package exec

// exec is a small package to provide a wrapper around Cmd from os/exec to
// fulfill the Ensurer interface.

import (
	"bytes"
	"fmt"
	"io"
	"os/exec"
)

type (
	// E is a wrapper around Cmd from os/exec to fulfill Ensurer.
	E exec.Cmd
)

// Ensure runs the command in the current context.
func (e *E) Ensure() error {
	var (
		stdout io.ReadWriter
		stderr io.ReadWriter
	)
	if e.Stdout == nil {
		stdout = bytes.NewBuffer([]byte{})
		e.Stdout = stdout
	}
	if e.Stderr == nil {
		stderr = bytes.NewBuffer([]byte{})
		e.Stderr = stderr
	}
	cmd := (*exec.Cmd)(e)
	if err := cmd.Start(); err != nil {
		return fmt.Errorf("could not run command: %w", err)
	}
	err := cmd.Wait()

	if procState, ok := err.(*exec.ExitError); ok && procState.ExitCode() > 0 {
		fmt.Printf("could not run command: %s\nstdout: %s\nstderr: %s\n", err, stdout, stderr)
		return fmt.Errorf("error when calling command: %s", err)
	}
	return fmt.Errorf("could not run command: %s", err)
}