From 9652df93660411e826ef3ccad546ab184b02fd9d Mon Sep 17 00:00:00 2001
From: Anna Rose Wiggins <annabunches@gmail.com>
Date: Fri, 1 Aug 2025 13:49:03 -0400
Subject: [PATCH] Add device locking with a flag to disable for testing.

---
 cmd/joyful/main.go         | 8 +++++---
 internal/config/devices.go | 9 +++++++--
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/cmd/joyful/main.go b/cmd/joyful/main.go
index 17482bf..41eaae5 100644
--- a/cmd/joyful/main.go
+++ b/cmd/joyful/main.go
@@ -52,8 +52,8 @@ func getVirtualDevices(buffers map[string]*virtualdevice.EventBuffer) map[string
 	return devices
 }
 
-func initPhysicalDevices(config *config.ConfigParser) map[string]*evdev.InputDevice {
-	pDeviceMap := config.ConnectPhysicalDevices()
+func initPhysicalDevices(config *config.ConfigParser, lock bool) map[string]*evdev.InputDevice {
+	pDeviceMap := config.ConnectPhysicalDevices(lock)
 	if len(pDeviceMap) == 0 {
 		logger.Log("Warning: no physical devices found in configuration. No rules will work.")
 	}
@@ -63,7 +63,9 @@ func initPhysicalDevices(config *config.ConfigParser) map[string]*evdev.InputDev
 func main() {
 	// parse command-line
 	var configFlag string
+	var noLockFlag bool
 	flag.BoolVarP(&logger.IsDebugMode, "debug", "d", false, "Output very verbose debug messages.")
+	flag.BoolVar(&noLockFlag, "no-lock", false, "Disable locking the physical devices for exclusive reading.")
 	flag.StringVarP(&configFlag, "config", "c", "~/.config/joyful", "Directory to read configuration from.")
 	ttsOps := addTTSFlags()
 	flag.Parse()
@@ -80,7 +82,7 @@ func main() {
 	vBuffersByName, vBuffersByDevice := initVirtualBuffers(config)
 
 	// Initialize physical devices
-	pDevices := initPhysicalDevices(config)
+	pDevices := initPhysicalDevices(config, !noLockFlag)
 
 	// Load the rules
 	rules, eventChannel, cancel, wg := loadRules(config, pDevices, getVirtualDevices(vBuffersByName))
diff --git a/internal/config/devices.go b/internal/config/devices.go
index 5da9849..d77147d 100644
--- a/internal/config/devices.go
+++ b/internal/config/devices.go
@@ -66,7 +66,7 @@ func (parser *ConfigParser) CreateVirtualDevices() map[string]*evdev.InputDevice
 // This function assumes you have already called Parse() on the config directory.
 //
 // This function should only be called once.
-func (parser *ConfigParser) ConnectPhysicalDevices() map[string]*evdev.InputDevice {
+func (parser *ConfigParser) ConnectPhysicalDevices(lock bool) map[string]*evdev.InputDevice {
 	deviceMap := make(map[string]*evdev.InputDevice)
 
 	for _, deviceConfig := range parser.config.Devices {
@@ -80,7 +80,12 @@ func (parser *ConfigParser) ConnectPhysicalDevices() map[string]*evdev.InputDevi
 			continue
 		}
 
-		// TODO: grab exclusive access to device (add config option)
+		if lock {
+			err := device.Grab()
+			if err != nil {
+				logger.LogError(err, "Failed to grab device for exclusive access")
+			}
+		}
 
 		logger.Log(fmt.Sprintf("Connected to '%s' as '%s'", deviceConfig.DeviceName, deviceConfig.Name))
 		deviceMap[deviceConfig.Name] = device