package commander

import (
	"bytes"
	"errors"
	"gitea.d3m0k1d.ru/d3m0k1d/HellreigN/proto/proto"
	"golang.org/x/sync/errgroup"
	"io"
	"os/exec"
)

type CommandExecutor struct{}

func (*CommandExecutor) Execute(command *proto.Command) (fc *proto.FinishedCommand, err error) {
	fc = new(proto.FinishedCommand)
	fc.Id = command.Id
	cmd := exec.Command(command.Command[0], command.Command[1:]...)
	var stdin io.WriteCloser
	if command.Stdin != nil {
		stdin, err = cmd.StdinPipe()
		if err != nil {
			return nil, err
		}
	}
	stdout, err1 := cmd.StdoutPipe()
	stderr, err2 := cmd.StderrPipe()
	if err := errors.Join(err1, err2); err != nil {
		return nil, err
	}
	if err := cmd.Start(); err != nil {
		return nil, err
	}
	if command.Stdin != nil {
		io.WriteString(stdin, *command.Stdin)
		if err := stdin.Close(); err != nil {
			return nil, err
		}
	}
	eg := new(errgroup.Group)
	stdoutbuf := new(bytes.Buffer)
	stderrbuf := new(bytes.Buffer)
	eg.Go(func() error {
		_, err := io.Copy(stdoutbuf, stdout)
		return err
	})
	eg.Go(func() error {
		_, err := io.Copy(stderrbuf, stderr)
		return err
	})
	if waitErr := cmd.Wait(); waitErr != nil {
		var exitErr *exec.ExitError
		if !errors.As(waitErr, &exitErr) {
			return nil, waitErr
		}
		fc.Status = int32(exitErr.ExitCode())
	} else {
		fc.Status = int32(cmd.ProcessState.ExitCode())
	}
	if err := eg.Wait(); err != nil {
		return nil, err
	}
	fc.Status = int32(cmd.ProcessState.ExitCode())
	fc.Stdout = stdoutbuf.String()
	fc.Stderr = stderrbuf.String()
	return
}