🤖 AI-Powered Code Review Assistant

This is a dual-mode, AI-powered assistant that uses a locally hosted Large Language Model (Ollama) to analyze code.
It functions as both:

• an automated GitHub Bot that reviews pull requests, and
• a local Web App for reviewing, refactoring, and explaining code snippets.

All AI interactions are enhanced with real-time web search to provide up-to-date, high-quality feedback.

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✨ Features

1. GitHub Bot (Automated PR Review)

• Automatic Reviews – Triggers on pull_request events (when a PR is opened or a new commit is pushed).
• Strict Analysis – Acts like a senior principal engineer, checking for logic, security, performance, and style issues.
• Web-Enhanced Context – Uses Google Search (via Serper API) for up-to-date insights about code.
• Structured Output – Posts per-file breakdowns, a Code Health Score, a key takeaway, and line-by-line comments.

2. Local Web App (Development Tool)

A full-featured local dashboard with multiple modes:

Mode	Description
Review/Refactor Snippet	Get a full, strict review of any code snippet.
Security Audit	Detect potential security vulnerabilities.
Performance Check	Identify performance bottlenecks.
Code Refactor	View a side-by-side diff of your code vs. an AI-improved version.
Review PR	Paste a PR URL for a full review identical to the bot's.
Explain Code	Get a step-by-step explanation of any snippet.
History	View all past reviews, refactors, and explanations saved in your browser.

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🧠 Core AI Features

• Local LLM Integration – Uses Ollama (qwen2:0.5b) locally, ensuring privacy of your code.
• Web-Enhanced AI – Real-time search results improve accuracy and modern relevance.
• Interactive Chat – A “💬 Discuss” button lets you ask follow-up questions in a chatbot.
• Structured Analysis Output includes:
  • Overall Feedback Summary
  • Code Health Score (e.g., A+, B-, etc.)
  • Line-by-line comments with severity (Error, Warning, Info)
  • Suggested Fixes
  • Effort Estimation

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🧩 Technology Stack

Backend

• Node.js / Express – Core API and webhook handler
• Ollama SDK – Communication with the local LLM
• @octokit/app – GitHub App authentication (for the bot)
• octokit – Personal Access Token auth (for web app)
• gitdiff-parser – Parses git diff output from PRs

Frontend

• React – Interactive UI
• @git-diff-view/react – Displays code diffs
• react-diff-viewer-continued – Side-by-side refactor comparisons
• react-markdown – Renders AI feedback

Services

• Smee.io – Public webhook tunnel for local development
• Serper.dev – Real-time web search API

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🚀 Getting Started

Prerequisites

• Node.js v18+
• Git
• Ollama installed and running
• The qwen2:0.5b model pulled:

  ollama pull qwen2:0.5b

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⚙️ Installation

1. Clone the repository

   git clone https://github.com/YourUsername/Your-Repo-Name.git
   cd Your-Repo-Name

2. Install Backend Dependencies

   cd backend
   npm install

3. Install Frontend Dependencies

   cd ../frontend
   npm install

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🔐 Configuration (.env Setup)

You need 4 sets of keys.

1. GitHub App (for the Bot)

1. Go to GitHub Settings → Developer settings → GitHub Apps → New GitHub App
2. Name it, e.g. My-Review-Bot
3. Set:
   • Homepage URL: https://github.com
   • Webhook URL: temporary from https://smee.io
4. Save the app and get your App ID and Private Key (.pem).

2. Smee.io

• Go to https://smee.io → “Start a new channel” → Copy your unique URL.

3. Personal Access Token (for the Web App)

• Go to GitHub → Developer settings → Personal Access Tokens → Generate new token (classic).
• Scope: repo access.

4. Serper API Key (for Web Search)

• Get it from https://serper.dev.

Example .env:

GITHUB_APP_ID=123456
GITHUB_WEBHOOK_SECRET=YourWebhookSecret
GITHUB_PRIVATE_KEY_PATH=your-app-private-key.pem
SERPER_API_KEY=yourSerperApiKeyGoesHere
GITHUB_PAT=ghp_YourPersonalAccessTokenGoesHere

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🧰 Running the Application (3 Terminals)

Terminal 1 – Backend

cd backend
npm start

Output: Backend server running at http://127.0.0.1:3001

Terminal 2 – Frontend

cd frontend
npm run dev

Opens: http://localhost:5180

Terminal 3 – Smee Bridge

npx smee-client --url https://smee.io/Your-Unique-ID --path /api/github-event --port 3001

Output: Forwarding ... to http://127.0.0.1:3001/api/github-event

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🧪 Usage

Local Web App

• Visit http://localhost:5180
• Use Review PR, Explain Code, or Review/Refactor options

GitHub Bot

1. Install your app on a repo.
2. Create a branch, push a change, and open a PR.
3. The bot will post a "checking..." comment followed by a full review.