/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 */

import * as React from 'react';
import {useCallback, useContext, useMemo} from 'react';
import AutoSizer from 'react-virtualized-auto-sizer';
import {FixedSizeList} from 'react-window';
import {ProfilerContext} from './ProfilerContext';
import InteractionListItem from './InteractionListItem';
import NoInteractions from './NoInteractions';
import {StoreContext} from '../context';
import {scale} from './utils';

import styles from './Interactions.css';

import type {ProfilingDataForRootFrontend} from './types';
import type {ChartData} from './InteractionsChartBuilder';
import type {TabID} from './ProfilerContext';

export type ItemData = {|
  chartData: ChartData,
  dataForRoot: ProfilingDataForRootFrontend,
  labelWidth: number,
  scaleX: (value: number, fallbackValue: number) => number,
  selectedInteractionID: number | null,
  selectCommitIndex: (id: number | null) => void,
  selectInteraction: (id: number | null) => void,
  selectTab: (id: TabID) => void,
|};

export default function InteractionsAutoSizer(_: {||}) {
  return (
    <div className={styles.Container}>
      <AutoSizer>
        {({height, width}) => <Interactions height={height} width={width} />}
      </AutoSizer>
    </div>
  );
}

function Interactions({height, width}: {|height: number, width: number|}) {
  const {
    rootID,
    selectedInteractionID,
    selectInteraction,
    selectCommitIndex,
    selectTab,
  } = useContext(ProfilerContext);
  const {profilerStore} = useContext(StoreContext);
  const {profilingCache} = profilerStore;

  const dataForRoot = profilerStore.getDataForRoot(((rootID: any): number));

  const chartData = profilingCache.getInteractionsChartData({
    rootID: ((rootID: any): number),
  });

  const {interactions} = chartData;

  const handleKeyDown = useCallback(
    event => {
      let index;
      switch (event.key) {
        case 'ArrowDown':
          index = interactions.findIndex(
            interaction => interaction.id === selectedInteractionID,
          );
          selectInteraction(Math.min(interactions.length - 1, index + 1));
          event.stopPropagation();
          break;
        case 'ArrowUp':
          index = interactions.findIndex(
            interaction => interaction.id === selectedInteractionID,
          );
          selectInteraction(Math.max(0, index - 1));
          event.stopPropagation();
          break;
        default:
          break;
      }
    },
    [interactions, selectedInteractionID, selectInteraction],
  );

  const itemData = useMemo<ItemData>(() => {
    const interactionCommitSize = parseInt(
      getComputedStyle((document.body: any)).getPropertyValue(
        '--interaction-commit-size',
      ),
      10,
    );
    const interactionLabelWidth = parseInt(
      getComputedStyle((document.body: any)).getPropertyValue(
        '--interaction-label-width',
      ),
      10,
    );

    const labelWidth = Math.min(interactionLabelWidth, width / 5);
    const timelineWidth = width - labelWidth - interactionCommitSize;

    return {
      chartData,
      dataForRoot,
      labelWidth,
      scaleX: scale(0, chartData.lastInteractionTime, 0, timelineWidth),
      selectedInteractionID,
      selectCommitIndex,
      selectInteraction,
      selectTab,
    };
  }, [
    chartData,
    dataForRoot,
    selectedInteractionID,
    selectCommitIndex,
    selectInteraction,
    selectTab,
    width,
  ]);

  // If a commit contains no fibers with an actualDuration > 0,
  // Display a fallback message.
  if (interactions.length === 0) {
    return <NoInteractions height={height} width={width} />;
  }

  return (
    <div className={styles.FocusTarget} onKeyDown={handleKeyDown} tabIndex={0}>
      <FixedSizeList
        height={height}
        itemCount={interactions.length}
        itemData={itemData}
        itemSize={30}
        width={width}>
        {InteractionListItem}
      </FixedSizeList>
    </div>
  );
}