clipty.go

package clipty

import (
	"context"
	"net/url"
	"os"

	"github.com/creack/pty"
)

type Std struct {
	Stdin  *os.File
	Stdout *os.File
	Stderr *os.File
}

// MainFunc is CLI main loop  function.
type MainFunc func(ctx context.Context, params url.Values, std Std)

type clipty struct {
	params map[string][]string
	pty    *os.File
	tty    *os.File
	cancel context.CancelFunc
}

func newClipty(params url.Values, mf MainFunc) (*clipty, error) {
	pty, tty, err := pty.Open()
	if err != nil {
		return nil, err
	}

	ctx, cancel := context.WithCancel(context.Background())
	c := &clipty{
		params: params,
		pty:    pty,
		tty:    tty,
		cancel: cancel,
	}

	// When the process is closed by the user,
	// close pty so that Read() on the pty breaks with an EOF.
	go func() {
		defer func() {
			tty.Sync()
			c.Close()
		}()

		mf(ctx, params, Std{tty, tty, tty})
	}()

	return c, nil
}

func (c *clipty) Read(p []byte) (n int, err error) {
	return c.pty.Read(p)
}

func (c *clipty) Write(p []byte) (n int, err error) {
	return c.pty.Write(p)
}

func (c *clipty) Close() error {
	c.cancel()
	c.tty.Close()
	return c.pty.Close()
}

func (c *clipty) WindowTitleVariables() map[string]interface{} {
	return map[string]interface{}{
		//"command": c.command,
		"params": c.params,
	}
}

func (c *clipty) ResizeTerminal(width int, height int) error {
	window := pty.Winsize{
		Rows: uint16(height),
		Cols: uint16(width),
		X:    0,
		Y:    0,
	}
	err := pty.Setsize(c.pty, &window)
	if err != nil {
		return err
	} else {
		return nil
	}
}