Search Engine Project

A full-stack search engine application with an inverted index, TF-IDF, and cosine similarity for efficient text search. The backend is built with TypeScript and Express, using Prisma and PostgreSQL for data storage. The frontend is a React application for user interaction.

Tech Stack

• Backend: TypeScript, Express.js, Node.js, Prisma, PostgreSQL
• Frontend: React.js
• Development Tools: nodemon, ts-node, npm, Visual Studio Code
• Containerization: Docker, Docker Compose

Project Structure

Search/
├── Server/                 # Backend (Express, TypeScript)
│   ├── app.ts              # Main server file
│   ├── prisma/             # Prisma schema and migrations
│   │   └── schema.prisma
│   ├── package.json
│   ├── nodemon.json
│   ├── tsconfig.json
│   └── .env
├── client/                 # Frontend (React)
│   ├── src/
│   │   └── App.js
│   └── package.json
├── docker-compose.yml      # Docker Compose configuration
└── README.md

Prerequisites

• Node.js (v20+)
• Docker Desktop
• PostgreSQL (optional for local dev without Docker)
• Git

Setup Instructions

Clone the Repository

git clone https://github.com/your-username/search-engine.git
cd search-engine

Option 1: Run with Docker (Recommended)

1. Ensure Docker Desktop is running.

2. Start services:

   docker-compose up --build

3. Run Prisma migrations (in a new terminal):

   docker-compose exec backend bash
   npx prisma migrate dev --name init

4. Access the application:

   • Frontend: http://localhost:3000
   • Backend API: http://localhost:5000
   • PostgreSQL: localhost:5432

5. Stop services:

   docker-compose down

Option 2: Run Locally

1. Backend Setup:

   cd Server
   npm install

2. Configure Environment:

   • Create Server/.env:

     DATABASE_URL=postgresql://postgres:your_password@localhost:5432/search_engine_db?schema=public
     

   • Replace your_password with your PostgreSQL password.

3. Set Up PostgreSQL:

   • Create database:

     psql -U postgres -c "CREATE DATABASE search_engine_db;"

4. Run Prisma Migrations:

   npx prisma migrate dev --name init

5. Start Backend:

   npm run dev

6. Frontend Setup:

   cd ../client
   npm install
   npm start

7. Access the application:

   • Frontend: http://localhost:3000
   • Backend API: http://localhost:5000

Usage

1. Add a Document:

   • Send a POST request to http://localhost:5000/api/documents:

     {
       "content": "Python is a versatile, high-level programming language..."
     }

2. Search Documents:

   • Use the frontend at http://localhost:3000 or send a GET request to http://localhost:5000/api/search?query=python.

3. Sample Database Dump:

   • To simulate data, apply the SQL dump (search_engine_db_dump.sql):

     docker-compose exec db psql -U postgres -d search_engine_db -f /app/search_engine_db_dump.sql

     Or locally:

     psql -U postgres -d search_engine_db -f Server/search_engine_db_dump.sql

API Endpoints

• POST /api/documents: Add a document (body: { "content": "text" })
• GET /api/search?query=: Search documents by query term

Troubleshooting

• Empty search results: Ensure computeTfIdf in app.ts handles df=0 cases (see Server/app.ts).
• Prisma errors: Run npx prisma generate and npx prisma migrate dev.
• Docker issues: Verify Docker Desktop is running and ports 3000, 5000, 5432 are free.

Contributing

1. Fork the repository.
2. Create a feature branch (git checkout -b feature/YourFeature).
3. Commit changes (git commit -m "Add YourFeature").
4. Push to the branch (git push origin feature/YourFeature).
5. Open a Pull Request.

License

MIT License