#!/usr/bin/env python3
"""System health check - collects key metrics and writes JSON report."""

import json
import os
import platform
import subprocess
from datetime import datetime, timezone
from pathlib import Path

def get_disk_usage(path="/"):
    result = subprocess.run(["df", "-h", path], capture_output=True, text=True)
    lines = result.stdout.strip().split("\n")
    if len(lines) >= 2:
        parts = lines[1].split()
        return {"total": parts[1], "used": parts[2], "available": parts[3], "use_percent": parts[4]}
    return None

def get_memory_info():
    try:
        with open("/proc/meminfo") as f:
            lines = f.readlines()[:6]
        return {line.split(":")[0].strip(): line.split(":")[1].strip() for line in lines}
    except:
        return None

def get_load_avg():
    try:
        with open("/proc/loadavg") as f:
            parts = f.read().strip().split()
        return {"1min": parts[0], "5min": parts[1], "15min": parts[2], "processes": parts[3]}
    except:
        return None

def get_process_count():
    try:
        return len([p for p in Path("/proc").iterdir() if p.name.isdigit()])
    except:
        return None

def main():
    report = {
        "timestamp": datetime.now(timezone.utc).isoformat().replace("+00:00", "Z"),
        "hostname": platform.node(),
        "os": platform.system(),
        "kernel": platform.release(),
        "python": platform.python_version(),
        "disk_root": get_disk_usage("/"),
        "memory": get_memory_info(),
        "load_avg": get_load_avg(),
        "process_count": get_process_count(),
    }
    print(json.dumps(report, indent=2))
    return report

if __name__ == "__main__":
    main()