package session

import (
	"os"
	"os/exec"
	"syscall"

	"github.com/creack/pty"
)

type DefaultPTYFactory struct{}

type shellProcess struct {
	cmd *exec.Cmd
	pty *os.File
}

func (f DefaultPTYFactory) Start(command string) (PTYProcess, error) {
	cmd := exec.Command("bash", "-lc", command)
	cmd.Env = os.Environ()
	ptmx, err := pty.Start(cmd)
	if err != nil {
		return nil, err
	}
	return &shellProcess{cmd: cmd, pty: ptmx}, nil
}

func (p *shellProcess) Read(b []byte) (int, error) {
	return p.pty.Read(b)
}

func (p *shellProcess) Write(b []byte) (int, error) {
	return p.pty.Write(b)
}

func (p *shellProcess) Close() error {
	return p.pty.Close()
}

func (p *shellProcess) Wait() error {
	return p.cmd.Wait()
}

func (p *shellProcess) Resize(cols, rows uint16) error {
	return pty.Setsize(p.pty, &pty.Winsize{Cols: cols, Rows: rows})
}

func (p *shellProcess) SignalStop() error {
	if p.cmd.Process == nil {
		return nil
	}
	return p.cmd.Process.Signal(syscall.SIGTERM)
}