This project is a backend system for a dating mobile app similar to Tinder/Bumble. The system includes functionalities such as sign-up, login, profile swiping, premium package purchases, and package management. This backend is built using Golang and includes a RESTful API service for these functionalities.

• Golang 1.22.x
• PostgreSQL
• Git

• Golang: The primary programming language used for the backend.
• PostgreSQL: Database to store user information, swipes, purchases, etc.
• Gorilla Sessions: For handling user sessions.
• Swaggo: For generating API documentation.
• bcrypt: For hashing OTPs.
• httpSwagger: For serving the Swagger UI.

This guide helps you set up the necessary environment to run the project locally.

Follow these steps to set up the PostgreSQL database:

• Install PostgreSQL:

  • Linux:

    sudo apt install postgresql postgresql-contrib

  • Mac (using Homebrew):

    brew install postgresql

  • Windows:

  • Download PostgreSQL: Download PostgreSQL version 16.2 from EnterpriseDB.

  • Installation Process:

    • Uncheck "Stack Builder" when prompted to select components to save time.
    • Use port 5432 when prompted for port selection.
    • Set the temporary password for the superuser as "123123123" when prompted.

• Start PostgreSQL service:

  • Linux and Mac:

    sudo systemctl start postgresql.service

  • Windows: Start PostgreSQL service from the Services panel.

• Create a PostgreSQL role and database:

  • Linux and Mac: To create a PostgreSQL role and database on Linux and Mac, execute the following commands in your terminal:

    sudo -u postgres psql -c "CREATE ROLE root WITH SUPERUSER CREATEDB CREATEROLE PASSWORD '123123123';”
    sudo -u postgres createdb -O root dating_app

  • Windows: After PostgreSQL installation:

    • Create a user/role named "root" with the password "123123123".
    • Create a database (not a schema) named "dating_app".

    For detailed instructions, you can refer to this guide: How to Create PostgreSQL Database and Users using psql and pgAdmin.

Create tables using the provided SQL script

CREATE  TABLE users (
  id SERIAL  PRIMARY  KEY,
  phone_number VARCHAR(15) UNIQUE NOT  NULL,
  is_premium BOOLEAN DEFAULT FALSE,
  verified BOOLEAN DEFAULT FALSE,
  is_deleted BOOLEAN DEFAULT FALSE,
  signup_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  login_at TIMESTAMP,
  logout_at TIMESTAMP,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE  TABLE profiles (
  id SERIAL  PRIMARY  KEY,
  user_id  INT  REFERENCES users(id),
  name  VARCHAR(50),
  age INT,
  bio TEXT,
  photo_url TEXT,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE  TABLE otp_auth (
  id SERIAL  PRIMARY  KEY,
  user_id  INT  REFERENCES users(id),
  otp_hash VARCHAR(60) NOT  NULL,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE  TABLE swipes (
  id SERIAL  PRIMARY  KEY,
  swiper_id INT  REFERENCES users(id),
  profile_id INT  REFERENCES users(id),
  swipe_type VARCHAR(10),
  swipe_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE  TABLE purchases (
  id SERIAL  PRIMARY  KEY,
  user_id  INT  REFERENCES users(id),
  purchase_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

CREATE  TABLE preferences (
  id SERIAL  PRIMARY  KEY,
  user_id  INT  REFERENCES users(id),
  date_mode BOOLEAN DEFAULT FALSE,
  bff_mode BOOLEAN DEFAULT FALSE,
  preferred_gender VARCHAR(10),
  min_age INT,
  max_age INT,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);


CREATE  TABLE packages (
  id SERIAL  PRIMARY  KEY,
  name  VARCHAR(50) NOT  NULL,
  feature TEXT  NOT  NULL,
  price FLOAT  NOT  NULL,
  currency VARCHAR(10) NOT  NULL,
  is_deleted BOOLEAN DEFAULT FALSE,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

• users: Stores user information and is the primary entity for user-related operations.
• profiles: Stores user profile details such as name, age, bio, and photo URL.
• otp_auth: Stores OTP hashes for user authentication.
• swipes: Records swipes made by users (left or right).
• purchases: Records purchases of premium memberships.
• preferences: Stores user preferences for matching (e.g., preferred gender, age range).
• packages: Stores information about available premium packages.

git  clone  [email protected]:andregit1/dating_app.git
cd  dating_app

go get -u github.com/gorilla/sessions
go get -u github.com/lib/pq
go get -u github.com/swaggo/http-swagger
go get -u golang.org/x/crypto/bcrypt

swag init
go mod tidy

go run main.go

Access the API documentation at http:https://localhost:8080/swagger/index.html.

• Public Endpoints

  • POST /signup: Register a new user.

  • POST /login: Login and get OTP.

  • POST /verify-otp: Verify OTP and create a session.

• Authenticated Endpoints

  • POST /swipe: Swipe left or right on a profile.

  • POST /purchase: Purchase premium membership.

  • GET /cards: Retrieve users based on preferences.

  • Package Management Endpoints

    • POST /packages/create: Create a new package.

    • GET /packages: Retrieve all packages.

    • PUT /packages/edit/{id}: Update an existing package.

    • PATCH /packages/delete/{id}: Soft delete a package.

Unit tests can be added in the *_test.go files and executed using:

go  test  ./...

This sequence diagram demonstrates the interaction between the components for the login flow:

sequenceDiagram

participant User

participant Backend

participant DB


User ->> Backend: POST /signup

Backend ->> DB: Insert user

DB ->> Backend: Return user ID

Backend ->> User: Send OTP


User ->> Backend: POST /login

Backend ->> DB: Validate phone number

Backend ->> DB: Generate OTP and save OTP hash

Backend ->> User: Send OTP


User ->> Backend: POST /verify-otp

Backend ->> DB: Verify OTP hash

Backend ->> User: OTP verified, create session

This sequence diagram for complete user interaction:

sequenceDiagram
    participant User
    participant Router
    participant AuthRouter
    participant PackageRouter
    participant Handler
    participant Database

    User ->> Router: POST /signup
    Router ->> Handler: handler.Signup(db)
    Handler ->> Database: Database Operation (Insert User)
    Database -->> Handler: Success/Failure
    Handler -->> Router: Response

    User ->> Router: POST /login
    Router ->> Handler: handler.Login(db)
    Handler ->> Database: Database Operation (Validate Phone Number, Generate OTP)
    Database -->> Handler: OTP Hash
    Handler -->> Router: OTP Sent Response

    User ->> Router: POST /verify-otp
    Router ->> Handler: handler.VerifyOTP(db)
    Handler ->> Database: Database Operation (Verify OTP)
    Database -->> Handler: OTP Verification Result
    Handler -->> Router: OTP Verification Response

    User ->> AuthRouter: POST /swipe
    AuthRouter ->> Handler: handler.Swipe(db)
    Handler ->> Database: Database Operation (Record Swipe)
    Database -->> Handler: Success/Failure
    Handler -->> AuthRouter: Response

    User ->> AuthRouter: POST /purchase
    AuthRouter ->> Handler: handler.Purchase(db)
    Handler ->> Database: Database Operation (Record Purchase)
    Database -->> Handler: Success/Failure
    Handler -->> AuthRouter: Response

    User ->> AuthRouter: GET /cards
    AuthRouter ->> Handler: handler.Card(db)
    Handler ->> Database: Database Operation (Retrieve User Cards)
    Database -->> Handler: User Cards
    Handler -->> AuthRouter: Response

    User ->> AuthRouter: POST /preferences
    AuthRouter ->> Handler: handler.SetPreferences(db)
    Handler ->> Database: Database Operation (Set User Preferences)
    Database -->> Handler: Success/Failure
    Handler -->> AuthRouter: Response

    User ->> AuthRouter: GET /preferences
    AuthRouter ->> Handler: handler.GetPreferences(db)
    Handler ->> Database: Database Operation (Retrieve User Preferences)
    Database -->> Handler: User Preferences
    Handler -->> AuthRouter: Response

    User ->> PackageRouter: POST /packages/create
    PackageRouter ->> Handler: handler.CreatePackage(db)
    Handler ->> Database: Database Operation (Create Package)
    Database -->> Handler: Success/Failure
    Handler -->> PackageRouter: Response

    User ->> PackageRouter: GET /packages
    PackageRouter ->> Handler: handler.GetPackage(db)
    Handler ->> Database: Database Operation (Retrieve Packages)
    Database -->> Handler: Packages
    Handler -->> PackageRouter: Response

    User ->> PackageRouter: PUT /packages/edit/{id}
    PackageRouter ->> Handler: handler.UpdatePackage(db)
    Handler ->> Database: Database Operation (Update Package)
    Database -->> Handler: Success/Failure
    Handler -->> PackageRouter: Response

    User ->> PackageRouter: PATCH /packages/delete/{id}
    PackageRouter ->> Handler: handler.DeletePackage(db)
    Handler ->> Database: Database Operation (Soft Delete Package)
    Database -->> Handler: Success/Failure
    Handler -->> PackageRouter: Response

• User can sign up using their phone number.

• User can login using their phone number and OTP.

• User can only view and swipe 10 profiles per day.

• Premium users have no swipe quota and can have a verified label.

• Users cannot see the same profile more than once in a day.

• Scalability: The system should handle a large number of users and swipes.

• Security: OTPs should be securely hashed, and user sessions should be managed securely.

• Performance: The system should respond quickly to user actions.

• Signup Tests: Verify that a new user can sign up with a valid phone number.

• Login Tests: Verify that a user can login and receive an OTP.

• OTP Verification Tests: Verify that OTP verification works correctly.

• Swipe Tests: Ensure that users cannot exceed their daily swipe limit and cannot swipe the same profile twice - in a day.

• Purchase Tests: Verify that purchasing premium membership updates the user status correctly.

• Package Tests: Verify that CRUD operations on packages work correctly.

Description: Introduce real-time chat functionality allowing users to communicate with their matches. This feature enhances user engagement and interaction within the app.

Tech Stack:

• WebSocket Protocol: For real-time bidirectional communication between clients and the server.
• Redis: To manage WebSocket connections and facilitate pub/sub messaging for chat updates.
• Message Broker (e.g., RabbitMQ or Kafka): For handling message queuing and ensuring reliable message delivery.

Description: Implement a more sophisticated matching algorithm based on user preferences, behavior analysis, and machine learning techniques. This algorithm can provide more accurate and relevant match suggestions to users, improving the overall user experience.

Tech Stack:

• Machine Learning Frameworks (e.g., TensorFlow, PyTorch): For training and deploying machine learning models to predict user preferences and compatibility.
• Apache Spark: For processing large datasets and performing complex data analytics to derive insights for matchmaking.
• Redis or Memcached: To cache user profiles and preferences for faster retrieval and matching.

Description: Enhance the matching algorithm to consider user location and proximity when suggesting matches. This feature enables users to discover potential matches nearby, facilitating real-world connections and meetups.

Tech Stack:

• Geospatial Databases (e.g., PostGIS): For storing and querying location-based data such as user coordinates and geographical regions.
• GPS or Geolocation APIs: To retrieve and update user locations in real-time.
• Spatial Indexing Techniques (e.g., R-tree): For efficient spatial queries and proximity-based matchmaking.

Description: Integrate social media platforms (e.g., Facebook, Instagram) into the app to allow users to import photos, interests, and social connections from their existing profiles. This integration enriches user profiles, improves match accuracy, and enhances user engagement.

Tech Stack:

• OAuth 2.0: For authenticating users and obtaining access tokens to interact with social media APIs.
• Social Media APIs: To fetch user data (e.g., profile information, photos) from platforms like Facebook, Instagram, and Twitter.
• Data Scraping and Crawling Tools (e.g., Scrapy): For collecting and aggregating public social media data to enhance user profiles and preferences.