NIP-50 搜尋

// 基本搜尋
["REQ", "search-sub", {
  "search": "bitcoin lightning",
  "kinds": [1],
  "limit": 50
}]

// search 欄位會搜尋事件的 content
// 可以與其他過濾器組合使用

// 搜尋特定語言
{
  "search": "bitcoin language:zh"
}

// 搜尋特定領域（由中繼器定義）
{
  "search": "bitcoin domain:finance"
}

// 搜尋特定情感（部分中繼器支援）
{
  "search": "bitcoin sentiment:positive"
}

// 注意：擴展語法由各中繼器自行定義
// 使用前請查閱中繼器文件

async function searchNotes(relay, query, limit = 50) {
  return new Promise((resolve) => {
    const results = []

    const sub = relay.subscribe([{
      kinds: [1],
      search: query,
      limit: limit
    }])

    sub.on('event', (event) => {
      results.push(event)
    })

    sub.on('eose', () => {
      sub.close()
      resolve(results)
    })
  })
}

// 使用
const notes = await searchNotes(relay, 'bitcoin lightning')
console.log(`找到 ${notes.length} 條結果`)

// 搜尋特定用戶的內容
{
  "kinds": [1],
  "authors": ["pubkey1", "pubkey2"],
  "search": "bitcoin",
  "limit": 100
}

// 搜尋特定時間範圍
{
  "kinds": [1],
  "search": "announcement",
  "since": 1704067200,  // 2024-01-01
  "until": 1706745600,  // 2024-02-01
  "limit": 50
}

// 搜尋長文章
{
  "kinds": [30023],
  "search": "tutorial",
  "limit": 20
}

async function findSearchRelays(relayUrls) {
  const searchRelays = []

  for (const url of relayUrls) {
    const info = await getRelayInfo(url)
    if (info?.supported_nips?.includes(50)) {
      searchRelays.push({
        url,
        name: info.name || url
      })
    }
  }

  return searchRelays
}

// 只在支援搜尋的中繼器上搜尋
async function smartSearch(relayUrls, query) {
  const searchRelays = await findSearchRelays(relayUrls)

  if (searchRelays.length === 0) {
    throw new Error('沒有找到支援搜尋的中繼器')
  }

  console.log(`在 ${searchRelays.length} 個中繼器上搜尋`)

  // 並行搜尋所有中繼器
  const results = await Promise.all(
    searchRelays.map(r => searchNotes(r.url, query))
  )

  // 合併並去重
  return deduplicateEvents(results.flat())
}

// 搜尋結果可能包含相關性分數
// 這是中繼器特定的擴展

function sortByRelevance(events) {
  // 如果中繼器提供了排序，結果通常已按相關性排序
  // 否則可以按時間排序
  return events.sort((a, b) => b.created_at - a.created_at)
}

function highlightMatches(content, query) {
  const words = query.split(' ').filter(w => !w.startsWith('-'))

  let highlighted = content
  for (const word of words) {
    const regex = new RegExp(`(${word})`, 'gi')
    highlighted = highlighted.replace(regex, '<mark>$1</mark>')
  }

  return highlighted
}

// 顯示搜尋結果
function displayResults(events, query) {
  for (const event of events) {
    console.log('---')
    console.log('ID:', event.id.slice(0, 8))
    console.log('內容:', highlightMatches(event.content, query))
    console.log('時間:', new Date(event.created_at * 1000))
  }
}