feat: publish notable fight results to Nostr relays

NIP-01 kind:1 notes posted for KOs, perfects, upsets, and big Elo
swings. Includes bot names, Elo changes, arena, and replay link.
Configurable via BOTFIGHTS_NOSTR_RELAYS and BOTFIGHTS_NOSTR_NSEC env
vars. Silently skips if NSEC not set.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/engine/nostr-publish.ts

@@ -0,0 +1,82 @@
+// Publish notable fight results to Nostr relays as kind:1 notes
+import { finalizeEvent, getPublicKey } from 'nostr-tools'
+import { Relay } from 'nostr-tools/relay'
+import { hexToBytes } from 'nostr-tools/utils'
+
+const RELAYS = (process.env.BOTFIGHTS_NOSTR_RELAYS || 'wss://relay.damus.io').split(',').map(r => r.trim())
+const NSEC = process.env.BOTFIGHTS_NOSTR_NSEC || ''
+const SITE_URL = process.env.BOTFIGHTS_URL || 'https://botfights.io'
+
+interface FightResult {
+  fightId: string
+  winnerName: string
+  loserName: string
+  winnerId: string
+  winnerElo: number
+  loserElo: number
+  winnerEloChange: number
+  loserEloChange: number
+  isPerfect: boolean
+  isKO: boolean
+  isUpset: boolean
+  totalRounds: number
+  arena: string
+}
+
+function isNotable(result: FightResult): boolean {
+  return result.isKO || result.isPerfect || result.isUpset ||
+    Math.abs(result.winnerEloChange) >= 20
+}
+
+function formatNote(result: FightResult): string {
+  const lines: string[] = []
+
+  if (result.isPerfect) {
+    lines.push(`FLAWLESS VICTORY! ${result.winnerName} demolished ${result.loserName} with a PERFECT finish!`)
+  } else if (result.isKO) {
+    lines.push(`KO! ${result.winnerName} knocked out ${result.loserName}!`)
+  } else if (result.isUpset) {
+    lines.push(`UPSET! ${result.winnerName} (${result.winnerElo - result.winnerEloChange} Elo) defeats ${result.loserName} (${result.loserElo - result.loserEloChange} Elo)!`)
+  } else {
+    lines.push(`${result.winnerName} defeats ${result.loserName}!`)
+  }
+
+  lines.push(``)
+  lines.push(`${result.winnerName}: ${result.winnerElo} Elo (${result.winnerEloChange >= 0 ? '+' : ''}${result.winnerEloChange})`)
+  lines.push(`${result.loserName}: ${result.loserElo} Elo (${result.loserEloChange >= 0 ? '+' : ''}${result.loserEloChange})`)
+  lines.push(`Arena: ${result.arena} | Rounds: ${result.totalRounds}`)
+  lines.push(``)
+  lines.push(`Watch the replay: ${SITE_URL}/arena/${result.fightId}`)
+  lines.push(``)
+  lines.push(`#botfights #bitcoin #nostr`)
+
+  return lines.join('\n')
+}
+
+export async function publishFightResult(result: FightResult): Promise<void> {
+  if (!NSEC) return
+  if (!isNotable(result)) return
+
+  const secretKey = hexToBytes(NSEC)
+  const content = formatNote(result)
+
+  const event = finalizeEvent({
+    kind: 1,
+    content,
+    tags: [
+      ['t', 'botfights'],
+      ['t', 'bitcoin'],
+    ],
+    created_at: Math.floor(Date.now() / 1000),
+  }, secretKey)
+
+  for (const relayUrl of RELAYS) {
+    try {
+      const relay = await Relay.connect(relayUrl)
+      await relay.publish(event)
+      relay.close()
+    } catch (err) {
+      console.warn(`[nostr] Failed to publish to ${relayUrl}:`, err)
+    }
+  }
+}

server/src/engine/orchestrator.ts

@@ -11,6 +11,7 @@ import { setCooldown } from './queue.js'
 import { isHumanPlayer, waitForHumanResponse } from './human-responses.js'
 import { payWinner, refundEntry, ENTRY_FEE_SATS } from './payments.js'
 import { settleBets, lockBets } from './betting.js'
+import { publishFightResult } from './nostr-publish.js'
 
 interface BotRecord {
   id: string
@@ -333,12 +334,14 @@ async function executeFightRounds(fightId: string, botA: BotRecord, botB: BotRec
   let comboA = 0
   let comboB = 0
   let winnerId: string | null = null
+  let lastRound = 0
   const usedTypes = new Set<string>()
 
   // Pick a random round for retro mode (rounds 3-8, ensuring it's not too early or late)
   const retroRound = 3 + Math.floor(Math.random() * Math.min(6, MAX_ROUNDS - 4))
 
   for (let round = 1; round <= MAX_ROUNDS; round++) {
+    lastRound = round
     const challenge = round === retroRound
       ? generateRetroChallenge()
       : pickChallenge(usedTypes, arena.modifier)
@@ -447,6 +450,10 @@ async function executeFightRounds(fightId: string, botA: BotRecord, botB: BotRec
   // Finalize fight + update bot stats atomically
   const isMockFight = isMockBot(botA.webhookUrl) || isMockBot(botB.webhookUrl) || isClassicBot(botA.webhookUrl) || isClassicBot(botB.webhookUrl)
   const kFactor = isMockFight ? 12 : 32 // Dampened Elo for mock/classic fights
+  let winnerEloChange = 0
+  let loserEloChange = 0
+  let newWinnerEloFinal = 0
+  let newLoserEloFinal = 0
 
   const finalize = sqlite.transaction(() => {
     // Mark fight finished
@@ -463,6 +470,10 @@ async function executeFightRounds(fightId: string, botA: BotRecord, botB: BotRec
       const loser = winnerId === botA.id ? botB : botA
 
       const { newWinnerElo, newLoserElo } = calculateElo(winner.eloRating, loser.eloRating, kFactor)
+      winnerEloChange = Math.round(newWinnerElo - winner.eloRating)
+      loserEloChange = Math.round(newLoserElo - loser.eloRating)
+      newWinnerEloFinal = newWinnerElo
+      newLoserEloFinal = newLoserElo
       const newWinStreak = winner.winStreak + 1
       const newBestStreak = Math.max(winner.bestStreak, newWinStreak)
 
@@ -510,6 +521,21 @@ async function executeFightRounds(fightId: string, botA: BotRecord, botB: BotRec
     potSats: mode === 'ranked' ? 42 : 0,
   })
 
+  // Publish notable results to Nostr
+  if (winnerId) {
+    const winner = winnerId === botA.id ? botA : botB
+    const loser = winnerId === botA.id ? botB : botA
+    const isUpset = loser.eloRating - winner.eloRating > 150
+    const isKO = (winnerId === botA.id && hpB <= 0) || (winnerId === botB.id && hpA <= 0)
+    publishFightResult({
+      fightId, winnerName: winner.name, loserName: loser.name, winnerId,
+      winnerElo: newWinnerEloFinal, loserElo: newLoserEloFinal,
+      winnerEloChange, loserEloChange,
+      isPerfect: !!isPerfect, isKO, isUpset,
+      totalRounds: lastRound, arena: arena.name,
+    }).catch(err => console.warn('[nostr] publish failed:', err))
+  }
+
   // Settle bets
   try {
     const settlements = await settleBets(fightId, winnerId)