package main

import (
	"errors"
	"fmt"
	"io"
	"os"
	"os/exec"
	"strings"
	"syscall"
)

// Run the given command, showing output.
func run_command(command []string) (bool, error) {
	fmt.Println(strings.Repeat("=", 64))
	fmt.Println(command)
	cmd := exec.Command(command[0], command[1:]...)
	// Connections
	stdout, err := cmd.StdoutPipe()
	if err != nil {
		return false, fmt.Errorf("Failed getting stdout pipe: %v", err)
	}
	var do_autoremove bool = false
	go func() {
		var (
			buf  []byte = make([]byte, 1024)
			read int
			err  error
			text string
		)
		for {
			read, err = stdout.Read(buf)
			if err != nil {
				if errors.Is(err, os.ErrClosed) || errors.Is(err, io.EOF) {
					return
				}
				fmt.Println("While reading:", err)
				return
			}
			if read != 0 {
				text = string(buf[0:read])
				fmt.Print(text)
				if strings.Contains(text, "autoremove") {
					do_autoremove = true
					return
				}
			}
		}
	}()

	//cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	cmd.Stdin = os.Stdin

	cmd.SysProcAttr = &syscall.SysProcAttr{}
	cmd.SysProcAttr.Credential = &syscall.Credential{Uid: 0, Gid: 0}
	err = cmd.Run()
	fmt.Println(strings.Repeat("=", 50))
	return do_autoremove, err
}

func main() {
	if os.Geteuid() != 0 {
		fmt.Println("Use `sudo install -g 0 -o 0 -m 4755 aptgrade ~/bin/aptgrade`")
		fmt.Println("This program requires SETUID.")
		os.Exit(2)
	}
	_, err := run_command([]string{"/usr/bin/apt", "update"})
	if err != nil {
		fmt.Println("Did you forget to:")
		fmt.Println("  sudo chown root:root aptgrade")
		fmt.Println("  sudo chmod a+s aptgrade")
		fmt.Println("Command failed:", err)
		os.Exit(2)
	}
	do_autoremove, err := run_command([]string{"/usr/bin/apt", "upgrade", "-y"})
	if err != nil {
		fmt.Println("Command failed:", err)
		os.Exit(2)
	}
	if do_autoremove {
		_, err = run_command([]string{"/usr/bin/apt", "autoremove", "-y"})
		if err != nil {
			fmt.Println("Command failed:", err)
			os.Exit(2)
		}
	}
	fmt.Println("Done")
}