feat: add zapReceiptService to fetch and aggregate kind:9735 receipts

src/services/zapReceiptService.ts

@@ -0,0 +1,151 @@
+import { RelayPool, completeOnEose, onlyEvents } from 'applesauce-relay'
+import { lastValueFrom, merge, Observable, takeUntil, timer, toArray } from 'rxjs'
+import { NostrEvent } from 'nostr-tools'
+import { prioritizeLocalRelays, partitionRelays } from '../utils/helpers'
+import { BORIS_PUBKEY } from './highlightCreationService'
+
+export interface ZapSender {
+  pubkey: string
+  totalSats: number
+  zapCount: number
+  isWhale: boolean // >= 69420 sats
+}
+
+/**
+ * Fetches zap receipts (kind:9735) for Boris and aggregates by sender
+ * @param relayPool - The relay pool to query
+ * @returns Array of senders who zapped >= 2100 sats, sorted by total desc
+ */
+export async function fetchBorisZappers(
+  relayPool: RelayPool
+): Promise<ZapSender[]> {
+  try {
+    console.log('⚡ Fetching zap receipts for Boris...')
+    
+    const relayUrls = Array.from(relayPool.relays.values()).map(relay => relay.url)
+    const prioritized = prioritizeLocalRelays(relayUrls)
+    const { local: localRelays, remote: remoteRelays } = partitionRelays(prioritized)
+
+    // Fetch zap receipts with Boris as recipient
+    const filter = {
+      kinds: [9735],
+      '#p': [BORIS_PUBKEY]
+    }
+
+    const local$ = localRelays.length > 0
+      ? relayPool
+          .req(localRelays, filter)
+          .pipe(
+            onlyEvents(),
+            completeOnEose(),
+            takeUntil(timer(1200))
+          )
+      : new Observable<NostrEvent>((sub) => sub.complete())
+
+    const remote$ = remoteRelays.length > 0
+      ? relayPool
+          .req(remoteRelays, filter)
+          .pipe(
+            onlyEvents(),
+            completeOnEose(),
+            takeUntil(timer(6000))
+          )
+      : new Observable<NostrEvent>((sub) => sub.complete())
+
+    const zapReceipts = await lastValueFrom(
+      merge(local$, remote$).pipe(toArray())
+    )
+
+    console.log(`📊 Fetched ${zapReceipts.length} zap receipts`)
+
+    // Dedupe by event ID
+    const uniqueReceipts = new Map<string, NostrEvent>()
+    zapReceipts.forEach(receipt => {
+      if (!uniqueReceipts.has(receipt.id)) {
+        uniqueReceipts.set(receipt.id, receipt)
+      }
+    })
+
+    // Aggregate by sender
+    const senderTotals = new Map<string, { totalSats: number; zapCount: number }>()
+
+    for (const receipt of uniqueReceipts.values()) {
+      const senderPubkey = extractSenderPubkey(receipt)
+      const amountSats = extractAmountSats(receipt)
+
+      if (!senderPubkey || amountSats === null) {
+        continue
+      }
+
+      const existing = senderTotals.get(senderPubkey) || { totalSats: 0, zapCount: 0 }
+      senderTotals.set(senderPubkey, {
+        totalSats: existing.totalSats + amountSats,
+        zapCount: existing.zapCount + 1
+      })
+    }
+
+    // Filter >= 2100 sats, mark whales >= 69420 sats, sort by total desc
+    const zappers: ZapSender[] = Array.from(senderTotals.entries())
+      .filter(([_, data]) => data.totalSats >= 2100)
+      .map(([pubkey, data]) => ({
+        pubkey,
+        totalSats: data.totalSats,
+        zapCount: data.zapCount,
+        isWhale: data.totalSats >= 69420
+      }))
+      .sort((a, b) => b.totalSats - a.totalSats)
+
+    console.log(`✅ Found ${zappers.length} supporters (${zappers.filter(z => z.isWhale).length} whales)`)
+
+    return zappers
+  } catch (error) {
+    console.error('Failed to fetch zap receipts:', error)
+    return []
+  }
+}
+
+/**
+ * Extract sender pubkey from zap receipt
+ * Try description.pubkey first, fallback to P tag
+ */
+function extractSenderPubkey(receipt: NostrEvent): string | null {
+  // Try description tag (JSON-encoded zap request)
+  const descTag = receipt.tags.find(t => t[0] === 'description')
+  if (descTag && descTag[1]) {
+    try {
+      const zapRequest = JSON.parse(descTag[1])
+      if (zapRequest.pubkey) {
+        return zapRequest.pubkey
+      }
+    } catch {
+      // Invalid JSON, continue
+    }
+  }
+
+  // Fallback to P tag (sender from zap request)
+  const pTag = receipt.tags.find(t => t[0] === 'P')
+  if (pTag && pTag[1]) {
+    return pTag[1]
+  }
+
+  return null
+}
+
+/**
+ * Extract amount in sats from zap receipt
+ * Use amount tag (millisats), skip if missing
+ */
+function extractAmountSats(receipt: NostrEvent): number | null {
+  const amountTag = receipt.tags.find(t => t[0] === 'amount')
+  if (!amountTag || !amountTag[1]) {
+    return null
+  }
+
+  const millisats = parseInt(amountTag[1], 10)
+  if (isNaN(millisats) || millisats <= 0) {
+    return null
+  }
+
+  return Math.floor(millisats / 1000)
+}
+