a href="export.php" class="btn btn-secondary">
<i class="fas fa-download"></i> Export
</a>
</div>
</div>
<!-- Filters -->
<div class="filters-card">
<form method="GET" class="filters-form">
<div class="filter-group">
<input type="text" name="search" placeholder="Search products..." 
value="<?php echo htmlspecialchars($search); ?>" class="form-control">
</div>
<div class="filter-group">
<select name="category" class="form-select">
<option value="0">All Categories</option>
<?php foreach ($categories as $cat): ?>
<option value="<?php echo $cat['category_id']; ?>" 
<?php echo $category == $cat['category_id'] ? 'selected' : ''; ?>>
<?php echo htmlspecialchars($cat['category_name']); ?>
</option>
<?php endforeach; ?>
</select>
</div>
<div class="filter-group">
<select name="warehouse" class="form-select">
<option value="0">All Warehouses</option>
<?php foreach ($warehouses as $wh): ?>
<option value="<?php echo $wh['warehouse_id']; ?>" 
<?php echo $warehouse == $wh['warehouse_id'] ? 'selected' : ''; ?>>
<?php echo htmlspecialchars($wh['warehouse_name']); ?>
</option>
<?php endforeach; ?>
</select>
</div>
<button type="submit" class="btn btn-primary">Filter</button>
<a href="index.php" class="btn btn-secondary">Clear</a>
</form>
</div>
<!-- Products Table -->
<div class="table-card">
<div class="table-responsive">
<table class="table" id="productsTable">
<thead>
<tr>
<th>Image</th>
<th>Code</th>
<th>Name</th>
<th>Category</th>
<th>Price</th>
<th>Stock</th>
<th>Status</th>
<th>Actions</th>
</tr>
</thead>
<tbody>
<?php foreach ($products as $product): ?>
<tr>
<td>
<img src="../../uploads/products/<?php echo $product['product_image'] ?? 'default.jpg'; ?>" 
alt="<?php echo htmlspecialchars($product['product_name']); ?>"
class="product-thumbnail">
</td>
<td><?php echo htmlspecialchars($product['product_code']); ?></td>
<td>
<a href="view.php?id=<?php echo $product['product_id']; ?>">
<?php echo htmlspecialchars($product['product_name']); ?>
</a>
</td>
<td><?php echo htmlspecialchars($product['category_name'] ?? 'Uncategorized'); ?></td>
<td>
<div>Purchase: <?php echo formatCurrency($product['purchase_price']); ?></div>
<div>Selling: <?php echo formatCurrency($product['selling_price']); ?></div>
</td>
<td>
<?php
$stock = $product['total_stock'] ?? 0;
$stock_class = $stock <= $product['reorder_level'] ? 'text-danger' : 'text-success';
?>
<span class="<?php echo $stock_class; ?>">
<?php echo $stock; ?> <?php echo $product['unit']; ?>
</span>
<?php if ($stock <= $product['reorder_level']): ?>
<i class="fas fa-exclamation-triangle text-warning" title="Low Stock"></i>
<?php endif; ?>
</td>
<td>
<span class="badge badge-<?php echo $product['is_active'] ? 'success' : 'danger'; ?>">
<?php echo $product['is_active'] ? 'Active' : 'Inactive'; ?>
</span>
</td>
<td>
<div class="action-buttons">
<a href="view.php?id=<?php echo $product['product_id']; ?>" class="btn-icon" title="View">
<i class="fas fa-eye"></i>
</a>
<a href="edit.php?id=<?php echo $product['product_id']; ?>" class="btn-icon" title="Edit">
<i class="fas fa-edit"></i>
</a>
<a href="barcode.php?id=<?php echo $product['product_id']; ?>" class="btn-icon" title="Print Barcode">
<i class="fas fa-barcode"></i>
</a>
<?php if (isAdmin()): ?>
<a href="delete.php?id=<?php echo $product['product_id']; ?>" 
class="btn-icon text-danger" 
onclick="return confirm('Are you sure you want to delete this product?')"
title="Delete">
<i class="fas fa-trash"></i>
</a>
<?php endif; ?>
</div>
</td>
</tr>
<?php endforeach; ?>
<?php if (empty($products)): ?>
<tr>
<td colspan="8" class="text-center">No products found</td>
</tr>
<?php endif; ?>
</tbody>
</table>
</div>
<!-- Pagination -->
<?php if ($total_pages > 1): ?>
<div class="pagination-wrapper">
<?php
$url_pattern = "index.php?page={page}&search=" . urlencode($search) . "&category=$category&warehouse=$warehouse";
echo paginate($page, $total_pages, $url_pattern);
?>
</div>
<?php endif; ?>
</div>
</div>
</div>
</div>
<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
<script src="https://cdn.datatables.net/1.11.5/js/jquery.dataTables.min.js"></script>
<script src="https://cdn.datatables.net/1.11.5/js/dataTables.bootstrap5.min.js"></script>
<script>
$(document).ready(function() {
$('#productsTable').DataTable({
paging: false,
searching: false,
ordering: true,
info: false
});
});
</script>
</body>
</html>

6. staff/sales/create.php (Point of Sale Interface)

<?php
require_once '../../includes/config.php';
require_once '../../includes/functions.php';
require_once '../../includes/auth.php';
// Check if staff is logged in
if (!isLoggedIn() || !isStaff()) {
redirect('login.php');
}
$warehouse_id = $_SESSION['warehouse_id'];
// Get products for this warehouse
$sql = "SELECT p.*, s.quantity, s.available_quantity 
FROM products p 
JOIN stock s ON p.product_id = s.product_id 
WHERE s.warehouse_id = ? AND p.is_active = 1 AND s.quantity > 0 
ORDER BY p.product_name";
$stmt = $conn->prepare($sql);
$stmt->bind_param("i", $warehouse_id);
$stmt->execute();
$products = $stmt->get_result()->fetch_all(MYSQLI_ASSOC);
?>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Point of Sale - <?php echo SITE_NAME; ?></title>
<link rel="stylesheet" href="../../assets/css/admin-style.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.0.0/css/all.min.css">
</head>
<body>
<div class="pos-container">
<!-- POS Header -->
<div class="pos-header">
<div class="pos-title">
<h1>Point of Sale</h1>
<span class="warehouse-badge"><?php echo $_SESSION['warehouse_name'] ?? 'Main Warehouse'; ?></span>
</div>
<div class="pos-actions">
<button class="btn btn-secondary" onclick="window.location.href='history.php'">
<i class="fas fa-history"></i> Sales History
</button>
<button class="btn btn-secondary" onclick="window.location.href='../dashboard.php'">
<i class="fas fa-arrow-left"></i> Back to Dashboard
</button>
</div>
</div>
<!-- POS Main Content -->
<div class="pos-main">
<!-- Products Grid -->
<div class="products-section">
<div class="search-bar">
<i class="fas fa-search"></i>
<input type="text" id="productSearch" placeholder="Search products by name or scan barcode...">
</div>
<div class="category-tabs">
<button class="category-tab active" data-category="all">All</button>
<?php
$categories = $conn->query("SELECT * FROM categories WHERE is_active = 1 ORDER BY category_name");
while ($cat = $categories->fetch_assoc()):
?>
<button class="category-tab" data-category="<?php echo $cat['category_id']; ?>">
<?php echo htmlspecialchars($cat['category_name']); ?>
</button>
<?php endwhile; ?>
</div>
<div class="products-grid" id="productsGrid">
<?php foreach ($products as $product): ?>
<div class="product-card" 
data-id="<?php echo $product['product_id']; ?>"
data-name="<?php echo htmlspecialchars($product['product_name']); ?>"
data-price="<?php echo $product['selling_price']; ?>"
data-stock="<?php echo $product['available_quantity']; ?>"
data-category="<?php echo $product['category_id']; ?>">
<div class="product-image">
<img src="../../uploads/products/<?php echo $product['product_image'] ?? 'default.jpg'; ?>" 
alt="<?php echo htmlspecialchars($product['product_name']); ?>">
</div>
<div class="product-info">
<h4><?php echo htmlspecialchars($product['product_name']); ?></h4>
<p class="product-code"><?php echo $product['product_code']; ?></p>
<div class="product-price">
<?php echo formatCurrency($product['selling_price']); ?>
</div>
<div class="product-stock">
Stock: <?php echo $product['available_quantity']; ?> <?php echo $product['unit']; ?>
</div>
</div>
<button class="add-to-cart-btn" onclick="addToCart(<?php echo $product['product_id']; ?>)">
<i class="fas fa-cart-plus"></i>
</button>
</div>
<?php endforeach; ?>
</div>
</div>
<!-- Cart Section -->
<div class="cart-section">
<h3>Shopping Cart</h3>
<div class="cart-items" id="cartItems">
<!-- Cart items will be added here dynamically -->
</div>
<div class="cart-summary">
<div class="summary-row">
<span>Subtotal:</span>
<span id="subtotal">$0.00</span>
</div>
<div class="summary-row">
<span>Tax (<?php echo DEFAULT_TAX_RATE; ?>%):</span>
<span id="tax">$0.00</span>
</div>
<div class="summary-row total">
<span>Total:</span>
<span id="total">$0.00</span>
</div>
</div>
<div class="customer-info">
<input type="text" id="customerName" placeholder="Customer Name (optional)">
<input type="text" id="customerPhone" placeholder="Customer Phone (optional)">
</div>
<div class="payment-section">
<select id="paymentMethod" class="form-select">
<option value="cash">Cash</option>
<option value="card">Credit/Debit Card</option>
<option value="mobile">Mobile Money</option>
<option value="credit">Credit Account</option>
</select>
<div class="payment-actions">
<button class="btn btn-success btn-large" onclick="processSale()">
<i class="fas fa-check"></i> Complete Sale
</button>
<button class="btn btn-secondary" onclick="clearCart()">
<i class="fas fa-trash"></i> Clear Cart
</button>
</div>
</div>
</div>
</div>
</div>
<script>
// Cart array
let cart = [];
// Add to cart function
function addToCart(productId) {
const productCard = document.querySelector(`.product-card[data-id="${productId}"]`);
const productName = productCard.dataset.name;
const productPrice = parseFloat(productCard.dataset.price);
const maxStock = parseInt(productCard.dataset.stock);
// Check if product already in cart
const existingItem = cart.find(item => item.id === productId);
if (existingItem) {
if (existingItem.quantity < maxStock) {
existingItem.quantity++;
} else {
alert('Maximum stock limit reached');
return;
}
} else {
cart.push({
id: productId,
name: productName,
price: productPrice,
quantity: 1,
maxStock: maxStock
});
}
updateCartDisplay();
}
// Update cart display
function updateCartDisplay() {
const cartContainer = document.getElementById('cartItems');
const subtotalSpan = document.getElementById('subtotal');
const taxSpan = document.getElementById('tax');
const totalSpan = document.getElementById('total');
let subtotal = 0;
let html = '';
cart.forEach((item, index) => {
subtotal += item.price * item.quantity;
html += `
<div class="cart-item">
<div class="item-details">
<h5>${item.name}</h5>
<div class="item-price">${formatCurrency(item.price)} x ${item.quantity}</div>
</div>
<div class="item-actions">
<div class="quantity-controls">
<button onclick="updateQuantity(${index}, -1)" ${item.quantity <= 1 ? 'disabled' : ''}>-</button>
<span>${item.quantity}</span>
<button onclick="updateQuantity(${index}, 1)" ${item.quantity >= item.maxStock ? 'disabled' : ''}>+</button>
</div>
<button class="remove-item" onclick="removeFromCart(${index})">
<i class="fas fa-trash"></i>
</button>
</div>
</div>
`;
});
if (cart.length === 0) {
html = '<div class="empty-cart">Your cart is empty</div>';
}
cartContainer.innerHTML = html;
const tax = subtotal * (<?php echo DEFAULT_TAX_RATE; ?> / 100);
const total = subtotal + tax;
subtotalSpan.textContent = formatCurrency(subtotal);
taxSpan.textContent = formatCurrency(tax);
totalSpan.textContent = formatCurrency(total);
}
// Update quantity
function updateQuantity(index, change) {
const item = cart[index];
const newQuantity = item.quantity + change;
if (newQuantity >= 1 && newQuantity <= item.maxStock) {
item.quantity = newQuantity;
updateCartDisplay();
}
}
// Remove from cart
function removeFromCart(index) {
cart.splice(index, 1);
updateCartDisplay();
}
// Clear cart
function clearCart() {
if (confirm('Clear all items from cart?')) {
cart = [];
updateCartDisplay();
}
}
// Process sale
function processSale() {
if (cart.length === 0) {
alert('Cart is empty');
return;
}
const customerName = document.getElementById('customerName').value || 'Walk-in Customer';
const customerPhone = document.getElementById('customerPhone').value;
const paymentMethod = document.getElementById('paymentMethod').value;
const saleData = {
customer_name: customerName,
customer_phone: customerPhone,
payment_method: paymentMethod,
items: cart
};
// Send to server
fetch('../../api/process-sale.php', {
method: 'POST',
headers: {
'Content-Type': 'application/json'
},
body: JSON.stringify(saleData)
})
.then(response => response.json())
.then(data => {
if (data.success) {
alert('Sale completed successfully!');
window.location.href = 'invoice.php?id=' + data.sale_id;
} else {
alert('Error: ' + data.message);
}
})
.catch(error => {
console.error('Error:', error);
alert('An error occurred');
});
}
// Search products
document.getElementById('productSearch').addEventListener('input', function(e) {
const searchTerm = e.target.value.toLowerCase();
const products = document.querySelectorAll('.product-card');
products.forEach(product => {
const name = product.dataset.name.toLowerCase();
if (name.includes(searchTerm)) {
product.style.display = 'block';
} else {
product.style.display = 'none';
}
});
});
// Category filter
document.querySelectorAll('.category-tab').forEach(tab => {
tab.addEventListener('click', function() {
// Update active tab
document.querySelectorAll('.category-tab').forEach(t => t.classList.remove('active'));
this.classList.add('active');
const category = this.dataset.category;
const products = document.querySelectorAll('.product-card');
products.forEach(product => {
if (category === 'all' || product.dataset.category === category) {
product.style.display = 'block';
} else {
product.style.display = 'none';
}
});
});
});
// Format currency
function formatCurrency(amount) {
return '$' + amount.toFixed(2);
}
</script>
<style>
.pos-container {
display: flex;
flex-direction: column;
height: 100vh;
background: #f8f9fa;
}
.pos-header {
background: white;
padding: 1rem 2rem;
box-shadow: 0 2px 10px rgba(0,0,0,0.1);
display: flex;
justify-content: space-between;
align-items: center;
}
.pos-title {
display: flex;
align-items: center;
gap: 1rem;
}
.pos-title h1 {
margin: 0;
font-size: 1.5rem;
}
.warehouse-badge {
background: var(--primary-color);
color: white;
padding: 0.25rem 0.75rem;
border-radius: 20px;
font-size: 0.875rem;
}
.pos-main {
display: flex;
flex: 1;
overflow: hidden;
}
.products-section {
flex: 2;
padding: 1rem;
overflow-y: auto;
}
.search-bar {
position: relative;
margin-bottom: 1rem;
}
.search-bar i {
position: absolute;
left: 1rem;
top: 50%;
transform: translateY(-50%);
color: var(--gray-color);
}
.search-bar input {
width: 100%;
padding: 0.75rem 1rem 0.75rem 2.5rem;
border: 1px solid var(--border-color);
border-radius: 8px;
font-size: 1rem;
}
.category-tabs {
display: flex;
gap: 0.5rem;
margin-bottom: 1rem;
overflow-x: auto;
padding-bottom: 0.5rem;
}
.category-tab {
padding: 0.5rem 1rem;
background: white;
border: 1px solid var(--border-color);
border-radius: 20px;
cursor: pointer;
white-space: nowrap;
}
.category-tab.active {
background: var(--primary-color);
color: white;
border-color: var(--primary-color);
}
.products-grid {
display: grid;
grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
gap: 1rem;
}
.product-card {
background: white;
border-radius: 8px;
overflow: hidden;
box-shadow: 0 2px 5px rgba(0,0,0,0.1);
position: relative;
cursor: pointer;
transition: var(--transition);
}
.product-card:hover {
transform: translateY(-3px);
box-shadow: 0 5px 15px rgba(0,0,0,0.15);
}
.product-image {
height: 150px;
overflow: hidden;
}
.product-image img {
width: 100%;
height: 100%;
object-fit: cover;
}
.product-info {
padding: 1rem;
}
.product-info h4 {
margin: 0 0 0.25rem;
font-size: 1rem;
}
.product-code {
color: var(--gray-color);
font-size: 0.75rem;
margin-bottom: 0.5rem;
}
.product-price {
font-weight: bold;
color: var(--primary-color);
margin-bottom: 0.25rem;
}
.product-stock {
font-size: 0.75rem;
color: var(--gray-color);
}
.add-to-cart-btn {
position: absolute;
top: 0.5rem;
right: 0.5rem;
width: 32px;
height: 32px;
border-radius: 50%;
background: var(--primary-color);
color: white;
border: none;
cursor: pointer;
display: flex;
align-items: center;
justify-content: center;
opacity: 0;
transition: var(--transition);
}
.product-card:hover .add-to-cart-btn {
opacity: 1;
}
.cart-section {
flex: 1;
background: white;
border-left: 1px solid var(--border-color);
display: flex;
flex-direction: column;
padding: 1rem;
}
.cart-section h3 {
margin: 0 0 1rem;
padding-bottom: 0.5rem;
border-bottom: 2px solid var(--border-color);
}
.cart-items {
flex: 1;
overflow-y: auto;
margin-bottom: 1rem;
}
.cart-item {
background: var(--light-color);
padding: 0.75rem;
border-radius: 8px;
margin-bottom: 0.5rem;
}
.item-details h5 {
margin: 0 0 0.25rem;
font-size: 0.9rem;
}
.item-price {
font-size: 0.8rem;
color: var(--gray-color);
}
.item-actions {
display: flex;
justify-content: space-between;
align-items: center;
margin-top: 0.5rem;
}
.quantity-controls {
display: flex;
align-items: center;
gap: 0.5rem;
}
.quantity-controls button {
width: 24px;
height: 24px;
border-radius: 4px;
border: 1px solid var(--border-color);
background: white;
cursor: pointer;
}
.quantity-controls button:disabled {
opacity: 0.5;
cursor: not-allowed;
}
.remove-item {
color: var(--danger-color);
background: none;
border: none;
cursor: pointer;
}
.cart-summary {
border-top: 2px solid var(--border-color);
padding-top: 1rem;
margin-bottom: 1rem;
}
.summary-row {
display: flex;
justify-content: space-between;
margin-bottom: 0.5rem;
}
.summary-row.total {
font-size: 1.25rem;
font-weight: bold;
color: var(--primary-color);
border-top: 1px solid var(--border-color);
padding-top: 0.5rem;
margin-top: 0.5rem;
}
.customer-info input {
width: 100%;
padding: 0.5rem;
margin-bottom: 0.5rem;
border: 1px solid var(--border-color);
border-radius: 4px;
}
.payment-section select {
width: 100%;
padding: 0.5rem;
margin-bottom: 1rem;
}
.payment-actions {
display: flex;
gap: 0.5rem;
}
.btn-large {
flex: 1;
padding: 1rem;
}
.empty-cart {
text-align: center;
color: var(--gray-color);
padding: 2rem;
}
</style>
</body>
</html>

7. api/process-sale.php

<?php
require_once '../includes/config.php';
require_once '../includes/functions.php';
require_once '../includes/auth.php';
header('Content-Type: application/json');
// Check if user is logged in
if (!isLoggedIn()) {
echo json_encode(['success' => false, 'message' => 'Not authenticated']);
exit();
}
// Get POST data
$data = json_decode(file_get_contents('php://input'), true);
if (!$data || empty($data['items'])) {
echo json_encode(['success' => false, 'message' => 'Invalid request data']);
exit();
}
$user_id = $_SESSION['user_id'];
$warehouse_id = $_SESSION['warehouse_id'] ?? 1;
$customer_name = $conn->escapeString($data['customer_name'] ?? 'Walk-in Customer');
$customer_phone = $conn->escapeString($data['customer_phone'] ?? '');
$payment_method = $conn->escapeString($data['payment_method'] ?? 'cash');
// Begin transaction
$conn->begin_transaction();
try {
// Calculate totals
$subtotal = 0;
$items = $data['items'];
foreach ($items as $item) {
// Verify stock availability
$sql = "SELECT available_quantity, selling_price FROM stock s 
JOIN products p ON s.product_id = p.product_id 
WHERE s.product_id = ? AND s.warehouse_id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("ii", $item['id'], $warehouse_id);
$stmt->execute();
$result = $stmt->get_result();
$product = $result->fetch_assoc();
if (!$product || $product['available_quantity'] < $item['quantity']) {
throw new Exception("Insufficient stock for product ID: " . $item['id']);
}
$subtotal += $product['selling_price'] * $item['quantity'];
}
$tax_rate = DEFAULT_TAX_RATE;
$tax_amount = $subtotal * ($tax_rate / 100);
$total_amount = $subtotal + $tax_amount;
// Generate order number
$so_number = generateCode('SALE');
// Insert sales order
$sql = "INSERT INTO sales_orders (so_number, customer_name, customer_phone, warehouse_id, user_id, 
subtotal, tax_amount, total_amount, payment_method, payment_status, status) 
VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, 'paid', 'completed')";
$stmt = $conn->prepare($sql);
$stmt->bind_param("sssidddds", $so_number, $customer_name, $customer_phone, $warehouse_id, 
$user_id, $subtotal, $tax_amount, $total_amount, $payment_method);
$stmt->execute();
$so_id = $conn->insert_id;
// Insert order items and update stock
foreach ($items as $item) {
// Get product price
$sql = "SELECT selling_price FROM products WHERE product_id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("i", $item['id']);
$stmt->execute();
$price = $stmt->get_result()->fetch_assoc()['selling_price'];
// Insert order item
$sql = "INSERT INTO sales_order_items (so_id, product_id, quantity, unit_price) 
VALUES (?, ?, ?, ?)";
$stmt = $conn->prepare($sql);
$stmt->bind_param("iiid", $so_id, $item['id'], $item['quantity'], $price);
$stmt->execute();
// Update stock
$sql = "UPDATE stock SET quantity = quantity - ? 
WHERE product_id = ? AND warehouse_id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("iii", $item['quantity'], $item['id'], $warehouse_id);
$stmt->execute();
// Log stock movement
logStockMovement($item['id'], $warehouse_id, null, $item['quantity'], 'sale', 'sales_order', $so_id);
}
// Log activity
logActivity('Created sale', 'sales_order', $so_id, "Sale amount: " . formatCurrency($total_amount));
$conn->commit();
echo json_encode([
'success' => true,
'sale_id' => $so_id,
'sale_number' => $so_number,
'message' => 'Sale completed successfully'
]);
} catch (Exception $e) {
$conn->rollback();
echo json_encode(['success' => false, 'message' => $e->getMessage()]);
}
?>

8. assets/css/admin-style.css

/* Admin Panel Styles */
:root {
--sidebar-width: 250px;
--sidebar-bg: #1e1b4b;
--sidebar-hover: #2a2356;
--primary-color: #4361ee;
--success-color: #4cc9f0;
--warning-color: #f8961e;
--danger-color: #f72585;
--dark-color: #1e1b4b;
--light-color: #f8f9fa;
--gray-color: #6c757d;
--border-color: #dee2e6;
}
/* Admin Container */
.admin-container {
display: flex;
min-height: 100vh;
}
/* Sidebar */
.sidebar {
width: var(--sidebar-width);
background: var(--sidebar-bg);
color: white;
position: fixed;
height: 100vh;
overflow-y: auto;
transition: all 0.3s;
}
.sidebar-header {
padding: 1.5rem;
border-bottom: 1px solid rgba(255,255,255,0.1);
}
.sidebar-header h3 {
margin: 0;
color: white;
font-size: 1.25rem;
}
.sidebar-header p {
margin: 0.25rem 0 0;
font-size: 0.75rem;
opacity: 0.7;
}
.sidebar-menu {
padding: 1rem 0;
}
.sidebar-menu ul {
list-style: none;
padding: 0;
margin: 0;
}
.sidebar-menu li {
margin-bottom: 0.25rem;
}
.sidebar-menu a {
display: flex;
align-items: center;
padding: 0.75rem 1.5rem;
color: rgba(255,255,255,0.8);
text-decoration: none;
transition: all 0.3s;
}
.sidebar-menu a:hover,
.sidebar-menu a.active {
background: var(--sidebar-hover);
color: white;
}
.sidebar-menu i {
width: 24px;
margin-right: 0.75rem;
font-size: 1.1rem;
}
.sidebar-menu .menu-arrow {
margin-left: auto;
transition: transform 0.3s;
}
.sidebar-menu .submenu {
display: none;
padding-left: 2.5rem;
background: rgba(0,0,0,0.1);
}
.sidebar-menu .submenu a {
padding: 0.5rem 1.5rem;
font-size: 0.9rem;
}
.sidebar-menu li.open > .submenu {
display: block;
}
.sidebar-menu li.open > a > .menu-arrow {
transform: rotate(90deg);
}
/* Main Content */
.main-content {
flex: 1;
margin-left: var(--sidebar-width);
background: #f5f5f5;
min-height: 100vh;
}
/* Top Navigation */
.top-nav {
background: white;
padding: 1rem 2rem;
box-shadow: 0 2px 10px rgba(0,0,0,0.1);
display: flex;
justify-content: space-between;
align-items: center;
}
.nav-left {
display: flex;
align-items: center;
}
.menu-toggle {
display: none;
background: none;
border: none;
font-size: 1.5rem;
color: var(--dark-color);
cursor: pointer;
margin-right: 1rem;
}
.page-title {
font-size: 1.25rem;
font-weight: 500;
color: var(--dark-color);
}
.nav-right {
display: flex;
align-items: center;
gap: 1.5rem;
}
.nav-item {
position: relative;
}
.nav-icon {
font-size: 1.25rem;
color: var(--gray-color);
cursor: pointer;
position: relative;
}
.badge {
position: absolute;
top: -5px;
right: -5px;
background: var(--danger-color);
color: white;
font-size: 0.65rem;
padding: 0.15rem 0.35rem;
border-radius: 50%;
}
.user-profile {
display: flex;
align-items: center;
gap: 0.5rem;
cursor: pointer;
}
.user-profile img {
width: 32px;
height: 32px;
border-radius: 50%;
object-fit: cover;
}
/* Content Wrapper */
.content-wrapper {
padding: 2rem;
}
/* Page Header */
.page-header {
display: flex;
justify-content: space-between;
align-items: center;
margin-bottom: 2rem;
}
.page-header h1 {
margin: 0;
font-size: 1.75rem;
color: var(--dark-color);
}
.header-actions {
display: flex;
gap: 0.5rem;
}
/* Statistics Cards */
.stats-grid {
display: grid;
grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
gap: 1.5rem;
margin-bottom: 2rem;
}
.stat-card {
background: white;
border-radius: 10px;
padding: 1.5rem;
box-shadow: 0 2px 10px rgba(0,0,0,0.1);
display: flex;
align-items: center;
gap: 1rem;
}
.stat-icon {
width: 60px;
height: 60px;
border-radius: 10px;
display: flex;
align-items: center;
justify-content: center;
font-size: 2rem;
}
.stat-icon.bg-primary {
background: rgba(67, 97, 238, 0.1);
color: var(--primary-color);
}
.stat-icon.bg-success {
background: rgba(76, 201, 240, 0.1);
color: var(--success-color);
}
.stat-icon.bg-warning {
background: rgba(248, 150, 30, 0.1);
color: var(--warning-color);
}
.stat-icon.bg-danger {
background: rgba(247, 37, 133, 0.1);
color: var(--danger-color);
}
.stat-details h3 {
margin: 0;
font-size: 1.5rem;
color: var(--dark-color);
}
.stat-details p {
margin: 0.25rem 0 0;
color: var(--gray-color);
font-size: 0.875rem;
}
.stat-details h4 {
margin: 0.25rem 0 0;
font-size: 1rem;
color: var(--primary-color);
}
/* Charts Row */
.charts-row {
display: grid;
grid-template-columns: 2fr 1fr;
gap: 1.5rem;
margin-bottom: 2rem;
}
.chart-container {
background: white;
border-radius: 10px;
padding: 1.5rem;
box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}
.chart-container h3 {
margin: 0 0 1rem;
font-size: 1.1rem;
color: var(--dark-color);
}
.chart-container canvas {
width: 100% !important;
height: 300px !important;
}
/* Alerts Section */
.alerts-section {
margin-bottom: 2rem;
}
.alerts-section h3 {
margin-bottom: 1rem;
}
.alerts-grid {
display: grid;
grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
gap: 1.5rem;
}
.alert-card {
background: white;
border-radius: 10px;
padding: 1.5rem;
display: flex;
gap: 1rem;
box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}
.alert-card.alert-warning {
border-left: 4px solid var(--warning-color);
}
.alert-card.alert-danger {
border-left: 4px solid var(--danger-color);
}
.alert-icon {
font-size: 2rem;
}
.alert-warning .alert-icon {
color: var(--warning-color);
}
.alert-danger .alert-icon {
color: var(--danger-color);
}
.alert-content {
flex: 1;
}
.alert-content h4 {
margin: 0 0 0.5rem;
font-size: 1rem;
}
.alert-content ul {
margin: 0 0 0.5rem;
padding-left: 1rem;
}
.alert-content li {
margin-bottom: 0.25rem;
color: var(--gray-color);
}
.btn-link {
color: var(--primary-color);
text-decoration: none;
font-size: 0.875rem;
}
/* Tables */
.table-card {
background: white;
border-radius: 10px;
padding: 1.5rem;
box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}
.table-responsive {
overflow-x: auto;
}
.table {
width: 100%;
border-collapse: collapse;
}
.table th {
text-align: left;
padding: 1rem;
background: var(--light-color);
color: var(--dark-color);
font-weight: 600;
font-size: 0.875rem;
border-bottom: 2px solid var(--border-color);
}
.table td {
padding: 1rem;
border-bottom: 1px solid var(--border-color);
vertical-align: middle;
}
.table tbody tr:hover {
background: var(--light-color);
}
/* Product Thumbnail */
.product-thumbnail {
width: 50px;
height: 50px;
border-radius: 5px;
object-fit: cover;
}
/* Badges */
.badge {
display: inline-block;
padding: 0.25rem 0.5rem;
border-radius: 4px;
font-size: 0.75rem;
font-weight: 500;
}
.badge-success {
background: rgba(76, 201, 240, 0.1);
color: var(--success-color);
}
.badge-warning {
background: rgba(248, 150, 30, 0.1);
color: var(--warning-color);
}
.badge-danger {
background: rgba(247, 37, 133, 0.1);
color: var(--danger-color);
}
.badge-info {
background: rgba(67, 97, 238, 0.1);
color: var(--primary-color);
}
.badge-paid {
background: #d4edda;
color: #155724;
}
.badge-unpaid {
background: #f8d7da;
color: #721c24;
}
/* Action Buttons */
.action-buttons {
display: flex;
gap: 0.5rem;
}
.btn-icon {
width: 32px;
height: 32px;
border-radius: 6px;
display: flex;
align-items: center;
justify-content: center;
background: var(--light-color);
color: var(--gray-color);
transition: var(--transition);
border: none;
cursor: pointer;
}
.btn-icon:hover {
background: var(--primary-color);
color: white;
}
.btn-icon.text-danger:hover {
background: var(--danger-color);
color: white;
}
/* Forms */
.form-group {
margin-bottom: 1rem;
}
.form-group label {
display: block;
margin-bottom: 0.5rem;
font-weight: 500;
color: var(--dark-color);
}
.form-control {
width: 100%;
padding: 0.5rem 0.75rem;
border: 1px solid var(--border-color);
border-radius: 4px;
font-size: 1rem;
transition: var(--transition);
}
.form-control:focus {
outline: none;
border-color: var(--primary-color);
box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.1);
}
.form-select {
width: 100%;
padding: 0.5rem 0.75rem;
border: 1px solid var(--border-color);
border-radius: 4px;
background: white;
font-size: 1rem;
}
textarea.form-control {
min-height: 100px;
resize: vertical;
}
/* Filters Card */
.filters-card {
background: white;
border-radius: 10px;
padding: 1.5rem;
margin-bottom: 1.5rem;
box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}
.filters-form {
display: flex;
gap: 1rem;
align-items: flex-end;
flex-wrap: wrap;
}
.filter-group {
flex: 1;
min-width: 200px;
}
/* Pagination */
.pagination-wrapper {
margin-top: 2rem;
display: flex;
justify-content: center;
}
.pagination {
display: flex;
gap: 0.25rem;
list-style: none;
padding: 0;
}
.page-item {
margin: 0;
}
.page-link {
display: block;
padding: 0.5rem 0.75rem;
border: 1px solid var(--border-color);
border-radius: 4px;
color: var(--primary-color);
text-decoration: none;
transition: var(--transition);
}
.page-item.active .page-link {
background: var(--primary-color);
color: white;
border-color: var(--primary-color);
}
.page-item.disabled .page-link {
color: var(--gray-color);
pointer-events: none;
}
/* Responsive */
@media (max-width: 768px) {
.sidebar {
transform: translateX(-100%);
z-index: 1000;
}
.sidebar.open {
transform: translateX(0);
}
.main-content {
margin-left: 0;
}
.menu-toggle {
display: block;
}
.stats-grid {
grid-template-columns: 1fr;
}
.charts-row {
grid-template-columns: 1fr;
}
.alerts-grid {
grid-template-columns: 1fr;
}
.filters-form {
flex-direction: column;
}
.filter-group {
width: 100%;
}
}

How to Use This Project - Step by Step Guide

Step 1: System Requirements

XAMPP/WAMP/MAMP (PHP 7.4+)
MySQL 5.7+
Web browser (Chrome, Firefox)
2GB RAM minimum
1GB free disk space

Step 2: Installation

Download and Extract

   # Navigate to htdocs (XAMPP) or www (WAMP)
cd C:\xampp\htdocs\
# Create project folder
mkdir inventory-management-system
# Extract all files into this folder

Database Setup

Open phpMyAdmin (http://localhost/phpmyadmin)
Create new database: inventory_db
Import database/inventory_db.sql
Verify all tables are created (users, products, categories, etc.)

Configure Project

Open includes/config.php
Update database credentials if needed:

   define('DB_HOST', 'localhost');
define('DB_USER', 'root');
define('DB_PASS', ''); // Add password if set
define('DB_NAME', 'inventory_db');

Create Required Directories

   # Create upload directories
mkdir uploads
mkdir uploads/products
mkdir uploads/imports
mkdir exports
mkdir exports/reports
# Set permissions (Linux/Mac)
chmod -R 755 uploads/
chmod -R 755 exports/
# Windows: Ensure write permissions for these folders

Step 3: Initial Login

Default Admin Account:

URL: http://localhost/inventory-management-system/admin/login.php
Username: admin
Password: Admin@123

Default Manager Account:

Username: manager
Password: Manager@123

Default Staff Account:

Username: staff
Password: Staff@123

Step 4: Initial Setup

Configure Company Settings

Login as admin
Go to Settings > General
Update:
- Company name and address
- Currency and tax rate
- Date format
- Low stock threshold

Add Warehouses

Go to Warehouses > Add Warehouse
Add your physical warehouse locations
Assign managers to each warehouse

Add Categories

Go to Categories > Add Category
Create product categories (Electronics, Clothing, etc.)

Add Suppliers

Go to Suppliers > Add Supplier
Add your supplier information

Add Products

Go to Products > Add Product
Add initial stock products
Upload product images
Set prices and stock levels

Step 5: Using the System

Admin Functions:

Dashboard Overview

View key metrics
Monitor low stock alerts
Check recent sales
View charts and statistics

Product Management

Add new products
Edit product details
Import products via CSV
Export product list
Generate barcodes

Category Management

Create categories
Set parent categories
Organize product hierarchy

Supplier Management

Add supplier details
Track supplier performance
Manage contact information

Purchase Orders

Create purchase orders
Track order status
Receive stock
Print purchase orders

Sales Management

View all sales
Process returns
Print invoices
Track payment status

Warehouse Management

Manage multiple warehouses
Transfer stock between warehouses
Monitor stock levels per warehouse

Stock Adjustments

Add/remove stock
Record damaged items
Track expired products
Inventory counts

Reports

Stock reports
Sales reports
Purchase reports
Profit/Loss statements
Low stock alerts
Expiry reports

User Management
- Create staff accounts
- Set permissions
- Manage roles
- View activity logs

Manager Functions:

Dashboard Access

View warehouse-specific stats
Monitor team performance
Check stock alerts

Product Management

View products
Update stock
Request purchases

Sales Processing

Create sales
Print invoices
Process returns

Stock Transfers

Request transfers
Receive transfers
Track transfer status

Reports

Generate warehouse reports
View team performance

Staff Functions:

Point of Sale (POS)

Process customer sales
Scan barcodes
Calculate totals
Print receipts

Stock Check

View available stock
Check product locations
Report low stock

Purchase Requests

Create purchase requests
Receive incoming stock

Simple Reports

View current stock
Daily sales summary

Step 6: Daily Operations

Processing a Sale:

Go to Staff > Point of Sale
Scan products or search manually
Add items to cart
Enter customer details
Select payment method
Complete sale
Print receipt/invoice

Receiving Stock:

Go to Purchases > Purchase Orders
Select pending order
Click "Receive Stock"
Verify quantities
Confirm receipt
Stock is automatically updated

Transferring Stock:

Go to Transfers > Create Transfer
Select source and destination warehouses
Add products and quantities
Submit transfer request
Approve and process transfer
Receive at destination

Stock Adjustment:

Go to Adjustments > Create Adjustment
Select warehouse and product
Enter new quantity
Select adjustment type (add/remove/damage)
Add reason
Submit adjustment

Step 7: Reports and Analysis

Daily Sales Report

Go to Reports > Sales Report
Select date range
View sales summary
Export to PDF/Excel

Stock Status Report

Go to Reports > Stock Report
View all products with stock levels
Filter by category/warehouse
Export for inventory count

Low Stock Alert

Automated alerts on dashboard
Email notifications (if configured)
Reorder suggestions

Profit/Loss Report

Compare sales vs purchases
Calculate profit margins
View by period

Step 8: Advanced Features

Barcode Scanning

Generate barcodes for products
Print barcode labels
Scan at POS for quick entry
Mobile scanner support

Batch Tracking

Track by batch numbers
Monitor expiry dates
FIFO/FEFO support

Multiple Warehouses

Separate stock locations
Inter-warehouse transfers
Consolidated reporting

Import/Export

Bulk product import via CSV
Export reports to Excel
Data backup

Step 9: Security Settings

User Roles

Admin: Full access
Manager: Limited admin access
Staff: POS and basic functions

Password Policies

Minimum 8 characters
Mix of letters and numbers
Password expiry (optional)

Session Management

Auto logout after inactivity
Concurrent login prevention
IP tracking

Data Backup

Automated database backups
File system backups
Backup restoration

Step 10: Troubleshooting

Common Issues and Solutions:

Login Failed

Check username/password
Verify user is active
Clear browser cache
Check database connection

Stock Not Updating

Verify transaction completed
Check warehouse selection
Review stock movements
Check for pending transfers

Reports Not Generating

Check date range selection
Verify data exists
Check file permissions
Memory limit issues

Upload Errors

Check file size limits
Verify file types
Check folder permissions
Disk space availability

Step 11: Performance Optimization

Database Optimization

Regular indexing
Query optimization
Archive old data
Regular cleanup

Caching

Enable query caching
Session caching
Page caching for reports

File Management

Compress images
Clean up temp files
Archive old exports

Step 12: Deployment to Production

Server Requirements

PHP 7.4 or higher
MySQL 5.7 or higher
Apache/Nginx
SSL certificate
20GB+ storage

Security Hardening

Change default passwords
Enable HTTPS
Set proper file permissions
Disable error display
Enable firewall
Regular security updates

Backup Strategy

Daily database backups
Weekly full backups
Offsite backup storage
Test restoration process

Monitoring

Server monitoring
Error logging
Performance monitoring
User activity logs

Key Features Summary