Requirements

Let's design a simplified car rental system, similar to Zoomcar. The core idea is to allow users to rent cars from a fleet. We need to manage the cars, their availability, users, reservations, and pricing. This problem requires careful consideration of object-oriented principles to ensure the system is flexible, maintainable, and scalable (within a single machine/process context). The simulation should focus on in-memory operations, avoiding external database interactions (although the design should accommodate persistence later). We need to model the core business logic accurately and efficiently. Consider different car models, pricing strategies (hourly, daily), and reservation management (creation, cancellation, modification). The system needs to handle concurrent requests from multiple users. # Requirements ## Functional Requirements 1. **User Management:** * Register new users with necessary details (name, contact information, driver's license). * Authenticate users (login). * Update user profile information. 2. **Car Management:** * Add new cars to the fleet with details (model, make, year, license plate, location, availability status). * Remove cars from the fleet. * Update car information (location, availability, maintenance status). * Search for available cars based on criteria (location, car type, dates). * Implement a strategy for car maintenance scheduling and tracking. 3. **Reservation Management:** * Create reservations for a specific car for a specified duration (start date/time, end date/time). * Calculate the rental cost based on the car type, rental duration, and pricing strategy. * Cancel reservations. * Modify reservations (e.g., change rental duration, change car). * Track reservation history for each user. * Prevent overlapping reservations for the same car. * Implement functionality to handle car returns, including recording mileage and checking for damage. 4. **Pricing:** * Define different pricing strategies (e.g., hourly, daily, weekly). * Implement dynamic pricing based on demand (e.g., surge pricing). * Apply discounts and promotions. 5. **Location Management:** * Associate cars with specific locations. * Enable searching for cars within a certain radius of a location. 6. **Concurrency:** * Ensure that multiple users can concurrently search for cars, create reservations, and perform other operations without data corruption or race conditions. ## Non-Functional Requirements 1. **Thread Safety:** The system must be thread-safe to handle concurrent requests from multiple users. Pay close attention to data structures and shared resources to prevent race conditions and ensure data consistency. 2. **Extensibility:** The system should be designed to easily accommodate new features and changes in requirements. Consider using design patterns to promote loose coupling and modularity. Examples include: * Adding new car types (e.g., electric vehicles, luxury cars) * Adding new pricing strategies (e.g., mileage-based pricing) * Integrating with external services (e.g., payment gateways, mapping services) 3. **Modularity:** The system should be divided into well-defined modules with clear responsibilities. This will make the code easier to understand, maintain, and test. Consider how to group related functionalities into separate classes and interfaces. 4. **Testability:** The code should be written in a way that makes it easy to test. Use dependency injection to decouple components and make them easier to mock. 5. **Maintainability:** The code should be well-documented and easy to understand. Follow coding conventions and use meaningful names for variables and methods. 6. **SOLID Principles:** Apply SOLID principles throughout the design to ensure the code is robust, flexible, and maintainable. Specific examples: * **Single Responsibility Principle:** Each class should have a single, well-defined responsibility. * **Open/Closed Principle:** The system should be open for extension but closed for modification. * **Liskov Substitution Principle:** Subtypes should be substitutable for their base types without altering the correctness of the program. * **Interface Segregation Principle:** Clients should not be forced to depend on methods they do not use. * **Dependency Inversion Principle:** High-level modules should not depend on low-level modules. Both should depend on abstractions. ## Core Entities 1. **User:** Represents a user of the car rental system. Attributes include user ID, name, contact information, driver's license details, and potentially a list of past reservations. 2. **Car:** Represents a car in the fleet. Attributes include car ID, model, make, year, license plate, location, availability status, mileage, and maintenance history. 3. **CarType:** An enum or class representing the type of car (e.g., Sedan, SUV, Hatchback, Electric). This allows for different pricing or features based on car type. 4. **Location:** Represents a geographical location where cars are available. Attributes include location ID, address, latitude, and longitude. 5. **Reservation:** Represents a car reservation. Attributes include reservation ID, user ID, car ID, start date/time, end date/time, rental cost, and status (e.g., confirmed, cancelled, completed). 6. **PricingStrategy:** An interface or abstract class representing different pricing strategies (e.g., hourly, daily, weekly). Concrete implementations would calculate the rental cost based on the chosen strategy. 7. **Payment:** Represents a payment made for a reservation. Attributes include payment ID, reservation ID, amount, payment date, and payment method. 8. **LockingStrategy:** An interface that abstracts the locking mechanism used to prevent concurrent access to shared resources like car availability. This allows for different locking implementations (e.g., optimistic locking, pessimistic locking).

Design Car Rental System like Zoomcar.

Requirements

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Functional Requirements

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Non-Functional Requirements

Core Entity Identification

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