// Package terminal renders captions using terminal control sequences.
package terminal

import (
	"fmt"
	"io"

	"tea.chunkbyte.com/kato/captioneer/src/captions"
)

type Sink struct {
	writer         io.Writer
	previewVisible bool
}

func New(writer io.Writer) *Sink {
	return &Sink{writer: writer}
}

func (s *Sink) Publish(event captions.Event) error {
	switch event.Kind {
	case captions.Provisional:
		_, err := fmt.Fprintf(s.writer, "\r\033[2K… %s", event.Text)
		if err == nil {
			s.previewVisible = true
		}
		return err
	case captions.Final:
		if err := s.clearPreview(); err != nil {
			return err
		}
		_, err := fmt.Fprintf(s.writer, "[%.2fs-%.2fs] %s\n", event.StartedAt.Seconds(), event.EndedAt.Seconds(), event.Text)
		return err
	case captions.Hide:
		return s.clearPreview()
	default:
		return fmt.Errorf("unsupported caption event kind %d", event.Kind)
	}
}

func (s *Sink) Close() error {
	return s.clearPreview()
}

func (s *Sink) clearPreview() error {
	if !s.previewVisible {
		return nil
	}
	_, err := fmt.Fprint(s.writer, "\r\033[2K")
	if err == nil {
		s.previewVisible = false
	}
	return err
}