Adding Nostr adapter library

lib/adapters/nostr.js

@@ -0,0 +1,136 @@
+/*
+  Adapter library for working with Nostr.
+*/
+
+// Global npm libraries
+import BchNostr from 'bch-nostr'
+import { RelayPool } from 'nostr'
+import RetryQueue from '@chris.troutner/retry-queue'
+import * as nip19 from 'nostr-tools/nip19'
+
+class NostrAdapter {
+  constructor (localConfig = { nostrRelay: '', nostrTopic: '' }) {
+    this.relayWs = localConfig.nostrRelay //
+    this.topic = localConfig.nostrTopic
+
+    if (!this.relayWs) {
+      throw new Error(
+        '"nostrRelay" must be passed when instantiate NostrAdapter'
+      )
+    }
+
+    if (!this.topic) {
+      throw new Error(
+        '"nostrTopic" must be passed when instantiate NostrAdapter'
+      )
+    }
+
+    // Encapsulate dependencies
+    this.bchNostr = new BchNostr()
+    this.RelayPool = RelayPool
+    this.retryQueue = new RetryQueue({
+      concurrency: 1,
+      attempts: 5,
+      retryPeriod: 1000
+    })
+
+    // Bind the 'this' object
+    this.start = this.start.bind(this)
+    this.post = this.post.bind(this)
+    this.read = this.read.bind(this)
+    this.eventId2note = this.eventId2note.bind(this)
+  }
+
+  // Create nostr keys.
+  // NOTE:  WIF must be provided in this function instead the constructor function
+  // we can provide it after app wallet creation.
+  async start (WIF) {
+    try {
+      if (!WIF || typeof WIF !== 'string') {
+        throw new Error('WIF must be a string!')
+      }
+
+      const { privKeyBuf, nostrPubKey } =
+        this.bchNostr.keys.createNostrPubKeyFromWif({ wif: WIF })
+
+      this.privKeyBuf = privKeyBuf
+      this.nostrPubKey = nostrPubKey
+
+      console.log(`Nostr Pub Key : ${nostrPubKey}`)
+
+      return true
+    } catch (error) {
+      console.log(`Error in nostr.js/start() ${error.message} `)
+      throw error
+    }
+  }
+
+  // Post a message over the instance-topic.
+  async post (msg = '') {
+    try {
+      if (!msg || typeof msg !== 'string') {
+        throw new Error('msg must be a string!')
+      }
+
+      const inObj = {
+        kind: 867,
+        privKeyBuf: this.privKeyBuf,
+        nostrPubKey: this.nostrPubKey,
+        relayWs: this.relayWs,
+        msg,
+        tags: [['t', this.topic]]
+      }
+      const eventId = await this.retryQueue.addToQueue(this.bchNostr.post.uploadToNostr, inObj)
+      return eventId
+    } catch (error) {
+      console.log(`Error in nostr.js/post() ${error.message} `)
+      throw error
+    }
+  }
+
+  // Read a message over the instance-topic.
+  async read (limit = 10) {
+    try {
+      if (typeof limit !== 'number' || limit < 1) {
+        throw new Error('Limit must be greater than 0')
+      }
+
+      const relays = [this.relayWs]
+      const pool = this.RelayPool(relays)
+
+      const nostrData = new Promise((resolve, reject) => {
+        const messages = []
+
+        pool.on('open', (relay) => {
+          // relay.subscribe('REQ', { ids: [eventId] })
+          relay.subscribe('REQ', { limit, kinds: [867], '#t': [this.topic] })
+        })
+
+        pool.on('eose', (relay) => {
+          relay.close()
+          resolve(messages)
+        })
+
+        pool.on('event', (relay, subId, ev) => {
+          // console.log('ev: ', ev)
+          messages.push({ content: ev.content, eventId: ev.id })
+        })
+      })
+
+      const messages = await nostrData
+
+      return messages
+    } catch (error) {
+      console.log(`Error in nostr.js/read() ${error.message} `)
+      throw error
+    }
+  }
+
+  // Convert an Event ID into a `noteabc..` syntax that Astral expects.
+  // This can be used to generate a link to Astral to display the post.
+  eventId2note(eventId) {
+    return nip19.noteEncode(eventId)
+  }
+}
+
+export default NostrAdapter