import { SSESession } from '../utils/sse-session.js';
import { BaseTransport } from './base-transport.js';

export class TransportSSE extends BaseTransport {
  static async from(url: string) {
    const session = await SSESession.from(url);
    return new TransportSSE(session);
  }

  static fromSSESession(session: SSESession) {
    return new TransportSSE(session);
  }

  constructor(private readonly session: SSESession) {
    super();

    console.log('created transport sse');

    this.session.on('message', (message) => this.emit('message', message));
    this.session.on('connected', () => this.emit('connected', true));
    this.session.on('disconnected', () => this.emit('disconnected', true));
  }

  /**
   * Send fetch request to the url, ignoring SSE client as it's not needed for this transport
   * @param url - The URL to send the message to
   * @param body - The body to send
   */
  async send(url: string, body: unknown): Promise<unknown> {
    const response = await fetch(url, {
      method: 'POST',
      body: JSON.stringify(body),
    });

    return response.json();
  }

  /**
   * Connect the SSE session
   */
  async connect(): Promise<void> {
    await this.session.connect();
  }

  /**
   * Disconnect the SSE session
   */
  async disconnect(): Promise<void> {
    this.session.close();
  }
}