import { socketAction } from 'state/actions';
import { setConnected } from 'state/app';
import { broadcast, inform, print, addMessage, addMessages } from 'state/messages';
import { reconnect } from 'state/servers';
import { select } from 'state/tab';
import { normalizeChannel } from 'utils';

function withReason(message, reason) {
  return message + (reason ? ` (${reason})` : '');
}

function findChannels(state, server, user) {
  const channels = [];

  state.channels.get(server).forEach((channel, channelName) => {
    if (channel.get('users').find(u => u.nick === user)) {
      channels.push(channelName);
    }
  });

  return channels;
}

export default function handleSocket({ socket, store: { dispatch, getState } }) {
  const handlers = {
    message(message) {
      dispatch(addMessage(message, message.server, message.to));
    },

    pm(message) {
      dispatch(addMessage(message, message.server, message.from));
    },

    messages({ messages, server, to, prepend, next }) {
      dispatch(addMessages(messages, server, to, prepend, next));
    },

    join({ user, server, channels }) {
      const state = getState();
      const tab = state.tab.selected;
      const [joinedChannel] = channels;
      if (tab.server && tab.name) {
        const { nick } = state.servers.get(tab.server);
        if (tab.server === server &&
          nick === user &&
          tab.name !== joinedChannel &&
          normalizeChannel(tab.name) === normalizeChannel(joinedChannel)) {
          dispatch(select(server, joinedChannel));
        }
      }

      dispatch(inform(`${user} joined the channel`, server, joinedChannel));
    },

    part({ user, server, channel, reason }) {
      dispatch(inform(withReason(`${user} left the channel`, reason), server, channel));
    },

    quit({ user, server, reason }) {
      const channels = findChannels(getState(), server, user);
      dispatch(broadcast(withReason(`${user} quit`, reason), server, channels));
    },

    nick({ server, oldNick, newNick }) {
      const channels = findChannels(getState(), server, oldNick);
      dispatch(broadcast(`${oldNick} changed nick to ${newNick}`, server, channels));
    },

    topic({ server, channel, topic, nick }) {
      if (nick) {
        if (topic) {
          dispatch(inform(`${nick} changed the topic to:`, server, channel));
          dispatch(print(topic, server, channel));
        } else {
          dispatch(inform(`${nick} cleared the topic`, server, channel));
        }
      }
    },

    motd({ content, server }) {
      dispatch(addMessages(content.map(line => ({ content: line })), server));
    },

    whois(data) {
      const tab = getState().tab.selected;

      dispatch(print([
        `Nick: ${data.nick}`,
        `Username: ${data.username}`,
        `Realname: ${data.realname}`,
        `Host: ${data.host}`,
        `Server: ${data.server}`,
        `Channels: ${data.channels}`
      ], tab.server, tab.name));
    },

    print(message) {
      const tab = getState().tab.selected;
      dispatch(addMessage(message, tab.server, tab.name));
    },

    connection_update({ server, errorType }) {
      if (errorType === 'verify' &&
        confirm('The server is using a self-signed certificate, continue anyway?')) {
        dispatch(reconnect(server, {
          skipVerify: true
        }));
      }
    },

    _connected(connected) {
      dispatch(setConnected(connected));
    }
  };

  socket.onMessage((type, data) => {
    let action;
    if (Array.isArray(data)) {
      action = { type: socketAction(type), data: [...data] };
    } else {
      action = { ...data, type: socketAction(type) };
    }

    if (type in handlers) {
      handlers[type](data);
    }

    dispatch(action);
  });
}