package interactionPlugins.fileSubmission.cards

import com.raquo.laminar.api.L
import com.raquo.laminar.api.L.*
import com.raquo.laminar.nodes.ReactiveHtmlElement
import TurtleFileButtonCard.*
import TurtleFileButtonCard.StorageFormat.{BYTES_AS_BASE64_STRING, BYTES_AS_RAW_STRING}
import interactionPlugins.fileSubmission.*
import interactionPlugins.fileSubmission.TurtleStitchFileFactory.*
import org.scalajs.dom
import org.scalajs.dom.{File, HTMLButtonElement, HTMLDivElement, HTMLInputElement}
import util.TypeConversion
import workbook.model.info.WorkbookInfo
import workbook.model.interaction.InteractionVariable
import workbook.model.interaction.history.UpdateImportance
import workbook.workbookHtmlElements.abstractions.WorkbookInteraction

import scala.concurrent.{ExecutionContext, Future}
import scala.scalajs.js
import scala.scalajs.js.typedarray.*
import scala.util.{Failure, Success}

case class TurtleFileButtonCard(
                                 workbookInfoVar: L.Var[WorkbookInfo],
                                 id: String, acceptedTypes: List[String],
                                 storageFormat: StorageFormat = BYTES_AS_BASE64_STRING
                               ) extends WorkbookInteraction[String] {

  override val interactionVariable: InteractionVariable[String] = InteractionVariable.stringVariable(this, "")

  private lazy val uploadInput: ReactiveHtmlElement[HTMLInputElement] = input(
    styleAttr := "display:none;",
    typ := "file",
    accept := acceptedTypes.mkString(","),
    onChange --> { event =>
      val inputElement = event.target.asInstanceOf[dom.html.Input]
      if (inputElement.files.length > 0) onNewFileSelected(inputElement.files.item(0))
    }
  )

  private lazy val uploadButton: ReactiveHtmlElement[HTMLButtonElement] = button(
    child <-- workbookInfoVar.signal.map(_.config.currentWorkbookLanguage).map(languageMapUploaddButton.getInLanguage),
    uploadInput,
    onClick --> { _ =>
      uploadInput.ref.click()
    }
  )

  private lazy val fileDom: ReactiveHtmlElement[HTMLDivElement] = div(
    cls := "preview-card",
    h3(
      child <-- workbookInfoVar.signal.map(_.config.currentWorkbookLanguage).map(languageMapUploaddButton.getInLanguage),
    ),
    div(
      cls := "preview-content",
      uploadButton
    )
  )


  private def onFileReadSuccessfully(bytes: Array[Byte]): Unit = {
    val contentAsString: String = storageFormat match {
      case BYTES_AS_RAW_STRING => new String(bytes.map(_.toByte), "UTF-8")
      case BYTES_AS_BASE64_STRING => TypeConversion.byteArrayToBase64String(bytes)
    }

    interactionVariable.updateStateFromUserInteraction(contentAsString, System.currentTimeMillis(), UpdateImportance.MAJOR)

  }

  private def onNewFileSelected(file: File): Unit = {
    val fileFut: Future[Array[Byte]] = readBytes(file)

    fileFut.onComplete {
      case Success(data) => onFileReadSuccessfully(data)
      case Failure(error) => println("[WARN] could not load file, ignoring content: " + error.getMessage)
    }(ExecutionContext.global)

  }

  def readBytes(file: File): Future[Array[Byte]] = {
    file.arrayBuffer().toFuture.map { buffer =>
      val array = new Uint8Array(buffer)
      Array.tabulate(array.length)(i => array(i).toByte)
    }(scala.concurrent.ExecutionContext.global)
  }

  def getDomElement(): Element = fileDom

}

object TurtleFileButtonCard {

  enum StorageFormat {
    case BYTES_AS_RAW_STRING, BYTES_AS_BASE64_STRING
  }

}