Octagram (Instagram Clone) API

Introduction

Octagram is a social media platform inspired by Instagram, built using ASP.NET Core 8 Web API. This documentation provides a detailed overview of the project's architecture, API endpoints, data models, and implementation details.

Project Structure

The project is structured in a classic layered architecture:

• Octagram.API: Contains the ASP.NET Core Web API project, responsible for handling HTTP requests and responses.
• Octagram.Application: Holds the application logic, including services, interfaces, and DTOs.
• Octagram.Domain: Defines the core business entities and domain logic.
• Octagram.Infrastructure: Implements data access, repositories, and other infrastructure concerns.

Data Model

The following entities make up the core data model of Octagram:

• User: Represents a user of the platform. Includes attributes like Username, Email, PasswordHash, Bio, and ProfileImageUrl.
• Post: A post created by a user, containing an ImageUrl, Caption, and related Likes, Comments, and Hashtags.
• Like: Represents a user liking a post.
• Comment: A comment on a post, created by a user.
• Follow: Tracks follower/following relationships between users.
• Story: A time-limited visual content shared by users.
• Hashtag: Used to categorize posts, allowing for searching and discovery.
• PostHashtag: Links posts and hashtags in a many-to-many relationship.
• DirectMessage: Represents a private message between two users.
• Notification: Stores notifications for users, such as likes, comments, follows, or messages.

API Endpoints

The API endpoints are grouped by functionality:

1. Authentication

• POST /api/authentication/register: Registers a new user.
• POST /api/authentication/login: Authenticates a user and returns a JWT token.
• POST /api/authentication/refresh: Refreshes a user's expired JWT token.

2. Users

• GET /api/users/{userId}: Retrieves a user profile by ID.
• GET /api/users/username/{username}: Retrieves a user profile by username.
• PUT /api/users/: Updates current user's profile information.
• GET /api/users/search/{query}: Searches for users based on a query string.
• POST /api/users/follow/{followingId}: Follows another user.
• DELETE /api/users/follow/{followingId}: Unfollows another user.
• GET /api/users/{userId}/followers: Retrieves a list of a user's followers.
• GET /api/users/{userId}/following: Retrieves a list of users a user is following.

3. Posts

• GET /api/posts: Retrieves all posts, with optional pagination and hashtag filtering.
• GET /api/posts/feed: Gets posts from followed users for the current user, with optional pagination.
• GET /api/posts/{postId}: Retrieves a specific post by ID.
• GET /api/posts/user/{userId}: Retrieves posts by a specific user.
• POST /api/posts: Creates a new post.
• PUT /api/posts/{postId}: Updates a post's caption.
• DELETE /api/posts/{postId}: Deletes a post.
• POST /api/posts/{postId}/like: Likes a post.
• DELETE /api/posts/{postId}/like: Unlikes a post.
• POST /api/posts/{postId}/comments: Adds a comment to a post.
• DELETE /api/posts/{postId}/comments/{commentId}: Deletes a comment.

4. Stories

• GET /api/stories/user/{userId}: Retrieves stories for a specific user.
• GET /api/stories/following: Retrieves stories from followed users.
• POST /api/stories: Creates a new story (image or video).
• DELETE /api/stories/{storyId}: Deletes a story.

5. Search

• GET /api/search/users/{query}: Searches for users.
• GET /api/search/posts/{query}: Searches for posts.
• GET /api/search/hashtags/{query}: Searches for hashtags.

6. Direct Messages

• GET /api/directmessage/{targetUserId}: Retrieves conversation between current user and target user, with pagination.
• POST /api/directmessage: Sends a direct message (for testing, see DirectMessagesHub for real-time functionality).
• PATCH /api/directmessage/{messageId}/read: Marks a message as read.

7. Notifications

• GET /api/notifications: Retrieves notifications for the authenticated user, with pagination.
• PATCH /api/notifications/{notificationId}/read: Marks a notification as read.

8. SignalR Hubs

• DirectMessageHub: Handles real-time direct message communication between users.
• NotificationHub: Provides real-time notification updates to clients.

Key Technologies and Concepts

• ASP.NET Core 8 Web API: Framework for building RESTful APIs.
• Entity Framework Core: ORM for database interaction.
• AutoMapper: Object-object mapping library used for DTO mapping.
• JWT (JSON Web Tokens): Authentication and authorization mechanism.
• SignalR: Real-time communication framework for instant updates.
• Cloud Storage: Azure Blob Storage is used for storing media files (images, videos).

Authentication and Authorization

• Authentication is handled using JWT tokens.
• The AuthorizeMiddlewareAttribute custom attribute is used to enforce role-based authorization on specific endpoints.

Image Processing and Storage

• The IImageHelper interface and ImageHelper class handle image resizing and optimization.
• The ICloudStorageHelper interface and CloudStorageHelper class manage file uploads to Azure Blob Storage.

Real-time Communication

• The DirectMessageHub and NotificationHub SignalR hubs facilitate real-time communication for messages and notifications, respectively.

Data Seeding

• The DataSeeder class is responsible for seeding the database with sample data for testing purposes.

Further Development

• Implement video upload and processing for stories.
• Add additional social features (e.g., sharing, reposting).
• Improve error handling and logging.

License

This project is licensed under the MIT License.