import { css, cx } from '@emotion/css';
import React, { FC, ReactNode, useCallback, useEffect, useState, useRef } from 'react';
import { useLocalStorage } from 'react-use';

import { GrafanaTheme2 } from '@grafana/data';
import { selectors } from '@grafana/e2e-selectors';
import { Counter, useStyles2 } from '@grafana/ui';
import { useQueryParams } from 'app/core/hooks/useQueryParams';
import { CollapseToggle } from 'app/features/alerting/unified/components/CollapseToggle';

import { PANEL_EDITOR_UI_STATE_STORAGE_KEY } from './state/reducers';

export interface OptionsPaneCategoryProps {
  id: string;
  title?: string;
  renderTitle?: (isExpanded: boolean) => React.ReactNode;
  isOpenDefault?: boolean;
  itemsCount?: number;
  forceOpen?: number;
  className?: string;
  isNested?: boolean;
  children: ReactNode;
}

const CATEGORY_PARAM_NAME = 'showCategory';

export const OptionsPaneCategory: FC<OptionsPaneCategoryProps> = React.memo(
  ({ id, title, children, forceOpen, isOpenDefault, renderTitle, className, itemsCount, isNested = false }) => {
    const initialIsExpanded = isOpenDefault !== false;
    const [savedState, setSavedState] = useLocalStorage(getOptionGroupStorageKey(id), {
      isExpanded: initialIsExpanded,
    });

    const styles = useStyles2(getStyles);
    const [queryParams, updateQueryParams] = useQueryParams();
    const [isExpanded, setIsExpanded] = useState(savedState?.isExpanded ?? initialIsExpanded);
    const manualClickTime = useRef(0);
    const ref = useRef<HTMLDivElement>(null);
    const isOpenFromUrl = queryParams[CATEGORY_PARAM_NAME] === id;

    useEffect(() => {
      if (manualClickTime.current) {
        // ignore changes since the click handled the expected behavior
        if (Date.now() - manualClickTime.current < 200) {
          return;
        }
      }
      if (isOpenFromUrl || forceOpen) {
        if (!isExpanded) {
          setIsExpanded(true);
        }
        if (isOpenFromUrl) {
          ref.current?.scrollIntoView();
        }
      }
    }, [forceOpen, isExpanded, isOpenFromUrl]);

    const onToggle = useCallback(() => {
      manualClickTime.current = Date.now();
      updateQueryParams({
        [CATEGORY_PARAM_NAME]: isExpanded ? undefined : id,
      });
      setSavedState({ isExpanded: !isExpanded });
      setIsExpanded(!isExpanded);
    }, [setSavedState, setIsExpanded, updateQueryParams, isExpanded, id]);

    if (!renderTitle) {
      renderTitle = function defaultTitle(isExpanded: boolean) {
        if (isExpanded || itemsCount === undefined || itemsCount === 0) {
          return title;
        }

        return (
          <span>
            {title} <Counter value={itemsCount} />
          </span>
        );
      };
    }

    const boxStyles = cx(
      {
        [styles.box]: true,
        [styles.boxNestedExpanded]: isNested && isExpanded,
      },
      className,
      'options-group'
    );

    const headerStyles = cx(styles.header, {
      [styles.headerExpanded]: isExpanded,
      [styles.headerNested]: isNested,
    });

    const bodyStyles = cx(styles.body, {
      [styles.bodyNested]: isNested,
    });

    return (
      <div
        className={boxStyles}
        data-testid="options-category"
        aria-label={selectors.components.OptionsGroup.group(id)}
        ref={ref}
      >
        <div className={headerStyles} onClick={onToggle} aria-label={selectors.components.OptionsGroup.toggle(id)}>
          <CollapseToggle isCollapsed={!isExpanded} idControlled={id} onToggle={onToggle} />
          <h6 id={`button-${id}`} className={styles.title}>
            {renderTitle(isExpanded)}
          </h6>
        </div>
        {isExpanded && (
          <div className={bodyStyles} id={id} aria-labelledby={`button-${id}`}>
            {children}
          </div>
        )}
      </div>
    );
  }
);

OptionsPaneCategory.displayName = 'OptionsPaneCategory';

const getStyles = (theme: GrafanaTheme2) => {
  return {
    box: css`
      border-top: 1px solid ${theme.colors.border.weak};
    `,
    boxNestedExpanded: css`
      margin-bottom: ${theme.spacing(2)};
    `,
    title: css`
      flex-grow: 1;
      overflow: hidden;
      line-height: 1.5;
      font-size: 1rem;
      font-weight: ${theme.typography.fontWeightMedium};
      margin: 0;
    `,
    header: css`
      display: flex;
      cursor: pointer;
      align-items: baseline;
      padding: ${theme.spacing(0.5)};
      color: ${theme.colors.text.primary};
      font-weight: ${theme.typography.fontWeightMedium};

      &:hover {
        background: ${theme.colors.emphasize(theme.colors.background.primary, 0.03)};
      }
    `,
    headerExpanded: css`
      color: ${theme.colors.text.primary};
    `,
    headerNested: css`
      padding: ${theme.spacing(0.5, 0, 0.5, 0)};
    `,
    body: css`
      padding: ${theme.spacing(1, 2, 1, 4)};
    `,
    bodyNested: css`
      position: relative;
      padding-right: 0;
      &:before {
        content: '';
        position: absolute;
        top: 0;
        left: 8px;
        width: 1px;
        height: 100%;
        background: ${theme.colors.border.weak};
      }
    `,
  };
};

const getOptionGroupStorageKey = (id: string): string => `${PANEL_EDITOR_UI_STATE_STORAGE_KEY}.optionGroup[${id}]`;