import { writable } from 'svelte/store';
import { browser } from '$app/environment';
import { Channels, ChannelsMeta } from '$lib/store/channels.svelte.js';
import { Messages } from '$lib/store/messages.svelte.js';
import { Logins } from '$lib/store/logins';
import { STORE_KEY_CHANNELS_DATA } from '$lib/constants';

// Get channelsList content from the local storage
const channelsMetaData =
  (browser && JSON.parse(localStorage.getItem(STORE_KEY_CHANNELS_DATA))) || {};

export const currentUser = writable(null);
export const logins = writable(new Logins());
export const channelsMetaList = writable(new ChannelsMeta({ channelsMetaData }));
export const channelsList = writable(new Channels({ channelsMetaList }));
export const messages = writable(new Messages());

export function onEvent(event) {
  switch (event.type) {
    case 'login':
      onLoginEvent(event);
      break;
    case 'channel':
      onChannelEvent(event);
      break;
    case 'message':
      onMessageEvent(event);
      break;
  }
}

onEvent.fromJson = (event) => {
  const parsed = JSON.parse(event);
  return onEvent(parsed);
};

onEvent.fromMessage = (message) => {
  const data = message.data;
  return onEvent.fromJson(data);
};

function onLoginEvent(event) {
  switch (event.event) {
    case 'created':
      logins.update((value) => value.addLogin(event.id, event.name));
      break;
  }
}

function onChannelEvent(event) {
  switch (event.event) {
    case 'created':
      channelsList.update((value) => value.addChannel(event.id, event.name));
      break;
    case 'deleted':
      channelsList.update((value) => value.deleteChannel(event.id));
      messages.update((value) => value.deleteChannel(event.id));
      break;
  }
}

function onMessageEvent(event) {
  switch (event.event) {
    case 'sent':
      messages.update((value) =>
        value.addMessage(event.channel, event.id, {
          at: event.at,
          sender: event.sender,
          body: event.body
        })
      );
      break;
    case 'deleted':
      messages.update((value) => value.deleteMessage(event.id));
      break;
  }
}