🧠 MinDrift – Emotion-Based Chat & AI Diary Web App

ITM519 Term Project – Full-Stack JavaScript RESTful Web Application

TEAM MinDrift

21102033 Kwon Daehoon
21102052 Lee Jeongyun
21102056 Joo Youngjin

📌 Project Overview

MinDrift is an AI-powered web application that enables users to reflect on their day through emotion-centered conversations. Based on this interaction, a personalized diary is automatically generated.
Users engage in expressive dialogue and receive empathic feedback, allowing GPT to summarize their emotional flow and create a diary entry.

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🛠️ Technology Stack

Backend

• Node.js, Express.js
• SQLite3 (file-based RDBMS)
• OpenAI GPT-4o-mini (chat & diary generation)
• JWT authentication (jsonwebtoken)
• Bcrypt: password hashing
• CORS, Helmet: security measures
• node-cron: scheduled message cleanup

Frontend

• React (Next.js framework)
• Tailwind CSS, TypeScript
• Lucide Icons (for archive page)

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🌐 Deployment Info

• Frontend: Vercel
• Backend + DB: Railway
• GitHub: Fully CI/CD integrated via repository connections

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🔐 Security Features

• JWT-based access control
• Password hashing via bcrypt
• Output sanitization (sanitize-html) to prevent XSS
• CORS configuration with credentials
• HTTP security headers via Helmet

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📁 Database Schema

Table	Primary Key	Foreign Key	Fields
users	id	-	user_id, username, password, created_at
messages	id	user_id → users(id)	role, content, created_at
diaries	id	user_id → users(id)	content, summary, created_at

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📮 RESTful API Endpoints

Auth (/auth)

Method	Endpoint	Description
POST	/register	Register a new user
POST	/login	Log in and receive JWT token
GET	/me	Retrieve current user info
PUT	/username	Update username

Chat (/api)

Method	Endpoint	Description
POST	/chat	Send user message, receive GPT reply
GET	/messages	Retrieve all user chat history

Diary (/api/diary)

Method	Endpoint	Description
POST	/diary	Generate diary from user input
POST	/diary/from-history	Generate diary from chat history
GET	/diary/archive?date=YYYY-MM-DD	Get diary and messages for specific date
GET	/diary/dates	Get all dates with diary entries
GET	/diary/id-by-date	Get diary ID for specific date (for deletion)
DELETE	/diary/:id	Delete diary entry by ID

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✨ Core Features

Feature	Description	Status
🧠 Emotion-based GPT chat	Empathic dialogue using GPT-4o-mini	✅
📓 AI diary generation	Diary automatically generated from conversations	✅
📁 Diary archive & management	View, delete, and browse diary entries	✅
🔐 JWT authentication system	User login and protected access	✅
🕓 Daily message reset	Clears chat log at 4:00 AM daily	✅

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🎨 Frontend Summary

• Pages Implemented:
  • Login Page
  • Signup Page
  • Chat Page
  • Archive Page (List + Detail)
  • Username Edit Feature
• Auth State: JWT-based session persisted via localStorage

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📂 Server Directory Structure

server/
├── __tests__/
│   ├── auth.test.js
│   ├── chat.test.js
│   ├── diary.test.js
│   ├── messages.test.js
│   ├── user.test.js
│   └── archive.test.js
├── auth/
│   └── middleware.js
├── db/
│   ├── db.js
│   ├── db.memory.js
│   └── index.js
├── public/
│   └── demo/
│       ├── demo.html
│       └── demo.js
├── routes/
│   ├── auth.js
│   ├── chat.js
│   └── diary.js
├── .env, .env.example, .env.setup.js
├── app.js
├── cron.js
├── jest.config.js
├── users.db

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🧪 Testing

Please execute npm install before testing at server/ and client/

• Jest-based test suite implemented
• Located in __tests__ with route-specific tests
• Ensure .env includes valid OpenAI API key for test success
• Execute npm run test or npm run test:coverage at server/. (Details in server/coverage/lcov-report/index.html)
• GitHub Action is implemented.
• Tech-demo webpage for implementing functions in practice. Please execute npm run dev and access to http://localhost:8080/demo.html.

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🔮 Future Development Ideas

• Emotion trend analytics and visualization
• Multi-language support for UI & GPT
• Export diary to PDF/Markdown
• Token usage optimization for GPT API