// Not used by Repeat
class MyDataSource implements IDataSource {
  private list: number[] = [];
  private listener: DataChangeListener | undefined;

  constructor(list: number[]) {
    this.list = list
  }

  totalCount(): number {
    return this.list.length
  }

  getData(index: number): number {
    return this.list[index]
  }

  registerDataChangeListener(listener: DataChangeListener): void {
    this.listener = listener
  }

  unregisterDataChangeListener() {
  }
}

@Entry
@ComponentV2
struct Index {
  @Local arr: Array<string> = Array(5).fill('').map((v,i) => `${i}`);
  @Local totalCount:number = this.arr.length;

  private data: MyDataSource = new MyDataSource([]);
  private swiperController: SwiperController = new SwiperController()

  aboutToAppear(): void {
    let list = []
    for (let i = 1; i <= 10; i++) {
      list.push(i.toString() as never);
    }
    this.data = new MyDataSource(list)
  }

  shift() {
    this.arr.shift();
    this.totalCount = this.arr.length;
  }

  unshift() {
    // TBD need better logic
    let min = Math.min(...this.arr.map(v => (+v || 0)));
    if (min === Infinity) min = 0;
    this.arr.unshift(`${min - 1}`);
    this.totalCount = this.arr.length;
  }

  update(index: number) {
    // TBD need better logic
    this.arr[index] = `${-this.arr[index] || 0}`;
    this.totalCount = this.arr.length;
  }

  build() {
    Column({ space: 5 }) {
      Text('4_swiper_hq.ets')

      Row({space: 3}) {
        Button('shift').onClick(() => this.shift())
        Button('unshift').onClick(() => this.unshift())
        Button('update #0').onClick(() => this.update(0))
      }.padding(10)

      Swiper(this.swiperController) {
        Repeat(this.arr)
          // @ts-ignore 
          .virtualScroll({
            totalCount: this.totalCount
          })
          .each((ri) => {
            Text(`${ri.item}`).width('90%').height(160).backgroundColor(0xAFEEEE).textAlign(TextAlign.Center).fontSize(30)
          })
          .key((item:string) => item)

       /* LazyForEach analog
       LazyForEach(this.data, (item: string) => {
         Text(item).width('90%').height(160).backgroundColor(0xAFEEEE).textAlign(TextAlign.Center).fontSize(30)
       }, (item:string) => item)
       */  
      }
      .onChange((index) => {
        console.log('onChange', index);
      })
      .cachedCount(2)
      .index(1)
      .autoPlay(true)
      .interval(4000)
      .indicator(true)
      .loop(true)
      .duration(100)
      .itemSpace(0)
      .curve(Curve.Linear)
      .onChange((index: number) => {
        console.info(index.toString())
      })

      Row({ space: 12 }) {
        Button('showNext')
          .onClick(() => {
            this.swiperController.showNext()
          })
        Button('showPrevious')
          .onClick(() => {
            this.swiperController.showPrevious()
          })
      }.margin(5)
    }.width('100%')
    .margin({ top: 5 })
  }
}