Enhance single instance and deep link functionality for Windows

- Introduced a Windows pipe server to facilitate communication between instances, improving single instance management.
- Updated `ensureSingleInstanceLock` to handle payload forwarding and signal writing more effectively.
- Refactored deep link handling to utilize the new protocol detection logic, enhancing URL parsing and navigation.
- Improved error handling and connection management for the Windows-specific implementation.

src/desktop/single-instance.js

@@ -8,18 +8,23 @@ import {
   watch,
   writeFileSync
 } from 'node:fs'
+import net from 'node:net'
 import { join } from 'node:path'
 import {
   getWindowsLaunchSources,
   getWindowsLaunchUrl
 } from './windows-launch-args.js'
 
+const PROTOCOL_PREFIX = 'farmcontrol://'
 const LOCK_FILE = 'primary.lock'
 const SIGNAL_FILE = 'instance-signal.json'
+const WINDOWS_PIPE_NAME = '\\\\.\\pipe\\com.tombutcher.farmcontrol.instance'
+const FORWARD_TIMEOUT_MS = 750
 
 let lockFd = null
 let pollInterval = null
 let fsWatcher = null
+let pipeServer = null
 let handlers = {
   onDeepLink: null,
   onFocus: null
@@ -111,6 +116,14 @@ function releasePrimaryLock() {
 }
 
 export function findProtocolUrl(args) {
+  const directMatch = args.find(
+    (arg) => typeof arg === 'string' && arg.startsWith(PROTOCOL_PREFIX)
+  )
+
+  if (directMatch) {
+    return directMatch
+  }
+
   const sources = args.filter((arg) => typeof arg === 'string')
 
   for (const arg of sources) {
@@ -126,8 +139,7 @@ export function findProtocolUrl(args) {
     }
   }
 
-  const combined = sources.join(' ')
-  const combinedMatch = combined.match(/farmcontrol:\/\/\S+/i)
+  const combinedMatch = sources.join(' ').match(/farmcontrol:\/\/\S+/i)
   if (combinedMatch) {
     const rawUrl = combinedMatch[0].replace(/['"]+$/g, '')
     try {
@@ -151,6 +163,11 @@ function collectLaunchSources() {
 }
 
 export function captureLaunchUrl() {
+  const argvUrl = findProtocolUrl(process.argv)
+  if (argvUrl) {
+    return argvUrl
+  }
+
   if (process.platform === 'win32') {
     return getWindowsLaunchUrl() || findProtocolUrl(collectLaunchSources())
   }
@@ -159,12 +176,12 @@ export function captureLaunchUrl() {
 }
 
 function buildLaunchPayload(launchUrl = captureLaunchUrl()) {
-  const sources = collectLaunchSources()
-  const url = launchUrl || findProtocolUrl(sources)
+  const commandLine = collectLaunchSources()
+  const url = launchUrl || findProtocolUrl(commandLine)
 
   return url
-    ? { type: 'deeplink', url, argv: sources }
-    : { type: 'focus', argv: sources }
+    ? { type: 'deeplink', url, argv: commandLine }
+    : { type: 'focus', argv: commandLine }
 }
 
 function readSignalQueue({ clear = true } = {}) {
@@ -274,17 +291,103 @@ function startInstanceSignalWatcher() {
   pollInterval = setInterval(processInstanceSignals, 100)
 }
 
+function forwardToRunningInstance(payload) {
+  if (process.platform !== 'win32') {
+    return Promise.resolve(false)
+  }
+
+  return new Promise((resolve) => {
+    let settled = false
+    const finish = (forwarded) => {
+      if (settled) return
+      settled = true
+      resolve(forwarded)
+    }
+
+    const client = net.connect(WINDOWS_PIPE_NAME)
+    const message = JSON.stringify(payload)
+
+    client.on('connect', () => {
+      client.write(message)
+      client.end()
+      finish(true)
+    })
+
+    client.on('error', () => {
+      finish(false)
+    })
+
+    client.setTimeout(FORWARD_TIMEOUT_MS, () => {
+      client.destroy()
+      finish(false)
+    })
+  })
+}
+
+function startWindowsPipeServer() {
+  if (process.platform !== 'win32' || pipeServer) {
+    return
+  }
+
+  const server = net.createServer((socket) => {
+    let buffer = ''
+
+    socket.on('data', (chunk) => {
+      buffer += chunk.toString()
+    })
+
+    socket.on('end', () => {
+      if (!buffer) return
+
+      try {
+        dispatchMessage(JSON.parse(buffer))
+      } catch {
+        // Ignore malformed payloads.
+      }
+    })
+  })
+
+  server.on('error', (error) => {
+    if (error?.code !== 'EADDRINUSE') {
+      console.warn('[single-instance] pipe server error:', error)
+    }
+  })
+
+  server.listen(WINDOWS_PIPE_NAME)
+  pipeServer = server
+}
+
 export async function ensureSingleInstanceLock({ launchUrl } = {}) {
   if (process.platform === 'darwin') {
     return true
   }
 
+  const payload = buildLaunchPayload(launchUrl)
+
+  if (process.platform === 'win32') {
+    if (await forwardToRunningInstance(payload)) {
+      return false
+    }
+
+    if (!tryAcquirePrimaryLock()) {
+      if (await forwardToRunningInstance(payload)) {
+        return false
+      }
+
+      writeInstanceSignal(payload)
+      return false
+    }
+
+    startWindowsPipeServer()
+    return true
+  }
+
   if (tryAcquirePrimaryLock()) {
     startInstanceSignalWatcher()
     return true
   }
 
-  writeInstanceSignal(buildLaunchPayload(launchUrl))
+  writeInstanceSignal(payload)
   return false
 }
 
@@ -299,6 +402,15 @@ export function setSingleInstanceHandlers({ onDeepLink, onFocus }) {
 }
 
 export function closeSingleInstanceServer() {
+  if (pipeServer) {
+    try {
+      pipeServer.close()
+    } catch {
+      // Ignore close failures.
+    }
+    pipeServer = null
+  }
+
   if (pollInterval) {
     clearInterval(pollInterval)
     pollInterval = null

src/desktop/window.js

@@ -10,7 +10,7 @@ const isMacOS = process.platform === 'darwin'
 
 const DEV_SERVER_PORT = 5780
 const DEV_SERVER_URL = `http://localhost:${DEV_SERVER_PORT}`
-import { captureLaunchUrl, setSingleInstanceHandlers } from './single-instance.js'
+import { findProtocolUrl, setSingleInstanceHandlers } from './single-instance.js'
 
 let mainWindow = null
 let webviewDomReady = false
@@ -90,6 +90,8 @@ export function openInternalUrl(url) {
   return true
 }
 
+const PROTOCOL_PREFIX = 'farmcontrol://'
+
 function parseDeepLinkPath(url) {
   if (!url || typeof url !== 'string') {
     return null
@@ -99,12 +101,11 @@ function parseDeepLinkPath(url) {
     return url
   }
 
-  const match = url.match(/^farmcontrol:\/\/app(.*)$/i)
-  if (!match) {
+  if (!url.startsWith(`${PROTOCOL_PREFIX}app`)) {
     return null
   }
 
-  const redirectPath = match[1] || '/'
+  const redirectPath = url.slice(`${PROTOCOL_PREFIX}app`.length) || '/'
   const normalizedPath = redirectPath.startsWith('/')
     ? redirectPath
     : `/${redirectPath}`
@@ -127,11 +128,12 @@ export function handleDeepLink(url) {
   return true
 }
 
-export function handleDeepLinkFromArgv(launchUrl = captureLaunchUrl()) {
+export function handleDeepLinkFromArgv(launchUrl) {
   if (process.platform === 'darwin') return
 
-  if (launchUrl) {
-    handleDeepLink(launchUrl)
+  const url = launchUrl || findProtocolUrl(process.argv)
+  if (url) {
+    handleDeepLink(url)
   }
 }