src/controllers/MetadataController.ts

@@ -14,71 +14,130 @@ import { NostrController } from '.'
 import { toast } from 'react-toastify'
 import { queryNip05 } from '../utils'
 import NDK, { NDKEvent, NDKSubscription } from '@nostr-dev-kit/ndk'
+import { EventEmitter } from 'tseep'
+import { localCache } from '../services'
 
-export class MetadataController {
+export class MetadataController extends EventEmitter {
   private nostrController: NostrController
   private specialMetadataRelay = 'wss://purplepag.es'
 
   constructor() {
+    super()
     this.nostrController = NostrController.getInstance()
   }
 
-  public getEmptyMetadataEvent = (): Event => {
+  /**
-    return {
+   * Asynchronously checks for more recent metadata events authored by a specific key.
-      content: '',
+   * If a more recent metadata event is found, it is handled and returned.
-      created_at: new Date().valueOf(),
+   * If no more recent event is found, the current event is returned.
-      id: '',
+   * @param hexKey The hexadecimal key of the author to filter metadata events.
-      kind: 0,
+   * @param currentEvent The current metadata event, if any, to compare with newer events.
-      pubkey: '',
+   * @returns A promise resolving to the most recent metadata event found, or null if none is found.
-      sig: '',
+   */
-      tags: []
+  private async checkForMoreRecentMetadata(
-    }
+    hexKey: string,
-  }
+    currentEvent: Event | null
-
+  ): Promise<Event | null> {
-  public findMetadata = async (hexKey: string) => {
+    // Define the event filter to only include metadata events authored by the given key
     const eventFilter: Filter = {
-      kinds: [kinds.Metadata],
+      kinds: [kinds.Metadata], // Only metadata events
-      authors: [hexKey]
+      authors: [hexKey] // Authored by the specified key
     }
 
     const pool = new SimplePool()
 
+    // Try to get the metadata event from a special relay (wss://purplepag.es)
     const metadataEvent = await pool
       .get([this.specialMetadataRelay], eventFilter)
       .catch((err) => {
-        console.error(err)
+        console.error(err) // Log any errors
-        return null
+        return null // Return null if an error occurs
       })
 
+    // If a valid metadata event is found from the special relay
     if (
       metadataEvent &&
-      validateEvent(metadataEvent) &&
+      validateEvent(metadataEvent) && // Validate the event
-      verifyEvent(metadataEvent)
+      verifyEvent(metadataEvent) // Verify the event's authenticity
     ) {
-      return metadataEvent
+      // If there's no current event or the new metadata event is more recent
+      if (!currentEvent || metadataEvent.created_at > currentEvent.created_at) {
+        // Handle the new metadata event
+        this.handleNewMetadataEvent(metadataEvent)
+        return metadataEvent
+      }
     }
 
+    // If no valid metadata event is found from the special relay, get the most popular relays
     const mostPopularRelays = await this.nostrController.getMostPopularRelays()
 
+    // Query the most popular relays for metadata events
     const events = await pool
       .querySync(mostPopularRelays, eventFilter)
       .catch((err) => {
-        console.error(err)
+        console.error(err) // Log any errors
-
+        return null // Return null if an error occurs
-        return null
       })
 
+    // If events are found from the popular relays
     if (events && events.length) {
-      events.sort((a, b) => b.created_at - a.created_at)
+      events.sort((a, b) => b.created_at - a.created_at) // Sort events by creation date (descending)
 
+      // Iterate through the events
       for (const event of events) {
-        if (validateEvent(event) && verifyEvent(event)) {
+        // If the event is valid, authentic, and more recent than the current event
+        if (
+          validateEvent(event) &&
+          verifyEvent(event) &&
+          (!currentEvent || event.created_at > currentEvent.created_at)
+        ) {
+          // Handle the new metadata event
+          this.handleNewMetadataEvent(event)
           return event
         }
       }
     }
 
-    throw new Error('Mo metadata found.')
+    return currentEvent // Return the current event if no newer event is found
+  }
+
+  /**
+   * Handle new metadata events and emit them to subscribers
+   */
+  private async handleNewMetadataEvent(event: VerifiedEvent) {
+    // update the event in local cache
+    localCache.addUserMetadata(event)
+    // Emit the event to subscribers.
+    this.emit(event.pubkey, event.kind, event)
+  }
+
+  /**
+   * Finds metadata for a given hexadecimal key.
+   *
+   * @param hexKey - The hexadecimal key to search for metadata.
+   * @returns A promise that resolves to the metadata event.
+   */
+  public findMetadata = async (hexKey: string): Promise<Event | null> => {
+    // Attempt to retrieve the metadata event from the local cache
+    const cachedMetadataEvent = await localCache.getUserMetadata(hexKey)
+
+    // If cached metadata is found, check its validity
+    if (cachedMetadataEvent) {
+      const oneDayInMS = 24 * 60 * 60 * 1000 // Number of milliseconds in one day
+
+      // Check if the cached metadata is older than one day
+      if (Date.now() - cachedMetadataEvent.cachedAt > oneDayInMS) {
+        // If older than one day, find the metadata from relays in background
+
+        this.checkForMoreRecentMetadata(hexKey, cachedMetadataEvent.event)
+      }
+
+      // Return the cached metadata event
+      return cachedMetadataEvent.event
+    }
+
+    // If no cached metadata is found, retrieve it from relays
+    return this.checkForMoreRecentMetadata(hexKey, null)
   }
 
   public findRelayListMetadata = async (hexKey: string) => {
@@ -142,7 +201,7 @@ export class MetadataController {
     throw new Error('No relay list metadata found.')
   }
 
-  public extractProfileMetadataContent = (event: VerifiedEvent) => {
+  public extractProfileMetadataContent = (event: Event) => {
     try {
       if (!event.content) return {}
       return JSON.parse(event.content) as ProfileMetadata
@@ -175,6 +234,7 @@ export class MetadataController {
       .publishEvent(signedMetadataEvent, [this.specialMetadataRelay])
       .then((relays) => {
         toast.success(`Metadata event published on: ${relays.join('\n')}`)
+        this.handleNewMetadataEvent(signedMetadataEvent as VerifiedEvent)
       })
       .catch((err) => {
         toast.error(err.message)
@@ -193,6 +253,8 @@ export class MetadataController {
       userRelays.push(...relaySet.write)
     } else {
       const metadata = await this.findMetadata(hexKey)
+      if (!metadata) return null
+
       const metadataContent = this.extractProfileMetadataContent(metadata)
 
       if (metadataContent?.nip05) {
@@ -306,4 +368,16 @@ export class MetadataController {
   }
 
   public validate = (event: Event) => validateEvent(event) && verifyEvent(event)
+
+  public getEmptyMetadataEvent = (): Event => {
+    return {
+      content: '',
+      created_at: new Date().valueOf(),
+      id: '',
+      kind: 0,
+      pubkey: '',
+      sig: '',
+      tags: []
+    }
+  }
 }

src/layouts/Main.tsx

@@ -18,8 +18,7 @@ import { MetadataController, NostrController } from '../controllers'
 import { LoginMethods } from '../store/auth/types'
 import { setUserRobotImage } from '../store/userRobotImage/action'
 import { State } from '../store/rootReducer'
-
+import { Event, kinds } from 'nostr-tools'
-const metadataController = new MetadataController()
 
 export const MainLayout = () => {
   const dispatch: Dispatch = useDispatch()
@@ -27,6 +26,8 @@ export const MainLayout = () => {
   const authState = useSelector((state: State) => state.auth)
 
   useEffect(() => {
+    const metadataController = new MetadataController()
+
     const logout = () => {
       dispatch(
         setAuthState({
@@ -68,6 +69,20 @@ export const MainLayout = () => {
             nostrController.createNsecBunkerSigner(usersPubkey)
           })
         }
+
+        const handleMetadataEvent = (event: Event) => {
+          dispatch(setMetadataEvent(event))
+        }
+
+        metadataController.on(usersPubkey, (kind: number, event: Event) => {
+          if (kind === kinds.Metadata) {
+            handleMetadataEvent(event)
+          }
+        })
+
+        metadataController.findMetadata(usersPubkey).then((metadataEvent) => {
+          if (metadataEvent) handleMetadataEvent(metadataEvent)
+        })
       }
     }
 

src/pages/create/index.tsx

@@ -49,6 +49,7 @@ import type { Identifier, XYCoord } from 'dnd-core'
 import { useDrag, useDrop } from 'react-dnd'
 import saveAs from 'file-saver'
 import CopyModal from '../../components/copyModal'
+import { Event, kinds } from 'nostr-tools'
 
 export const CreatePage = () => {
   const navigate = useNavigate()
@@ -517,16 +518,26 @@ const DisplayUser = ({
       if (!(user.pubkey in metadata)) {
         const metadataController = new MetadataController()
 
+        const handleMetadataEvent = (event: Event) => {
+          const metadataContent =
+            metadataController.extractProfileMetadataContent(event)
+          if (metadataContent)
+            setMetadata((prev) => ({
+              ...prev,
+              [user.pubkey]: metadataContent
+            }))
+        }
+
+        metadataController.on(user.pubkey, (kind: number, event: Event) => {
+          if (kind === kinds.Metadata) {
+            handleMetadataEvent(event)
+          }
+        })
+
         metadataController
           .findMetadata(user.pubkey)
           .then((metadataEvent) => {
-            const metadataContent =
+            if (metadataEvent) handleMetadataEvent(metadataEvent)
-              metadataController.extractProfileMetadataContent(metadataEvent)
-            if (metadataContent)
-              setMetadata((prev) => ({
-                ...prev,
-                [user.pubkey]: metadataContent
-              }))
           })
           .catch((err) => {
             console.error(

src/pages/profile/index.tsx

@@ -2,7 +2,7 @@ import ContentCopyIcon from '@mui/icons-material/ContentCopy'
 import EditIcon from '@mui/icons-material/Edit'
 import { Box, IconButton, SxProps, Theme, Typography } from '@mui/material'
 import { truncate } from 'lodash'
-import { VerifiedEvent, nip19 } from 'nostr-tools'
+import { Event, VerifiedEvent, kinds, nip19 } from 'nostr-tools'
 import { useEffect, useMemo, useState } from 'react'
 import { useSelector } from 'react-redux'
 import { Link, useNavigate, useParams } from 'react-router-dom'
@@ -75,6 +75,20 @@ export const ProfilePage = () => {
 
     if (pubkey) {
       const getMetadata = async (pubkey: string) => {
+        const handleMetadataEvent = (event: Event) => {
+          const metadataContent =
+            metadataController.extractProfileMetadataContent(event)
+          if (metadataContent) {
+            setProfileMetadata(metadataContent)
+          }
+        }
+
+        metadataController.on(pubkey, (kind: number, event: Event) => {
+          if (kind === kinds.Metadata) {
+            handleMetadataEvent(event)
+          }
+        })
+
         const metadataEvent = await metadataController
           .findMetadata(pubkey)
           .catch((err) => {
@@ -82,13 +96,7 @@ export const ProfilePage = () => {
             return null
           })
 
-        if (metadataEvent) {
+        if (metadataEvent) handleMetadataEvent(metadataEvent)
-          const metadataContent =
-            metadataController.extractProfileMetadataContent(metadataEvent)
-          if (metadataContent) {
-            setProfileMetadata(metadataContent)
-          }
-        }
 
         setIsLoading(false)
       }

src/pages/settings/profile/index.tsx

@@ -11,7 +11,7 @@ import {
   Typography,
   useTheme
 } from '@mui/material'
-import { UnsignedEvent, nip19, kinds, VerifiedEvent } from 'nostr-tools'
+import { UnsignedEvent, nip19, kinds, VerifiedEvent, Event } from 'nostr-tools'
 import { useEffect, useMemo, useRef, useState } from 'react'
 import { Link, useParams } from 'react-router-dom'
 import { toast } from 'react-toastify'
@@ -95,6 +95,20 @@ export const ProfileSettingsPage = () => {
 
     if (pubkey) {
       const getMetadata = async (pubkey: string) => {
+        const handleMetadataEvent = (event: Event) => {
+          const metadataContent =
+            metadataController.extractProfileMetadataContent(event)
+          if (metadataContent) {
+            setProfileMetadata(metadataContent)
+          }
+        }
+
+        metadataController.on(pubkey, (kind: number, event: Event) => {
+          if (kind === kinds.Metadata) {
+            handleMetadataEvent(event)
+          }
+        })
+
         const metadataEvent = await metadataController
           .findMetadata(pubkey)
           .catch((err) => {
@@ -102,13 +116,7 @@ export const ProfileSettingsPage = () => {
             return null
           })
 
-        if (metadataEvent) {
+        if (metadataEvent) handleMetadataEvent(metadataEvent)
-          const metadataContent =
-            metadataController.extractProfileMetadataContent(metadataEvent)
-          if (metadataContent) {
-            setProfileMetadata(metadataContent)
-          }
-        }
 
         setIsLoading(false)
       }

src/pages/sign/index.tsx

@@ -20,7 +20,7 @@ import saveAs from 'file-saver'
 import JSZip from 'jszip'
 import _ from 'lodash'
 import { MuiFileInput } from 'mui-file-input'
-import { Event, verifyEvent } from 'nostr-tools'
+import { Event, kinds, verifyEvent } from 'nostr-tools'
 import { useEffect, useState } from 'react'
 import { useSelector } from 'react-redux'
 import { useNavigate, useSearchParams } from 'react-router-dom'
@@ -846,17 +846,27 @@ const DisplayMeta = ({
 
     hexKeys.forEach((key) => {
       if (!(key in metadata)) {
+        const handleMetadataEvent = (event: Event) => {
+          const metadataContent =
+            metadataController.extractProfileMetadataContent(event)
+
+          if (metadataContent)
+            setMetadata((prev) => ({
+              ...prev,
+              [key]: metadataContent
+            }))
+        }
+
+        metadataController.on(key, (kind: number, event: Event) => {
+          if (kind === kinds.Metadata) {
+            handleMetadataEvent(event)
+          }
+        })
+
         metadataController
           .findMetadata(key)
           .then((metadataEvent) => {
-            const metadataContent =
+            if (metadataEvent) handleMetadataEvent(metadataEvent)
-              metadataController.extractProfileMetadataContent(metadataEvent)
-
-            if (metadataContent)
-              setMetadata((prev) => ({
-                ...prev,
-                [key]: metadataContent
-              }))
           })
           .catch((err) => {
             console.error(`error occurred in finding metadata for: ${key}`, err)

src/pages/verify/index.tsx

@@ -10,7 +10,7 @@ import {
 } from '@mui/material'
 import JSZip from 'jszip'
 import { MuiFileInput } from 'mui-file-input'
-import { Event, verifyEvent } from 'nostr-tools'
+import { Event, kinds, verifyEvent } from 'nostr-tools'
 import { useEffect, useState } from 'react'
 import { toast } from 'react-toastify'
 import { LoadingSpinner } from '../../components/LoadingSpinner'
@@ -107,16 +107,26 @@ export const VerifyPage = () => {
         const pubkey = npubToHex(user)!
 
         if (!(pubkey in metadata)) {
+          const handleMetadataEvent = (event: Event) => {
+            const metadataContent =
+              metadataController.extractProfileMetadataContent(event)
+            if (metadataContent)
+              setMetadata((prev) => ({
+                ...prev,
+                [pubkey]: metadataContent
+              }))
+          }
+
+          metadataController.on(pubkey, (kind: number, event: Event) => {
+            if (kind === kinds.Metadata) {
+              handleMetadataEvent(event)
+            }
+          })
+
           metadataController
             .findMetadata(pubkey)
             .then((metadataEvent) => {
-              const metadataContent =
+              if (metadataEvent) handleMetadataEvent(metadataEvent)
-                metadataController.extractProfileMetadataContent(metadataEvent)
-              if (metadataContent)
-                setMetadata((prev) => ({
-                  ...prev,
-                  [pubkey]: metadataContent
-                }))
             })
             .catch((err) => {
               console.error(