package main

import (
	"fmt"
	"os"
	"strconv"
	"strings"
)

// getProcessArgs reads /proc/<pid>/cmdline to get process arguments.
func getProcessArgs(pid int) ([]string, error) {
	data, err := os.ReadFile(fmt.Sprintf("/proc/%d/cmdline", pid))
	if err != nil {
		return nil, fmt.Errorf("reading /proc/%d/cmdline: %w", pid, err)
	}

	s := strings.TrimRight(string(data), "\x00")
	if s == "" {
		return nil, fmt.Errorf("empty cmdline for pid %d", pid)
	}

	return strings.Split(s, "\x00"), nil
}

// getParentPID reads /proc/<pid>/status to find the parent PID.
func getParentPID(pid int) (int, error) {
	data, err := os.ReadFile(fmt.Sprintf("/proc/%d/status", pid))
	if err != nil {
		return 0, err
	}

	for _, line := range strings.Split(string(data), "\n") {
		if strings.HasPrefix(line, "PPid:") {
			fields := strings.Fields(line)
			if len(fields) >= 2 {
				return strconv.Atoi(fields[1])
			}
		}
	}

	return 0, fmt.Errorf("PPid not found in /proc/%d/status", pid)
}