discordeno/module/gateway.ts

import { WebSocket } from "https://deno.land/std/ws/mod.ts"
import { GatewayOpcode, Status } from "../types/discord.ts"
import { FulfilledClientOptions } from "../types/options.ts"
import { delay } from "https://deno.land/std/util/async.ts"

export default class Gateway {
  constructor(public socket: WebSocket) {}

  identify(options: FulfilledClientOptions) {
    return this.sendObject({
      op: GatewayOpcode.Identify,
      d: {
        token: options.token,
        // TOOD: Let's get compression working, eh?
        compress: false,
        properties: options.properties
      }
    })
  }

  sendHeartbeat(previousSequenceNumber: number | null = null) {
    return this.sendObject({
      op: GatewayOpcode.Heartbeat,
      d: previousSequenceNumber
    })
  }

  updateStatus(status: Status) {
    this.sendObject({
      op: GatewayOpcode.StatusUpdate,
      d: status
    })
  }

  async sendConstantHeartbeats(
    interval: number,
    previousSequenceNumber: number | null = null,
    shouldContinue: () => boolean = () => true
  ): Promise<void> {
    await delay(interval)

    if (!shouldContinue()) {
      return
    }

    // TODO: If the initial seq num is null, this will make it forever null until a restart. Is this good?
    this.sendHeartbeat(previousSequenceNumber === null ? previousSequenceNumber : previousSequenceNumber++)
    return this.sendConstantHeartbeats(interval, previousSequenceNumber)
  }

  sendObject(object: object) {
    return this.socket.send(JSON.stringify(object))
  }
}