// @flow
import * as ICONS from 'constants/icons';
import { BLOCK_LEVEL } from 'constants/comment';
import React from 'react';
import classnames from 'classnames';
import moment from 'moment';
import humanizeDuration from 'humanize-duration';
import BlockList from 'component/blockList';
import ClaimPreview from 'component/claimPreview';
import Page from 'component/page';
import Spinner from 'component/spinner';
import Button from 'component/button';
import usePersistedState from 'effects/use-persisted-state';
import ChannelBlockButton from 'component/channelBlockButton';
import ChannelMuteButton from 'component/channelMuteButton';

const VIEW = {
  BLOCKED: 'blocked',
  ADMIN: 'admin',
  MODERATOR: 'moderator',
  MUTED: 'muted',
};

type Props = {
  mutedUris: ?Array<string>,
  personalBlockList: ?Array<string>,
  adminBlockList: ?Array<string>,
  moderatorBlockList: ?Array<string>,
  personalTimeoutMap: { [uri: string]: { blockedAt: string, bannedFor: number, banRemaining: number } },
  adminTimeoutMap: { [uri: string]: { blockedAt: string, bannedFor: number, banRemaining: number } },
  moderatorTimeoutMap: { [uri: string]: { blockedAt: string, bannedFor: number, banRemaining: number } },
  moderatorBlockListDelegatorsMap: { [string]: Array<string> },
  fetchingModerationBlockList: boolean,
  fetchModBlockedList: () => void,
  fetchModAmIList: () => void,
  delegatorsById: { [string]: { global: boolean, delegators: { name: string, claimId: string } } },
  myChannelClaimIds: ?Array<string>,
};

function ListBlocked(props: Props) {
  const {
    mutedUris,
    personalBlockList,
    adminBlockList,
    moderatorBlockList,
    personalTimeoutMap,
    adminTimeoutMap,
    moderatorTimeoutMap,
    moderatorBlockListDelegatorsMap: delegatorsMap,
    fetchingModerationBlockList,
    fetchModBlockedList,
    fetchModAmIList,
    delegatorsById,
    myChannelClaimIds,
  } = props;
  const [viewMode, setViewMode] = usePersistedState('blocked-muted:display', VIEW.BLOCKED);

  const [localDelegatorsMap, setLocalDelegatorsMap] = React.useState(undefined);

  const stringifiedDelegatorsMap = JSON.stringify(delegatorsMap);
  const stringifiedLocalDelegatorsMap = JSON.stringify(localDelegatorsMap);

  const isAdmin = myChannelClaimIds && myChannelClaimIds.some((id) => delegatorsById[id] && delegatorsById[id].global);

  const isModerator =
    myChannelClaimIds &&
    myChannelClaimIds.some((id) => delegatorsById[id] && Object.keys(delegatorsById[id].delegators).length > 0);

  // **************************************************************************

  function getList(view) {
    switch (view) {
      case VIEW.BLOCKED:
        return personalBlockList;
      case VIEW.ADMIN:
        return adminBlockList;
      case VIEW.MODERATOR:
        return moderatorBlockList;
      case VIEW.MUTED:
        return mutedUris;
    }
  }

  function getActionButtons(uri) {
    const getDurationStr = (durationNs) => {
      const NANO_TO_MS = 1000000;
      return humanizeDuration(durationNs / NANO_TO_MS, { round: true });
    };

    const getBanInfoElem = (timeoutInfo) => {
      return (
        <div>
          <div className="help">
            <blockquote>
              {moment(timeoutInfo.blockedAt).format('MMMM Do, YYYY @ HH:mm')}
              <br />
              {getDurationStr(timeoutInfo.bannedFor)}{' '}
              {__('(Remaining: %duration%) --[timeout ban duration]--', {
                duration: getDurationStr(timeoutInfo.banRemaining),
              })}
            </blockquote>
          </div>
        </div>
      );
    };

    switch (viewMode) {
      case VIEW.BLOCKED:
        return (
          <>
            <ChannelBlockButton uri={uri} />
            <ChannelMuteButton uri={uri} />
            {personalTimeoutMap[uri] && getBanInfoElem(personalTimeoutMap[uri])}
          </>
        );

      case VIEW.ADMIN:
        return (
          <>
            <ChannelBlockButton uri={uri} blockLevel={BLOCK_LEVEL.ADMIN} />
            {adminTimeoutMap[uri] && getBanInfoElem(adminTimeoutMap[uri])}
          </>
        );

      case VIEW.MODERATOR:
        const delegatorUrisForBlockedUri = localDelegatorsMap && localDelegatorsMap[uri];
        if (!delegatorUrisForBlockedUri) return null;
        return (
          <>
            {delegatorUrisForBlockedUri.map((delegatorUri) => {
              return (
                <div className="block-list--delegator" key={delegatorUri}>
                  <label>{__('Blocked on behalf of:')}</label>
                  <ul className="section">
                    <div className="content__non-clickable">
                      <ClaimPreview uri={delegatorUri} hideMenu hideActions type="inline" properties={false} />
                      {moderatorTimeoutMap[uri] && getBanInfoElem(moderatorTimeoutMap[uri])}
                    </div>
                    <ChannelBlockButton uri={uri} blockLevel={BLOCK_LEVEL.MODERATOR} creatorUri={delegatorUri} />
                  </ul>
                </div>
              );
            })}
          </>
        );

      case VIEW.MUTED:
        return (
          <>
            <ChannelMuteButton uri={uri} />
            <ChannelBlockButton uri={uri} />
          </>
        );
    }
  }

  function getHelpText(view) {
    switch (view) {
      case VIEW.BLOCKED:
        return __(
          "Blocked channels will be invisible to you in the app. They will not be able to comment on your content, nor reply to your comments left on other channels' content."
        );
      case VIEW.ADMIN:
        return __('This is the global block list.');
      case VIEW.MODERATOR:
        return __('List of channels that you have blocked as a moderator, along with the list of delegators.');
      case VIEW.MUTED:
        return __(
          'Muted channels will be invisible to you in the app. They will not know they are muted and can still interact with you and your content.'
        );
    }
  }

  function getEmptyListTitle(view) {
    switch (view) {
      case VIEW.BLOCKED:
        return __('You do not have any blocked channels');
      case VIEW.MUTED:
        return __('You do not have any muted channels');
      case VIEW.ADMIN:
        return __('You do not have any globally-blocked channels');
      case VIEW.MODERATOR:
        return __('You do not have any blocked channels as a moderator');
    }
  }

  function getEmptyListSubtitle(view) {
    switch (view) {
      case VIEW.BLOCKED:
      case VIEW.MUTED:
        return getHelpText(view);

      case VIEW.ADMIN:
      case VIEW.MODERATOR:
        return null;
    }
  }

  function isSourceListLarger(source, local) {
    // Comparing the length of stringified is not perfect, but what are the
    // chances of having different lists with the exact same length?
    return source && (!local || local.length < source.length);
  }

  function getViewElem(view, label, icon) {
    return (
      <Button
        icon={icon}
        button="alt"
        label={__(label)}
        className={classnames(`button-toggle`, {
          'button-toggle--active': viewMode === view,
        })}
        onClick={() => setViewMode(view)}
      />
    );
  }

  function getRefreshElem() {
    return (
      myChannelClaimIds && (
        <Button
          icon={ICONS.REFRESH}
          button="alt"
          label={__('Refresh')}
          onClick={() => {
            fetchModBlockedList();
            fetchModAmIList();
          }}
        />
      )
    );
  }

  // **************************************************************************

  React.useEffect(() => {
    if (stringifiedDelegatorsMap && isSourceListLarger(stringifiedDelegatorsMap, stringifiedLocalDelegatorsMap)) {
      setLocalDelegatorsMap(JSON.parse(stringifiedDelegatorsMap));
    }
  }, [stringifiedDelegatorsMap, stringifiedLocalDelegatorsMap]);

  // **************************************************************************

  return (
    <Page
      noFooter
      noSideNavigation
      settingsPage
      backout={{ title: __('Blocked and muted channels'), backLabel: __('Back') }}
    >
      {fetchingModerationBlockList && (
        <div className="main--empty">
          <Spinner />
        </div>
      )}

      {!fetchingModerationBlockList && (
        <>
          <div className="section__header--actions">
            <div className="section__actions--inline">
              {getViewElem(VIEW.BLOCKED, 'Blocked', ICONS.BLOCK)}
              {isAdmin && getViewElem(VIEW.ADMIN, 'Global', ICONS.BLOCK)}
              {isModerator && getViewElem(VIEW.MODERATOR, 'Moderator', ICONS.BLOCK)}
              {getViewElem(VIEW.MUTED, 'Muted', ICONS.MUTE)}
            </div>
            <div className="section__actions--inline">{getRefreshElem()}</div>
          </div>

          <BlockList
            key={viewMode}
            uris={getList(viewMode)}
            help={getHelpText(viewMode)}
            titleEmptyList={getEmptyListTitle(viewMode)}
            subtitle={getEmptyListSubtitle(viewMode)}
            getActionButtons={getActionButtons}
            className={viewMode === VIEW.MODERATOR ? 'block-list--moderator' : undefined}
          />
        </>
      )}
    </Page>
  );
}

export default ListBlocked;
