// +build example jsgo

package main

import (
        "log"
        "strings"

        "github.com/hajimehoshi/ebiten"
        "github.com/hajimehoshi/ebiten/ebitenutil"
)

var (
        text          = "Type on the keyboard:\n"
        counter       = 0
        bsPrevPressed = false
)

func update(screen *ebiten.Image) error {
        // Add a string from InputChars, that returns string input by users.
        // Note that InputChars result changes every frame, so you need to call this
        // every frame.
        text += string(ebiten.InputChars())

        // Adjust the string to be at most 10 lines.
        ss := strings.Split(text, "\n")
        if len(ss) > 10 {
                text = strings.Join(ss[len(ss)-10:], "\n")
        }

        // If the enter key is pressed, add a line break.
        if ebiten.IsKeyPressed(ebiten.KeyEnter) && !strings.HasSuffix(text, "\n") {
                text += "\n"
        }

        // If the backspace key is pressed, remove one character.
        bsPressed := ebiten.IsKeyPressed(ebiten.KeyBackspace)
        if !bsPrevPressed && bsPressed {
                if len(text) >= 1 {
                        text = text[:len(text)-1]
                }
        }
        bsPrevPressed = bsPressed

        counter++

        if ebiten.IsRunningSlowly() {
                return nil
        }

        // Blink the cursor.
        t := text
        if counter%60 < 30 {
                t += "_"
        }
        ebitenutil.DebugPrint(screen, t)
        return nil
}

func main() {
        if err := ebiten.Run(update, 320, 240, 2.0, "Typewriter (Ebiten Demo)"); err != nil {
                log.Fatal(err)
        }
}