ACDown Client

A powerful command-line download client for ACDown Server with chunked, authenticated downloads.

Features

• 🔐 Secure Authentication: TOTP-based authentication with token caching
• ⚡ Concurrent Downloads: Download file chunks in parallel for maximum speed
• 📊 Beautiful Progress: Rich progress bars with speed and ETA tracking
  • Multi-line progress display for concurrent downloads (optional)
  • Individual thread progress bars showing real-time download status
• 🔄 Auto Retry: Automatic retry with exponential backoff on failures
• 💾 Smart Storage: Binary format storage for better security
• ⚙️ Configurable: Flexible configuration for server URL, concurrency, and more
• 🎯 Streaming: Memory-efficient streaming downloads

Installation

Prerequisites

• Python 3.13 or higher
• uv package manager (recommended)

Setup

# Clone the repository
git clone <repository-url>
cd acdown-client

# Create virtual environment and install dependencies
uv sync

# Activate virtual environment (optional, uv run handles this)
source .venv/bin/activate  # On Linux/macOS

Quick Start

1. Configure Server URL (Required)

# Set your ACDown server URL (required before first use)
acdown config set server_url http://your-server:3000

Note: The server URL must be configured before using any other commands. The application will prompt you if it's not set.

2. Authenticate

# Get a TOTP code from your authenticator app
acdown auth 123456

3. Download Files

# Simple download
acdown https://example.com/file.zip

# Download with custom output path
acdown https://example.com/file.zip -o ./downloads/myfile.zip

# Download with custom concurrency
acdown https://example.com/large-file.iso -c 5

# Verbose mode
acdown https://example.com/file.zip -v

Commands Reference

Download Files

acdown <url> [OPTIONS]

Arguments:

• URL: The URL to download (required)

Options:

• -o, --output PATH: Output file path (default: extract from URL)
• -c, --concurrent INT: Number of concurrent downloads (default: 3)
• -v, --verbose: Enable verbose logging
• -ip, --individual-progress: Show individual progress bars for each download thread
• --help: Show help message

Examples:

# Basic download
acdown https://github.com/example/app/releases/download/v1.0/app.zip

# Custom output location
acdown https://example.com/file.iso -o ~/Downloads/file.iso

# High concurrency for fast connection
acdown https://example.com/huge-file.zip -c 10

# Show individual progress bars for each concurrent thread
acdown https://example.com/large-file.zip -c 5 --individual-progress

# Debug mode
acdown https://example.com/file.zip -v

Authentication

acdown auth <totp-code>

Authenticate with the ACDown server using a 6-digit TOTP code.

Example:

acdown auth 654321

Output:

╭─────────────────────────────────────╮
│         Authentication              │
├─────────────────────────────────────┤
│ ✓ Authentication successful         │
│                                     │
│ Server URL: http://localhost:3000   │
│ Token saved to: data.bin            │
│ Expires: 2024-01-02 15:30:00        │
╰─────────────────────────────────────╯

Configuration Management

acdown config <action> [key] [value]

Manage server configuration settings.

Actions:

• set <key> <value>: Set a configuration value
• get [key]: Get configuration value(s)

Configuration Keys:

• server_url: ACDown server base URL (required, no default)
• parallel: Number of concurrent downloads (default: 3)
• verbose: Enable verbose logging (default: false)
• output: Default output directory (default: .)

Examples:

# Set ACDown server URL
acdown config set server_url http://myserver.com:3000

# Set concurrent downloads
acdown config set parallel 5

# Enable verbose mode
acdown config set verbose true

# Set default output directory
acdown config set output ./downloads

# Get specific config value
acdown config get server_url

# Get all configuration
acdown config get

Logout

acdown logout

Clear the saved authentication token while keeping configuration.

Output:

╭─────────────────────────────────────╮
│            Logout                   │
├─────────────────────────────────────┤
│ ✓ Logged out successfully           │
│                                     │
│ Authentication token has been       │
│ cleared.                            │
╰─────────────────────────────────────╯

Usage Scenarios

Scenario 1: First-Time Setup

# 1. Set server URL
acdown config set server_url http://my-acdown-server.com:3000

# 2. Authenticate
acdown auth 123456

# 3. Download a file
acdown https://example.com/software.zip

Scenario 2: Large File Download

# Use high concurrency for large files
acdown https://example.com/ubuntu-24.04.iso -c 8 -o ~/Downloads/ubuntu.iso

Scenario 3: Batch Downloads

# Create a script for multiple downloads
for url in $(cat urls.txt); do
    acdown "$url" -o ./downloads/
done

Scenario 4: Debugging Issues

# Enable verbose mode to see detailed information
acdown https://example.com/file.zip -v

Configuration Storage

All configuration and authentication data is stored in data.bin using a secure binary format.

Storage Location

The data file is stored in the system's application data directory:

• Linux: ~/.local/share/acdown/data.bin
• macOS: ~/Library/Application Support/acdown/data.bin
• Windows: C:\Users\<username>\AppData\Local\acdown\data.bin

Binary Format

[config_length(4 bytes)][config_json][token_length(4 bytes)][token][expires_at(8 bytes)]

The file has restrictive permissions (600) for security.

Error Handling

The client handles various error scenarios gracefully:

• Network Errors: Automatic retry with exponential backoff (max 3 retries)
• Authentication Errors: Clear messages when token is expired or invalid
• Invalid URLs: Validation before attempting download
• Server Errors: Detailed error messages from server responses
• Disk Space: Pre-check before starting download
• Interruption: Graceful cleanup on Ctrl+C

Common Error Messages

✗ Authentication failed
  Error: Invalid TOTP code
  Hint: TOTP codes expire every 30 seconds

✗ Download failed
  Error: Connection timeout
  Retrying... (attempt 2/3)

✗ Not authenticated. Please run 'acdown auth <code>' first.

Performance Tips

1. Increase Concurrency: For fast connections, increase concurrent downloads

   acdown config set parallel 8
   

2. Use Verbose Mode: Monitor download details

   acdown <url> -v
   

3. Check Server Health: Ensure server is running before downloading

   curl http://your-server:3000/health
   

Troubleshooting

Authentication Issues

Problem: "Not authenticated" error

Solution:

# Re-authenticate with fresh TOTP code
acdown auth <new-code>

Connection Issues

Problem: Connection timeout or refused

Solutions:

1. Check server is running: curl http://server:3000/health
2. Verify server URL: acdown config get url
3. Check network connectivity

Download Failures

Problem: Download fails repeatedly

Solutions:

1. Enable verbose mode: acdown <url> -v
2. Reduce concurrency: acdown <url> -c 1
3. Check disk space
4. Verify URL is accessible

Token Expiration

Problem: Token expires frequently

Solution: Tokens have a fixed lifetime set by the server. Re-authenticate when needed:

acdown auth <new-code>

Architecture

acdown-client/
├── acdown/                 # Main package
│   ├── __init__.py        # Package exports
│   ├── cli.py             # CLI commands (Typer)
│   ├── auth.py            # Authentication manager
│   ├── downloader.py      # Download engine
│   ├── progress.py        # Progress tracking
│   ├── logger.py          # Logging configuration
│   └── utils.py           # Utility functions
├── config.example.toml    # Example configuration
├── pyproject.toml         # Project metadata
└── README.md              # This file

Key Components

• AuthManager (acdown/auth.py): Handles TOTP authentication, token storage, and configuration
• Downloader (acdown/downloader.py): Manages file analysis, chunked downloads, and concatenation
• ProgressTracker (acdown/progress.py): Beautiful progress display using Rich library
• Logger (acdown/logger.py): Configurable logging system
• Utils (acdown/utils.py): Helper functions for URL validation, size formatting, etc.
• CLI (acdown/cli.py): Typer-based command-line interface

Security Considerations

1. Token Storage: Stored in binary format with restrictive permissions (600)
2. TOTP Codes: Never hardcoded; always provided at runtime
3. Input Validation: URLs validated before processing
4. Path Sanitization: Prevents directory traversal attacks
5. No Plaintext Secrets: All sensitive data in binary format

API Compatibility

This client is designed to work with ACDown Server API endpoints:

• POST /api/auth/login - Authentication
• POST /api/proxy/analyze - File analysis
• GET /api/proxy/part/:encryptedParams - Chunk download
• GET /health - Health check

Development

Running from Source

# Using uv (recommended)
uv run acdown --help

# Or activate virtual environment first
source .venv/bin/activate
acdown --help

Import as Package

from acdown import AuthManager, Downloader, ProgressTracker
from acdown import validate_url, format_size

# Create instances
auth = AuthManager()
downloader = Downloader(config)

Adding New Features

1. Add dependencies to pyproject.toml
2. Run uv sync to update lock file
3. Implement feature in appropriate module
4. Update this README if needed

License

This project is open source. See LICENSE file for details.

Support

For issues and feature requests, please visit the project repository.

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Happy Downloading! 🚀