客戶端開發

# 安裝
npm install nostr-tools

# 基本引入
import {
  generateSecretKey,
  getPublicKey,
  finalizeEvent,
  verifyEvent,
  SimplePool
} from 'nostr-tools'

import {
  generateSecretKey,
  getPublicKey,
  nip19
} from 'nostr-tools'

// 生成新密鑰對
const sk = generateSecretKey()  // Uint8Array
const pk = getPublicKey(sk)     // hex string

// 編碼為 bech32 格式
const nsec = nip19.nsecEncode(sk)  // nsec1...
const npub = nip19.npubEncode(pk)  // npub1...

console.log('Public Key:', npub)
console.log('Secret Key:', nsec)  // 保密！

// 解碼 bech32
const { type, data } = nip19.decode(npub)
// type: 'npub', data: hex pubkey

// 使用 NIP-07 瀏覽器擴展
if (window.nostr) {
  const pubkey = await window.nostr.getPublicKey()
  // 簽名時使用 window.nostr.signEvent()
}

import { SimplePool } from 'nostr-tools'

// 創建連接池
const pool = new SimplePool()

// 定義中繼器列表
const relays = [
  'wss://relay.damus.io',
  'wss://nos.lol',
  'wss://relay.nostr.band'
]

// 發送事件到所有中繼器
await pool.publish(relays, signedEvent)

// 查詢事件
const events = await pool.querySync(relays, {
  kinds: [1],
  authors: [pubkey],
  limit: 20
})

// 訂閱事件（即時）
const sub = pool.subscribeMany(
  relays,
  [{ kinds: [1], authors: [pubkey] }],
  {
    onevent(event) {
      console.log('New event:', event)
    },
    oneose() {
      console.log('End of stored events')
    }
  }
)

// 關閉訂閱
sub.close()

import { finalizeEvent, verifyEvent } from 'nostr-tools'

// 創建短文本事件（kind:1）
const event = finalizeEvent({
  kind: 1,
  created_at: Math.floor(Date.now() / 1000),
  tags: [],
  content: 'Hello Nostr!'
}, sk)

// 驗證事件
const isValid = verifyEvent(event)
console.log('Valid:', isValid)

// 發布
await pool.publish(relays, event)

// 創建回覆
const reply = finalizeEvent({
  kind: 1,
  created_at: Math.floor(Date.now() / 1000),
  tags: [
    ['e', originalEventId, relays[0], 'root'],
    ['e', parentEventId, relays[0], 'reply'],
    ['p', originalAuthorPubkey]
  ],
  content: 'This is a reply!'
}, sk)

// 創建反應（kind:7）
const reaction = finalizeEvent({
  kind: 7,
  created_at: Math.floor(Date.now() / 1000),
  tags: [
    ['e', targetEventId],
    ['p', targetAuthorPubkey]
  ],
  content: '+'  // 或其他反應符號
}, sk)

// 更新個人資料（kind:0）
const metadata = finalizeEvent({
  kind: 0,
  created_at: Math.floor(Date.now() / 1000),
  tags: [],
  content: JSON.stringify({
    name: 'Alice',
    about: 'Nostr developer',
    picture: 'https://example.com/avatar.jpg',
    nip05: '[email protected]',
    lud16: '[email protected]'
  })
}, sk)

// 查詢特定用戶的貼文
const posts = await pool.querySync(relays, {
  kinds: [1],
  authors: [pubkey],
  limit: 50
})

// 查詢用戶個人資料
const profiles = await pool.querySync(relays, {
  kinds: [0],
  authors: [pubkey1, pubkey2, pubkey3]
})

// 查詢特定事件的回覆
const replies = await pool.querySync(relays, {
  kinds: [1],
  '#e': [eventId]
})

// 查詢帶特定標籤的事件
const taggedPosts = await pool.querySync(relays, {
  kinds: [1],
  '#t': ['bitcoin', 'nostr']
})

// 時間範圍查詢
const recentPosts = await pool.querySync(relays, {
  kinds: [1],
  since: Math.floor(Date.now() / 1000) - 3600,  // 過去一小時
  limit: 100
})

// 多過濾器（OR 關係）
const events = await pool.querySync(relays, [
  { kinds: [1], authors: [pubkey] },  // 用戶的貼文
  { kinds: [7], '#p': [pubkey] }      // 對用戶的反應
])

// 訂閱動態消息
const sub = pool.subscribeMany(
  relays,
  [
    { kinds: [1], limit: 50 },  // 最近的貼文
    { kinds: [7], '#p': [myPubkey] }  // 對我的反應
  ],
  {
    onevent(event) {
      switch (event.kind) {
        case 1:
          handleNewPost(event)
          break
        case 7:
          handleReaction(event)
          break
      }
    },
    oneose() {
      console.log('Historical events loaded')
      // 可以在這裡更新 UI 狀態
    },
    onclose(reason) {
      console.log('Subscription closed:', reason)
    }
  }
)

// 頁面卸載時關閉
window.addEventListener('beforeunload', () => {
  sub.close()
})

// 動態添加過濾器
// 創建新訂閱，舊的會自動替換

// 使用 REQ 自動重連
// SimplePool 會自動處理連接斷開和重連

import { nip05 } from 'nostr-tools'

// 查詢 NIP-05 資料
const profile = await nip05.queryProfile('[email protected]')

if (profile) {
  console.log('Public Key:', profile.pubkey)
  console.log('Relays:', profile.relays)
}

// 驗證用戶的 NIP-05
async function verifyNip05(event) {
  // 解析個人資料
  const metadata = JSON.parse(event.content)
  const nip05Addr = metadata.nip05

  if (!nip05Addr) {
    return { verified: false, reason: 'No NIP-05' }
  }

  const profile = await nip05.queryProfile(nip05Addr)

  if (!profile) {
    return { verified: false, reason: 'Query failed' }
  }

  if (profile.pubkey !== event.pubkey) {
    return { verified: false, reason: 'Pubkey mismatch' }
  }

  return { verified: true, relays: profile.relays }
}

// 檢查是否有 NIP-07 擴展
function hasNostrExtension() {
  return typeof window.nostr !== 'undefined'
}

// 使用 NIP-07 簽名
async function signWithExtension(event) {
  if (!hasNostrExtension()) {
    throw new Error('No Nostr extension found')
  }

  // 獲取公鑰
  const pubkey = await window.nostr.getPublicKey()

  // 準備事件（不包含 id 和 sig）
  const unsignedEvent = {
    kind: event.kind,
    created_at: event.created_at || Math.floor(Date.now() / 1000),
    tags: event.tags || [],
    content: event.content,
    pubkey: pubkey
  }

  // 擴展會計算 id 並簽名
  const signedEvent = await window.nostr.signEvent(unsignedEvent)

  return signedEvent
}

// 加密訊息
async function encryptMessage(recipientPubkey, plaintext) {
  if (!hasNostrExtension()) {
    throw new Error('No Nostr extension found')
  }

  // NIP-04（舊版）
  const ciphertext = await window.nostr.nip04.encrypt(
    recipientPubkey,
    plaintext
  )

  // 或 NIP-44（新版，更安全）
  // const ciphertext = await window.nostr.nip44.encrypt(
  //   recipientPubkey,
  //   plaintext
  // )

  return ciphertext
}

// 簡易 Nostr 客戶端架構

class NostrClient {
  constructor(relays) {
    this.pool = new SimplePool()
    this.relays = relays
    this.subscriptions = new Map()
  }

  // 登入（使用擴展或私鑰）
  async login(method = 'extension') {
    if (method === 'extension') {
      this.pubkey = await window.nostr.getPublicKey()
      this.signMethod = 'extension'
    } else {
      this.sk = generateSecretKey()
      this.pubkey = getPublicKey(this.sk)
      this.signMethod = 'local'
    }
    return this.pubkey
  }

  // 簽名事件
  async signEvent(event) {
    if (this.signMethod === 'extension') {
      return await window.nostr.signEvent(event)
    } else {
      return finalizeEvent(event, this.sk)
    }
  }

  // 發布貼文
  async post(content, replyTo = null) {
    const tags = []
    if (replyTo) {
      tags.push(['e', replyTo.id, this.relays[0], 'reply'])
      tags.push(['p', replyTo.pubkey])
    }

    const event = await this.signEvent({
      kind: 1,
      created_at: Math.floor(Date.now() / 1000),
      tags,
      content
    })

    await this.pool.publish(this.relays, event)
    return event
  }

  // 獲取動態消息
  async getFeed(limit = 50) {
    // 先獲取關注列表
    const contactEvent = await this.pool.get(this.relays, {
      kinds: [3],
      authors: [this.pubkey]
    })

    const following = contactEvent?.tags
      .filter(t => t[0] === 'p')
      .map(t => t[1]) || []

    // 獲取關注者的貼文
    return await this.pool.querySync(this.relays, {
      kinds: [1],
      authors: following,
      limit
    })
  }

  // 訂閱通知
  subscribeNotifications(callback) {
    const sub = this.pool.subscribeMany(
      this.relays,
      [
        { kinds: [1], '#p': [this.pubkey] },  // 提及
        { kinds: [7], '#p': [this.pubkey] },  // 反應
        { kinds: [9735], '#p': [this.pubkey] }  // Zaps
      ],
      {
        onevent: callback
      }
    )
    this.subscriptions.set('notifications', sub)
    return sub
  }

  // 清理
  cleanup() {
    this.subscriptions.forEach(sub => sub.close())
    this.pool.close(this.relays)
  }
}