import React, {
  forwardRef,
  RefObject,
  useCallback,
  useEffect,
  useRef,
} from 'react';
import {m} from 'framer-motion';
import {mergeProps, useObjectRef} from '@react-aria/utils';
import {PopoverAnimation} from './popover-animation';
import {OverlayProps} from './overlay-props';
import {useOverlayViewport} from './use-overlay-viewport';
import {FocusScope} from '@react-aria/focus';
import {VirtualElement} from '@floating-ui/react-dom';

export const Popover = forwardRef<HTMLDivElement, OverlayProps>(
  (
    {
      children,
      style,
      autoFocus = false,
      restoreFocus = true,
      isDismissable,
      isContextMenu,
      isOpen,
      onClose,
      triggerRef,
      arrowRef,
      arrowStyle,
      onPointerLeave,
      onPointerEnter,
    },
    ref
  ) => {
    const viewPortStyle = useOverlayViewport();
    const objRef = useObjectRef(ref);

    const {domProps} = useCloseOnInteractOutside(
      {
        isDismissable,
        isOpen,
        onClose,
        triggerRef,
        isContextMenu,
      },
      objRef
    );

    return (
      <m.div
        className="z-popover isolate"
        role="presentation"
        ref={objRef}
        style={{...viewPortStyle, ...style, position: 'fixed'}}
        {...PopoverAnimation}
        {...mergeProps(domProps as any, {onPointerLeave, onPointerEnter})}
      >
        <FocusScope
          restoreFocus={restoreFocus}
          autoFocus={autoFocus}
          contain={false}
        >
          {children}
        </FocusScope>
      </m.div>
    );
  }
);

// this should only be rendered when overlay is open
const visibleOverlays: RefObject<Element>[] = [];
interface useCloseOnInteractOutsideProps {
  isOpen: boolean;
  onClose: () => void;
  isDismissable: boolean;
  isContextMenu?: boolean;
  triggerRef: OverlayProps['triggerRef'];
}
function useCloseOnInteractOutside(
  {
    onClose,
    isDismissable = true,
    triggerRef,
    isContextMenu = false,
  }: useCloseOnInteractOutsideProps,
  ref: RefObject<Element>
) {
  const stateRef = useRef({
    isPointerDown: false,
    isContextMenu,
    onClose,
  });
  const state = stateRef.current;
  state.isContextMenu = isContextMenu;
  state.onClose = onClose;

  const isValidEvent = useCallback(
    (e: PointerEvent | MouseEvent) => {
      // if (e.button > 0 && (!state.isContextMenu || e.button !== 2)) {
      //   return false;
      // }

      const target = e.target as Element;

      // if the event target is no longer in the document
      if (target) {
        const ownerDocument = target.ownerDocument;
        if (!ownerDocument || !ownerDocument.documentElement.contains(target)) {
          return false;
        }
      }

      return ref.current && !ref.current.contains(target);
    },
    [ref]
  );

  // Only hide the overlay when it is the topmost visible overlay in the stack.
  // For context menu, hide it regardless
  const isTopMostPopover = useCallback(() => {
    return visibleOverlays[visibleOverlays.length - 1] === ref;
  }, [ref]);

  const hideOverlay = useCallback(() => {
    if (isTopMostPopover()) {
      state.onClose();
    }
  }, [isTopMostPopover, state]);

  const clickedOnTriggerElement = useCallback(
    (el: Element) => {
      if (triggerRef.current && 'contains' in triggerRef.current) {
        return triggerRef.current.contains?.(el);
      }
      return false;
    },
    [triggerRef]
  );

  const onInteractOutsideStart = useCallback(
    (e: PointerEvent) => {
      if (!clickedOnTriggerElement(e.target as Element)) {
        if (isTopMostPopover()) {
          e.stopPropagation();
          e.preventDefault();
        }
      }
    },
    [clickedOnTriggerElement, isTopMostPopover]
  );

  const onInteractOutside = useCallback(
    (e: PointerEvent) => {
      if (!clickedOnTriggerElement(e.target as Element)) {
        if (isTopMostPopover()) {
          e.stopPropagation();
          e.preventDefault();
        }
        // don't close context menu on right click, it will be done in "onInteractOutsideStart" already.
        // And it would prevent repositioning of context menu when right-clicking on the same element
        if (!state.isContextMenu || e.button !== 2) {
          hideOverlay();
        }
      }
    },
    [clickedOnTriggerElement, hideOverlay, state, isTopMostPopover]
  );

  // Add popover ref to the stack of visible popovers on mount, and remove on unmount.
  useEffect(() => {
    visibleOverlays.push(ref);

    // handle pointer up and down events
    const onPointerDown = (e: PointerEvent) => {
      if (isValidEvent(e)) {
        onInteractOutsideStart(e);
        stateRef.current.isPointerDown = true;
      }
    };
    const onPointerUp = (e: PointerEvent) => {
      if (stateRef.current.isPointerDown && isValidEvent(e)) {
        stateRef.current.isPointerDown = false;
        onInteractOutside(e);
      }
    };

    // handle context menu event
    const onContextMenu = (e: MouseEvent) => {
      e.preventDefault();
      if (isValidEvent(e)) {
        hideOverlay();
      }
    };

    // handle closing on scroll
    const onScroll = (e: Event) => {
      if (!triggerRef.current) {
        return;
      }

      const scrollableRegion = e.target;
      let triggerEl: Element | undefined;
      if (triggerRef.current instanceof Node) {
        triggerEl = triggerRef.current;
      } else if ('contextElement' in triggerRef.current) {
        triggerEl = (triggerRef.current as VirtualElement).contextElement;
      }
      // window is not a Node and doesn't have "contain", but window contains everything
      if (
        !(scrollableRegion instanceof Node) ||
        !triggerEl ||
        scrollableRegion.contains(triggerEl)
      ) {
        state.onClose();
      }
    };

    document.addEventListener('pointerdown', onPointerDown, true);
    document.addEventListener('pointerup', onPointerUp, true);
    document.addEventListener('contextmenu', onContextMenu, true);
    document.addEventListener('scroll', onScroll, true);

    return () => {
      const index = visibleOverlays.indexOf(ref);
      if (index >= 0) {
        visibleOverlays.splice(index, 1);
      }
      document.removeEventListener('pointerdown', onPointerDown, true);
      document.removeEventListener('pointerup', onPointerUp, true);
      document.removeEventListener('contextmenu', onContextMenu, true);
      document.removeEventListener('scroll', onScroll, true);
    };
  }, [
    ref,
    isValidEvent,
    state,
    onInteractOutside,
    onInteractOutsideStart,
    triggerRef,
    clickedOnTriggerElement,
    hideOverlay,
  ]);

  // Handle the escape key
  const onKeyDown = (e: KeyboardEvent) => {
    if (e.key === 'Escape') {
      e.stopPropagation();
      e.preventDefault();
      hideOverlay();
    }
  };

  return {
    domProps: {
      onKeyDown,
    },
  };
}