package commander

import (
	"bytes"
	"errors"
	"io"
	"os/exec"

	"gitea.d3m0k1d.ru/d3m0k1d/HellreigN/proto"
	"golang.org/x/sync/errgroup"
)

type Commander struct {
}

func (*Commander) Execute(command *proto.Command) (*proto.FinishedCommand, error) {
	cmd := exec.Command(command.Command[0], command.Command[1:]...)
	var (
		stdin io.WriteCloser
		err   error
	)
	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 err := cmd.Wait(); err != nil {
		return nil, err
	}
	if err := eg.Wait(); err != nil {
		return nil, err
	}
	return &proto.FinishedCommand{
		Id:     command.Id,
		Status: int32(cmd.ProcessState.ExitCode()),
		Stdout: stdoutbuf.String(),
		Stderr: stderrbuf.String(),
	}, nil
}