package hyperone

import (
	"io/ioutil"
	"net"
	"os"

	"golang.org/x/crypto/ssh"
	"golang.org/x/crypto/ssh/agent"

	"github.com/hashicorp/packer/common/json"
)

const (
	sshAddress   = "api.hyperone.com:22"
	sshSubsystem = "rbx-auth"
)

type sshData struct {
	ID string `json:"_id"`
}

func sshAgent() ssh.AuthMethod {
	if sshAgent, err := net.Dial("unix", os.Getenv("SSH_AUTH_SOCK")); err == nil {
		return ssh.PublicKeysCallback(agent.NewClient(sshAgent).Signers)
	}
	return nil
}

func fetchTokenBySSH(user string) (string, error) {
	sshConfig := &ssh.ClientConfig{
		User: user,
		Auth: []ssh.AuthMethod{
			sshAgent(),
		},
		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
	}

	client, err := ssh.Dial("tcp", sshAddress, sshConfig)
	if err != nil {
		return "", err
	}
	defer client.Close()

	session, err := client.NewSession()
	if err != nil {
		return "", err
	}
	defer session.Close()

	stdout, err := session.StdoutPipe()
	if err != nil {
		return "", err
	}

	err = session.RequestSubsystem(sshSubsystem)
	if err != nil {
		return "", err
	}

	out, err := ioutil.ReadAll(stdout)
	if err != nil {
		return "", err
	}

	var data sshData
	err = json.Unmarshal(out, &data)
	if err != nil {
		return "", err
	}

	return data.ID, nil
}