// @flow strict

import * as React from 'react';
import {
  // $FlowFixMe[untyped-import]
  autoUpdate,
  // $FlowFixMe[untyped-import]
  flip,
  // $FlowFixMe[untyped-import]
  offset,
  // $FlowFixMe[untyped-import]
  shift,
  // $FlowFixMe[untyped-import]
  useFloating,
} from '@floating-ui/react-dom';

import {sizeFluid} from '../../styles/variables/_size';
import {spaceNone, spaceXXSmall} from '../../styles/variables/_space';
import {classify} from '../../utils/classify';
import {ClickAway} from '../../utils/click-away';
import type {ButtonProps} from '../Button';
import {Button} from '../Button';
import type {MenuOption, MenuProps} from '../Menu';
import {Menu} from '../Menu';

import css from './ButtonDropdown.module.css';


export const ANCHOR_POSITION_TYPE = Object.freeze({
  top: 'top',
  topStart: 'top-start',
  topEnd: 'top-end',
  bottom: 'bottom',
  bottomStart: 'bottom-start',
  bottomEnd: 'bottom-end',
});

export type AnchorType = $Values<typeof ANCHOR_POSITION_TYPE>;
type ClassNames = $ReadOnly<{
  buttonWrapper?: string,
  dropdownContainer?: string,
  buttonIcon?: string,
}>;

export type ButtonDropdownProps = {
  ...ButtonProps,
  classNames?: ClassNames,
  menu?: MenuProps,
  anchorPosition?: AnchorType,
  onOptionSelect?: (option: MenuOption) => mixed,
  onMenuOpen?: () => mixed,
  onMenuClose?: () => mixed,
  ...
};

export const ButtonDropdown: React$AbstractComponent<
  ButtonDropdownProps,
  HTMLDivElement,
> = React.forwardRef<ButtonDropdownProps, HTMLDivElement>(
  (
    {
      anchorPosition = 'bottom-start',
      size = 'medium',
      onOptionSelect,
      menu,
      classNames,
      disabled,
      onMenuOpen,
      onMenuClose,
      children,
      iconRightName,
      iconRightType = 'solid',
      isFluid,
      ...restButtonProps
    }: ButtonDropdownProps,
    forwardRef,
  ) => {
    const menuBtnRef = React.useRef(null);
    React.useImperativeHandle(forwardRef, () => menuBtnRef.current);
    const {x, y, reference, floating, strategy} = useFloating({
      strategy: 'absolute',
      placement: anchorPosition,
      whileElementsMounted: autoUpdate,
      middleware: [shift(), flip(), offset(parseInt(spaceXXSmall))],
    });

    const onMenuToggle = (isOpen: boolean) => {
      isOpen ? onMenuOpen && onMenuOpen() : onMenuClose && onMenuClose();
    };

    return (
      <ClickAway onChange={onMenuToggle}>
        {({isOpen, onOpen, cancelNext, clickAway}) => (
          <div
            data-testid="ButtonDropdown"
            className={classify(
              css.buttonDropdownContainer,
              {
                [css.isFluid]: isFluid === true,
              },
              classNames?.dropdownContainer,
            )}
            ref={menuBtnRef}
          >
            <Button
              {...restButtonProps}
              iconRightName={
                children
                  ? iconRightName || (isOpen ? 'caret-up' : 'caret-down')
                  : iconRightName
              }
              iconRightType={iconRightType}
              disabled={disabled}
              size={size}
              ref={reference}
              onClick={(e) => {
                e.stopPropagation();
                onOpen();
              }}
              isFluid={isFluid}
              classNames={{
                wrapper: classNames?.buttonWrapper,
                icon: classNames?.buttonIcon,
              }}
            >
              {children}
            </Button>

            {isOpen && menu && (
              <div
                onClickCapture={cancelNext}
                ref={floating}
                style={{
                  display: 'flex',
                  position: strategy,
                  top: y ?? spaceNone,
                  left: x ?? spaceNone,
                  ...(isFluid && {width: sizeFluid}),
                }}
              >
                <Menu
                  {...menu}
                  onSelect={(option) => {
                    onOptionSelect && onOptionSelect(option);
                    if (
                      !menu.optionsVariant ||
                      menu.optionsVariant === 'normal'
                    ) {
                      clickAway();
                    }
                  }}
                  size={menu.size || size}
                />
              </div>
            )}
          </div>
        )}
      </ClickAway>
    );
  },
);