package com.weEat.view

import com.raquo.laminar.api.L._
import io.laminext.syntax.core._
import com.raquo.waypoint._

import play.api.libs.json.{JsValue,Json}
import com.weEat.controllers.{FoodController,USDAController}
import com.weEat.modules._
import com.weEat.shared.models.USDANodeNoId
import gov.usda.nal.fdc.models._
import gov.usda.nal.fdc.models.DataType._
import org.scalajs.dom.Event
import scala.concurrent.Future
import scala.util.Success

object UsdaImporter extends View[Option[String]] {
  import com.weEat.Main.headers

  implicit val ctx = com.weEat.shared.ctx

  val navName = Some("Usda Import")
  val tag = "importer"

  override val permissions = Set("admin")

  case class ViewPage(val q: Option[String] = None) extends P {
    val title = "USDA Import" + q.map((q) => s" - $q").getOrElse("")
    def jsonValue = Json.toJson(q)
  }
  def parseJson(jsVal: JsValue) = ViewPage(jsVal.asOpt[String])
  def route = Route.onlyQuery(
    encode = (page: ViewPage) => page.q,
    decode = (q: Option[String]) => ViewPage(q = q),
    pattern = (root / tag / endOfSegments) ? param[String]("q").?
  )
  def defaultPage = ViewPage()

  import com.raquo.airstream.custom.CustomSource._
  def lazyFutureSignal[T](fut: => Future[T]) =
    Signal.fromCustomSource(
      Success(fut),
      (_: SetCurrentValue[Future[T]], _: GetCurrentValue[Future[T]], _, _) => (),
      (_) => ()
    ).flatMap { (fut) =>
      Signal.fromFuture(fut)
    }
  def lazyFutureSignal[T](fut: => Future[T], default: => T) =
    Signal.fromCustomSource(
      Success(fut),
      (_: SetCurrentValue[Future[T]], _: GetCurrentValue[Future[T]], _, _) => (),
      (_) => ()
    ).flatMap { (fut) =>
      Signal.fromFuture(fut)
    }

  private val SEARCH_PAGE_SIZE = 40.asInstanceOf[Short]

  def content(queryPage: Signal[ViewPage]) = {
    val searchBar: SearchBar[Seq[Signal[Option[Seq[SearchResultFood]]]]] =
      SearchBar((term) =>
        USDAController.getFoodsSearch(term, Seq(
          // Branded,
          Foundation, SRLegacy
        ).map(_.toString), pageSize = Some(SEARCH_PAGE_SIZE))().map {
          case SearchResult(criteria, n, cur, tot, baseList) =>
            Val(Some(baseList)) +:
              (cur + 1 to tot).map({ (c) => lazyFutureSignal(
                USDAController.postFoodsSearch()(
                  criteria.copy(pageNumber = Some(c))
                ).map(_.foods),
                Nil
              ) })
        },
        inSignal = queryPage.map(_.q).withDefault("")
      )
    val searchResults = searchBar.result
    val pageSizeSel = Select(Val((10 to SEARCH_PAGE_SIZE by 10)))
    val numPages = pageSizeSel.value.combineWithFn(searchResults) {
      case (_, None) => 0
      case (size, Some(results)) => results.length * SEARCH_PAGE_SIZE / size
    }
    val pageSel = PageSelect(numPages)
    val currentSearchPageNum = pageSel.page.combineWithFn(pageSizeSel.value) {
      case (pageNum, pageSize) => pageNum * pageSize / SEARCH_PAGE_SIZE
    }
    val currentSearchPageOffset = pageSel.page.combineWithFn(pageSizeSel.value) {
      case (pageNum, pageSize) => pageNum % (SEARCH_PAGE_SIZE / pageSize)
    }
    val currentSearchPage = searchResults.combineWithFn(currentSearchPageNum) {
      case (Some(Nil), _) => Val(Nil)
      case (None, _) => Val(Nil)
      // [2023-09-26]@tflucke TODO: implement loading UI instead of default
      case (Some(res), pageNum) => res(pageNum).withDefault(Nil)
    }.flatMap(identity)
    // TODO: Prefetch next page

    div(
      h2("USDA Importer"),
      div(cls := "form-group",
        label(forId := "search", "Search: "),
        searchBar.render
      ),
      searchBar.searchTerm --> { (str: Option[String]) =>
        val oldQ = View.router.currentPageSignal.now().asInstanceOf[ViewPage].q
        if (oldQ != str)
          View.router.pushState(ViewPage(q = str))
      },
      PaginatedTable[SearchResultFood](Seq(
        ("", 1, { (x) => button(cls := "btn btn-light",
          onClick --> {(e: Event) =>
            val editor = USDAEditor(USDANodeNoId.fromSearchResult(x), true)
            Overlay.confirm(editor.render) { () =>
              import com.weEat.Main.headers
              FoodController.add()(editor.getUSDANode())
            }
          },
          "Add"
        )}),
        ("ID", 1, { (x) => span(x.fdcId.toString)}),
        ("Name", 3, { (x) => span(x.description)}),
        ("Desc", 4, { (x) => span(x.additionalDescriptions)}),
        ("Brand", 3, { (x) => span(x.brandOwner)})
      ),
        currentSearchPage,
        currentSearchPageOffset,
        pageSizeSel.value
      ).render,
      (pageSel.render).amendThis(
        (elm) => cls := s"${elm.ref.className} col-3 float-left"
      ),
      (pageSizeSel.render).amendThis(
        (elm) => cls := s"${elm.ref.className} col-1 float-right"
      )
    )
  }
}