import { isEmpty } from 'lodash';
import { useSelector } from 'react-redux';
import { AutoSizer, List, ListRowProps } from 'react-virtualized';
import styled from 'styled-components';
import { SearchResults } from '../search/SearchResults';
import { LeftPaneSectionHeader } from './LeftPaneSectionHeader';
import { MessageRequestsBanner } from './MessageRequestsBanner';

import { setLeftOverlayMode } from '../../state/ducks/section';
import { getLeftPaneConversationIds } from '../../state/selectors/conversations';
import { getSearchTerm } from '../../state/selectors/search';
import { getLeftOverlayMode } from '../../state/selectors/section';
import { assertUnreachable } from '../../types/sqlSharedTypes';
import { SessionSearchInput } from '../SessionSearchInput';
import { StyledLeftPaneList } from './LeftPaneList';
import { ConversationListItem } from './conversation-list-item/ConversationListItem';
import { OverlayClosedGroup } from './overlay/OverlayClosedGroup';
import { OverlayCommunity } from './overlay/OverlayCommunity';
import { OverlayInvite } from './overlay/OverlayInvite';
import { OverlayMessage } from './overlay/OverlayMessage';
import { OverlayMessageRequest } from './overlay/OverlayMessageRequest';
import { OverlayChooseAction } from './overlay/choose-action/OverlayChooseAction';

const StyledLeftPaneContent = styled.div`
  display: flex;
  flex-direction: column;
  flex: 1;
  overflow: hidden;
`;

const StyledConversationListContent = styled.div`
  background: var(--background-primary-color);
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
  transition: none;
`;

const ClosableOverlay = () => {
  const leftOverlayMode = useSelector(getLeftOverlayMode);

  switch (leftOverlayMode) {
    case 'choose-action':
      return <OverlayChooseAction />;
    case 'open-group':
      return <OverlayCommunity />;
    case 'closed-group':
      return <OverlayClosedGroup />;
    case 'message':
      return <OverlayMessage />;
    case 'message-requests':
      return <OverlayMessageRequest />;
    case 'invite-a-friend':
      return <OverlayInvite />;
    case undefined:
      return null;
    default:
      return assertUnreachable(
        leftOverlayMode,
        `ClosableOverlay: leftOverlayMode case not handled "${leftOverlayMode}"`
      );
  }
};

export const LeftPaneMessageSection = () => {
  const conversationIds = useSelector(getLeftPaneConversationIds);
  const leftOverlayMode = useSelector(getLeftOverlayMode);
  const searchTerm = useSelector(getSearchTerm);

  const renderRow = ({ index, key, style }: ListRowProps): JSX.Element | null => {
    // assume conversations that have been marked unapproved should be filtered out by selector.
    if (!conversationIds) {
      throw new Error('renderRow: Tried to render without conversations');
    }

    const conversationId = conversationIds[index];
    if (!conversationId) {
      throw new Error('renderRow: conversations selector returned element containing falsy value.');
    }

    return <ConversationListItem key={key} style={style} conversationId={conversationId} />;
  };

  const ConversationList = () => {
    if (!isEmpty(searchTerm)) {
      return <SearchResults />;
    }

    if (!conversationIds) {
      throw new Error('render: must provided conversations if no search results are provided');
    }

    const length = conversationIds.length;

    return (
      <StyledLeftPaneList key={0}>
        <AutoSizer>
          {({ height, width }) => (
            <List
              className="module-left-pane__virtual-list"
              height={height}
              rowCount={length}
              rowHeight={64}
              rowRenderer={renderRow}
              width={width}
              autoHeight={false}
              conversationIds={conversationIds}
            />
          )}
        </AutoSizer>
      </StyledLeftPaneList>
    );
  };

  const Conversations = () => {
    return (
      <StyledConversationListContent>
        <SessionSearchInput />
        <MessageRequestsBanner
          handleOnClick={() => {
            window.inboxStore?.dispatch(setLeftOverlayMode('message-requests'));
          }}
        />
        <ConversationList />
      </StyledConversationListContent>
    );
  };

  return (
    <StyledLeftPaneContent>
      <LeftPaneSectionHeader />
      {leftOverlayMode ? <ClosableOverlay /> : <Conversations />}
    </StyledLeftPaneContent>
  );
};