import { User, Users } from './users.svelte.js';
import { Conversations } from './conversations.svelte.js';
import { Messages } from './messages.svelte.js';

export class State {
  currentUser = $state();
  users = $state(new Users());
  conversations = $state(new Conversations());
  messages = $state(new Messages());

  static boot({ currentUser, heartbeat, resumePoint, events }) {
    const state = new State({
      currentUser: User.boot(currentUser),
      heartbeat,
      resumePoint,
    });
    for (const event of events) {
      state.onEvent(event);
    }
    return state;
  }

  constructor({ currentUser, heartbeat, resumePoint }) {
    this.currentUser = currentUser;
    this.heartbeat = heartbeat;
    this.resumePoint = resumePoint;
  }

  onEvent(event) {
    // Heartbeats are actually completely ignored here. They're handled in `Session`, but not as a
    // special case; _any_ event is a heartbeat event.
    switch (event.type) {
      case 'conversation':
        return this.onConversationEvent(event);
      case 'user':
        return this.onUserEvent(event);
      case 'message':
        return this.onMessageEvent(event);
    }
  }

  onConversationEvent(event) {
    switch (event.event) {
      case 'created':
        return this.onConversationCreated(event);
      case 'deleted':
        return this.onConversationDeleted(event);
    }
  }

  onConversationCreated(event) {
    const { id, name } = event;
    this.conversations.add({ id, name });
  }

  onConversationDeleted(event) {
    const { id } = event;
    this.conversations.remove(id);
  }

  onUserEvent(event) {
    switch (event.event) {
      case 'created':
        return this.onUserCreated(event);
    }
  }

  onUserCreated(event) {
    const { id, name } = event;
    this.users.add({ id, name });
  }

  onMessageEvent(event) {
    switch (event.event) {
      case 'sent':
        return this.onMessageSent(event);
      case 'deleted':
        return this.onMessageDeleted(event);
    }
  }

  onMessageSent(event) {
    const { id, at, conversation, sender, body } = event;
    this.messages.add({ id, at, conversation, sender, body });
  }

  onMessageDeleted(event) {
    const { id } = event;
    this.messages.remove(id);
  }
}