package readline

import (
	"fmt"
	"os"

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

// IsTerminal returns true if the given file descriptor is a terminal.
func IsTerminal(fd int) bool {
	return terminal.IsTerminal(fd)
}

func MakeRaw(fd int) (*terminal.State, error) {
	return terminal.MakeRaw(fd)
}

func Restore(fd int, state *terminal.State) error {
	return terminal.Restore(fd, state)
}

func IsPrintable(key rune) bool {
	isInSurrogateArea := key >= 0xd800 && key <= 0xdbff
	return key >= 32 && !isInSurrogateArea
}

func prefixKey(r rune) rune {
	switch r {
	case 'b':
		r = MetaPrev
	case 'f':
		r = MetaNext
	case 'd':
		r = MetaDelete
	}
	return r
}

func Debug(o ...interface{}) {
	f, _ := os.OpenFile("debug.tmp", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
	fmt.Fprintln(f, o...)
	f.Close()
}