//go:build js && wasm

package main

import "syscall/js"

func main() {
	document := js.Global().Get("document")
	element := func(id string) js.Value { return document.Call("getElementById", id) }
	source, width := element("source"), element("max-len")
	output, message := element("output"), element("message")
	render := func() {
		maxLen := width.Get("valueAsNumber").Int()
		element("width-value").Set("textContent", maxLen)
		tabLen := 4
		if maxLen < 80 {
			tabLen = 2
		}
		element("tab-value").Set("textContent", tabLen)
		source.Get("style").Set("tabSize", tabLen)
		output.Get("style").Set("tabSize", tabLen)
		formatted, err := formatSource(source.Get("value").String(), maxLen)
		if err != nil {
			output.Set("value", "")
			message.Set("textContent", err.Error())
			source.Call("setAttribute", "aria-invalid", "true")
			return
		}
		source.Call("removeAttribute", "aria-invalid")
		output.Set("value", string(formatted))
		message.Set("textContent", "")
	}
	listener := js.FuncOf(func(this js.Value, args []js.Value) any { render(); return nil })
	source.Call("addEventListener", "input", listener)
	width.Call("addEventListener", "input", listener)
	source.Set("disabled", false)
	width.Set("disabled", false)
	render()
	select {}
}