welshman/packages/net/src/publish.ts

import {EventEmitter} from "events"
import {on, fromPairs, sleep, yieldThread} from "@welshman/lib"
import {SignedEvent} from "@welshman/util"
import {RelayMessage, ClientMessageType, isRelayOk} from "./message.js"
import {AbstractAdapter, AdapterEvent, AdapterContext, getAdapter} from "./adapter.js"

export enum PublishStatus {
  Pending = "publish:status:pending",
  Success = "publish:status:success",
  Failure = "publish:status:failure",
  Timeout = "publish:status:timeout",
  Aborted = "publish:status:aborted",
}

export enum PublishEvent {
  Success = "publish:event:success",
  Failure = "publish:event:failure",
  Timeout = "publish:event:timeout",
  Aborted = "publish:event:aborted",
  Complete = "publish:event:complete",
}

// SinglePublish

export type SinglePublishOptions = {
  event: SignedEvent
  relay: string
  context?: AdapterContext
  timeout?: number
}

export class SinglePublish extends EventEmitter {
  status = PublishStatus.Pending

  _unsubscriber: () => void
  _adapter: AbstractAdapter

  constructor(readonly options: SinglePublishOptions) {
    super()

    // Set up our adapter
    this._adapter = getAdapter(this.options.relay, this.options.context)

    // Listen for SinglePublish result
    this._unsubscriber = on(
      this._adapter,
      AdapterEvent.Receive,
      (message: RelayMessage, url: string) => {
        if (isRelayOk(message)) {
          const [_, id, ok, detail] = message

          if (id !== this.options.event.id) return

          if (ok) {
            this.status = PublishStatus.Success
            this.emit(PublishEvent.Success, id, detail)
          } else {
            this.status = PublishStatus.Failure
            this.emit(PublishEvent.Failure, id, detail)
          }

          this.cleanup()
        }
      },
    )

    // Set timeout
    sleep(this.options.timeout || 10_000).then(() => {
      if (this.status === PublishStatus.Pending) {
        this.status = PublishStatus.Timeout
        this.emit(PublishEvent.Timeout)
      }

      this.cleanup()
    })

    // Start asynchronously so the caller can set up listeners
    yieldThread().then(() => {
      this._adapter.send([ClientMessageType.Event, this.options.event])
    })
  }

  abort = () => {
    if (this.status === PublishStatus.Pending) {
      this.status = PublishStatus.Aborted
      this.emit(PublishEvent.Aborted)
      this.cleanup()
    }
  }

  cleanup = () => {
    this.emit(PublishEvent.Complete)
    this.removeAllListeners()
    this._adapter.cleanup()
    this._unsubscriber()
  }
}

// MultiPublish

export type MultiPublishOptions = Omit<SinglePublishOptions, "relay"> & {
  relays: string[]
}

export class MultiPublish extends EventEmitter {
  status: Record<string, PublishStatus>

  _children: SinglePublish[] = []
  _completed = new Set<string>()

  constructor({relays, ...options}: MultiPublishOptions) {
    super()

    this.status = fromPairs(relays.map(relay => [relay, PublishStatus.Pending]))

    for (const relay of relays) {
      const unicast = new SinglePublish({relay, ...options})

      unicast.on(PublishEvent.Success, (id: string, detail: string) => {
        this.status[relay] = unicast.status
        this.emit(PublishEvent.Success, id, detail, relay)
      })

      unicast.on(PublishEvent.Failure, (id: string, detail: string) => {
        this.status[relay] = unicast.status
        this.emit(PublishEvent.Failure, id, detail, relay)
      })

      unicast.on(PublishEvent.Timeout, () => {
        this.status[relay] = unicast.status
        this.emit(PublishEvent.Timeout, relay)
      })

      unicast.on(PublishEvent.Aborted, () => {
        this.status[relay] = unicast.status
        this.emit(PublishEvent.Aborted, relay)
      })

      unicast.on(PublishEvent.Complete, () => {
        this._completed.add(relay)
        this.status[relay] = unicast.status

        if (this._completed.size === relays.length) {
          this.emit(PublishEvent.Complete)
          this.cleanup()
        }
      })

      this._children.push(unicast)
    }
  }

  abort() {
    for (const child of this._children) {
      child.abort()
    }
  }

  cleanup() {
    this.removeAllListeners()
  }
}