Define REST as an architectural style.

Explain the six architectural constraints of REST (Client-Server, Stateless, Cacheable, Uniform Interface, Layered System, Code-On-Demand). Elaborate briefly on what each constraint means and why it's important for RESTful design. Mention that Code-On-Demand is optional.

Explain the proper use cases for the following HTTP verbs in a RESTful context: GET, POST, PUT, PATCH, and DELETE. For each verb, discuss its idempotency and safety characteristics.

Explain the concept of resource-based URLs. Contrast this with verb-based URLs, providing clear examples of both good (resource-based) and bad (verb-based) practices for common operations (e.g., fetching a list, retrieving a single item, creating, updating, deleting).

Briefly explain the different categories of HTTP status codes (1xx, 2xx, 3xx, 4xx, 5xx).

For the following scenario, identify the most appropriate HTTP status code(s): Successful retrieval of a resource.

For the following scenario, identify the most appropriate HTTP status code(s): Successful creation of a new resource.

For the following scenario, identify the most appropriate HTTP status code(s): Successful update (full replacement) of a resource.

For the following scenario, identify the most appropriate HTTP status code(s): Successful partial update of a resource.

For the following scenario, identify the most appropriate HTTP status code(s): Successful deletion of a resource (with no content to return).

For the following scenario, identify the most appropriate HTTP status code(s): Request missing required parameters or having invalid data.

For the following scenario, identify the most appropriate HTTP status code(s): Client is not authenticated.

For the following scenario, identify the most appropriate HTTP status code(s): Client is authenticated but lacks necessary permissions.

For the following scenario, identify the most appropriate HTTP status code(s): Resource not found.

For the following scenario, identify the most appropriate HTTP status code(s): Conflict due to current state of a resource (e.g., optimistic locking).

For the following scenario, identify the most appropriate HTTP status code(s): An unexpected error occurred on the server.

Scenario 1: Request to create a new post. Flawed Design: POST /posts/createPost

1. Identify Violations: State which REST principle(s) are violated.
2. Explain Why: Briefly explain why the current design is problematic.
3. Propose Refactoring: Provide the corrected HTTP Method and URL path, adhering to RESTful principles.
4. Suggest Status Codes: Suggest appropriate HTTP status codes for a successful response and one common failure scenario for your refactored endpoint.

Scenario 2: Request to delete a specific post. Flawed Design: GET /posts/deletePost?id=123

1. Identify Violations: State which REST principle(s) are violated.
2. Explain Why: Briefly explain why the current design is problematic.
3. Propose Refactoring: Provide the corrected HTTP Method and URL path, adhering to RESTful principles.
4. Suggest Status Codes: Suggest appropriate HTTP status codes for a successful response and one common failure scenario for your refactored endpoint.

Scenario 3: Request to update a user's profile information (full replacement). Flawed Design: POST /users/updateUser/456 (with user data in request body)

1. Identify Violations: State which REST principle(s) are violated.
2. Explain Why: Briefly explain why the current design is problematic.
3. Propose Refactoring: Provide the corrected HTTP Method and URL path, adhering to RESTful principles.
4. Suggest Status Codes: Suggest appropriate HTTP status codes for a successful response and one common failure scenario for your refactored endpoint.

Scenario 4: Request to retrieve a list of all products. Flawed Design: GET /products/getAllProducts

1. Identify Violations: State which REST principle(s) are violated.
2. Explain Why: Briefly explain why the current design is problematic.
3. Propose Refactoring: Provide the corrected HTTP Method and URL path, adhering to RESTful principles.
4. Suggest Status Codes: Suggest appropriate HTTP status codes for a successful response and one common failure scenario for your refactored endpoint.

Scenario 5: Request to change the status of an order (e.g., from 'pending' to 'shipped'). Flawed Design: PUT /orders/changeOrderStatus/789 (with new status in request body)

1. Identify Violations: State which REST principle(s) are violated.
2. Explain Why: Briefly explain why the current design is problematic.
3. Propose Refactoring: Provide the corrected HTTP Method and URL path, adhering to RESTful principles.
4. Suggest Status Codes: Suggest appropriate HTTP status codes for a successful response and one common failure scenario for your refactored endpoint.