# Janus

> A blazingly fast live-reloader for Go applications with a built-in, crash-proof safety net and an interactive TUI dashboard.

Janus watches your Go project for file changes, automatically rebuilds your application, and intelligently handles runtime crashes. If a new version crashes on startup, Janus instantly reverts to the last stable version, ensuring your development flow is never interrupted.

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## ✨ Core Features

- **Crash-Proof Safety Net**: Automatically reverts to the last stable version if a reload causes a runtime crash.
- **Interactive TUI Dashboard**: See your app's status, view its logs, and monitor Janus events in a clean, full-screen terminal interface.
- **Blazing Fast**: Built in Go for maximum performance.
- **Robust Process Management**: Reliably stops your application and any child processes it may have started, preventing "address already in use" errors.
- **Intelligent Reloading**: Uses debouncing to prevent a storm of rebuilds when saving multiple files.
- **Simple Configuration**: Configure everything in a single, clear `.janus.toml` file.

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## 🚀 Installation

Make sure you have Go installed (version 1.18+ recommended). Then, run:

```bash
go install github.com/pitko/Janus/cmd/janus@latest

This will compile and install the janus binary in your Go bin directory.

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Getting Started

Navigate to your Go project's root directory:

cd /path/to/your/project

Create a default configuration file:

janus init

This will create a .janus.toml file in your directory.

Run Janus!

janus

That's it! Janus will now display its TUI, watch your files, and keep your application running safely.

Keyboard Shortcuts

• Arrow Keys (↑/↓): Scroll the active panel.
• Tab: Switch between the Application and Aegis log panels.
• q or Ctrl+C: Quit Janus.

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⚙ Configuration

The janus init command creates this default .janus.toml file. Customize it to fit your project's needs.

# .janus.toml

# Command to build your Go application.
[build]
  # This command is run from the `watch.root` directory.
  cmd = "go build -o ./tmp/app ./main.go"

  # The path to the binary that the command above creates.
  # This path is relative to the `watch.root` directory.
  bin = "./tmp/app"

# Settings for watching files.
[watch]
  # The application directory you want to watch.
  root = "."

  # Directories to ignore.
  exclude_dir = ["tmp", "vendor", ".git"]

# The crash-proof safety net configuration.
[safety_net]
  # How long to wait in milliseconds to see if the new app crashes.
  # If the app runs for this long, it's considered "stable".
  probation_ms = 2500

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🛡️ How The Safety Net Works

1. Detect: Janus detects a file change in your project.

2. Build: It runs your build command to create a new challenger binary.

3. Probation: It stops the old stable app and starts the new challenger with a short probation timer (e.g., 2.5 seconds).

4. Analyze:

   • Success: If the challenger survives the probation period, it's promoted to the new stable version.
   • Failure: If the challenger crashes during probation, Janus logs the error, discards the failed binary, and immediately restarts the old stable version.

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License

This project is licensed under the MIT License.

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✅ You can now copy and paste this entire block directly into a `README.md` file in your project root.

Would you like me to add:
- Contribution guidelines?
- Build status or Go Report Card badges?
- A GIF of the TUI in action?

Just let me know!