import { useEffect, useRef } from 'react';
import {
  type EmitterSubscription,
  Keyboard,
  View,
  useWindowDimensions,
} from 'react-native';
import type { HeightAnimationDriver, UseHandleKeyboardEvents } from './types.d';

/**
 * Handles keyboard pop out by adjusting sheet's layout when a `TextInput` within
 * the sheet receives focus.
 *
 * @param {boolean} keyboardHandlingEnabled Determines whether this hook will go on to handle keyboard
 * @param {number} sheetHeight Initial sheet's height before keyboard pop out
 * @param {boolean} sheetOpen Indicates whether the sheet is open or closed
 * @param {HeightAnimationDriver} heightAnimationDriver Animator function to be called with new
 * sheet height when keyboard is out so it can adjust the sheet height with animation
 * @param {React.MutableRefObject<View>} contentWrapperRef Reference to the content wrapper view
 * @return {{removeKeyboardListeners:Function;} | null} An Object with an unsubscriber function or `null`
 *  when `keyboardHandlingEnabled` is false
 */
const useHandleKeyboardEvents: UseHandleKeyboardEvents = (
  keyboardHandlingEnabled: boolean,
  sheetHeight: number,
  sheetOpen: boolean,
  heightAnimationDriver: HeightAnimationDriver,
  contentWrapperRef: React.RefObject<View>
) => {
  const SCREEN_HEIGHT = useWindowDimensions().height;
  const keyboardHideSubscription = useRef<EmitterSubscription>();
  const keyboardShowSubscription = useRef<EmitterSubscription>();

  const unsubscribe = () => {
    keyboardHideSubscription.current?.remove?.();
    keyboardShowSubscription.current?.remove?.();
  };

  useEffect(() => {
    if (keyboardHandlingEnabled) {
      keyboardShowSubscription.current = Keyboard.addListener(
        'keyboardDidShow',
        ({ endCoordinates: { height: keyboardHeight } }) => {
          if (sheetOpen) {
            // Exaggeration of the actual height (24) of the autocorrect view
            // that appears atop android keyboard
            const keyboardAutoCorrectViewHeight = 50;
            contentWrapperRef.current?.measure?.((...result) => {
              const sheetYOffset = result[5]; // Y offset of the sheet after keyboard is out
              const actualSheetHeight = SCREEN_HEIGHT - sheetYOffset; // new height of the sheet (after keyboard offset)
              /**
               * We determine soft input/keyboard mode based on the difference between the new sheet height and the
               * initial height after keyboard is opened. If there's no much difference, it's adjustPan
               * (keyboard overlays sheet), else it's adjustResize (sheet is pushed up)
               */
              const sheetIsOverlayed =
                actualSheetHeight - sheetHeight < keyboardAutoCorrectViewHeight;
              const remainingSpace = SCREEN_HEIGHT - keyboardHeight;

              /**
               * this is 50% of the remaining space (SCREEN_HEIGHT - keyboardHeight) that remains atop the keybaord
               */
              const fiftyPercent = 0.5 * remainingSpace;
              const minSheetHeight = 50;
              // allow very short sheet e.g 10 to increase to 50 and
              // very long to clamp withing availablle space;
              let newSheetHeight = Math.max(
                minSheetHeight,
                Math.min(sheetHeight, fiftyPercent)
              );
              if (sheetIsOverlayed) newSheetHeight += keyboardHeight;
              heightAnimationDriver(newSheetHeight, 400).start();
            });
          }
        }
      );

      keyboardHideSubscription.current = Keyboard.addListener(
        'keyboardDidHide',
        (_) => {
          if (sheetOpen) heightAnimationDriver(sheetHeight, 200).start();
        }
      );
      return unsubscribe;
    }
    return;
  }, [
    keyboardHandlingEnabled,
    sheetHeight,
    SCREEN_HEIGHT,
    sheetOpen,
    heightAnimationDriver,
    contentWrapperRef,
  ]);

  return keyboardHandlingEnabled
    ? {
        removeKeyboardListeners: unsubscribe,
      }
    : null;
};

export default useHandleKeyboardEvents;