package mos

import (
	"net"
	"time"

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

type Conn struct {
	net.Conn
	ReadTimeout  time.Duration
	WriteTimeout time.Duration
}

func (c *Conn) Read(b []byte) (int, error) {
	err := c.Conn.SetReadDeadline(time.Now().Add(c.ReadTimeout))
	if err != nil {
		return 0, err
	}
	return c.Conn.Read(b)
}

func (c *Conn) Write(b []byte) (int, error) {
	err := c.Conn.SetWriteDeadline(time.Now().Add(c.WriteTimeout))
	if err != nil {
		return 0, err
	}
	return c.Conn.Write(b)
}

// SSHDialTimeout dials in SSH with a timeout. It sends periodic keepalives such as the remote host don't make the go client sit on Wait()
func SSHDialTimeout(network, addr string, config *ssh.ClientConfig, timeout time.Duration) (*ssh.Client, error) {
	conn, err := net.DialTimeout(network, addr, timeout)
	if err != nil {
		return nil, err
	}

	timeoutConn := &Conn{conn, timeout, timeout}
	c, chans, reqs, err := ssh.NewClientConn(timeoutConn, addr, config)
	if err != nil {
		return nil, err
	}
	client := ssh.NewClient(c, chans, reqs)

	// this sends keepalive packets every 2 seconds
	// there's no useful response from these, so we can just abort if there's an error
	go func() {
		t := time.NewTicker(2 * time.Second)
		defer t.Stop()
		for range t.C {
			_, _, err := client.Conn.SendRequest("keepalive@golang.org", true, nil)
			if err != nil {
				return
			}
		}
	}()
	return client, nil
}

type SSHConn struct {
	username string
	password string
	host     string
}

func NewSSH(user, pass, host string) *SSHConn {
	return &SSHConn{user, pass, host}
}

func (s *SSHConn) Command(cmd string) (out string, err error) {
	return SSHCommand(s.username, s.password, s.host, cmd)
}