#!/usr/bin/env python3
"""Disk usage reporter - outputs JSON format."""
import shutil
import json

def main():
    total, used, free = shutil.disk_usage('/')
    report = {
        "path": "/",
        "total_gb": round(total / (1024**3), 3),
        "used_gb": round(used / (1024**3), 3),
        "free_gb": round(free / (1024**3), 3),
        "percent_used": round((used / total) * 100, 1)
    }
    print(json.dumps(report, indent=2))

if __name__ == "__main__":
    main()