import React, { useCallback, useEffect, useMemo, useState } from 'react';
import { useCallState } from '../../contexts/CallProvider';
import { useWaitingRoom } from '../../contexts/WaitingRoomProvider';
import { ReactComponent as IconWaiting } from '../../icons/add-person-lg.svg';
import Button from '../Button';
import { Card, CardBody, CardFooter } from '../Card';

export const WaitingRoomNotification = () => {
  const { callObject } = useCallState();
  const {
    denyAccess,
    grantAccess,
    showModal,
    setShowModal,
    waitingParticipants,
    multipleWaiting,
  } = useWaitingRoom();
  const [showNotification, setShowNotification] = useState(false);

  /**
   * Click handlers passed to render functions
   */
  const handleViewAllClick = useCallback(() => {
    setShowModal(true);
    setShowNotification(false);
  }, [setShowModal]);

  const handleAllowClick = useCallback(() => {
    grantAccess(waitingParticipants[0].id);
  }, [grantAccess, waitingParticipants]);

  const handleDenyClick = useCallback(() => {
    denyAccess(multipleWaiting ? 'all' : waitingParticipants[0].id);
  }, [denyAccess, waitingParticipants, multipleWaiting]);

  /**
   * Render the full participant waiting list
   */
  const showMultipleParticipants = useMemo(() => {
    return (
      <CardBody>
        <p>
          <strong>{waitingParticipants.length}</strong> people would like to
          join the call
        </p>
        <CardFooter>
          <Button onClick={handleViewAllClick} size="small" variant="success">
            View all
          </Button>
          <Button onClick={handleDenyClick} size="small" variant="warning">
            Deny all
          </Button>
        </CardFooter>
      </CardBody>
    );
  }, [waitingParticipants, handleDenyClick, handleViewAllClick]);

  /**
   * Render the single waiting participant
   */
  const showSingleParticipant = useMemo(() => {
    return (
      <CardBody>
        <p>
          <strong>{waitingParticipants[0]?.name}</strong> would like to join the
          call
        </p>
        <CardFooter>
          <Button onClick={handleAllowClick} size="small" variant="success">
            Allow
          </Button>
          <Button onClick={handleDenyClick} size="small" variant="warning">
            Deny
          </Button>
        </CardFooter>
      </CardBody>
    );
  }, [waitingParticipants, handleAllowClick, handleDenyClick]);

  /**
   * Show notification when waiting participants change.
   */
  useEffect(() => {
    if (showModal) return false;

    const handleWaitingParticipantAdded = () => {
      setShowNotification(
        Object.keys(callObject.waitingParticipants()).length > 0
      );
    };

    callObject.on('waiting-participant-added', handleWaitingParticipantAdded);
    return () => {
      callObject.off(
        'waiting-participant-added',
        handleWaitingParticipantAdded
      );
    };
  }, [callObject, showModal]);

  /**
   * Hide notification when people panel is opened.
   */
  useEffect(() => {
    if (showModal) setShowNotification(false);
  }, [showModal]);

  if (!showNotification || waitingParticipants.length === 0) return null;

  return (
    <Card className="waiting-room-notification">
      <aside>
        <IconWaiting />
      </aside>
      {multipleWaiting ? showMultipleParticipants : showSingleParticipant}
      <style jsx>{`
        :global(.card.waiting-room-notification) {
          position: absolute;
          right: var(--spacing-sm);
          top: var(--spacing-sm);
          z-index: 999;
          padding: 0px;
          display: grid;
          align-items: center;
          grid-template-columns: auto auto;
          overflow: hidden;
          box-shadow: var(--shadow-depth-2);
        }

        strong {
          color: var(--text-default);
        }
        aside {
          background: var(--gray-wash);
          display: flex;
          padding: var(--spacing-md);
          height: 100%;
          align-items: center;
          color: var(--gray-default);
        }

        :global(.waiting-room-notification .card-footer) {
          display: flex;
          column-gap: var(--spacing-xxs);
          margin-top: var(--spacing-xs);
        }

        :global(.waiting-room-notification .card-body) {
          padding: var(--spacing-md);
        }
      `}</style>
    </Card>
  );
};

export default WaitingRoomNotification;