package tx

import "golang.org/x/term"
import "surdeus.su/core/cli/aes"
import "bufio"
import "fmt"
import "os"
import "os/signal"
import "syscall"

type Signal = os.Signal
const (
	SignalWinChange = syscall.SIGWINCH
)

type Terminal struct {
	x *term.Terminal
	file *os.File
	input *bufio.Reader
	fd int
	prevState *term.State

	signals chan Signal
	keys chan Key
}

func NewTerminal(input *os.File) (*Terminal, error) {
	if input == nil {
		return nil, ErrNoInputProvided
	}

	fd := int(input.Fd())
	if !term.IsTerminal(fd) {
		return nil, ErrNotTerminal
	}

	ret := Terminal{}
	ret.file = input
	ret.input = bufio.NewReader(input)
	ret.fd = fd
	ret.x = term.NewTerminal(input, "")

	return &ret, nil
}

func (t *Terminal) MakeRaw() (chan Key, chan Signal, error) {
	state, err := term.MakeRaw(t.fd)
	if err != nil {
		return nil, nil, err
	}

	t.prevState = state
	t.signals = make(chan Signal, 1)
	signal.Notify(
		t.signals,
		syscall.SIGWINCH,
	)
	t.keys = make(chan Key, 1)
	go func() {
		for {
			r, _, _ := t.input.ReadRune()
			t.keys <- Key(r)
		}
	} ()

	return t.keys, t.signals, nil
}

func (t *Terminal) Restore() error {
	t.DisableAltBuffer()
	if t == nil || t.prevState == nil {
		return nil
	}

	err := term.Restore(t.fd, t.prevState)
	if err != nil {
		return err
	}

	return nil
}

func (t *Terminal) Size() (int, int, error) {
	return term.GetSize(t.fd)
}

func (t *Terminal) ReadLine() (string, error) {
	return t.x.ReadLine()
}

/*
func (t *Terminal) ReadKey() (Key, int, error) {
	r, size, err := t.input.ReadRune()
	return Key(r), size, err
}
*/

func (t *Terminal) Write(bts []byte) (int, error) {
	return t.x.Write(bts)
}

func (t *Terminal) Printf(
	format string, v ...any,
) (int, error) {
	str := fmt.Sprintf(format, v...)
	return t.Write([]byte(str))
}

func (t *Terminal) Print(v ...any) (int, error) {
	str := fmt.Sprint(v...)
	return t.Write([]byte(str))
}

func (t *Terminal) MoveCursorRight(n int) {
	t.Printf(aes.MoveCursorRightFormat, n)
}

func (t *Terminal) MoveCursorLeft(n int) {
	t.Printf(aes.MoveCursorLeftFormat, n)
}

func (t *Terminal) MoveCursorUp(n int) {
	t.Printf(aes.MoveCursorUpFormat, n)
}

func (t *Terminal) MoveCursorDown(n int) {
	t.Printf(aes.MoveCursorDownFormat, n)
}

func (t *Terminal) MoveCursorBy(xd, yd int) {
	if xd != 0 {
		if yd < 0 {
			t.MoveCursorLeft(xd)
		} else {
			t.MoveCursorRight(xd)
		}
	}

	if yd != 0 {
		if yd < 0 {
			t.MoveCursorUp(yd)
		} else {
			t.MoveCursorDown(yd)
		}
	}
}

func (t *Terminal) MoveCursorTo(x, y int) {
	t.Printf(aes.MoveCursorToFormat, y, x)
}

func (t *Terminal) MoveCursorHome() {
	t.Printf("%s", aes.MoveCursorHome)
}

func (t *Terminal) SaveCursor() {
	t.Printf("%s", aes.SaveCursorPositionSCO)
}

func (t *Terminal) UndoCursor() {
	t.Printf("%s", aes.UndoCursorPositionSCO)
}

func (t *Terminal) NextLine(n int) {
	t.Printf(
		aes.MoveCursorToBeginOfNextLineDownFormat,
		n,
	)
}

func (t *Terminal) EraseLine() {
	t.Print(aes.EraseEntireLine)
}

func (t *Terminal) EnableAltBuffer() {
	t.Printf("%s", aes.EnableAltBuffer)
}

func (t *Terminal) DisableAltBuffer() {
	t.Printf("%s", aes.DisableAltBuffer)
}

func (t *Terminal) ClearScreen() {
	t.Write([]byte(aes.EraseEntireScreen))
}