package com.swmansion.reanimated.keyboard

import androidx.core.view.WindowInsetsCompat
import com.facebook.react.uimanager.PixelUtil

class Keyboard {
    private var mState = KeyboardState.UNKNOWN
    private var mHeight = 0
    private var mActiveTransitionCounter = 0

    companion object {
        private val CONTENT_TYPE_MASK = WindowInsetsCompat.Type.ime()
        private val SYSTEM_BAR_TYPE_MASK = WindowInsetsCompat.Type.systemBars()
    }

    fun getState(): KeyboardState = mState

    fun getHeight(): Int = mHeight

    fun updateHeight(
        insets: WindowInsetsCompat,
        isNavigationBarTranslucent: Boolean,
    ) {
        val contentBottomInset = insets.getInsets(CONTENT_TYPE_MASK).bottom
        val systemBarBottomInset =
            if (isNavigationBarTranslucent) 0 else insets.getInsets(SYSTEM_BAR_TYPE_MASK).bottom
        val keyboardHeightDip = contentBottomInset - systemBarBottomInset
        val keyboardHeight = PixelUtil.toDIPFromPixel(Math.max(0, keyboardHeightDip).toFloat()).toInt()
        if (keyboardHeight <= 0 && mState == KeyboardState.OPEN) {
      /*
      When the keyboard is being canceling, for one frame the insets show a keyboard height of 0,
      causing a jump of the keyboard. We can avoid it by ignoring that frame and calling
      the listeners on the following frame.
       */
            return
        }
        mHeight = keyboardHeight
    }

    fun onAnimationStart() {
        if (mActiveTransitionCounter > 0) {
            mState = if (mState == KeyboardState.OPENING) KeyboardState.CLOSING else KeyboardState.OPENING
        } else {
            mState = if (mHeight <= 0) KeyboardState.OPENING else KeyboardState.CLOSING
        }
        mActiveTransitionCounter++
    }

    fun onAnimationEnd() {
        mActiveTransitionCounter--
        if (mActiveTransitionCounter == 0) {
            mState = if (mHeight <= 0) KeyboardState.CLOSED else KeyboardState.OPEN
        }
    }
}