/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

package com.facebook.react.views.scroll

import android.animation.Animator
import android.animation.ValueAnimator
import android.content.Context
import android.graphics.Point
import android.os.Build
import android.view.View
import android.view.ViewGroup
import android.widget.OverScroller
import androidx.annotation.RequiresApi
import androidx.core.view.ViewCompat.FocusDirection
import androidx.core.view.ViewCompat.FocusRealDirection
import com.facebook.common.logging.FLog
import com.facebook.react.bridge.ReactContext
import com.facebook.react.bridge.WritableMap
import com.facebook.react.bridge.WritableNativeMap
import com.facebook.react.common.ReactConstants
import com.facebook.react.fabric.FabricUIManager
import com.facebook.react.uimanager.PixelUtil.toDIPFromPixel
import com.facebook.react.uimanager.PixelUtil.toPixelFromDIP
import com.facebook.react.uimanager.ReactClippingViewGroup
import com.facebook.react.uimanager.StateWrapper
import com.facebook.react.uimanager.UIManagerHelper
import com.facebook.react.uimanager.common.UIManagerType
import com.facebook.react.uimanager.common.ViewUtil
import java.lang.ref.WeakReference
import java.util.concurrent.CopyOnWriteArrayList
import kotlin.math.abs
import kotlin.math.max

/** Helper class that deals with emitting Scroll Events. */
public object ReactScrollViewHelper {
  private val TAG = ReactScrollView::class.java.simpleName
  private val DEBUG_MODE = false // ReactBuildConfig.DEBUG

  private const val CONTENT_OFFSET_LEFT = "contentOffsetLeft"
  private const val CONTENT_OFFSET_TOP = "contentOffsetTop"
  private const val SCROLL_AWAY_PADDING_TOP = "scrollAwayPaddingTop"

  public const val MOMENTUM_DELAY: Long = 20
  public const val OVER_SCROLL_ALWAYS: String = "always"
  public const val AUTO: String = "auto"
  public const val OVER_SCROLL_NEVER: String = "never"
  public const val SNAP_ALIGNMENT_DISABLED: Int = 0
  public const val SNAP_ALIGNMENT_START: Int = 1
  public const val SNAP_ALIGNMENT_CENTER: Int = 2
  public const val SNAP_ALIGNMENT_END: Int = 3

  // Support global native listeners for scroll events
  private val scrollListeners = CopyOnWriteArrayList<WeakReference<ScrollListener>>()
  private val layoutChangeListeners = CopyOnWriteArrayList<WeakReference<LayoutChangeListener>>()

  // If all else fails, this is the hardcoded value in OverScroller.java, in AOSP.
  // The default is defined here (as of this diff):
  // https://android.googlesource.com/platform/frameworks/base/+/ae5bcf23b5f0875e455790d6af387184dbd009c1/core/java/android/widget/OverScroller.java#44
  private var SMOOTH_SCROLL_DURATION = 250
  private var smoothScrollDurationInitialized = false

  /** Shared by [ReactScrollView] and [ReactHorizontalScrollView]. */
  @JvmStatic
  public fun <T> emitScrollEvent(scrollView: T, xVelocity: Float, yVelocity: Float)
      where T : HasScrollEventThrottle?, T : ViewGroup {
    emitScrollEvent(scrollView, ScrollEventType.SCROLL, xVelocity, yVelocity)
  }

  @JvmStatic
  public fun <T> emitScrollBeginDragEvent(scrollView: T)
      where T : HasScrollEventThrottle?, T : ViewGroup {
    emitScrollEvent(scrollView, ScrollEventType.BEGIN_DRAG)
  }

  @JvmStatic
  public fun <T> emitScrollEndDragEvent(scrollView: T, xVelocity: Float, yVelocity: Float)
      where T : HasScrollEventThrottle?, T : ViewGroup {
    emitScrollEvent(scrollView, ScrollEventType.END_DRAG, xVelocity, yVelocity)
  }

  @JvmStatic
  public fun <T> emitScrollMomentumBeginEvent(scrollView: T, xVelocity: Int, yVelocity: Int)
      where T : HasScrollEventThrottle?, T : ViewGroup {
    emitScrollEvent(
        scrollView,
        ScrollEventType.MOMENTUM_BEGIN,
        xVelocity.toFloat(),
        yVelocity.toFloat(),
    )
  }

  @JvmStatic
  public fun <T> emitScrollMomentumEndEvent(scrollView: T)
      where T : HasScrollEventThrottle?, T : ViewGroup {
    emitScrollEvent(scrollView, ScrollEventType.MOMENTUM_END)
  }

  private fun <T> emitScrollEvent(scrollView: T, scrollEventType: ScrollEventType)
      where T : HasScrollEventThrottle?, T : ViewGroup {
    emitScrollEvent(scrollView, scrollEventType, 0f, 0f)
  }

  private fun <T> emitScrollEvent(
      scrollView: T,
      scrollEventType: ScrollEventType,
      xVelocity: Float,
      yVelocity: Float,
  ) where T : HasScrollEventThrottle?, T : ViewGroup {
    val now = System.currentTimeMillis()
    // Throttle the scroll event if scrollEventThrottle is set to be equal or more than 17 ms.
    // We limit the delta to 17ms so that small throttles intended to enable 60fps updates will not
    // inadvertently filter out any scroll events.
    if (
        scrollEventType == ScrollEventType.SCROLL &&
            scrollView.scrollEventThrottle >= max(17, now - scrollView.lastScrollDispatchTime)
    ) {
      // Scroll events are throttled.
      return
    }
    val contentView = scrollView.getChildAt(0) ?: return
    for (scrollListener in scrollListeners.toList()) {
      scrollListener.get()?.onScroll(scrollView, scrollEventType, xVelocity, yVelocity)
    }
    val reactContext = scrollView.context as ReactContext
    val surfaceId = UIManagerHelper.getSurfaceId(reactContext)

    // It's possible for the EventDispatcher to go away - for example,
    // if there's a crash initiated from JS and we tap on a ScrollView
    // around teardown of RN, this will cause a NPE. We can safely ignore
    // this since the crash is usually a red herring.
    val eventDispatcher = UIManagerHelper.getEventDispatcher(reactContext)
    if (eventDispatcher != null) {
      eventDispatcher.dispatchEvent(
          ScrollEvent.obtain(
              surfaceId,
              scrollView.id,
              scrollEventType,
              scrollView.scrollX.toFloat(),
              scrollView.scrollY.toFloat(),
              xVelocity,
              yVelocity,
              contentView.width,
              contentView.height,
              scrollView.width,
              scrollView.height,
          )
      )
      if (scrollEventType == ScrollEventType.SCROLL) {
        scrollView.lastScrollDispatchTime = now
      }
    }
  }

  @JvmStatic
  @JvmName("notifyUserDrivenScrollEnded_internal")
  internal fun notifyUserDrivenScrollEnded(scrollView: ViewGroup) {
    val reactContext = scrollView.context as? ReactContext
    reactContext?.scrollEndedListeners?.notifyScrollEnded(scrollView)
  }

  /** This is only for Java listeners. onLayout events emitted to JS are handled elsewhere. */
  @JvmStatic
  public fun emitLayoutEvent(scrollView: ViewGroup) {
    for (scrollListener in scrollListeners) {
      scrollListener.get()?.onLayout(scrollView)
    }
  }

  @JvmStatic
  public fun emitLayoutChangeEvent(scrollView: ViewGroup) {
    for (listener in layoutChangeListeners) {
      listener.get()?.onLayoutChange(scrollView)
    }
  }

  @JvmStatic
  public fun parseOverScrollMode(jsOverScrollMode: String?): Int {
    return if (jsOverScrollMode == null || jsOverScrollMode == AUTO) {
      View.OVER_SCROLL_IF_CONTENT_SCROLLS
    } else if (jsOverScrollMode == OVER_SCROLL_ALWAYS) {
      View.OVER_SCROLL_ALWAYS
    } else if (jsOverScrollMode == OVER_SCROLL_NEVER) {
      View.OVER_SCROLL_NEVER
    } else {
      FLog.w(ReactConstants.TAG, "wrong overScrollMode: $jsOverScrollMode")
      View.OVER_SCROLL_IF_CONTENT_SCROLLS
    }
  }

  @JvmStatic
  public fun parseSnapToAlignment(alignment: String?): Int {
    return if (alignment == null) {
      SNAP_ALIGNMENT_DISABLED
    } else if ("start".equals(alignment, ignoreCase = true)) {
      SNAP_ALIGNMENT_START
    } else if ("center".equals(alignment, ignoreCase = true)) {
      SNAP_ALIGNMENT_CENTER
    } else if ("end" == alignment) {
      SNAP_ALIGNMENT_END
    } else {
      FLog.w(ReactConstants.TAG, "wrong snap alignment value: $alignment")
      SNAP_ALIGNMENT_DISABLED
    }
  }

  @JvmStatic
  public fun getDefaultScrollAnimationDuration(context: Context?): Int {
    if (!smoothScrollDurationInitialized) {
      smoothScrollDurationInitialized = true
      try {
        val overScrollerDurationGetter = OverScrollerDurationGetter(context)
        SMOOTH_SCROLL_DURATION = overScrollerDurationGetter.scrollAnimationDuration
      } catch (e: Throwable) {}
    }
    return SMOOTH_SCROLL_DURATION
  }

  /**
   * Adds a scroll listener.
   *
   * Note that you must keep a reference to this scroll listener because this class only keeps a
   * weak reference to it (to prevent memory leaks). This means that code like `
   * addScrollListener(new ScrollListener() {...})` won't work, you need to do this instead: `
   * mScrollListener = new ScrollListener() {...};
   * ReactScrollViewHelper.addScrollListener(mScrollListener); ` * instead.
   *
   * @param listener
   */
  @JvmStatic
  public fun addScrollListener(listener: ScrollListener) {
    scrollListeners.add(WeakReference(listener))
  }

  @RequiresApi(Build.VERSION_CODES.N)
  @JvmStatic
  public fun removeScrollListener(listener: ScrollListener) {
    // Avoid using removeIf, only available in API 26+
    val toRemove = ArrayList<WeakReference<ScrollListener>>()
    for (ref in scrollListeners) {
      val target = ref.get()
      if (target == null || target == listener) {
        toRemove.add(ref)
      }
    }
    scrollListeners.removeAll(toRemove)
  }

  @JvmStatic
  public fun addLayoutChangeListener(listener: LayoutChangeListener) {
    layoutChangeListeners.add(WeakReference(listener))
  }

  @RequiresApi(Build.VERSION_CODES.N)
  @JvmStatic
  public fun removeLayoutChangeListener(listener: LayoutChangeListener) {
    // Avoid using removeIf, only available in API 26+
    val toRemove = ArrayList<WeakReference<LayoutChangeListener>>()
    for (ref in layoutChangeListeners) {
      val target = ref.get()
      if (target == null || target == listener) {
        toRemove.add(ref)
      }
    }
    layoutChangeListeners.removeAll(toRemove)
  }

  /**
   * Scroll the given view to the location (x, y), with provided initial velocity. This method works
   * by calculate the "would be" initial velocity with internal friction to move to the point (x,
   * y), then apply that to the animator.
   */
  @JvmStatic
  public fun <T> smoothScrollTo(scrollView: T, x: Int, y: Int)
      where T : HasFlingAnimator?, T : HasScrollState?, T : HasStateWrapper?, T : ViewGroup {
    if (DEBUG_MODE) {
      FLog.i(TAG, "smoothScrollTo[%d] x %d y %d", scrollView.id, x, y)
    }

    // Register the listeners for the fling animator if there isn't any
    val flingAnimator = scrollView.getFlingAnimator()
    if (flingAnimator.listeners == null || flingAnimator.listeners.size == 0) {
      registerFlingAnimator(scrollView)
    }
    val scrollState = scrollView.reactScrollViewScrollState
    scrollState.setFinalAnimatedPositionScroll(x, y)
    val scrollX = scrollView.scrollX
    val scrollY = scrollView.scrollY
    // Only one fling animator will be started. For the horizontal scroll view, scrollY will always
    // be the same to y. This is the same to the vertical scroll view.
    if (scrollX != x) {
      scrollView.startFlingAnimator(scrollX, x)
    }
    if (scrollY != y) {
      scrollView.startFlingAnimator(scrollY, y)
    }
  }

  /** Get current position or position after current animation finishes, if any. */
  @JvmStatic
  public fun <T> getNextFlingStartValue(
      scrollView: T,
      currentValue: Int,
      postAnimationValue: Int,
      velocity: Int,
  ): Int where T : HasFlingAnimator?, T : HasScrollState?, T : ViewGroup {
    val scrollState = scrollView.reactScrollViewScrollState
    val velocityDirectionMask = if (velocity != 0) velocity / abs(velocity) else 0
    val isMovingTowardsAnimatedValue =
        velocityDirectionMask * (postAnimationValue - currentValue) > 0

    // When the fling animation is not finished, or it was canceled and now we are moving towards
    // the final animated value, we will return the final animated value. This is because follow up
    // animation should consider the "would be" animated location, so that previous quick small
    // scrolls are still working.
    return if (
        !scrollState.isFinished || (scrollState.isCanceled && isMovingTowardsAnimatedValue)
    ) {
      postAnimationValue
    } else {
      currentValue
    }
  }

  @JvmStatic
  public fun <T> updateFabricScrollState(scrollView: T)
      where T : HasFlingAnimator?, T : HasScrollState?, T : HasStateWrapper?, T : ViewGroup {
    updateFabricScrollState(scrollView, scrollView.scrollX, scrollView.scrollY)
  }

  /**
   * Called on any stabilized onScroll change to propagate content offset value to a Shadow Node.
   */
  public fun <T> updateFabricScrollState(scrollView: T, scrollX: Int, scrollY: Int)
      where T : HasScrollState?, T : HasStateWrapper?, T : ViewGroup {
    if (DEBUG_MODE) {
      FLog.i(
          TAG,
          "updateFabricScrollState[%d] scrollX %d scrollY %d",
          scrollView.id,
          scrollX,
          scrollY,
      )
    }
    if (ViewUtil.getUIManagerType(scrollView.id) == UIManagerType.LEGACY) {
      return
    }
    // NOTE: if the state wrapper is null, we shouldn't even update
    // the scroll state because there is a chance of going out of sync!
    if (scrollView.stateWrapper == null) {
      return
    }
    val scrollState = scrollView.reactScrollViewScrollState

    // User driven scrolling should disable scroll state updates coming from Fabric
    scrollState.isUpdatedByScroll = true

    // Dedupe events to reduce JNI traffic
    if (scrollState.lastStateUpdateScroll.equals(scrollX, scrollY)) {
      return
    }
    scrollState.setLastStateUpdateScroll(scrollX, scrollY)
    forceUpdateState(scrollView)
  }

  @JvmStatic
  public fun <T> forceUpdateState(scrollView: T)
      where T : HasScrollState?, T : HasStateWrapper?, T : ViewGroup {
    val scrollState = scrollView.reactScrollViewScrollState
    val scrollAwayPaddingTop = scrollState.scrollAwayPaddingTop
    val scrollPos = scrollState.lastStateUpdateScroll
    val scrollX = scrollPos.x
    val scrollY = scrollPos.y
    if (DEBUG_MODE) {
      FLog.i(
          TAG,
          "updateFabricScrollState[%d] scrollX %d scrollY %d",
          scrollView.id,
          scrollX,
          scrollY,
      )
    }
    val stateWrapper = scrollView.stateWrapper
    if (stateWrapper != null) {
      val newStateData: WritableMap = WritableNativeMap()
      newStateData.putDouble(CONTENT_OFFSET_LEFT, toDIPFromPixel(scrollX.toFloat()).toDouble())
      newStateData.putDouble(CONTENT_OFFSET_TOP, toDIPFromPixel(scrollY.toFloat()).toDouble())
      newStateData.putDouble(
          SCROLL_AWAY_PADDING_TOP,
          toDIPFromPixel(scrollAwayPaddingTop.toFloat()).toDouble(),
      )
      stateWrapper.updateState(newStateData)
    }
  }

  @JvmStatic
  internal fun <T> loadFabricScrollState(scrollView: T, stateWrapper: StateWrapper)
      where T : HasScrollState?, T : HasStateWrapper?, T : ViewGroup {
    if (scrollView.reactScrollViewScrollState.isUpdatedByScroll) {
      return
    }

    val stateData = stateWrapper.stateData
    if (stateData == null) {
      return
    }

    // Assign the data loaded from the shadow node state
    val scrollX = toPixelFromDIP(stateData.getDouble(CONTENT_OFFSET_LEFT)).toInt()
    val scrollY = toPixelFromDIP(stateData.getDouble(CONTENT_OFFSET_TOP)).toInt()
    val scrollAwayPaddingTop = toPixelFromDIP(stateData.getDouble(SCROLL_AWAY_PADDING_TOP)).toInt()

    val scrollState =
        scrollView.reactScrollViewScrollState.copy(scrollAwayPaddingTop = scrollAwayPaddingTop)
    scrollState.setLastStateUpdateScroll(scrollX, scrollY)
    scrollView.reactScrollViewScrollState = scrollState
  }

  @JvmStatic
  public fun <T> updateStateOnScrollChanged(scrollView: T, xVelocity: Float, yVelocity: Float)
      where
          T : HasFlingAnimator?,
          T : HasScrollEventThrottle?,
          T : HasScrollState?,
          T : HasStateWrapper?,
          T : ViewGroup {
    // Race an UpdateState with every onScroll. This makes it more likely that, in Fabric,
    // when JS processes the scroll event, the C++ ShadowNode representation will have a
    // "more correct" scroll position. It will frequently be /incorrect/ but this decreases
    // the error as much as possible.
    updateFabricScrollState(scrollView, scrollView.scrollX, scrollView.scrollY)
    emitScrollEvent(scrollView, xVelocity, yVelocity)
  }

  public fun <T> registerFlingAnimator(scrollView: T)
      where T : HasFlingAnimator?, T : HasScrollState?, T : HasStateWrapper?, T : ViewGroup {
    scrollView
        .getFlingAnimator()
        .addListener(
            object : Animator.AnimatorListener {
              override fun onAnimationStart(animator: Animator) {
                val scrollState = scrollView.reactScrollViewScrollState
                scrollState.isCanceled = false
                scrollState.isFinished = false
              }

              override fun onAnimationEnd(animator: Animator) {
                scrollView.reactScrollViewScrollState.isFinished = true
                notifyUserDrivenScrollEnded(scrollView)
                updateFabricScrollState(scrollView)
              }

              override fun onAnimationCancel(animator: Animator) {
                scrollView.reactScrollViewScrollState.isCanceled = true
                notifyUserDrivenScrollEnded(scrollView)
              }

              override fun onAnimationRepeat(animator: Animator) = Unit
            }
        )
  }

  @JvmStatic
  public fun <T> dispatchMomentumEndOnAnimationEnd(scrollView: T)
      where T : HasFlingAnimator?, T : HasScrollEventThrottle?, T : ViewGroup {
    scrollView
        .getFlingAnimator()
        .addListener(
            object : Animator.AnimatorListener {
              override fun onAnimationStart(animator: Animator) = Unit

              override fun onAnimationEnd(animator: Animator) {
                emitScrollMomentumEndEvent(scrollView)
                animator.removeListener(this)
              }

              override fun onAnimationCancel(animator: Animator) {
                emitScrollMomentumEndEvent(scrollView)
                animator.removeListener(this)
              }

              override fun onAnimationRepeat(animator: Animator) = Unit
            }
        )
  }

  @JvmStatic
  public fun <T> predictFinalScrollPosition(
      scrollView: T,
      velocityX: Int,
      velocityY: Int,
      maximumOffsetX: Int,
      maximumOffsetY: Int,
  ): Point where T : HasFlingAnimator?, T : HasScrollState?, T : ViewGroup {
    val scrollState = scrollView.reactScrollViewScrollState
    // ScrollView can *only* scroll for 250ms when using smoothScrollTo and there's
    // no way to customize the scroll duration. So, we create a temporary OverScroller
    // so we can predict where a fling would land and snap to nearby that point.
    val scroller = OverScroller(scrollView.context)
    scroller.setFriction(1.0f - scrollState.decelerationRate)

    // predict where a fling would end up so we can scroll to the nearest snap offset
    val width = scrollView.width - scrollView.paddingStart - scrollView.paddingEnd
    val height = scrollView.height - scrollView.paddingBottom - scrollView.paddingTop
    val finalAnimatedPositionScroll = scrollState.finalAnimatedPositionScroll
    scroller.fling(
        getNextFlingStartValue(
            scrollView,
            scrollView.scrollX,
            finalAnimatedPositionScroll.x,
            velocityX,
        ), // startX
        getNextFlingStartValue(
            scrollView,
            scrollView.scrollY,
            finalAnimatedPositionScroll.y,
            velocityY,
        ), // startY
        velocityX, // velocityX
        velocityY, // velocityY
        0, // minX
        maximumOffsetX, // maxX
        0, // minY
        maximumOffsetY, // maxY
        width / 2, // overX
        height / 2, // overY
    )
    return Point(scroller.finalX, scroller.finalY)
  }

  @JvmStatic
  public fun findNextFocusableView(
      host: ViewGroup,
      focused: View,
      @FocusDirection direction: Int,
  ): View? {
    if (host !is ReactClippingViewGroup) {
      return null
    }

    val uimanager =
        UIManagerHelper.getUIManager(host.context as ReactContext, UIManagerType.FABRIC)
            ?: return null

    val nextFocusableViewId =
        (uimanager as FabricUIManager).findNextFocusableElement(host.id, focused.id, direction)
            ?: return null

    val ancestorIdList =
        uimanager
            .getRelativeAncestorList(host.getChildAt(0).id, nextFocusableViewId)
            ?.toMutableSet() ?: return null

    ancestorIdList.add(nextFocusableViewId)

    host.updateClippingRect(ancestorIdList)

    return host.findViewById(nextFocusableViewId)
  }

  @JvmStatic
  public fun resolveAbsoluteDirection(
      @FocusRealDirection direction: Int,
      horizontal: Boolean,
      layoutDirection: Int,
  ): Int {
    val rtl: Boolean = layoutDirection == View.LAYOUT_DIRECTION_RTL

    return if (direction == View.FOCUS_FORWARD || direction == View.FOCUS_BACKWARD) {
      if (horizontal) {
        if ((direction == View.FOCUS_FORWARD) != rtl) View.FOCUS_RIGHT else View.FOCUS_LEFT
      } else {
        if (direction == View.FOCUS_FORWARD) View.FOCUS_DOWN else View.FOCUS_UP
      }
    } else {
      direction
    }
  }

  public interface ScrollListener {
    public fun onScroll(
        scrollView: ViewGroup?,
        scrollEventType: ScrollEventType?,
        xVelocity: Float,
        yVelocity: Float,
    )

    public fun onLayout(scrollView: ViewGroup?)
  }

  public interface LayoutChangeListener {
    public fun onLayoutChange(scrollView: ViewGroup)
  }

  public interface HasStateWrapper {
    public val stateWrapper: StateWrapper?
  }

  private class OverScrollerDurationGetter(context: Context?) : OverScroller(context) {
    // This is the default in AOSP, hardcoded in OverScroller.java.
    private var currentScrollAnimationDuration = 250
    val scrollAnimationDuration: Int
      get() {
        // If startScroll is called without a duration, OverScroller will call `startScroll(x, y,
        // dx,
        // dy, duration)` with the default duration.
        super.startScroll(0, 0, 0, 0)
        return currentScrollAnimationDuration
      }

    override fun startScroll(startX: Int, startY: Int, dx: Int, dy: Int, duration: Int) {
      currentScrollAnimationDuration = duration
    }
  }

  public data class ReactScrollViewScrollState(
      /** Get the position after current animation is finished */
      val finalAnimatedPositionScroll: Point = Point(),
      /** Get the padding on the top for nav bar */
      var scrollAwayPaddingTop: Int = 0,
      /** Get the Fabric state of last scroll position */
      val lastStateUpdateScroll: Point = Point(-1, -1),
      /** Get true if the previous animation was canceled */
      var isCanceled: Boolean = false,
      /** Get true if previous animation was finished */
      var isFinished: Boolean = true,
      /** Get true if previous animation was finished */
      var decelerationRate: Float = 0.985f,
      /** Get true if the component submitted the state through user scrolling */
      var isUpdatedByScroll: Boolean = false,
  ) {
    /** Set the final scroll position after scrolling animation is finished */
    public fun setFinalAnimatedPositionScroll(
        finalAnimatedPositionScrollX: Int,
        finalAnimatedPositionScrollY: Int,
    ): ReactScrollViewScrollState {
      finalAnimatedPositionScroll.set(finalAnimatedPositionScrollX, finalAnimatedPositionScrollY)
      return this
    }

    /** Set the Fabric state of last scroll position */
    public fun setLastStateUpdateScroll(
        lastStateUpdateScrollX: Int,
        lastStateUpdateScrollY: Int,
    ): ReactScrollViewScrollState {
      lastStateUpdateScroll.set(lastStateUpdateScrollX, lastStateUpdateScrollY)
      return this
    }
  }

  public interface HasScrollState {
    /** Get the scroll state for the current ScrollView */
    public var reactScrollViewScrollState: ReactScrollViewScrollState
  }

  public interface HasFlingAnimator {
    /**
     * Start the fling animator that the ScrollView has to go from the start position to end
     * position.
     */
    public fun startFlingAnimator(start: Int, end: Int)

    /** Get the fling animator that is reused for the ScrollView to handle fling animation. */
    public fun getFlingAnimator(): ValueAnimator

    /** Get the fling distance with current velocity for prediction */
    public fun getFlingExtrapolatedDistance(velocity: Int): Int
  }

  public interface HasScrollEventThrottle {
    /**
     * The scroll event throttle in ms. This number is used to throttle the scroll events. The
     * default value is zero, which means the scroll events are sent with no throttle.
     */
    public var scrollEventThrottle: Int

    /** The scroll view's last dispatch time for throttling */
    public var lastScrollDispatchTime: Long
  }

  public interface HasSmoothScroll {
    public fun reactSmoothScrollTo(x: Int, y: Int)

    public fun scrollToPreservingMomentum(x: Int, y: Int)
  }
}
