kotlin-komponent/src/jsMain/kotlin/nl/astraeus/komp/ElementExtentions.kt

package nl.astraeus.komp

import org.w3c.dom.events.Event
import org.w3c.dom.Element
import org.w3c.dom.HTMLInputElement
import org.w3c.dom.events.EventListener
import org.w3c.dom.get

private fun Int.asSpaces(): String {
  val result = StringBuilder()

  repeat(this) {
    result.append(" ")
  }
  return result.toString()
}

fun Element.printTree(indent: Int = 0): String {
  val result = StringBuilder()

  result.append(indent.asSpaces())
  result.append(tagName)
  if (this.namespaceURI != "http://www.w3.org/1999/xhtml") {
    result.append(" [")
    result.append(namespaceURI)
    result.append("]")
  }
  result.append(" (")
  var first = true
  if (hasAttributes()) {
    for (index in 0 until attributes.length) {
      if (!first) {
        result.append(", ")
      } else {
        first = false
      }
      result.append(attributes[index]?.localName)
      result.append("=")
      result.append(attributes[index]?.value)
    }
  }
  result.append(") {")
  result.append("\n")
  for ((name, event) in getKompEvents()) {
    result.append(indent.asSpaces())
    result.append("on")
    result.append(name)
    result.append(" -> ")
    result.append(event)
    result.append("\n")
  }
  for (index in 0 until childNodes.length) {
    childNodes[index]?.let {
      if (it is Element) {
        result.append(it.printTree(indent + 2))
      } else {
        result.append((indent + 2).asSpaces())
        result.append(it.textContent)
        result.append("\n")
      }
    }
  }
  result.append(indent.asSpaces())
  result.append("}\n")

  return result.toString()
}

internal fun Element.setKompAttribute(attributeName: String, value: String?) {
  //val attributeName = name.lowercase()
  if (value == null || value.isBlank()) {
    if (this is HTMLInputElement) {
      when (attributeName) {
        "checked" -> {
          checked = false
        }
/*
        "class" -> {
          className = ""
        }
*/
        "value" -> {
          this.value = ""
        }
        else -> {
          removeAttribute(attributeName)
        }
      }
    } else {
      removeAttribute(attributeName)
    }
  } else {
    if (this is HTMLInputElement) {
      when (attributeName) {
        "checked" -> {
          checked = "checked" == value
        }
/*
        "class" -> {
          className = value
        }
*/
        "value" -> {
          this.value = value
        }
        else -> {
          setAttribute(attributeName, value)
        }
      }
    } else if (this.getAttribute(attributeName) != value) {
      setAttribute(attributeName, value)
    }
  }
}

internal fun Element.clearKompEvents() {
  val events = getKompEvents()
  for ((name, event) in getKompEvents()) {
    removeEventListener(name, event)
  }
  events.clear()
}

internal fun Element.setKompEvent(name: String, event: (Event) -> Unit) {
  val eventName: String = if (name.startsWith("on")) {
    name.substring(2)
  } else {
    name
  }

  getKompEvents()[eventName] = event

  this.addEventListener(eventName, event)
}

private val kompEvents = mutableMapOf<Element, MutableMap<String, (Event) -> Unit>>()

internal fun Element.getKompEvents(): MutableMap<String, (Event) -> Unit> {
  return kompEvents.getOrPut(this) { mutableMapOf() }
}

internal fun Element.findElementIndex(): Int {
  val childNodes = parentElement?.children
  if (childNodes != null) {
    for (index in 0 until childNodes.length) {
      if (childNodes[index] == this) {
        return index
      }
    }
  }

  return 0
}