feat: pow

src/lib/draft-event.ts

@@ -10,6 +10,7 @@ import {
   TPollCreateData,
   TRelaySet
 } from '@/types'
+import { sha256 } from '@noble/hashes/sha2'
 import dayjs from 'dayjs'
 import { Event, kinds, nip19 } from 'nostr-tools'
 import {
@@ -22,6 +23,39 @@ import {
 import { randomString } from './random'
 import { generateBech32IdFromETag, tagNameEquals } from './tag'
 
+const draftEventCache: Map<string, string> = new Map()
+
+export function deleteDraftEventCache(draftEvent: TDraftEvent) {
+  const key = generateDraftEventCacheKey(draftEvent)
+  draftEventCache.delete(key)
+}
+
+function setDraftEventCache(baseDraft: Omit<TDraftEvent, 'created_at'>): TDraftEvent {
+  const cacheKey = generateDraftEventCacheKey(baseDraft)
+  const cache = draftEventCache.get(cacheKey)
+  if (cache) {
+    return JSON.parse(cache)
+  }
+  const draftEvent = { ...baseDraft, created_at: dayjs().unix() }
+  draftEventCache.set(cacheKey, JSON.stringify(draftEvent))
+
+  return draftEvent
+}
+
+function generateDraftEventCacheKey(draft: Omit<TDraftEvent, 'created_at'>) {
+  const str = JSON.stringify({
+    content: draft.content,
+    kind: draft.kind,
+    tags: draft.tags
+  })
+
+  const encoder = new TextEncoder()
+  const data = encoder.encode(str)
+  const hashBuffer = sha256(data)
+  const hashArray = Array.from(new Uint8Array(hashBuffer))
+  return hashArray.map((b) => b.toString(16).padStart(2, '0')).join('')
+}
+
 // https://github.com/nostr-protocol/nips/blob/master/25.md
 export function createReactionDraftEvent(event: Event, emoji: TEmoji | string = '+'): TDraftEvent {
   const tags: string[][] = []
@@ -68,7 +102,6 @@ export function createRepostDraftEvent(event: Event): TDraftEvent {
   }
 }
 
-const shortTextNoteDraftEventCache: Map<string, TDraftEvent> = new Map()
 export async function createShortTextNoteDraftEvent(
   content: string,
   mentions: string[],
@@ -125,15 +158,7 @@ export async function createShortTextNoteDraftEvent(
     content: transformedEmojisContent,
     tags
   }
-  const cacheKey = JSON.stringify(baseDraft)
-  const cache = shortTextNoteDraftEventCache.get(cacheKey)
-  if (cache) {
-    return cache
-  }
-  const draftEvent = { ...baseDraft, created_at: dayjs().unix() }
-  shortTextNoteDraftEventCache.set(cacheKey, draftEvent)
-
-  return draftEvent
+  return setDraftEventCache(baseDraft)
 }
 
 // https://github.com/nostr-protocol/nips/blob/master/51.md
@@ -150,7 +175,6 @@ export function createRelaySetDraftEvent(relaySet: Omit<TRelaySet, 'aTag'>): TDr
   }
 }
 
-const commentDraftEventCache: Map<string, TDraftEvent> = new Map()
 export async function createCommentDraftEvent(
   content: string,
   parentEvent: Event,
@@ -228,15 +252,7 @@ export async function createCommentDraftEvent(
     content: transformedEmojisContent,
     tags
   }
-  const cacheKey = JSON.stringify(baseDraft)
-  const cache = commentDraftEventCache.get(cacheKey)
-  if (cache) {
-    return cache
-  }
-  const draftEvent = { ...baseDraft, created_at: dayjs().unix() }
-  commentDraftEventCache.set(cacheKey, draftEvent)
-
-  return draftEvent
+  return setDraftEventCache(baseDraft)
 }
 
 export function createRelayListDraftEvent(mailboxRelays: TMailboxRelay[]): TDraftEvent {
@@ -325,7 +341,6 @@ export function createBlossomServerListDraftEvent(servers: string[]): TDraftEven
   }
 }
 
-const pollDraftEventCache: Map<string, TDraftEvent> = new Map()
 export async function createPollDraftEvent(
   author: string,
   question: string,
@@ -389,15 +404,7 @@ export async function createPollDraftEvent(
     kind: ExtendedKind.POLL,
     tags
   }
-  const cacheKey = JSON.stringify(baseDraft)
-  const cache = pollDraftEventCache.get(cacheKey)
-  if (cache) {
-    return cache
-  }
-  const draftEvent = { ...baseDraft, created_at: dayjs().unix() }
-  pollDraftEventCache.set(cacheKey, draftEvent)
-
-  return draftEvent
+  return setDraftEventCache(baseDraft)
 }
 
 export function createPollResponseDraftEvent(

src/lib/event.ts

@@ -2,11 +2,12 @@ import { EMBEDDED_MENTION_REGEX, ExtendedKind } from '@/constants'
 import client from '@/services/client.service'
 import { TImetaInfo } from '@/types'
 import { LRUCache } from 'lru-cache'
-import { Event, kinds, nip19 } from 'nostr-tools'
+import { Event, kinds, nip19, UnsignedEvent } from 'nostr-tools'
+import { fastEventHash, getPow } from 'nostr-tools/nip13'
 import {
-  getImetaInfoFromImetaTag,
   generateBech32IdFromATag,
   generateBech32IdFromETag,
+  getImetaInfoFromImetaTag,
   tagNameEquals
 } from './tag'
 
@@ -256,6 +257,47 @@ export function createFakeEvent(event: Partial<Event>): Event {
   }
 }
 
+export async function minePow(
+  unsigned: UnsignedEvent,
+  difficulty: number
+): Promise<Omit<Event, 'sig'>> {
+  let count = 0
+
+  const event = unsigned as Omit<Event, 'sig'>
+  const tag = ['nonce', count.toString(), difficulty.toString()]
+
+  event.tags.push(tag)
+
+  return new Promise((resolve) => {
+    const mine = () => {
+      let iterations = 0
+
+      while (iterations < 1000) {
+        const now = Math.floor(new Date().getTime() / 1000)
+
+        if (now !== event.created_at) {
+          count = 0
+          event.created_at = now
+        }
+
+        tag[1] = (++count).toString()
+        event.id = fastEventHash(event)
+
+        if (getPow(event.id) >= difficulty) {
+          resolve(event)
+          return
+        }
+
+        iterations++
+      }
+
+      setTimeout(mine, 0)
+    }
+
+    mine()
+  })
+}
+
 // Legacy compare function for sorting compatibility
 // If return 0, it means the two events are equal.
 // If return a negative number, it means `b` should be retained, and `a` should be discarded.