text: import React from 'react';
  import PropTypes from 'prop-types';
  import config from 'config'; // eslint-disable-line require-path-exists/exists
  import deepEqual from 'deep-equal';
  import ifvisible from 'ifvisible.js';
  import { safelyParseJSON } from './helpers';
  import { ClientSessionIdContext } from './ClientSessionId';
  
  function createPusher({ cluster, pusherKey, debug }) {
    // Pusher is imported at runtime from a <script file> tag.
    // eslint-disable-next-line no-console
    if (!!debug && console && console.debug) {
      // eslint-disable-next-line no-undef, no-console
      Pusher.log = console.debug;
    }
    // eslint-disable-next-line no-undef
    const pusher = new Pusher(pusherKey, {
      cluster,
      encrypted: true,
    });
  
    // eslint-disable-next-line no-console
    const pusherLog = debug ? message => console.debug(`[Pusher] ${message}`) : () => {};
  
    const checkPusher = {
      messagesQueue: [],
      queue: {},
      currentChannels: {},
      subscribedChannels: {},
      callbacksToRun: {},
    };
    window.CheckPusher = checkPusher; // to help debug things
  
    window.setInterval(() => {
      pusherLog('Running throttle');
      const callbacks = Object.assign({}, checkPusher.callbacksToRun);
      checkPusher.callbacksToRun = {};
      Object.values(callbacks).forEach((callback) => {
        callback();
      });
    }, 5000);
  
    function processPusherMessage(data, run) {
      const message = safelyParseJSON(data.message, {});
      const eventName = message.pusherEvent;
      const callbacks = {};
      message.pusherChannels.forEach((channel) => {
        if (checkPusher.currentChannels[channel] &&
          checkPusher.currentChannels[channel][eventName]) {
          Object.keys(checkPusher.currentChannels[channel][eventName]).forEach((component) => {
            const { id, callback } =
              checkPusher.currentChannels[channel][eventName][component](data, false);
            if (id && callback) {
              if (run) {
                checkPusher.callbacksToRun[id] = callback;
              } else {
                callbacks[id] = callback;
              }
            }
            pusherLog(`Calling callback for channel ${channel} and event ${eventName} for component ${component}, which is currently mounted and focused`);
          });
        } else if (checkPusher.subscribedChannels[channel]) {
          if (!checkPusher.queue[channel]) {
            checkPusher.queue[channel] = {};
          }
          if (!checkPusher.queue[channel][eventName]) {
            checkPusher.queue[channel][eventName] = [];
          }
          checkPusher.subscribedChannels[channel].forEach((component) => {
            const eventData = Object.assign({ component }, data);
            const eventFinder = x => (deepEqual(x, eventData));
            if (checkPusher.queue[channel][eventName].find(eventFinder)) {
              pusherLog(`Not adding event ${eventName} to the queue of channel ${channel} because it is already there`);
            } else {
              checkPusher.queue[channel][eventName].push(eventData);
              pusherLog(`Adding event ${eventName} to queue of channel ${channel} for component ${component}`);
            }
          });
        } else {
          pusherLog(`Ignoring event ${eventName} for channel ${channel}`);
        }
      });
      return callbacks;
    }
  
    ifvisible.on('blur', () => {
      pusherLog('Page is not focused anymore');
    });
  
    ifvisible.on('focus', () => {
      pusherLog('Page is focused now');
      const messages = checkPusher.messagesQueue.slice(0);
      checkPusher.messagesQueue = [];
      const callbacks = {};
      messages.forEach((rawMessage) => {
        Object.assign(callbacks, processPusherMessage(JSON.parse(rawMessage), false));
      });
      Object.values(callbacks).forEach((callback) => {
        callback();
      });
    });
  
    pusher.unsubscribe('check-api-global-channel');
    pusher.subscribe('check-api-global-channel').bind('update', (data) => {
      const rawMessage = JSON.stringify(data);
      pusherLog(`Received global event: ${rawMessage}`);
      if (!ifvisible.now('hidden')) {
        processPusherMessage(data, true);
      } else {
        pusherLog(`Page is not focused, so message ${rawMessage} will go to the queue`);
        if (checkPusher.messagesQueue.indexOf(rawMessage) === -1) {
          checkPusher.messagesQueue.push(rawMessage);
          pusherLog(`Adding ${rawMessage} to queue because page is not focused and message is not in the queue yet`);
        } else {
          pusherLog(`Message ${rawMessage} is already in the queue, so just ignore it`);
        }
      }
    });
  
    return {
      unsubscribe: (channel, eventName, component) => {
        if (checkPusher.currentChannels[channel]) {
          if (eventName && component && checkPusher.currentChannels[channel][eventName] &&
            checkPusher.currentChannels[channel][eventName][component]) {
            delete checkPusher.currentChannels[channel][eventName][component];
            pusherLog(`Channel ${channel} is not a current channel for event ${eventName} and component ${component} anymore`);
          } else if (eventName && checkPusher.currentChannels[channel][eventName]) {
            delete checkPusher.currentChannels[channel][eventName];
            pusherLog(`Channel ${channel} is not a current channel for event ${eventName} anymore`);
          } else {
            checkPusher.currentChannels[channel] = null;
            pusherLog(`Channel ${channel} is not a current channel anymore`);
          }
        }
      },
  
      subscribe: (channel) => {
        if (!checkPusher.subscribedChannels[channel]) {
          checkPusher.subscribedChannels[channel] = [];
          pusherLog(`Subscribing to channel ${channel}`);
        }
        if (!checkPusher.currentChannels[channel]) {
          checkPusher.currentChannels[channel] = {}; // event: callback
          pusherLog(`Channel ${channel} is now a current channel`);
        }
        return {
          bind: (eventName, component, callback) => {
            if (checkPusher.queue[channel] && checkPusher.queue[channel][eventName]) {
              const updates = {};
              const indexes = [];
              checkPusher.queue[channel][eventName].forEach((data, j) => {
                const callbackMatch = callback(data, false);
                if (callbackMatch && data.component === component) {
                  const { id } = callbackMatch;
                  const update = callbackMatch.callback;
                  updates[id] = update;
                  indexes.push(j);
                }
              });
              indexes.forEach((index) => {
                checkPusher.queue[channel][eventName].splice(index, 1);
                pusherLog('Removing from the queue because it was applicable for the callback');
              });
              Object.values(updates).forEach((update) => {
                update();
              });
            }
            if (!checkPusher.currentChannels[channel][eventName]) {
              checkPusher.currentChannels[channel][eventName] = {};
            }
            if (checkPusher.subscribedChannels[channel].indexOf(component) === -1) {
              checkPusher.subscribedChannels[channel].push(component);
            }
            checkPusher.currentChannels[channel][eventName][component] = callback;
            pusherLog(`Event ${eventName} is now a current event of channel ${channel}`);
          },
        };
      },
    };
  }
  
  const NullPusher = {
    // https://mantis.meedan.com/view.php?id=8278
    subscribe: () => ({
      bind: () => null,
    }),
    unsubscribe: () => null,
  };
  
  const { subscribe, unsubscribe } = config.pusherKey ? createPusher({
    cluster: config.pusherCluster,
    pusherKey: config.pusherKey,
    debug: config.pusherDebug,
  }) : NullPusher;
  
  const PusherContext = React.createContext({ subscribe: () => {}, unsubscribe: () => {} });
  PusherContext.displayName = 'PusherContext';
  
  function withPusher(Component) {
    const inner = React.forwardRef((props, ref) => {
      const pusher = React.useContext(PusherContext);
      // TODO streamline design, so components don't need to check
      // clientSessionId.
      const clientSessionId = React.useContext(ClientSessionIdContext);
      return <Component ref={ref} pusher={pusher} clientSessionId={clientSessionId} {...props} />;
    });
    inner.displayName = `WithPusher(${Component.displayName || Component.name || 'Component'})`;
    return inner;
  }
  
  const pusherShape = PropTypes.shape({
    /**
     * Usage: subscribe(channel)(eventName, component, callback)
     */
    subscribe: PropTypes.func.isRequired,
  
    /**
     * Usage: unsubscribe(channel, eventName, component)
     */
    unsubscribe: PropTypes.func.isRequired,
  });
  
  export { subscribe, unsubscribe, PusherContext, withPusher, pusherShape };
  