package com.fireworksdk.bridge.components.videofeed

import kotlin.math.ceil

/** UI-thread state for bounded forced measurement and native -> Yoga height feedback. */
internal class FWAutosizingState {
  enum class Pass { NONE, NORMAL, FORCE }

  private var dirty = true
  private var measuredWidth = -1
  private var roundActive = false
  private var passesLeft = 0
  private var previousHeightPx: Int? = null
  private var contentEmpty = false
  private var lastReportedHeightDp: Float? = null

  fun invalidate() {
    dirty = true
  }

  fun setContentEmpty(empty: Boolean) {
    contentEmpty = empty
    invalidate()
  }

  fun nextPass(width: Int, layoutRequested: Boolean): Pass {
    if (width <= 0) return Pass.NONE

    if (dirty || measuredWidth != width || (!roundActive && layoutRequested)) {
      dirty = false
      measuredWidth = width
      roundActive = true
      passesLeft = MAX_SETTLE_PASSES
      previousHeightPx = null
    }
    if (passesLeft > 0) {
      passesLeft--
      return Pass.FORCE
    }
    // Never restart the force-measure budget merely because the same round requested layout
    // again. After the budget is spent, honor actual layout requests without forcing clean views.
    if (layoutRequested) return Pass.NORMAL

    roundActive = false
    // RN can remeasure the wrapper with the current Yoga height between our frames,
    // constraining the native child and clearing its layout-request flag. A stable content
    // height therefore cannot suppress the normal pass that restores unbounded measurement.
    // Only forced subtree measurement stops after convergence; normal passes can use caches.
    return Pass.NORMAL
  }

  fun didMeasure(heightPx: Int) {
    if (previousHeightPx == heightPx) passesLeft = 0
    previousHeightPx = heightPx
  }

  fun heightToReport(heightPx: Int, density: Float): Float? {
    val heightDp = when {
      contentEmpty -> 0f
      heightPx <= 0 -> return null
      else -> ceil(heightPx / density)
    }
    if (heightDp == lastReportedHeightDp) return null
    lastReportedHeightDp = heightDp
    return heightDp
  }

  private companion object {
    const val MAX_SETTLE_PASSES = 8
  }
}