Add server/transactions.js

Add Fulcrum transaction lookup module

server/transactions.js

@@ -0,0 +1,185 @@
+const net = require('net')
+
+const fulcrumTimeoutMs = 3000
+
+function queryFulcrum(fulcrumUrl, method, params = []) {
+  return new Promise((resolve) => {
+    if (!fulcrumUrl) {
+      resolve({
+        ok: false,
+        result: null,
+        error: 'Fulcrum URL is not configured',
+      })
+      return
+    }
+
+    let parsed
+
+    try {
+      parsed = new URL(fulcrumUrl)
+    } catch {
+      resolve({
+        ok: false,
+        result: null,
+        error: 'Invalid Fulcrum URL',
+      })
+      return
+    }
+
+    if (parsed.protocol !== 'tcp:') {
+      resolve({
+        ok: false,
+        result: null,
+        error: 'Fulcrum URL must use tcp://',
+      })
+      return
+    }
+
+    const host = parsed.hostname
+    const port = Number(parsed.port)
+
+    if (!host || !port) {
+      resolve({
+        ok: false,
+        result: null,
+        error: 'Fulcrum URL is missing host or port',
+      })
+      return
+    }
+
+    const socket = net.createConnection({
+      host,
+      port,
+    })
+
+    let response = ''
+    let settled = false
+
+    const finish = (value) => {
+      if (settled) {
+        return
+      }
+
+      settled = true
+      socket.destroy()
+      resolve(value)
+    }
+
+    socket.setTimeout(fulcrumTimeoutMs)
+
+    socket.on('connect', () => {
+      const request =
+        JSON.stringify({
+          jsonrpc: '2.0',
+          id: 1,
+          method,
+          params,
+        }) + '\n'
+
+      socket.write(request)
+    })
+
+    socket.on('data', (data) => {
+      response += data.toString()
+
+      const lines = response.split('\n')
+
+      for (const line of lines) {
+        if (!line.trim()) {
+          continue
+        }
+
+        let message
+
+        try {
+          message = JSON.parse(line)
+        } catch {
+          continue
+        }
+
+        if (message.error) {
+          finish({
+            ok: false,
+            result: null,
+            error: message.error,
+          })
+
+          return
+        }
+
+        if (
+          Object.prototype.hasOwnProperty.call(
+            message,
+            'result',
+          )
+        ) {
+          finish({
+            ok: true,
+            result: message.result,
+            error: null,
+          })
+
+          return
+        }
+      }
+    })
+
+    socket.on('timeout', () => {
+      finish({
+        ok: false,
+        result: null,
+        error: 'Connection timed out',
+      })
+    })
+
+    socket.on('error', (error) => {
+      finish({
+        ok: false,
+        result: null,
+        error: error.message,
+      })
+    })
+
+    socket.on('close', () => {
+      if (!settled) {
+        finish({
+          ok: false,
+          result: null,
+          error:
+            'Connection closed before a response was received',
+        })
+      }
+    })
+  })
+}
+
+async function getTransaction(txid) {
+  if (typeof txid !== 'string' || !txid.trim()) {
+    throw new Error('Transaction ID is required')
+  }
+
+  const fulcrumUrl =
+    process.env.MUNIN_FULCRUM_URL || null
+
+  if (!fulcrumUrl) {
+    throw new Error('Fulcrum URL is not configured')
+  }
+
+  const result = await queryFulcrum(
+    fulcrumUrl,
+    'blockchain.transaction.get',
+    [txid.trim(), true],
+  )
+
+  if (!result.ok) {
+    throw new Error(
+      `Failed to query transaction: ${JSON.stringify(result.error)}`,
+    )
+  }
+
+  return result.result
+}
+
+module.exports = {
+  getTransaction,
+}