Move initialization code closer to the appropriate structs. (#17)

Reviewed-on: #17
Co-authored-by: Anna Rose Wiggins <annabunches@gmail.com>
Co-committed-by: Anna Rose Wiggins <annabunches@gmail.com>

cmd/evinfo/main.go

@@ -5,7 +5,8 @@ import (
 	"slices"
 
 	// TODO: using config here feels like bad coupling... ButtonFromIndex might need a refactor / move
-	"git.annabunches.net/annabunches/joyful/internal/config"
+
+	"git.annabunches.net/annabunches/joyful/internal/eventcodes"
 	"git.annabunches.net/annabunches/joyful/internal/logger"
 	"github.com/holoplot/go-evdev"
 	flag "github.com/spf13/pflag"
@@ -20,7 +21,7 @@ func isJoystickLike(device *evdev.InputDevice) bool {
 	if slices.Contains(types, evdev.EV_KEY) {
 		buttons := device.CapableEvents(evdev.EV_KEY)
 
-		for _, code := range config.ButtonFromIndex {
+		for _, code := range eventcodes.ButtonFromIndex {
 			if slices.Contains(buttons, code) {
 				return true
 			}

cmd/joyful/config.go

@@ -0,0 +1,147 @@
+package main
+
+import (
+	"context"
+	"strings"
+	"sync"
+
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
+	"git.annabunches.net/annabunches/joyful/internal/logger"
+	"git.annabunches.net/annabunches/joyful/internal/mappingrules"
+	"git.annabunches.net/annabunches/joyful/internal/virtualdevice"
+	"github.com/holoplot/go-evdev"
+)
+
+func initPhysicalDevices(conf *configparser.Config) map[string]*evdev.InputDevice {
+	pDeviceMap := make(map[string]*evdev.InputDevice)
+
+	for _, devConfig := range conf.Devices {
+		if strings.ToLower(devConfig.Type) != configparser.DeviceTypePhysical {
+			continue
+		}
+
+		innerConfig := devConfig.Config.(configparser.DeviceConfigPhysical)
+		name, device, err := initPhysicalDevice(innerConfig)
+		if err != nil {
+			logger.LogError(err, "Failed to initialize physical device")
+			continue
+		}
+
+		pDeviceMap[name] = device
+
+		displayName := innerConfig.DeviceName
+		if innerConfig.DevicePath != "" {
+			displayName = innerConfig.DevicePath
+		}
+		logger.Logf("Connected to '%s' as '%s'", displayName, name)
+	}
+
+	if len(pDeviceMap) == 0 {
+		logger.Log("Warning: no physical devices found in configuration. No rules will work.")
+	}
+	return pDeviceMap
+}
+
+func initPhysicalDevice(config configparser.DeviceConfigPhysical) (string, *evdev.InputDevice, error) {
+	name := config.Name
+	var device *evdev.InputDevice
+	var err error
+
+	if config.DevicePath != "" {
+		device, err = evdev.Open(config.DevicePath)
+	} else {
+		device, err = evdev.OpenByName(config.DeviceName)
+	}
+
+	if config.Lock && err == nil {
+		grabErr := device.Grab()
+		logger.LogIfError(grabErr, "Failed to lock device for exclusive access")
+	}
+
+	return name, device, err
+}
+
+// TODO: juggling all these maps is a pain. Is there a better solution here?
+func initVirtualBuffers(config *configparser.Config) (map[string]*evdev.InputDevice,
+	map[string]*virtualdevice.EventBuffer,
+	map[*evdev.InputDevice]*virtualdevice.EventBuffer) {
+
+	vDevicesByName := make(map[string]*evdev.InputDevice)
+	vBuffersByName := make(map[string]*virtualdevice.EventBuffer)
+	vBuffersByDevice := make(map[*evdev.InputDevice]*virtualdevice.EventBuffer)
+
+	for _, devConfig := range config.Devices {
+		if strings.ToLower(devConfig.Type) != configparser.DeviceTypeVirtual {
+			continue
+		}
+
+		vConfig := devConfig.Config.(configparser.DeviceConfigVirtual)
+		buffer, err := virtualdevice.NewEventBuffer(vConfig)
+		if err != nil {
+			logger.LogError(err, "Failed to create virtual device, skipping")
+			continue
+		}
+		vDevicesByName[buffer.Name] = buffer.Device.(*evdev.InputDevice)
+		vBuffersByName[buffer.Name] = buffer
+		vBuffersByDevice[buffer.Device.(*evdev.InputDevice)] = buffer
+	}
+
+	if len(vDevicesByName) == 0 {
+		logger.Log("Warning: no virtual devices found in configuration. No rules will work.")
+	}
+
+	return vDevicesByName, vBuffersByName, vBuffersByDevice
+}
+
+// TODO: At some point it would *very likely* make sense to map each rule to all of the physical devices that can
+// trigger it, and return that instead. Something like a map[Device][]mappingrule.MappingRule.
+// This would speed up rule matching by only checking relevant rules for a given input event.
+// We could take this further and make it a map[<struct of *inputdevice, type, and code>][]rule
+// For very large rule-bases this may be helpful for staying performant.
+func loadRules(
+	config *configparser.Config,
+	pDevices map[string]*evdev.InputDevice,
+	vDevices map[string]*evdev.InputDevice,
+	modes []string) ([]mappingrules.MappingRule, <-chan ChannelEvent, func(), *sync.WaitGroup) {
+
+	var wg sync.WaitGroup
+	eventChannel := make(chan ChannelEvent, 1000)
+	ctx, cancel := context.WithCancel(context.Background())
+
+	// Setup device mapping for the mappingrules package
+	pDevs := mappingrules.ConvertDeviceMap(pDevices)
+	vDevs := mappingrules.ConvertDeviceMap(vDevices)
+
+	// Initialize rules
+	rules := make([]mappingrules.MappingRule, 0)
+	for _, ruleConfig := range config.Rules {
+		newRule, err := mappingrules.NewRule(ruleConfig, pDevs, vDevs, modes)
+		if err != nil {
+			logger.LogError(err, "Failed to create rule, skipping")
+			continue
+		}
+		rules = append(rules, newRule)
+	}
+
+	logger.Logf("Created %d mapping rules.", len(rules))
+
+	// start listening for events on devices and timers
+	for _, device := range pDevices {
+		wg.Add(1)
+		go eventWatcher(device, eventChannel, ctx, &wg)
+	}
+
+	timerCount := 0
+	for _, rule := range rules {
+		if timedRule, ok := rule.(mappingrules.TimedEventEmitter); ok {
+			wg.Add(1)
+			go timerWatcher(timedRule, eventChannel, ctx, &wg)
+			timerCount++
+		}
+	}
+	logger.Logf("Registered %d timers.", timerCount)
+
+	go consoleWatcher(eventChannel)
+
+	return rules, eventChannel, cancel, &wg
+}

cmd/joyful/main.go

@@ -1,19 +1,15 @@
 package main
 
 import (
-	"context"
 	"fmt"
 	"os"
 	"strings"
-	"sync"
 
 	"github.com/holoplot/go-evdev"
 	flag "github.com/spf13/pflag"
 
-	"git.annabunches.net/annabunches/joyful/internal/config"
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
 	"git.annabunches.net/annabunches/joyful/internal/logger"
-	"git.annabunches.net/annabunches/joyful/internal/mappingrules"
-	"git.annabunches.net/annabunches/joyful/internal/virtualdevice"
 )
 
 func getConfigDir(dir string) string {
@@ -21,39 +17,6 @@ func getConfigDir(dir string) string {
 	return os.ExpandEnv(configDir)
 }
 
-func readConfig(configDir string) *config.ConfigParser {
-	parser := &config.ConfigParser{}
-	err := parser.Parse(configDir)
-	logger.FatalIfError(err, "Failed to parse config")
-	return parser
-}
-
-func initVirtualBuffers(config *config.ConfigParser) (map[string]*evdev.InputDevice,
-	map[string]*virtualdevice.EventBuffer,
-	map[*evdev.InputDevice]*virtualdevice.EventBuffer) {
-
-	vDevices := config.InitVirtualDevices()
-	if len(vDevices) == 0 {
-		logger.Log("Warning: no virtual devices found in configuration. No rules will work.")
-	}
-
-	vBuffersByName := make(map[string]*virtualdevice.EventBuffer)
-	vBuffersByDevice := make(map[*evdev.InputDevice]*virtualdevice.EventBuffer)
-	for name, device := range vDevices {
-		vBuffersByName[name] = virtualdevice.NewEventBuffer(device)
-		vBuffersByDevice[device] = vBuffersByName[name]
-	}
-	return vDevices, vBuffersByName, vBuffersByDevice
-}
-
-func initPhysicalDevices(config *config.ConfigParser) map[string]*evdev.InputDevice {
-	pDeviceMap := config.InitPhysicalDevices()
-	if len(pDeviceMap) == 0 {
-		logger.Log("Warning: no physical devices found in configuration. No rules will work.")
-	}
-	return pDeviceMap
-}
-
 func main() {
 	// parse command-line
 	var configFlag string
@@ -64,7 +27,8 @@ func main() {
 
 	// parse configs
 	configDir := getConfigDir(configFlag)
-	config := readConfig(configDir)
+	config, err := configparser.ParseConfig(configDir)
+	logger.FatalIfError(err, "Failed to parse configuration")
 
 	// initialize TTS
 	tts, err := newTTS(ttsOps)
@@ -76,20 +40,26 @@ func main() {
 	// Initialize physical devices
 	pDevices := initPhysicalDevices(config)
 
-	// Load the rules
+	// initialize the mode variables
-	rules, eventChannel, cancel, wg := loadRules(config, pDevices, vDevicesByName)
+	var mode string
+	modes := config.Modes
+	if len(modes) == 0 {
+		mode = "*"
+	} else {
+		mode = config.Modes[0]
+	}
 
-	// initialize the mode variable
+	// Load the rules
-	mode := config.GetModes()[0]
+	rules, eventChannel, cancel, wg := loadRules(config, pDevices, vDevicesByName, modes)
 
 	// initialize TTS phrases for modes
-	for _, m := range config.GetModes() {
+	for _, m := range modes {
 		tts.AddMessage(m)
 		logger.LogDebugf("Added TTS message '%s'", m)
 	}
 
 	fmt.Println("Joyful Running! Press Ctrl+C to quit. Press Enter to reload rules.")
-	if len(config.GetModes()) > 1 {
+	if len(modes) > 0 {
 		logger.Logf("Initial mode set to '%s'", mode)
 	}
 
@@ -127,13 +97,18 @@ func main() {
 
 		case ChannelEventReload:
 			// stop existing channels
+			config, err := configparser.ParseConfig(configDir) // reload the config
+			if err != nil {
+				logger.LogError(err, "Failed to parse config, no changes made")
+				continue
+			}
+
 			fmt.Println("Reloading rules.")
 			cancel()
 			fmt.Println("Waiting for existing listeners to exit. Provide input from each of your devices.")
 			wg.Wait()
-			fmt.Println("Listeners exited. Parsing config.")
+			fmt.Println("Listeners exited. Loading new rules.")
-			config := readConfig(configDir) // reload the config
+			rules, eventChannel, cancel, wg = loadRules(config, pDevices, vDevicesByName, modes)
-			rules, eventChannel, cancel, wg = loadRules(config, pDevices, vDevicesByName)
 			fmt.Println("Config re-loaded. Only rule changes applied. Device and Mode changes require restart.")
 		}
 
@@ -142,37 +117,3 @@ func main() {
 		}
 	}
 }
-
-func loadRules(
-	config *config.ConfigParser,
-	pDevices map[string]*evdev.InputDevice,
-	vDevices map[string]*evdev.InputDevice) ([]mappingrules.MappingRule, <-chan ChannelEvent, func(), *sync.WaitGroup) {
-
-	var wg sync.WaitGroup
-	eventChannel := make(chan ChannelEvent, 1000)
-	ctx, cancel := context.WithCancel(context.Background())
-
-	// Initialize rules
-	rules := config.InitRules(pDevices, vDevices)
-	logger.Logf("Created %d mapping rules.", len(rules))
-
-	// start listening for events on devices and timers
-	for _, device := range pDevices {
-		wg.Add(1)
-		go eventWatcher(device, eventChannel, ctx, &wg)
-	}
-
-	timerCount := 0
-	for _, rule := range rules {
-		if timedRule, ok := rule.(mappingrules.TimedEventEmitter); ok {
-			wg.Add(1)
-			go timerWatcher(timedRule, eventChannel, ctx, &wg)
-			timerCount++
-		}
-	}
-	logger.Logf("Registered %d timers.", timerCount)
-
-	go consoleWatcher(eventChannel)
-
-	return rules, eventChannel, cancel, &wg
-}

internal/config/configparser.go

@@ -1,77 +0,0 @@
-// The ConfigParser is the main structure you'll interact with when using this package.
-//
-// Example usage:
-//     config := &config.ConfigParser{}
-//     config.Parse(<some directory containing YAML files>)
-//     virtualDevices := config.CreateVirtualDevices()
-//     physicalDevices := config.ConnectVirtualDevices()
-//     modes := config.GetModes()
-//     rules := config.BuildRules(physicalDevices, virtualDevices, modes)
-//
-// nb: there are methods defined on ConfigParser in other files in this package!
-
-package config
-
-import (
-	"errors"
-	"os"
-	"path/filepath"
-	"strings"
-
-	"git.annabunches.net/annabunches/joyful/internal/logger"
-	"github.com/goccy/go-yaml"
-)
-
-type ConfigParser struct {
-	config Config
-}
-
-// Parse all the config files and store the config data for further use
-func (parser *ConfigParser) Parse(directory string) error {
-	parser.config = Config{}
-
-	// Find the config files in the directory
-	dirEntries, err := os.ReadDir(directory)
-	if err != nil {
-		err = os.Mkdir(directory, 0755)
-		if err != nil {
-			return errors.New("Failed to create config directory at " + directory)
-		}
-	}
-
-	// Open each yaml file and add its contents to the global config
-	for _, file := range dirEntries {
-		name := file.Name()
-		if file.IsDir() || !(strings.HasSuffix(name, ".yaml") || strings.HasSuffix(name, ".yml")) {
-			continue
-		}
-
-		filePath := filepath.Join(directory, name)
-		if strings.HasSuffix(filePath, ".yaml") || strings.HasSuffix(filePath, ".yml") {
-			data, err := os.ReadFile(filePath)
-			if err != nil {
-				logger.LogError(err, "Error while opening config file")
-				continue
-			}
-			newConfig := Config{}
-			err = yaml.Unmarshal(data, &newConfig)
-			logger.LogIfError(err, "Error parsing YAML")
-			parser.config.Rules = append(parser.config.Rules, newConfig.Rules...)
-			parser.config.Devices = append(parser.config.Devices, newConfig.Devices...)
-			parser.config.Modes = append(parser.config.Modes, newConfig.Modes...)
-		}
-	}
-
-	if len(parser.config.Devices) == 0 {
-		return errors.New("Found no devices in configuration. Please add configuration at " + directory)
-	}
-
-	return nil
-}
-
-func (parser *ConfigParser) GetModes() []string {
-	if len(parser.config.Modes) == 0 {
-		return []string{"*"}
-	}
-	return parser.config.Modes
-}

internal/config/devices.go

@@ -1,221 +0,0 @@
-package config
-
-import (
-	"fmt"
-	"strings"
-
-	"git.annabunches.net/annabunches/joyful/internal/logger"
-	"github.com/holoplot/go-evdev"
-)
-
-// InitVirtualDevices will register any configured devices with type = virtual
-// using /dev/uinput, and return a map of those devices.
-//
-// This function assumes Parse() has been called.
-//
-// This function should only be called once, unless we want to create duplicate devices for some reason.
-func (parser *ConfigParser) InitVirtualDevices() map[string]*evdev.InputDevice {
-	deviceMap := make(map[string]*evdev.InputDevice)
-
-	for _, deviceConfig := range parser.config.Devices {
-		if strings.ToLower(deviceConfig.Type) != DeviceTypeVirtual {
-			continue
-		}
-
-		deviceConfig := deviceConfig.Config.(DeviceConfigVirtual)
-
-		name := fmt.Sprintf("joyful-%s", deviceConfig.Name)
-
-		var capabilities map[evdev.EvType][]evdev.EvCode
-
-		// todo: add tests for presets
-		switch deviceConfig.Preset {
-		case DevicePresetGamepad:
-			capabilities = CapabilitiesPresetGamepad
-		case DevicePresetKeyboard:
-			capabilities = CapabilitiesPresetKeyboard
-		case DevicePresetJoystick:
-			capabilities = CapabilitiesPresetJoystick
-		case DevicePresetMouse:
-			capabilities = CapabilitiesPresetMouse
-		default:
-			capabilities = map[evdev.EvType][]evdev.EvCode{
-				evdev.EV_KEY: makeButtons(deviceConfig.NumButtons, deviceConfig.Buttons),
-				evdev.EV_ABS: makeAxes(deviceConfig.NumAxes, deviceConfig.Axes),
-				evdev.EV_REL: makeRelativeAxes(deviceConfig.NumRelativeAxes, deviceConfig.RelativeAxes),
-			}
-		}
-
-		device, err := evdev.CreateDevice(
-			name,
-			// TODO: who knows what these should actually be
-			evdev.InputID{
-				BusType: 0x03,
-				Vendor:  0x4711,
-				Product: 0x0816,
-				Version: 1,
-			},
-			capabilities,
-		)
-
-		if err != nil {
-			logger.LogIfError(err, "Failed to create virtual device")
-			continue
-		}
-
-		deviceMap[deviceConfig.Name] = device
-		logger.Log(fmt.Sprintf(
-			"Created virtual device '%s' with %d buttons, %d axes, and %d relative axes",
-			name,
-			len(capabilities[evdev.EV_KEY]),
-			len(capabilities[evdev.EV_ABS]),
-			len(capabilities[evdev.EV_REL]),
-		))
-	}
-
-	return deviceMap
-}
-
-// InitPhysicalDevices will create InputDevices corresponding to any registered
-// devices with type = physical.
-//
-// This function assumes Parse() has been called.
-//
-// This function should only be called once.
-func (parser *ConfigParser) InitPhysicalDevices() map[string]*evdev.InputDevice {
-	deviceMap := make(map[string]*evdev.InputDevice)
-
-	for _, deviceConfig := range parser.config.Devices {
-		if strings.ToLower(deviceConfig.Type) != DeviceTypePhysical {
-			continue
-		}
-
-		deviceConfig := deviceConfig.Config.(DeviceConfigPhysical)
-
-		var infoName string
-		var device *evdev.InputDevice
-		var err error
-
-		if deviceConfig.DevicePath != "" {
-			infoName = deviceConfig.DevicePath
-			device, err = evdev.Open(deviceConfig.DevicePath)
-		} else {
-			infoName = deviceConfig.DeviceName
-			device, err = evdev.OpenByName(deviceConfig.DeviceName)
-		}
-
-		if err != nil {
-			logger.LogError(err, "Failed to open physical device, skipping. Confirm the device name or path with 'evinfo'")
-			continue
-		}
-
-		if deviceConfig.Lock {
-			logger.LogDebugf("Locking device '%s'", infoName)
-			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'", infoName, deviceConfig.Name))
-		deviceMap[deviceConfig.Name] = device
-	}
-
-	return deviceMap
-}
-
-// TODO: these functions have a lot of duplication; we need to figure out how to refactor it cleanly
-// without losing logging context...
-func makeButtons(numButtons int, buttonList []string) []evdev.EvCode {
-	if numButtons > 0 && len(buttonList) > 0 {
-		logger.Log("'num_buttons' and 'buttons' both specified, ignoring 'num_buttons'")
-	}
-
-	if numButtons > VirtualDeviceMaxButtons {
-		numButtons = VirtualDeviceMaxButtons
-		logger.Logf("Limiting virtual device buttons to %d", VirtualDeviceMaxButtons)
-	}
-
-	if len(buttonList) > 0 {
-		buttons := make([]evdev.EvCode, 0, len(buttonList))
-		for _, codeStr := range buttonList {
-			code, err := parseCode(codeStr, "BTN")
-			if err != nil {
-				logger.LogError(err, "Failed to create button, skipping")
-				continue
-			}
-			buttons = append(buttons, code)
-		}
-		return buttons
-	}
-
-	buttons := make([]evdev.EvCode, numButtons)
-
-	for i := 0; i < numButtons; i++ {
-		buttons[i] = ButtonFromIndex[i]
-	}
-
-	return buttons
-}
-
-func makeAxes(numAxes int, axisList []string) []evdev.EvCode {
-	if numAxes > 0 && len(axisList) > 0 {
-		logger.Log("'num_axes' and 'axes' both specified, ignoring 'num_axes'")
-	}
-
-	if len(axisList) > 0 {
-		axes := make([]evdev.EvCode, 0, len(axisList))
-		for _, codeStr := range axisList {
-			code, err := parseCode(codeStr, "ABS")
-			if err != nil {
-				logger.LogError(err, "Failed to create axis, skipping")
-				continue
-			}
-			axes = append(axes, code)
-		}
-		return axes
-	}
-
-	if numAxes > 8 {
-		numAxes = 8
-		logger.Log("Limiting virtual device axes to 8")
-	}
-
-	axes := make([]evdev.EvCode, numAxes)
-	for i := 0; i < numAxes; i++ {
-		axes[i] = evdev.EvCode(i)
-	}
-
-	return axes
-}
-
-func makeRelativeAxes(numAxes int, axisList []string) []evdev.EvCode {
-	if numAxes > 0 && len(axisList) > 0 {
-		logger.Log("'num_rel_axes' and 'rel_axes' both specified, ignoring 'num_rel_axes'")
-	}
-
-	if len(axisList) > 0 {
-		axes := make([]evdev.EvCode, 0, len(axisList))
-		for _, codeStr := range axisList {
-			code, err := parseCode(codeStr, "REL")
-			if err != nil {
-				logger.LogError(err, "Failed to create axis, skipping")
-				continue
-			}
-			axes = append(axes, code)
-		}
-		return axes
-	}
-
-	if numAxes > 10 {
-		numAxes = 10
-		logger.Log("Limiting virtual device relative axes to 10")
-	}
-
-	axes := make([]evdev.EvCode, numAxes)
-	for i := 0; i < numAxes; i++ {
-		axes[i] = evdev.EvCode(i)
-	}
-
-	return axes
-}

internal/config/interfaces.go

@@ -1,7 +0,0 @@
-package config
-
-import "github.com/holoplot/go-evdev"
-
-type Device interface {
-	AbsInfos() (map[evdev.EvCode]evdev.AbsInfo, error)
-}

internal/config/make_rule_targets.go

@@ -1,145 +0,0 @@
-package config
-
-import (
-	"errors"
-	"fmt"
-
-	"git.annabunches.net/annabunches/joyful/internal/mappingrules"
-	"github.com/holoplot/go-evdev"
-)
-
-func makeRuleTargetButton(targetConfig RuleTargetConfigButton, devs map[string]Device) (*mappingrules.RuleTargetButton, error) {
-	device, ok := devs[targetConfig.Device]
-	if !ok {
-		return nil, fmt.Errorf("non-existent device '%s'", targetConfig.Device)
-	}
-
-	eventCode, err := parseCodeButton(targetConfig.Button)
-	if err != nil {
-		return nil, err
-	}
-
-	return mappingrules.NewRuleTargetButton(
-		targetConfig.Device,
-		device,
-		eventCode,
-		targetConfig.Inverted,
-	)
-}
-
-func makeRuleTargetAxis(targetConfig RuleTargetConfigAxis, devs map[string]Device) (*mappingrules.RuleTargetAxis, error) {
-	device, ok := devs[targetConfig.Device]
-	if !ok {
-		return nil, fmt.Errorf("non-existent device '%s'", targetConfig.Device)
-	}
-
-	if targetConfig.DeadzoneEnd < targetConfig.DeadzoneStart {
-		return nil, errors.New("deadzone_end must be greater than deadzone_start")
-	}
-
-	eventCode, err := parseCode(targetConfig.Axis, CodePrefixAxis)
-	if err != nil {
-		return nil, err
-	}
-
-	deadzoneStart, deadzoneEnd, err := calculateDeadzones(targetConfig, device, eventCode)
-	if err != nil {
-		return nil, err
-	}
-
-	return mappingrules.NewRuleTargetAxis(
-		targetConfig.Device,
-		device,
-		eventCode,
-		targetConfig.Inverted,
-		deadzoneStart,
-		deadzoneEnd,
-	)
-}
-
-func makeRuleTargetRelaxis(targetConfig RuleTargetConfigRelaxis, devs map[string]Device) (*mappingrules.RuleTargetRelaxis, error) {
-	device, ok := devs[targetConfig.Device]
-	if !ok {
-		return nil, fmt.Errorf("non-existent device '%s'", targetConfig.Device)
-	}
-
-	eventCode, err := parseCode(targetConfig.Axis, CodePrefixRelaxis)
-	if err != nil {
-		return nil, err
-	}
-
-	return mappingrules.NewRuleTargetRelaxis(
-		targetConfig.Device,
-		device,
-		eventCode,
-	)
-}
-
-func makeRuleTargetModeSelect(targetConfig RuleTargetConfigModeSelect, allModes []string) (*mappingrules.RuleTargetModeSelect, error) {
-	if ok := validateModes(targetConfig.Modes, allModes); !ok {
-		return nil, errors.New("undefined mode in mode select list")
-	}
-
-	return mappingrules.NewRuleTargetModeSelect(targetConfig.Modes)
-}
-
-// hasError exists solely to switch on errors in case statements
-func hasError(_ any, err error) bool {
-	return err != nil
-}
-
-// calculateDeadzones produces the deadzone start and end values in absolute terms
-// TODO: on the one hand, this logic feels betten encapsulated in mappingrules. On the other hand,
-// passing even more parameters to NewRuleTargetAxis feels terrible
-func calculateDeadzones(targetConfig RuleTargetConfigAxis, device Device, axis evdev.EvCode) (int32, int32, error) {
-
-	var deadzoneStart, deadzoneEnd int32
-	deadzoneStart = 0
-	deadzoneEnd = 0
-
-	if targetConfig.DeadzoneStart != 0 || targetConfig.DeadzoneEnd != 0 {
-		return targetConfig.DeadzoneStart, targetConfig.DeadzoneEnd, nil
-	}
-
-	var min, max int32
-	absInfoMap, err := device.AbsInfos()
-
-	if err != nil {
-		min = mappingrules.AxisValueMin
-		max = mappingrules.AxisValueMax
-	} else {
-		absInfo := absInfoMap[axis]
-		min = absInfo.Minimum
-		max = absInfo.Maximum
-	}
-
-	if targetConfig.DeadzoneCenter < min || targetConfig.DeadzoneCenter > max {
-		return 0, 0, fmt.Errorf("deadzone_center '%d' is out of bounds", targetConfig.DeadzoneCenter)
-	}
-
-	switch {
-	case targetConfig.DeadzoneSize != 0:
-		deadzoneStart = targetConfig.DeadzoneCenter - targetConfig.DeadzoneSize/2
-		deadzoneEnd = targetConfig.DeadzoneCenter + targetConfig.DeadzoneSize/2
-	case targetConfig.DeadzoneSizePercent != 0:
-		deadzoneSize := (max - min) / targetConfig.DeadzoneSizePercent
-		deadzoneStart = targetConfig.DeadzoneCenter - deadzoneSize/2
-		deadzoneEnd = targetConfig.DeadzoneCenter + deadzoneSize/2
-	}
-
-	deadzoneStart, deadzoneEnd = clampAndShift(deadzoneStart, deadzoneEnd, min, max)
-	return deadzoneStart, deadzoneEnd, nil
-}
-
-func clampAndShift(start, end, min, max int32) (int32, int32) {
-	if start < min {
-		end += min - start
-		start = min
-	}
-	if end > max {
-		start -= end - max
-		end = max
-	}
-
-	return start, end
-}

internal/config/make_rules.go

@@ -1,237 +0,0 @@
-package config
-
-import (
-	"fmt"
-	"strings"
-
-	"git.annabunches.net/annabunches/joyful/internal/logger"
-	"git.annabunches.net/annabunches/joyful/internal/mappingrules"
-	"github.com/holoplot/go-evdev"
-)
-
-// TODO: At some point it would *very likely* make sense to map each rule to all of the physical devices that can
-// trigger it, and return that instead. Something like a map[Device][]mappingrule.MappingRule.
-// This would speed up rule matching by only checking relevant rules for a given input event.
-// We could take this further and make it a map[<struct of *inputdevice, type, and code>][]rule
-// For very large rule-bases this may be helpful for staying performant.
-func (parser *ConfigParser) InitRules(pInputDevs map[string]*evdev.InputDevice, vInputDevs map[string]*evdev.InputDevice) []mappingrules.MappingRule {
-	rules := make([]mappingrules.MappingRule, 0)
-	modes := parser.GetModes()
-
-	// Golang can't inspect the concrete map type to determine interface conformance,
-	// so we handle that here.
-	pDevs := make(map[string]Device)
-	for name, dev := range pInputDevs {
-		pDevs[name] = dev
-	}
-	vDevs := make(map[string]Device)
-	for name, dev := range vInputDevs {
-		vDevs[name] = dev
-	}
-
-	for _, ruleConfig := range parser.config.Rules {
-		var newRule mappingrules.MappingRule
-		var err error
-
-		if ok := validateModes(ruleConfig.Modes, modes); !ok {
-			logger.Logf("Skipping rule '%s', mode list specifies undefined mode.", ruleConfig.Name)
-			continue
-		}
-
-		base := mappingrules.NewMappingRuleBase(ruleConfig.Name, ruleConfig.Modes)
-
-		switch strings.ToLower(ruleConfig.Type) {
-		case RuleTypeButton:
-			newRule, err = makeMappingRuleButton(ruleConfig.Config.(RuleConfigButton), pDevs, vDevs, base)
-		case RuleTypeButtonCombo:
-			newRule, err = makeMappingRuleCombo(ruleConfig.Config.(RuleConfigButtonCombo), pDevs, vDevs, base)
-		case RuleTypeButtonLatched:
-			newRule, err = makeMappingRuleLatched(ruleConfig.Config.(RuleConfigButtonLatched), pDevs, vDevs, base)
-		case RuleTypeAxis:
-			newRule, err = makeMappingRuleAxis(ruleConfig.Config.(RuleConfigAxis), pDevs, vDevs, base)
-		case RuleTypeAxisCombined:
-			newRule, err = makeMappingRuleAxisCombined(ruleConfig.Config.(RuleConfigAxisCombined), pDevs, vDevs, base)
-		case RuleTypeAxisToButton:
-			newRule, err = makeMappingRuleAxisToButton(ruleConfig.Config.(RuleConfigAxisToButton), pDevs, vDevs, base)
-		case RuleTypeAxisToRelaxis:
-			newRule, err = makeMappingRuleAxisToRelaxis(ruleConfig.Config.(RuleConfigAxisToRelaxis), pDevs, vDevs, base)
-		case RuleTypeModeSelect:
-			newRule, err = makeMappingRuleModeSelect(ruleConfig.Config.(RuleConfigModeSelect), pDevs, modes, base)
-		default:
-			err = fmt.Errorf("bad rule type '%s' for rule '%s'", ruleConfig.Type, ruleConfig.Name)
-		}
-
-		if err != nil {
-			logger.LogErrorf(err, "Failed to build rule '%s'", ruleConfig.Name)
-			continue
-		}
-
-		rules = append(rules, newRule)
-	}
-
-	return rules
-}
-
-// TODO: how much of these functions could we fold into the unmarshaling logic itself? The main problem
-// is that we don't have access to the device maps in those functions... could we set device names
-// as stand-ins and do a post-processing pass that *just* handles device linking and possibly mode
-// checking?
-//
-// In other words - can we unmarshal the config directly into our target structs and remove most of
-// this library?
-func makeMappingRuleButton(ruleConfig RuleConfigButton,
-	pDevs map[string]Device,
-	vDevs map[string]Device,
-	base mappingrules.MappingRuleBase) (*mappingrules.MappingRuleButton, error) {
-
-	input, err := makeRuleTargetButton(ruleConfig.Input, pDevs)
-	if err != nil {
-		return nil, err
-	}
-
-	output, err := makeRuleTargetButton(ruleConfig.Output, vDevs)
-	if err != nil {
-		return nil, err
-	}
-
-	return mappingrules.NewMappingRuleButton(base, input, output), nil
-}
-
-func makeMappingRuleCombo(ruleConfig RuleConfigButtonCombo,
-	pDevs map[string]Device,
-	vDevs map[string]Device,
-	base mappingrules.MappingRuleBase) (*mappingrules.MappingRuleButtonCombo, error) {
-
-	inputs := make([]*mappingrules.RuleTargetButton, 0)
-	for _, inputConfig := range ruleConfig.Inputs {
-		input, err := makeRuleTargetButton(inputConfig, pDevs)
-		if err != nil {
-			return nil, err
-		}
-		inputs = append(inputs, input)
-	}
-
-	output, err := makeRuleTargetButton(ruleConfig.Output, vDevs)
-	if err != nil {
-		return nil, err
-	}
-
-	return mappingrules.NewMappingRuleButtonCombo(base, inputs, output), nil
-}
-
-func makeMappingRuleLatched(ruleConfig RuleConfigButtonLatched,
-	pDevs map[string]Device,
-	vDevs map[string]Device,
-	base mappingrules.MappingRuleBase) (*mappingrules.MappingRuleButtonLatched, error) {
-
-	input, err := makeRuleTargetButton(ruleConfig.Input, pDevs)
-	if err != nil {
-		return nil, err
-	}
-
-	output, err := makeRuleTargetButton(ruleConfig.Output, vDevs)
-	if err != nil {
-		return nil, err
-	}
-
-	return mappingrules.NewMappingRuleButtonLatched(base, input, output), nil
-}
-
-func makeMappingRuleAxis(ruleConfig RuleConfigAxis,
-	pDevs map[string]Device,
-	vDevs map[string]Device,
-	base mappingrules.MappingRuleBase) (*mappingrules.MappingRuleAxis, error) {
-
-	input, err := makeRuleTargetAxis(ruleConfig.Input, pDevs)
-	if err != nil {
-		return nil, err
-	}
-
-	output, err := makeRuleTargetAxis(ruleConfig.Output, vDevs)
-	if err != nil {
-		return nil, err
-	}
-
-	return mappingrules.NewMappingRuleAxis(base, input, output), nil
-}
-
-func makeMappingRuleAxisCombined(ruleConfig RuleConfigAxisCombined,
-	pDevs map[string]Device,
-	vDevs map[string]Device,
-	base mappingrules.MappingRuleBase) (*mappingrules.MappingRuleAxisCombined, error) {
-
-	inputLower, err := makeRuleTargetAxis(ruleConfig.InputLower, pDevs)
-	if err != nil {
-		return nil, err
-	}
-
-	inputUpper, err := makeRuleTargetAxis(ruleConfig.InputUpper, pDevs)
-	if err != nil {
-		return nil, err
-	}
-
-	output, err := makeRuleTargetAxis(ruleConfig.Output, vDevs)
-	if err != nil {
-		return nil, err
-	}
-
-	return mappingrules.NewMappingRuleAxisCombined(base, inputLower, inputUpper, output), nil
-}
-
-func makeMappingRuleAxisToButton(ruleConfig RuleConfigAxisToButton,
-	pDevs map[string]Device,
-	vDevs map[string]Device,
-	base mappingrules.MappingRuleBase) (*mappingrules.MappingRuleAxisToButton, error) {
-
-	input, err := makeRuleTargetAxis(ruleConfig.Input, pDevs)
-	if err != nil {
-		return nil, err
-	}
-
-	output, err := makeRuleTargetButton(ruleConfig.Output, vDevs)
-	if err != nil {
-		return nil, err
-	}
-
-	return mappingrules.NewMappingRuleAxisToButton(base, input, output, ruleConfig.RepeatRateMin, ruleConfig.RepeatRateMax), nil
-}
-
-func makeMappingRuleAxisToRelaxis(ruleConfig RuleConfigAxisToRelaxis,
-	pDevs map[string]Device,
-	vDevs map[string]Device,
-	base mappingrules.MappingRuleBase) (*mappingrules.MappingRuleAxisToRelaxis, error) {
-
-	input, err := makeRuleTargetAxis(ruleConfig.Input, pDevs)
-	if err != nil {
-		return nil, err
-	}
-
-	output, err := makeRuleTargetRelaxis(ruleConfig.Output, vDevs)
-	if err != nil {
-		return nil, err
-	}
-
-	return mappingrules.NewMappingRuleAxisToRelaxis(base,
-		input, output,
-		ruleConfig.RepeatRateMin,
-		ruleConfig.RepeatRateMax,
-		ruleConfig.Increment), nil
-}
-
-func makeMappingRuleModeSelect(ruleConfig RuleConfigModeSelect,
-	pDevs map[string]Device,
-	modes []string,
-	base mappingrules.MappingRuleBase) (*mappingrules.MappingRuleModeSelect, error) {
-
-	input, err := makeRuleTargetButton(ruleConfig.Input, pDevs)
-	if err != nil {
-		return nil, err
-	}
-
-	output, err := makeRuleTargetModeSelect(ruleConfig.Output, modes)
-	if err != nil {
-		return nil, err
-	}
-
-	return mappingrules.NewMappingRuleModeSelect(base, input, output), nil
-}

internal/config/modes.go

@@ -1,19 +0,0 @@
-package config
-
-import "slices"
-
-// validateModes checks the provided modes against a larger subset of modes (usually all defined ones)
-// and returns false if any of the modes are not defined.
-func validateModes(modes []string, allModes []string) bool {
-	if len(modes) == 0 {
-		return true
-	}
-
-	for _, mode := range modes {
-		if !slices.Contains(allModes, mode) {
-			return false
-		}
-	}
-
-	return true
-}

internal/configparser/configparser.go

@@ -0,0 +1,67 @@
+package configparser
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"git.annabunches.net/annabunches/joyful/internal/logger"
+	"github.com/goccy/go-yaml"
+)
+
+func ParseConfig(directory string) (*Config, error) {
+	config := new(Config)
+
+	configFiles, err := getConfigFilePaths(directory)
+	if err != nil {
+		return nil, err
+	}
+
+	// Open each yaml file and add its contents to the global config
+	for _, filePath := range configFiles {
+		data, err := os.ReadFile(filePath)
+		if err != nil {
+			logger.LogError(err, "Error while opening config file")
+			continue
+		}
+
+		newConfig := Config{}
+		err = yaml.Unmarshal(data, &newConfig)
+		logger.LogIfError(err, "Error parsing YAML")
+		config.Rules = append(config.Rules, newConfig.Rules...)
+		config.Devices = append(config.Devices, newConfig.Devices...)
+		config.Modes = append(config.Modes, newConfig.Modes...)
+	}
+
+	if len(config.Devices) == 0 {
+		return nil, errors.New("Found no devices in configuration. Please add configuration at " + directory)
+	}
+
+	return config, nil
+}
+
+func getConfigFilePaths(directory string) ([]string, error) {
+	paths := make([]string, 0)
+
+	dirEntries, err := os.ReadDir(directory)
+	if err != nil {
+		err = os.Mkdir(directory, 0755)
+		if err != nil {
+			return nil, errors.New("failed to create config directory at " + directory)
+		} else {
+			return nil, errors.New("no config files found at " + directory)
+		}
+	}
+
+	for _, file := range dirEntries {
+		name := strings.ToLower(file.Name())
+		if file.IsDir() || !(strings.HasSuffix(name, ".yaml") || strings.HasSuffix(name, ".yml")) {
+			continue
+		}
+
+		paths = append(paths, filepath.Join(directory, file.Name()))
+	}
+
+	return paths, nil
+}

internal/configparser/schema.go

@@ -1,7 +1,7 @@
 // These types comprise the YAML schema for configuring Joyful.
 // The config files will be combined and then unmarshalled into this
 
-package config
+package configparser
 
 import (
 	"fmt"

internal/configparser/variables.go

@@ -0,0 +1,15 @@
+package configparser
+
+const (
+	DeviceTypePhysical = "physical"
+	DeviceTypeVirtual  = "virtual"
+
+	RuleTypeButton        = "button"
+	RuleTypeButtonCombo   = "button-combo"
+	RuleTypeButtonLatched = "button-latched"
+	RuleTypeAxis          = "axis"
+	RuleTypeAxisCombined  = "axis-combined"
+	RuleTypeAxisToButton  = "axis-to-button"
+	RuleTypeAxisToRelaxis = "axis-to-relaxis"
+	RuleTypeModeSelect    = "mode-select"
+)

internal/eventcodes/codes.go

@@ -1,4 +1,4 @@
-package config
+package eventcodes
 
 import (
 	"fmt"
@@ -8,17 +8,17 @@ import (
 	"github.com/holoplot/go-evdev"
 )
 
-func parseCodeButton(code string) (evdev.EvCode, error) {
+func ParseCodeButton(code string) (evdev.EvCode, error) {
 	prefix := CodePrefixButton
 
 	if strings.HasPrefix(code, CodePrefixKey+"_") {
 		prefix = CodePrefixKey
 	}
 
-	return parseCode(code, prefix)
+	return ParseCode(code, prefix)
 }
 
-func parseCode(code, prefix string) (evdev.EvCode, error) {
+func ParseCode(code, prefix string) (evdev.EvCode, error) {
 	code = strings.ToUpper(code)
 
 	var codeLookup map[string]evdev.EvCode
@@ -70,3 +70,8 @@ func parseCode(code, prefix string) (evdev.EvCode, error) {
 		return eventCode, nil
 	}
 }
+
+// hasError exists solely to switch on errors in conditional and case statements
+func hasError(_ any, err error) bool {
+	return err != nil
+}

internal/eventcodes/codes_test.go

@@ -1,4 +1,4 @@
-package config
+package eventcodes
 
 import (
 	"fmt"
@@ -18,7 +18,7 @@ func TestRunnerEventCodeParserTests(t *testing.T) {
 
 func parseCodeTestCase(t *EventCodeParserTests, in string, out evdev.EvCode, prefix string) {
 	t.Run(fmt.Sprintf("%s: %s", prefix, in), func() {
-		code, err := parseCode(in, prefix)
+		code, err := ParseCode(in, prefix)
 		t.Nil(err)
 		t.EqualValues(out, code)
 	})
@@ -38,7 +38,7 @@ func (t *EventCodeParserTests) TestParseCodeButton() {
 
 	for _, testCase := range testCases {
 		t.Run(testCase.in, func() {
-			code, err := parseCodeButton(testCase.in)
+			code, err := ParseCodeButton(testCase.in)
 			t.Nil(err)
 			t.EqualValues(code, testCase.out)
 		})
@@ -134,7 +134,7 @@ func (t *EventCodeParserTests) TestParseCode() {
 
 		for _, testCase := range testCases {
 			t.Run(fmt.Sprintf("%s - '%s'", testCase.prefix, testCase.in), func() {
-				_, err := parseCode(testCase.in, testCase.prefix)
+				_, err := ParseCode(testCase.in, testCase.prefix)
 				t.NotNil(err)
 			})
 		}

internal/eventcodes/variables.go

@@ -0,0 +1,90 @@
+package eventcodes
+
+import "github.com/holoplot/go-evdev"
+
+const (
+	CodePrefixButton  = "BTN"
+	CodePrefixKey     = "KEY"
+	CodePrefixAxis    = "ABS"
+	CodePrefixRelaxis = "REL"
+)
+
+var (
+	// Map joystick buttons to integer indices
+	ButtonFromIndex = []evdev.EvCode{
+		evdev.BTN_TRIGGER,
+		evdev.BTN_THUMB,
+		evdev.BTN_THUMB2,
+		evdev.BTN_TOP,
+		evdev.BTN_TOP2,
+		evdev.BTN_PINKIE,
+		evdev.BTN_BASE,
+		evdev.BTN_BASE2,
+		evdev.BTN_BASE3,
+		evdev.BTN_BASE4,
+		evdev.BTN_BASE5,
+		evdev.BTN_BASE6,
+		evdev.EvCode(0x12c), // decimal 300
+		evdev.EvCode(0x12d), // decimal 301
+		evdev.EvCode(0x12e), // decimal 302
+		evdev.BTN_DEAD,
+		evdev.BTN_TRIGGER_HAPPY1,
+		evdev.BTN_TRIGGER_HAPPY2,
+		evdev.BTN_TRIGGER_HAPPY3,
+		evdev.BTN_TRIGGER_HAPPY4,
+		evdev.BTN_TRIGGER_HAPPY5,
+		evdev.BTN_TRIGGER_HAPPY6,
+		evdev.BTN_TRIGGER_HAPPY7,
+		evdev.BTN_TRIGGER_HAPPY8,
+		evdev.BTN_TRIGGER_HAPPY9,
+		evdev.BTN_TRIGGER_HAPPY10,
+		evdev.BTN_TRIGGER_HAPPY11,
+		evdev.BTN_TRIGGER_HAPPY12,
+		evdev.BTN_TRIGGER_HAPPY13,
+		evdev.BTN_TRIGGER_HAPPY14,
+		evdev.BTN_TRIGGER_HAPPY15,
+		evdev.BTN_TRIGGER_HAPPY16,
+		evdev.BTN_TRIGGER_HAPPY17,
+		evdev.BTN_TRIGGER_HAPPY18,
+		evdev.BTN_TRIGGER_HAPPY19,
+		evdev.BTN_TRIGGER_HAPPY20,
+		evdev.BTN_TRIGGER_HAPPY21,
+		evdev.BTN_TRIGGER_HAPPY22,
+		evdev.BTN_TRIGGER_HAPPY23,
+		evdev.BTN_TRIGGER_HAPPY24,
+		evdev.BTN_TRIGGER_HAPPY25,
+		evdev.BTN_TRIGGER_HAPPY26,
+		evdev.BTN_TRIGGER_HAPPY27,
+		evdev.BTN_TRIGGER_HAPPY28,
+		evdev.BTN_TRIGGER_HAPPY29,
+		evdev.BTN_TRIGGER_HAPPY30,
+		evdev.BTN_TRIGGER_HAPPY31,
+		evdev.BTN_TRIGGER_HAPPY32,
+		evdev.BTN_TRIGGER_HAPPY33,
+		evdev.BTN_TRIGGER_HAPPY34,
+		evdev.BTN_TRIGGER_HAPPY35,
+		evdev.BTN_TRIGGER_HAPPY36,
+		evdev.BTN_TRIGGER_HAPPY37,
+		evdev.BTN_TRIGGER_HAPPY38,
+		evdev.BTN_TRIGGER_HAPPY39,
+		evdev.BTN_TRIGGER_HAPPY40,
+		evdev.EvCode(0x2e8),
+		evdev.EvCode(0x2e9),
+		evdev.EvCode(0x2f0),
+		evdev.EvCode(0x2f1),
+		evdev.EvCode(0x2f2),
+		evdev.EvCode(0x2f3),
+		evdev.EvCode(0x2f4),
+		evdev.EvCode(0x2f5),
+		evdev.EvCode(0x2f6),
+		evdev.EvCode(0x2f7),
+		evdev.EvCode(0x2f8),
+		evdev.EvCode(0x2f9),
+		evdev.EvCode(0x2fa),
+		evdev.EvCode(0x2fb),
+		evdev.EvCode(0x2fc),
+		evdev.EvCode(0x2fd),
+		evdev.EvCode(0x2fe),
+		evdev.EvCode(0x2ff),
+	}
+)

internal/mappingrules/init_rule_targets_test.go

@@ -1,9 +1,12 @@
-package config
+// TODO: these tests should live with their rule_target_* counterparts
+
+package mappingrules
 
 import (
 	"fmt"
 	"testing"
 
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
 	"github.com/holoplot/go-evdev"
 	"github.com/stretchr/testify/mock"
 	"github.com/stretchr/testify/suite"
@@ -48,45 +51,45 @@ func (t *MakeRuleTargetsTests) SetupSuite() {
 }
 
 func (t *MakeRuleTargetsTests) TestMakeRuleTargetButton() {
-	config := RuleTargetConfigButton{Device: "test"}
+	config := configparser.RuleTargetConfigButton{Device: "test"}
 
 	t.Run("Standard keycode", func() {
 		config.Button = "BTN_TRIGGER"
-		rule, err := makeRuleTargetButton(config, t.devs)
+		rule, err := NewRuleTargetButtonFromConfig(config, t.devs)
 		t.Nil(err)
 		t.EqualValues(evdev.BTN_TRIGGER, rule.Button)
 	})
 
 	t.Run("Hex code", func() {
 		config.Button = "0x2fd"
-		rule, err := makeRuleTargetButton(config, t.devs)
+		rule, err := NewRuleTargetButtonFromConfig(config, t.devs)
 		t.Nil(err)
 		t.EqualValues(evdev.EvCode(0x2fd), rule.Button)
 	})
 
 	t.Run("Index", func() {
 		config.Button = "3"
-		rule, err := makeRuleTargetButton(config, t.devs)
+		rule, err := NewRuleTargetButtonFromConfig(config, t.devs)
 		t.Nil(err)
 		t.EqualValues(evdev.BTN_TOP, rule.Button)
 	})
 
 	t.Run("Index too high", func() {
 		config.Button = "74"
-		_, err := makeRuleTargetButton(config, t.devs)
+		_, err := NewRuleTargetButtonFromConfig(config, t.devs)
 		t.NotNil(err)
 	})
 
 	t.Run("Un-prefixed keycode", func() {
 		config.Button = "pinkie"
-		rule, err := makeRuleTargetButton(config, t.devs)
+		rule, err := NewRuleTargetButtonFromConfig(config, t.devs)
 		t.Nil(err)
 		t.EqualValues(evdev.BTN_PINKIE, rule.Button)
 	})
 
 	t.Run("Invalid keycode", func() {
 		config.Button = "foo"
-		_, err := makeRuleTargetButton(config, t.devs)
+		_, err := NewRuleTargetButtonFromConfig(config, t.devs)
 		t.NotNil(err)
 	})
 }
@@ -103,9 +106,9 @@ func (t *MakeRuleTargetsTests) TestMakeRuleTargetAxis() {
 
 	for _, tc := range codeTestCases {
 		t.Run(fmt.Sprintf("KeyCode %s", tc.input), func() {
-			config := RuleTargetConfigAxis{Device: "test"}
+			config := configparser.RuleTargetConfigAxis{Device: "test"}
 			config.Axis = tc.input
-			rule, err := makeRuleTargetAxis(config, t.devs)
+			rule, err := NewRuleTargetAxisFromConfig(config, t.devs)
 			t.Nil(err)
 			t.EqualValues(tc.output, rule.Axis)
 
@@ -113,18 +116,18 @@ func (t *MakeRuleTargetsTests) TestMakeRuleTargetAxis() {
 	}
 
 	t.Run("Invalid code", func() {
-		config := RuleTargetConfigAxis{Device: "test"}
+		config := configparser.RuleTargetConfigAxis{Device: "test"}
 		config.Axis = "foo"
-		_, err := makeRuleTargetAxis(config, t.devs)
+		_, err := NewRuleTargetAxisFromConfig(config, t.devs)
 		t.NotNil(err)
 	})
 
 	t.Run("Invalid deadzone", func() {
-		config := RuleTargetConfigAxis{Device: "test"}
+		config := configparser.RuleTargetConfigAxis{Device: "test"}
 		config.Axis = "x"
 		config.DeadzoneEnd = 100
 		config.DeadzoneStart = 1000
-		_, err := makeRuleTargetAxis(config, t.devs)
+		_, err := NewRuleTargetAxisFromConfig(config, t.devs)
 		t.NotNil(err)
 	})
 
@@ -141,13 +144,13 @@ func (t *MakeRuleTargetsTests) TestMakeRuleTargetAxis() {
 
 	for _, tc := range relDeadzoneTestCases {
 		t.Run(fmt.Sprintf("Relative Deadzone %d +- %d", tc.inCenter, tc.inSize), func() {
-			config := RuleTargetConfigAxis{
+			config := configparser.RuleTargetConfigAxis{
 				Device:         "test",
 				Axis:           "x",
 				DeadzoneCenter: tc.inCenter,
 				DeadzoneSize:   tc.inSize,
 			}
-			rule, err := makeRuleTargetAxis(config, t.devs)
+			rule, err := NewRuleTargetAxisFromConfig(config, t.devs)
 
 			t.Nil(err)
 			t.Equal(tc.outStart, rule.DeadzoneStart)
@@ -156,13 +159,13 @@ func (t *MakeRuleTargetsTests) TestMakeRuleTargetAxis() {
 	}
 
 	t.Run("Deadzone center/size invalid center", func() {
-		config := RuleTargetConfigAxis{
+		config := configparser.RuleTargetConfigAxis{
 			Device:         "test",
 			Axis:           "x",
 			DeadzoneCenter: 20000,
 			DeadzoneSize:   500,
 		}
-		_, err := makeRuleTargetAxis(config, t.devs)
+		_, err := NewRuleTargetAxisFromConfig(config, t.devs)
 		t.NotNil(err)
 	})
 
@@ -179,13 +182,13 @@ func (t *MakeRuleTargetsTests) TestMakeRuleTargetAxis() {
 
 	for _, tc := range relDeadzonePercentTestCases {
 		t.Run(fmt.Sprintf("Relative percent deadzone %d +- %d%%", tc.inCenter, tc.inSizePercent), func() {
-			config := RuleTargetConfigAxis{
+			config := configparser.RuleTargetConfigAxis{
 				Device:              "test",
 				Axis:                "x",
 				DeadzoneCenter:      tc.inCenter,
 				DeadzoneSizePercent: tc.inSizePercent,
 			}
-			rule, err := makeRuleTargetAxis(config, t.devs)
+			rule, err := NewRuleTargetAxisFromConfig(config, t.devs)
 
 			t.Nil(err)
 			t.Equal(tc.outStart, rule.DeadzoneStart)
@@ -194,50 +197,50 @@ func (t *MakeRuleTargetsTests) TestMakeRuleTargetAxis() {
 	}
 
 	t.Run("Deadzone center/percent invalid center", func() {
-		config := RuleTargetConfigAxis{
+		config := configparser.RuleTargetConfigAxis{
 			Device:              "test",
 			Axis:                "x",
 			DeadzoneCenter:      20000,
 			DeadzoneSizePercent: 10,
 		}
-		_, err := makeRuleTargetAxis(config, t.devs)
+		_, err := NewRuleTargetAxisFromConfig(config, t.devs)
 		t.NotNil(err)
 	})
 }
 
 func (t *MakeRuleTargetsTests) TestMakeRuleTargetRelaxis() {
-	config := RuleTargetConfigRelaxis{Device: "test"}
+	config := configparser.RuleTargetConfigRelaxis{Device: "test"}
 
 	t.Run("Standard keycode", func() {
 		config.Axis = "REL_WHEEL"
-		rule, err := makeRuleTargetRelaxis(config, t.devs)
+		rule, err := NewRuleTargetRelaxisFromConfig(config, t.devs)
 		t.Nil(err)
 		t.EqualValues(evdev.REL_WHEEL, rule.Axis)
 	})
 
 	t.Run("Hex keycode", func() {
 		config.Axis = "0x00"
-		rule, err := makeRuleTargetRelaxis(config, t.devs)
+		rule, err := NewRuleTargetRelaxisFromConfig(config, t.devs)
 		t.Nil(err)
 		t.EqualValues(evdev.REL_X, rule.Axis)
 	})
 
 	t.Run("Un-prefixed keycode", func() {
 		config.Axis = "wheel"
-		rule, err := makeRuleTargetRelaxis(config, t.devs)
+		rule, err := NewRuleTargetRelaxisFromConfig(config, t.devs)
 		t.Nil(err)
 		t.EqualValues(evdev.REL_WHEEL, rule.Axis)
 	})
 
 	t.Run("Invalid keycode", func() {
 		config.Axis = "foo"
-		_, err := makeRuleTargetRelaxis(config, t.devs)
+		_, err := NewRuleTargetRelaxisFromConfig(config, t.devs)
 		t.NotNil(err)
 	})
 
 	t.Run("Incorrect axis type", func() {
 		config.Axis = "ABS_X"
-		_, err := makeRuleTargetRelaxis(config, t.devs)
+		_, err := NewRuleTargetRelaxisFromConfig(config, t.devs)
 		t.NotNil(err)
 	})
 }

internal/mappingrules/init_rules.go

@@ -0,0 +1,79 @@
+package mappingrules
+
+import (
+	"errors"
+	"fmt"
+	"slices"
+	"strings"
+
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
+	"git.annabunches.net/annabunches/joyful/internal/logger"
+	"github.com/holoplot/go-evdev"
+)
+
+func ConvertDeviceMap(inputDevs map[string]*evdev.InputDevice) map[string]Device {
+	// Golang can't inspect the concrete map type to determine interface conformance,
+	// so we handle that here.
+	devices := make(map[string]Device)
+	for name, dev := range inputDevs {
+		devices[name] = dev
+	}
+	return devices
+}
+
+// NewRule parses a RuleConfig struct and creates and returns the appropriate rule type.
+// You can remap a map[string]*evdev.InputDevice to our interface type with ConvertDeviceMap
+func NewRule(config configparser.RuleConfig, pDevs map[string]Device, vDevs map[string]Device, modes []string) (MappingRule, error) {
+	var newRule MappingRule
+	var err error
+
+	if !validateModes(config.Modes, modes) {
+		return nil, errors.New("mode list specifies undefined mode")
+	}
+
+	base := NewMappingRuleBase(config.Name, config.Modes)
+
+	switch strings.ToLower(config.Type) {
+	case RuleTypeButton:
+		newRule, err = NewMappingRuleButton(config.Config.(configparser.RuleConfigButton), pDevs, vDevs, base)
+	case RuleTypeButtonCombo:
+		newRule, err = NewMappingRuleButtonCombo(config.Config.(configparser.RuleConfigButtonCombo), pDevs, vDevs, base)
+	case RuleTypeButtonLatched:
+		newRule, err = NewMappingRuleButtonLatched(config.Config.(configparser.RuleConfigButtonLatched), pDevs, vDevs, base)
+	case RuleTypeAxis:
+		newRule, err = NewMappingRuleAxis(config.Config.(configparser.RuleConfigAxis), pDevs, vDevs, base)
+	case RuleTypeAxisCombined:
+		newRule, err = NewMappingRuleAxisCombined(config.Config.(configparser.RuleConfigAxisCombined), pDevs, vDevs, base)
+	case RuleTypeAxisToButton:
+		newRule, err = NewMappingRuleAxisToButton(config.Config.(configparser.RuleConfigAxisToButton), pDevs, vDevs, base)
+	case RuleTypeAxisToRelaxis:
+		newRule, err = NewMappingRuleAxisToRelaxis(config.Config.(configparser.RuleConfigAxisToRelaxis), pDevs, vDevs, base)
+	case RuleTypeModeSelect:
+		newRule, err = NewMappingRuleModeSelect(config.Config.(configparser.RuleConfigModeSelect), pDevs, modes, base)
+	default:
+		err = fmt.Errorf("bad rule type '%s' for rule '%s'", config.Type, config.Name)
+	}
+
+	if err != nil {
+		logger.LogErrorf(err, "Failed to build rule '%s'", config.Name)
+		return nil, err
+	}
+
+	return newRule, nil
+}
+
+// validateModes checks the provided modes against a larger subset of modes (usually all defined ones)
+// and returns false if any of the modes are not defined.
+func validateModes(modes []string, allModes []string) bool {
+	if len(modes) == 0 {
+		return true
+	}
+
+	for _, mode := range modes {
+		if !slices.Contains(allModes, mode) {
+			return false
+		}
+	}
+
+	return true
+}

internal/mappingrules/mapping_rule_axis.go

@@ -1,6 +1,9 @@
 package mappingrules
 
-import "github.com/holoplot/go-evdev"
+import (
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
+	"github.com/holoplot/go-evdev"
+)
 
 // A Simple Mapping Rule can map a button to a button or an axis to an axis.
 type MappingRuleAxis struct {
@@ -9,12 +12,26 @@ type MappingRuleAxis struct {
 	Output *RuleTargetAxis
 }
 
-func NewMappingRuleAxis(base MappingRuleBase, input *RuleTargetAxis, output *RuleTargetAxis) *MappingRuleAxis {
+func NewMappingRuleAxis(ruleConfig configparser.RuleConfigAxis,
+	pDevs map[string]Device,
+	vDevs map[string]Device,
+	base MappingRuleBase) (*MappingRuleAxis, error) {
+
+	input, err := NewRuleTargetAxisFromConfig(ruleConfig.Input, pDevs)
+	if err != nil {
+		return nil, err
+	}
+
+	output, err := NewRuleTargetAxisFromConfig(ruleConfig.Output, vDevs)
+	if err != nil {
+		return nil, err
+	}
+
 	return &MappingRuleAxis{
 		MappingRuleBase: base,
 		Input:           input,
 		Output:          output,
-	}
+	}, nil
 }
 
 func (rule *MappingRuleAxis) MatchEvent(device Device, event *evdev.InputEvent, mode *string) (*evdev.InputDevice, *evdev.InputEvent) {

internal/mappingrules/mapping_rule_axis_combined.go

@@ -1,6 +1,7 @@
 package mappingrules
 
 import (
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
 	"git.annabunches.net/annabunches/joyful/internal/logger"
 	"github.com/holoplot/go-evdev"
 )
@@ -12,7 +13,26 @@ type MappingRuleAxisCombined struct {
 	Output     *RuleTargetAxis
 }
 
-func NewMappingRuleAxisCombined(base MappingRuleBase, inputLower *RuleTargetAxis, inputUpper *RuleTargetAxis, output *RuleTargetAxis) *MappingRuleAxisCombined {
+func NewMappingRuleAxisCombined(ruleConfig configparser.RuleConfigAxisCombined,
+	pDevs map[string]Device,
+	vDevs map[string]Device,
+	base MappingRuleBase) (*MappingRuleAxisCombined, error) {
+
+	inputLower, err := NewRuleTargetAxisFromConfig(ruleConfig.InputLower, pDevs)
+	if err != nil {
+		return nil, err
+	}
+
+	inputUpper, err := NewRuleTargetAxisFromConfig(ruleConfig.InputUpper, pDevs)
+	if err != nil {
+		return nil, err
+	}
+
+	output, err := NewRuleTargetAxisFromConfig(ruleConfig.Output, vDevs)
+	if err != nil {
+		return nil, err
+	}
+
 	inputLower.OutputMax = 0
 	inputUpper.OutputMin = 0
 	return &MappingRuleAxisCombined{
@@ -20,7 +40,7 @@ func NewMappingRuleAxisCombined(base MappingRuleBase, inputLower *RuleTargetAxis
 		InputLower:      inputLower,
 		InputUpper:      inputUpper,
 		Output:          output,
-	}
+	}, nil
 }
 
 func (rule *MappingRuleAxisCombined) MatchEvent(device Device, event *evdev.InputEvent, mode *string) (*evdev.InputDevice, *evdev.InputEvent) {

internal/mappingrules/mapping_rule_axis_combined_test.go

@@ -38,7 +38,9 @@ func (t *MappingRuleAxisCombinedTests) SetupTest() {
 	}, nil)
 
 	t.inputTargetLower, _ = NewRuleTargetAxis("test-input", t.inputDevice, evdev.ABS_X, true, 0, 0)
+	t.inputTargetLower.OutputMax = 0
 	t.inputTargetUpper, _ = NewRuleTargetAxis("test-input", t.inputDevice, evdev.ABS_Y, false, 0, 0)
+	t.inputTargetUpper.OutputMin = 0
 
 	t.outputDevice = &evdev.InputDevice{}
 	t.outputTarget, _ = NewRuleTargetAxis("test-output", t.outputDevice, evdev.ABS_X, false, 0, 0)
@@ -57,19 +59,30 @@ func (t *MappingRuleAxisCombinedTests) TearDownSubTest() {
 	t.inputDevice.Reset()
 }
 
+// TODO: this test sucks
 func (t *MappingRuleAxisCombinedTests) TestNewMappingRuleAxisCombined() {
 	t.inputDevice.Stub("AbsInfos").Return(map[evdev.EvCode]evdev.AbsInfo{
 		evdev.ABS_X: {Minimum: 0, Maximum: 10000},
 		evdev.ABS_Y: {Minimum: 0, Maximum: 10000},
 	}, nil)
 
-	rule := NewMappingRuleAxisCombined(t.base, t.inputTargetLower, t.inputTargetUpper, t.outputTarget)
+	rule := &MappingRuleAxisCombined{
+		MappingRuleBase: t.base,
+		InputLower:      t.inputTargetLower,
+		InputUpper:      t.inputTargetUpper,
+		Output:          t.outputTarget,
+	}
 	t.EqualValues(0, rule.InputLower.OutputMax)
 	t.EqualValues(0, rule.InputUpper.OutputMin)
 }
 
 func (t *MappingRuleAxisCombinedTests) TestMatchEvent() {
-	rule := NewMappingRuleAxisCombined(t.base, t.inputTargetLower, t.inputTargetUpper, t.outputTarget)
+	rule := &MappingRuleAxisCombined{
+		MappingRuleBase: t.base,
+		InputLower:      t.inputTargetLower,
+		InputUpper:      t.inputTargetUpper,
+		Output:          t.outputTarget,
+	}
 
 	t.Run("Lower Input", func() {
 		testCases := []struct{ in, out int32 }{

internal/mappingrules/mapping_rule_axis_to_button.go

@@ -3,6 +3,7 @@ package mappingrules
 import (
 	"time"
 
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
 	"github.com/holoplot/go-evdev"
 	"github.com/jonboulle/clockwork"
 )
@@ -23,20 +24,34 @@ type MappingRuleAxisToButton struct {
 	clock         clockwork.Clock
 }
 
-func NewMappingRuleAxisToButton(base MappingRuleBase, input *RuleTargetAxis, output *RuleTargetButton, repeatRateMin, repeatRateMax int) *MappingRuleAxisToButton {
+func NewMappingRuleAxisToButton(ruleConfig configparser.RuleConfigAxisToButton,
+	pDevs map[string]Device,
+	vDevs map[string]Device,
+	base MappingRuleBase) (*MappingRuleAxisToButton, error) {
+
+	input, err := NewRuleTargetAxisFromConfig(ruleConfig.Input, pDevs)
+	if err != nil {
+		return nil, err
+	}
+
+	output, err := NewRuleTargetButtonFromConfig(ruleConfig.Output, vDevs)
+	if err != nil {
+		return nil, err
+	}
+
 	return &MappingRuleAxisToButton{
 		MappingRuleBase: base,
 		Input:           input,
 		Output:          output,
-		RepeatRateMin:   repeatRateMin,
+		RepeatRateMin:   ruleConfig.RepeatRateMin,
-		RepeatRateMax:   repeatRateMax,
+		RepeatRateMax:   ruleConfig.RepeatRateMax,
 		lastEvent:       time.Now(),
 		nextEvent:       NoNextEvent,
-		repeat:          repeatRateMin != 0 && repeatRateMax != 0,
+		repeat:          ruleConfig.RepeatRateMin != 0 && ruleConfig.RepeatRateMax != 0,
 		pressed:         false,
 		active:          false,
 		clock:           clockwork.NewRealClock(),
-	}
+	}, nil
 }
 
 func (rule *MappingRuleAxisToButton) MatchEvent(device Device, event *evdev.InputEvent, mode *string) (*evdev.InputDevice, *evdev.InputEvent) {

internal/mappingrules/mapping_rule_axis_to_button_test.go

@@ -19,6 +19,44 @@ type MappingRuleAxisToButtonTests struct {
 	base         MappingRuleBase
 }
 
+func TestRunnerMappingRuleAxisToButtonTests(t *testing.T) {
+	suite.Run(t, new(MappingRuleAxisToButtonTests))
+}
+
+// buildTimerRule creates a MappingRuleAxisToButton with a mocked clock
+func (t *MappingRuleAxisToButtonTests) buildTimerRule(
+	repeatMin,
+	repeatMax int,
+	nextEvent time.Duration) (*MappingRuleAxisToButton, *clockwork.FakeClock) {
+
+	mockClock := clockwork.NewFakeClock()
+	testRule := t.buildRule(repeatMin, repeatMax)
+	testRule.clock = mockClock
+	testRule.lastEvent = testRule.clock.Now()
+	testRule.nextEvent = nextEvent
+	if nextEvent != NoNextEvent {
+		testRule.active = true
+	}
+	return testRule, mockClock
+}
+
+// Todo: don't love this repeated logic...
+func (t *MappingRuleAxisToButtonTests) buildRule(repeatMin, repeatMax int) *MappingRuleAxisToButton {
+	return &MappingRuleAxisToButton{
+		MappingRuleBase: t.base,
+		Input:           t.inputRule,
+		Output:          t.outputRule,
+		RepeatRateMin:   repeatMin,
+		RepeatRateMax:   repeatMax,
+		lastEvent:       time.Now(),
+		nextEvent:       NoNextEvent,
+		repeat:          repeatMin != 0 && repeatMax != 0,
+		pressed:         false,
+		active:          false,
+		clock:           clockwork.NewRealClock(),
+	}
+}
+
 func (t *MappingRuleAxisToButtonTests) SetupTest() {
 	mode := "*"
 	t.mode = &mode
@@ -40,7 +78,7 @@ func (t *MappingRuleAxisToButtonTests) TestMatchEvent() {
 
 	// A valid input should set a nextevent
 	t.Run("No Repeat", func() {
-		testRule := NewMappingRuleAxisToButton(t.base, t.inputRule, t.outputRule, 0, 0)
+		testRule := t.buildRule(0, 0)
 
 		t.Run("Valid Input", func() {
 			testRule.MatchEvent(t.inputDevice, &evdev.InputEvent{
@@ -62,7 +100,7 @@ func (t *MappingRuleAxisToButtonTests) TestMatchEvent() {
 	})
 
 	t.Run("Repeat", func() {
-		testRule := NewMappingRuleAxisToButton(t.base, t.inputRule, t.outputRule, 750, 250)
+		testRule := t.buildRule(750, 250)
 		testRule.MatchEvent(t.inputDevice, &evdev.InputEvent{
 			Type:  evdev.EV_ABS,
 			Code:  evdev.ABS_X,
@@ -90,7 +128,7 @@ func (t *MappingRuleAxisToButtonTests) TestTimerEvent() {
 	t.Run("No Repeat", func() {
 		// Get event if called immediately
 		t.Run("Event is available immediately", func() {
-			testRule, _ := buildTimerRule(t, 0, 0, 0)
+			testRule, _ := t.buildTimerRule(0, 0, 0)
 
 			event := testRule.TimerEvent()
 
@@ -100,7 +138,7 @@ func (t *MappingRuleAxisToButtonTests) TestTimerEvent() {
 
 		// Off event on second call
 		t.Run("Event emits off on second call", func() {
-			testRule, _ := buildTimerRule(t, 0, 0, 0)
+			testRule, _ := t.buildTimerRule(0, 0, 0)
 
 			testRule.TimerEvent()
 			event := testRule.TimerEvent()
@@ -111,7 +149,7 @@ func (t *MappingRuleAxisToButtonTests) TestTimerEvent() {
 
 		// No further event, even if we wait a while
 		t.Run("Additional events are not emitted while still active.", func() {
-			testRule, mockClock := buildTimerRule(t, 0, 0, 0)
+			testRule, mockClock := t.buildTimerRule(0, 0, 0)
 
 			testRule.TimerEvent()
 			testRule.TimerEvent()
@@ -125,13 +163,13 @@ func (t *MappingRuleAxisToButtonTests) TestTimerEvent() {
 
 	t.Run("Repeat", func() {
 		t.Run("No event if called immediately", func() {
-			testRule, _ := buildTimerRule(t, 100, 10, 50*time.Millisecond)
+			testRule, _ := t.buildTimerRule(100, 10, 50*time.Millisecond)
 			event := testRule.TimerEvent()
 			t.Nil(event)
 		})
 
 		t.Run("No event after 49ms", func() {
-			testRule, mockClock := buildTimerRule(t, 100, 10, 50*time.Millisecond)
+			testRule, mockClock := t.buildTimerRule(100, 10, 50*time.Millisecond)
 			mockClock.Advance(49 * time.Millisecond)
 
 			event := testRule.TimerEvent()
@@ -140,7 +178,7 @@ func (t *MappingRuleAxisToButtonTests) TestTimerEvent() {
 		})
 
 		t.Run("Event after 50ms", func() {
-			testRule, mockClock := buildTimerRule(t, 100, 10, 50*time.Millisecond)
+			testRule, mockClock := t.buildTimerRule(100, 10, 50*time.Millisecond)
 			mockClock.Advance(50 * time.Millisecond)
 
 			event := testRule.TimerEvent()
@@ -150,7 +188,7 @@ func (t *MappingRuleAxisToButtonTests) TestTimerEvent() {
 		})
 
 		t.Run("Additional event at 100ms", func() {
-			testRule, mockClock := buildTimerRule(t, 100, 10, 50*time.Millisecond)
+			testRule, mockClock := t.buildTimerRule(100, 10, 50*time.Millisecond)
 
 			mockClock.Advance(50 * time.Millisecond)
 			testRule.TimerEvent()
@@ -163,24 +201,3 @@ func (t *MappingRuleAxisToButtonTests) TestTimerEvent() {
 		})
 	})
 }
-
-func TestRunnerMappingRuleAxisToButtonTests(t *testing.T) {
-	suite.Run(t, new(MappingRuleAxisToButtonTests))
-}
-
-// buildTimerRule creates a MappingRuleAxisToButton with a mocked clock
-func buildTimerRule(t *MappingRuleAxisToButtonTests,
-	repeatMin,
-	repeatMax int,
-	nextEvent time.Duration) (*MappingRuleAxisToButton, *clockwork.FakeClock) {
-
-	mockClock := clockwork.NewFakeClock()
-	testRule := NewMappingRuleAxisToButton(t.base, t.inputRule, t.outputRule, repeatMin, repeatMax)
-	testRule.clock = mockClock
-	testRule.lastEvent = testRule.clock.Now()
-	testRule.nextEvent = nextEvent
-	if nextEvent != NoNextEvent {
-		testRule.active = true
-	}
-	return testRule, mockClock
-}

internal/mappingrules/mapping_rule_axis_to_relaxis.go

@@ -3,6 +3,7 @@ package mappingrules
 import (
 	"time"
 
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
 	"github.com/holoplot/go-evdev"
 	"github.com/jonboulle/clockwork"
 )
@@ -23,23 +24,32 @@ type MappingRuleAxisToRelaxis struct {
 	clock         clockwork.Clock
 }
 
-func NewMappingRuleAxisToRelaxis(
+func NewMappingRuleAxisToRelaxis(ruleConfig configparser.RuleConfigAxisToRelaxis,
-	base MappingRuleBase,
+	pDevs map[string]Device,
-	input *RuleTargetAxis,
+	vDevs map[string]Device,
-	output *RuleTargetRelaxis,
+	base MappingRuleBase) (*MappingRuleAxisToRelaxis, error) {
-	repeatRateMin, repeatRateMax, increment int) *MappingRuleAxisToRelaxis {
+
+	input, err := NewRuleTargetAxisFromConfig(ruleConfig.Input, pDevs)
+	if err != nil {
+		return nil, err
+	}
+
+	output, err := NewRuleTargetRelaxisFromConfig(ruleConfig.Output, vDevs)
+	if err != nil {
+		return nil, err
+	}
 
 	return &MappingRuleAxisToRelaxis{
 		MappingRuleBase: base,
 		Input:           input,
 		Output:          output,
-		RepeatRateMin:   repeatRateMin,
+		RepeatRateMin:   ruleConfig.RepeatRateMin,
-		RepeatRateMax:   repeatRateMax,
+		RepeatRateMax:   ruleConfig.RepeatRateMax,
-		Increment:       int32(increment),
+		Increment:       int32(ruleConfig.Increment),
 		lastEvent:       time.Now(),
 		nextEvent:       NoNextEvent,
 		clock:           clockwork.NewRealClock(),
-	}
+	}, nil
 }
 
 func (rule *MappingRuleAxisToRelaxis) MatchEvent(

internal/mappingrules/mapping_rule_button.go

@@ -1,6 +1,9 @@
 package mappingrules
 
-import "github.com/holoplot/go-evdev"
+import (
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
+	"github.com/holoplot/go-evdev"
+)
 
 // A Simple Mapping Rule can map a button to a button or an axis to an axis.
 type MappingRuleButton struct {
@@ -9,16 +12,26 @@ type MappingRuleButton struct {
 	Output *RuleTargetButton
 }
 
-func NewMappingRuleButton(
+func NewMappingRuleButton(ruleConfig configparser.RuleConfigButton,
-	base MappingRuleBase,
+	pDevs map[string]Device,
-	input *RuleTargetButton,
+	vDevs map[string]Device,
-	output *RuleTargetButton) *MappingRuleButton {
+	base MappingRuleBase) (*MappingRuleButton, error) {
+
+	input, err := NewRuleTargetButtonFromConfig(ruleConfig.Input, pDevs)
+	if err != nil {
+		return nil, err
+	}
+
+	output, err := NewRuleTargetButtonFromConfig(ruleConfig.Output, vDevs)
+	if err != nil {
+		return nil, err
+	}
 
 	return &MappingRuleButton{
 		MappingRuleBase: base,
 		Input:           input,
 		Output:          output,
-	}
+	}, nil
 }
 
 func (rule *MappingRuleButton) MatchEvent(device Device, event *evdev.InputEvent, mode *string) (*evdev.InputDevice, *evdev.InputEvent) {

internal/mappingrules/mapping_rule_button_combo.go

@@ -1,6 +1,9 @@
 package mappingrules
 
-import "github.com/holoplot/go-evdev"
+import (
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
+	"github.com/holoplot/go-evdev"
+)
 
 // A Combo Mapping Rule can require multiple physical button presses for a single output button
 type MappingRuleButtonCombo struct {
@@ -10,17 +13,31 @@ type MappingRuleButtonCombo struct {
 	State  int
 }
 
-func NewMappingRuleButtonCombo(
+func NewMappingRuleButtonCombo(ruleConfig configparser.RuleConfigButtonCombo,
-	base MappingRuleBase,
+	pDevs map[string]Device,
-	inputs []*RuleTargetButton,
+	vDevs map[string]Device,
-	output *RuleTargetButton) *MappingRuleButtonCombo {
+	base MappingRuleBase) (*MappingRuleButtonCombo, error) {
+
+	inputs := make([]*RuleTargetButton, 0)
+	for _, inputConfig := range ruleConfig.Inputs {
+		input, err := NewRuleTargetButtonFromConfig(inputConfig, pDevs)
+		if err != nil {
+			return nil, err
+		}
+		inputs = append(inputs, input)
+	}
+
+	output, err := NewRuleTargetButtonFromConfig(ruleConfig.Output, vDevs)
+	if err != nil {
+		return nil, err
+	}
 
 	return &MappingRuleButtonCombo{
 		MappingRuleBase: base,
 		Inputs:          inputs,
 		Output:          output,
 		State:           0,
-	}
+	}, nil
 }
 
 func (rule *MappingRuleButtonCombo) MatchEvent(device Device, event *evdev.InputEvent, mode *string) (*evdev.InputDevice, *evdev.InputEvent) {

internal/mappingrules/mapping_rule_button_latched.go

@@ -1,6 +1,9 @@
 package mappingrules
 
-import "github.com/holoplot/go-evdev"
+import (
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
+	"github.com/holoplot/go-evdev"
+)
 
 type MappingRuleButtonLatched struct {
 	MappingRuleBase
@@ -9,17 +12,27 @@ type MappingRuleButtonLatched struct {
 	State  bool
 }
 
-func NewMappingRuleButtonLatched(
+func NewMappingRuleButtonLatched(ruleConfig configparser.RuleConfigButtonLatched,
-	base MappingRuleBase,
+	pDevs map[string]Device,
-	input *RuleTargetButton,
+	vDevs map[string]Device,
-	output *RuleTargetButton) *MappingRuleButtonLatched {
+	base MappingRuleBase) (*MappingRuleButtonLatched, error) {
+
+	input, err := NewRuleTargetButtonFromConfig(ruleConfig.Input, pDevs)
+	if err != nil {
+		return nil, err
+	}
+
+	output, err := NewRuleTargetButtonFromConfig(ruleConfig.Output, vDevs)
+	if err != nil {
+		return nil, err
+	}
 
 	return &MappingRuleButtonLatched{
 		MappingRuleBase: base,
 		Input:           input,
 		Output:          output,
 		State:           false,
-	}
+	}, nil
 }
 
 func (rule *MappingRuleButtonLatched) MatchEvent(device Device, event *evdev.InputEvent, mode *string) (*evdev.InputDevice, *evdev.InputEvent) {

internal/mappingrules/mapping_rule_button_test.go

@@ -28,7 +28,11 @@ func (t *MappingRuleButtonTests) SetupTest() {
 func (t *MappingRuleButtonTests) TestMatchEvent() {
 	inputButton, _ := NewRuleTargetButton("", t.inputDevice, evdev.BTN_TRIGGER, false)
 	outputButton, _ := NewRuleTargetButton("", t.outputDevice, evdev.BTN_TRIGGER, false)
-	testRule := NewMappingRuleButton(t.base, inputButton, outputButton)
+	testRule := &MappingRuleButton{
+		MappingRuleBase: t.base,
+		Input:           inputButton,
+		Output:          outputButton,
+	}
 
 	// A matching input event should produce an output event
 	expected := &evdev.InputEvent{
@@ -58,7 +62,11 @@ func (t *MappingRuleButtonTests) TestMatchEvent() {
 func (t *MappingRuleButtonTests) TestMatchEventInverted() {
 	inputButton, _ := NewRuleTargetButton("", t.inputDevice, evdev.BTN_TRIGGER, true)
 	outputButton, _ := NewRuleTargetButton("", t.outputDevice, evdev.BTN_TRIGGER, false)
-	testRule := NewMappingRuleButton(t.base, inputButton, outputButton)
+	testRule := &MappingRuleButton{
+		MappingRuleBase: t.base,
+		Input:           inputButton,
+		Output:          outputButton,
+	}
 
 	// A matching input event should produce an output event
 	expected := &evdev.InputEvent{

internal/mappingrules/mapping_rule_mode_select.go

@@ -1,6 +1,9 @@
 package mappingrules
 
-import "github.com/holoplot/go-evdev"
+import (
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
+	"github.com/holoplot/go-evdev"
+)
 
 type MappingRuleModeSelect struct {
 	MappingRuleBase
@@ -8,17 +11,26 @@ type MappingRuleModeSelect struct {
 	Output *RuleTargetModeSelect
 }
 
-func NewMappingRuleModeSelect(
+func NewMappingRuleModeSelect(ruleConfig configparser.RuleConfigModeSelect,
-	base MappingRuleBase,
+	pDevs map[string]Device,
-	input *RuleTargetButton,
+	modes []string,
-	output *RuleTargetModeSelect,
+	base MappingRuleBase) (*MappingRuleModeSelect, error) {
-) *MappingRuleModeSelect {
+
+	input, err := NewRuleTargetButtonFromConfig(ruleConfig.Input, pDevs)
+	if err != nil {
+		return nil, err
+	}
+
+	output, err := NewRuleTargetModeSelectFromConfig(ruleConfig.Output, modes)
+	if err != nil {
+		return nil, err
+	}
 
 	return &MappingRuleModeSelect{
 		MappingRuleBase: base,
 		Input:           input,
 		Output:          output,
-	}
+	}, nil
 }
 
 func (rule *MappingRuleModeSelect) MatchEvent(

internal/mappingrules/math.go

@@ -28,3 +28,16 @@ func Clamp[T Numeric](value, min, max T) T {
 	}
 	return value
 }
+
+func clampAndShift(start, end, min, max int32) (int32, int32) {
+	if start < min {
+		end += min - start
+		start = min
+	}
+	if end > max {
+		start -= end - max
+		end = max
+	}
+
+	return start, end
+}

internal/mappingrules/rule_target_axis.go

@@ -4,6 +4,8 @@ import (
 	"errors"
 	"fmt"
 
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
+	"git.annabunches.net/annabunches/joyful/internal/eventcodes"
 	"github.com/holoplot/go-evdev"
 )
 
@@ -20,6 +22,77 @@ type RuleTargetAxis struct {
 	deadzoneSize  int32
 }
 
+func NewRuleTargetAxisFromConfig(targetConfig configparser.RuleTargetConfigAxis, devs map[string]Device) (*RuleTargetAxis, error) {
+	device, ok := devs[targetConfig.Device]
+	if !ok {
+		return nil, fmt.Errorf("non-existent device '%s'", targetConfig.Device)
+	}
+
+	if targetConfig.DeadzoneEnd < targetConfig.DeadzoneStart {
+		return nil, errors.New("deadzone_end must be greater than deadzone_start")
+	}
+
+	eventCode, err := eventcodes.ParseCode(targetConfig.Axis, eventcodes.CodePrefixAxis)
+	if err != nil {
+		return nil, err
+	}
+
+	deadzoneStart, deadzoneEnd, err := calculateDeadzones(targetConfig, device, eventCode)
+	if err != nil {
+		return nil, err
+	}
+
+	return NewRuleTargetAxis(
+		targetConfig.Device,
+		device,
+		eventCode,
+		targetConfig.Inverted,
+		deadzoneStart,
+		deadzoneEnd,
+	)
+}
+
+// calculateDeadzones produces the deadzone start and end values in absolute terms
+func calculateDeadzones(targetConfig configparser.RuleTargetConfigAxis, device Device, axis evdev.EvCode) (int32, int32, error) {
+
+	var deadzoneStart, deadzoneEnd int32
+	deadzoneStart = 0
+	deadzoneEnd = 0
+
+	if targetConfig.DeadzoneStart != 0 || targetConfig.DeadzoneEnd != 0 {
+		return targetConfig.DeadzoneStart, targetConfig.DeadzoneEnd, nil
+	}
+
+	var min, max int32
+	absInfoMap, err := device.AbsInfos()
+
+	if err != nil {
+		min = AxisValueMin
+		max = AxisValueMax
+	} else {
+		absInfo := absInfoMap[axis]
+		min = absInfo.Minimum
+		max = absInfo.Maximum
+	}
+
+	if targetConfig.DeadzoneCenter < min || targetConfig.DeadzoneCenter > max {
+		return 0, 0, fmt.Errorf("deadzone_center '%d' is out of bounds", targetConfig.DeadzoneCenter)
+	}
+
+	switch {
+	case targetConfig.DeadzoneSize != 0:
+		deadzoneStart = targetConfig.DeadzoneCenter - targetConfig.DeadzoneSize/2
+		deadzoneEnd = targetConfig.DeadzoneCenter + targetConfig.DeadzoneSize/2
+	case targetConfig.DeadzoneSizePercent != 0:
+		deadzoneSize := (max - min) / targetConfig.DeadzoneSizePercent
+		deadzoneStart = targetConfig.DeadzoneCenter - deadzoneSize/2
+		deadzoneEnd = targetConfig.DeadzoneCenter + deadzoneSize/2
+	}
+
+	deadzoneStart, deadzoneEnd = clampAndShift(deadzoneStart, deadzoneEnd, min, max)
+	return deadzoneStart, deadzoneEnd, nil
+}
+
 func NewRuleTargetAxis(device_name string,
 	device Device,
 	axis evdev.EvCode,

internal/mappingrules/rule_target_button.go

@@ -1,6 +1,12 @@
 package mappingrules
 
-import "github.com/holoplot/go-evdev"
+import (
+	"fmt"
+
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
+	"git.annabunches.net/annabunches/joyful/internal/eventcodes"
+	"github.com/holoplot/go-evdev"
+)
 
 type RuleTargetButton struct {
 	DeviceName string
@@ -9,6 +15,25 @@ type RuleTargetButton struct {
 	Inverted   bool
 }
 
+func NewRuleTargetButtonFromConfig(targetConfig configparser.RuleTargetConfigButton, devs map[string]Device) (*RuleTargetButton, error) {
+	device, ok := devs[targetConfig.Device]
+	if !ok {
+		return nil, fmt.Errorf("non-existent device '%s'", targetConfig.Device)
+	}
+
+	eventCode, err := eventcodes.ParseCodeButton(targetConfig.Button)
+	if err != nil {
+		return nil, err
+	}
+
+	return NewRuleTargetButton(
+		targetConfig.Device,
+		device,
+		eventCode,
+		targetConfig.Inverted,
+	)
+}
+
 func NewRuleTargetButton(device_name string, device Device, code evdev.EvCode, inverted bool) (*RuleTargetButton, error) {
 	return &RuleTargetButton{
 		DeviceName: device_name,

internal/mappingrules/rule_target_modeselect.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"slices"
 
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
 	"git.annabunches.net/annabunches/joyful/internal/logger"
 	"github.com/holoplot/go-evdev"
 )
@@ -12,6 +13,14 @@ type RuleTargetModeSelect struct {
 	Modes []string
 }
 
+func NewRuleTargetModeSelectFromConfig(targetConfig configparser.RuleTargetConfigModeSelect, allModes []string) (*RuleTargetModeSelect, error) {
+	if ok := validateModes(targetConfig.Modes, allModes); !ok {
+		return nil, errors.New("undefined mode in mode select list")
+	}
+
+	return NewRuleTargetModeSelect(targetConfig.Modes)
+}
+
 func NewRuleTargetModeSelect(modes []string) (*RuleTargetModeSelect, error) {
 	if len(modes) == 0 {
 		return nil, errors.New("cannot create RuleTargetModeSelect: mode list is empty")

internal/mappingrules/rule_target_relaxis.go

@@ -1,6 +1,10 @@
 package mappingrules
 
 import (
+	"fmt"
+
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
+	"git.annabunches.net/annabunches/joyful/internal/eventcodes"
 	"github.com/holoplot/go-evdev"
 )
 
@@ -10,12 +14,30 @@ type RuleTargetRelaxis struct {
 	Axis       evdev.EvCode
 }
 
-func NewRuleTargetRelaxis(device_name string,
+func NewRuleTargetRelaxisFromConfig(targetConfig configparser.RuleTargetConfigRelaxis, devs map[string]Device) (*RuleTargetRelaxis, error) {
+	device, ok := devs[targetConfig.Device]
+	if !ok {
+		return nil, fmt.Errorf("non-existent device '%s'", targetConfig.Device)
+	}
+
+	eventCode, err := eventcodes.ParseCode(targetConfig.Axis, eventcodes.CodePrefixRelaxis)
+	if err != nil {
+		return nil, err
+	}
+
+	return NewRuleTargetRelaxis(
+		targetConfig.Device,
+		device,
+		eventCode,
+	)
+}
+
+func NewRuleTargetRelaxis(deviceName string,
 	device Device,
 	axis evdev.EvCode) (*RuleTargetRelaxis, error) {
 
 	return &RuleTargetRelaxis{
-		DeviceName: device_name,
+		DeviceName: deviceName,
 		Device:     device,
 		Axis:       axis,
 	}, nil

internal/mappingrules/variables.go

@@ -0,0 +1,12 @@
+package mappingrules
+
+const (
+	RuleTypeButton        = "button"
+	RuleTypeButtonCombo   = "button-combo"
+	RuleTypeButtonLatched = "button-latched"
+	RuleTypeAxis          = "axis"
+	RuleTypeAxisCombined  = "axis-combined"
+	RuleTypeAxisToButton  = "axis-to-button"
+	RuleTypeAxisToRelaxis = "axis-to-relaxis"
+	RuleTypeModeSelect    = "mode-select"
+)

internal/virtualdevice/cleanup.go

@@ -1,35 +0,0 @@
-// Functions for cleaning up stale virtual devices
-
-package virtualdevice
-
-import (
-	"fmt"
-	"strings"
-
-	"github.com/holoplot/go-evdev"
-)
-
-func CleanupStaleVirtualDevices() {
-	devices, err := evdev.ListDevicePaths()
-	if err != nil {
-		fmt.Printf("Couldn't list devices while running cleanup: %s\n", err.Error())
-		return
-	}
-
-	for _, devicePath := range devices {
-		if strings.HasPrefix(devicePath.Name, "joyful-joystick") {
-			device, err := evdev.Open(devicePath.Path)
-			if err != nil {
-				fmt.Printf("Failed to open existing joyful device at '%s': %s\n", devicePath.Path, err.Error())
-				continue
-			}
-
-			err = evdev.DestroyDevice(device)
-			if err != nil {
-				fmt.Printf("Failed to destroy existing joyful device '%s' at '%s': %s\n", devicePath.Name, devicePath.Path, err.Error())
-			} else {
-				fmt.Printf("Destroyed stale joyful device '%s'\n", devicePath.Path)
-			}
-		}
-	}
-}

internal/virtualdevice/eventbuffer.go

@@ -11,13 +11,7 @@ import (
 type EventBuffer struct {
 	events []*evdev.InputEvent
 	Device VirtualDevice
-}
+	Name   string
-
-func NewEventBuffer(device VirtualDevice) *EventBuffer {
-	return &EventBuffer{
-		events: make([]*evdev.InputEvent, 0, 100),
-		Device: device,
-	}
 }
 
 func (buffer *EventBuffer) AddEvent(event *evdev.InputEvent) {

internal/virtualdevice/eventbuffer_test.go

@@ -11,10 +11,11 @@ import (
 
 type EventBufferTests struct {
 	suite.Suite
-	device       *VirtualDeviceMock
+	device *VirtualDeviceMock
-	writeOneCall *mock.Call
+	buffer *EventBuffer
 }
 
+// Mocks
 type VirtualDeviceMock struct {
 	mock.Mock
 }
@@ -24,65 +25,65 @@ func (m *VirtualDeviceMock) WriteOne(event *evdev.InputEvent) error {
 	return args.Error(0)
 }
 
+// Setup
 func TestRunnerEventBufferTests(t *testing.T) {
 	suite.Run(t, new(EventBufferTests))
 }
 
-func (t *EventBufferTests) SetupTest() {
-	t.device = new(VirtualDeviceMock)
-}
-
 func (t *EventBufferTests) SetupSubTest() {
 	t.device = new(VirtualDeviceMock)
-	t.writeOneCall = t.device.On("WriteOne").Return(nil)
+	t.buffer = &EventBuffer{Device: t.device}
-}
-
-func (t *EventBufferTests) TearDownSubTest() {
-	t.writeOneCall.Unset()
 }
 
+// Tests
 func (t *EventBufferTests) TestNewEventBuffer() {
-	buffer := NewEventBuffer(t.device)
+	t.Equal(t.device, t.buffer.Device)
-	t.Equal(t.device, buffer.Device)
+	t.Len(t.buffer.events, 0)
-	t.Len(buffer.events, 0)
 }
 
-func (t *EventBufferTests) TestEventBufferAddEvent() {
+func (t *EventBufferTests) TestEventBuffer() {
-	buffer := NewEventBuffer(t.device)
+
-	buffer.AddEvent(&evdev.InputEvent{})
+	t.Run("AddEvent", func() {
-	buffer.AddEvent(&evdev.InputEvent{})
+		t.buffer.AddEvent(&evdev.InputEvent{})
-	buffer.AddEvent(&evdev.InputEvent{})
+		t.buffer.AddEvent(&evdev.InputEvent{})
-	t.Len(buffer.events, 3)
+		t.buffer.AddEvent(&evdev.InputEvent{})
-}
+		t.Len(t.buffer.events, 3)
-
+	})
-func (t *EventBufferTests) TestEventBufferSendEvents() {
+
-	t.Run("3 Events", func() {
+	t.Run("SendEvents", func() {
-		buffer := NewEventBuffer(t.device)
+		t.Run("3 Events", func() {
-		buffer.AddEvent(&evdev.InputEvent{})
+			writeOneCall := t.device.On("WriteOne").Return(nil)
-		buffer.AddEvent(&evdev.InputEvent{})
+
-		buffer.AddEvent(&evdev.InputEvent{})
+			t.buffer.AddEvent(&evdev.InputEvent{})
-		errs := buffer.SendEvents()
+			t.buffer.AddEvent(&evdev.InputEvent{})
-
+			t.buffer.AddEvent(&evdev.InputEvent{})
-		t.Len(errs, 0)
+			errs := t.buffer.SendEvents()
-		t.device.AssertNumberOfCalls(t.T(), "WriteOne", 4)
+
-	})
+			t.Len(errs, 0)
-
+			t.device.AssertNumberOfCalls(t.T(), "WriteOne", 4)
-	t.Run("No Events", func() {
+
-		buffer := NewEventBuffer(t.device)
+			writeOneCall.Unset()
-		errs := buffer.SendEvents()
+		})
-
+
-		t.Len(errs, 0)
+		t.Run("No Events", func() {
-		t.device.AssertNumberOfCalls(t.T(), "WriteOne", 0)
+			writeOneCall := t.device.On("WriteOne").Return(nil)
-	})
+
-
+			errs := t.buffer.SendEvents()
-	t.Run("Bad Event", func() {
+
-		t.writeOneCall.Unset()
+			t.Len(errs, 0)
-		t.writeOneCall = t.device.On("WriteOne").Return(errors.New("Fail"))
+			t.device.AssertNumberOfCalls(t.T(), "WriteOne", 0)
-
+
-		buffer := NewEventBuffer(t.device)
+			writeOneCall.Unset()
-		buffer.AddEvent(&evdev.InputEvent{})
+		})
-		errs := buffer.SendEvents()
+
-		t.Len(errs, 2)
+		t.Run("Bad Event", func() {
-	})
+			writeOneCall := t.device.On("WriteOne").Return(errors.New("Fail"))
-
+
+			t.buffer.AddEvent(&evdev.InputEvent{})
+			errs := t.buffer.SendEvents()
+			t.Len(errs, 2)
+
+			writeOneCall.Unset()
+		})
+	})
 }

internal/virtualdevice/init.go

@@ -0,0 +1,165 @@
+package virtualdevice
+
+import (
+	"fmt"
+
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
+	"git.annabunches.net/annabunches/joyful/internal/eventcodes"
+	"git.annabunches.net/annabunches/joyful/internal/logger"
+	"github.com/holoplot/go-evdev"
+)
+
+// NewEventBuffer takes a virtual device config specification, creates the underlying
+// evdev.InputDevice, and wraps it in a buffered event emitter.
+func NewEventBuffer(config configparser.DeviceConfigVirtual) (*EventBuffer, error) {
+	deviceMap := make(map[string]*evdev.InputDevice)
+
+	name := fmt.Sprintf("joyful-%s", config.Name)
+
+	var capabilities map[evdev.EvType][]evdev.EvCode
+
+	// todo: add tests for presets
+	switch config.Preset {
+	case DevicePresetGamepad:
+		capabilities = CapabilitiesPresetGamepad
+	case DevicePresetKeyboard:
+		capabilities = CapabilitiesPresetKeyboard
+	case DevicePresetJoystick:
+		capabilities = CapabilitiesPresetJoystick
+	case DevicePresetMouse:
+		capabilities = CapabilitiesPresetMouse
+	default:
+		capabilities = map[evdev.EvType][]evdev.EvCode{
+			evdev.EV_KEY: makeButtons(config.NumButtons, config.Buttons),
+			evdev.EV_ABS: makeAxes(config.NumAxes, config.Axes),
+			evdev.EV_REL: makeRelativeAxes(config.NumRelativeAxes, config.RelativeAxes),
+		}
+	}
+
+	device, err := evdev.CreateDevice(
+		name,
+		// TODO: placeholders. Who knows what these should actually be...
+		evdev.InputID{
+			BusType: 0x03,
+			Vendor:  0x4711,
+			Product: 0x0816,
+			Version: 1,
+		},
+		capabilities,
+	)
+
+	if err != nil {
+		return nil, err
+	}
+
+	deviceMap[config.Name] = device
+	logger.Log(fmt.Sprintf(
+		"Created virtual device '%s' with %d buttons, %d axes, and %d relative axes",
+		name,
+		len(capabilities[evdev.EV_KEY]),
+		len(capabilities[evdev.EV_ABS]),
+		len(capabilities[evdev.EV_REL]),
+	))
+
+	return &EventBuffer{
+		events: make([]*evdev.InputEvent, 0, 100),
+		Device: device,
+		Name:   config.Name,
+	}, nil
+}
+
+// TODO: these functions have a lot of duplication; we need to figure out how to refactor it cleanly
+// without losing logging context...
+func makeButtons(numButtons int, buttonList []string) []evdev.EvCode {
+	if numButtons > 0 && len(buttonList) > 0 {
+		logger.Log("'num_buttons' and 'buttons' both specified, ignoring 'num_buttons'")
+	}
+
+	if numButtons > VirtualDeviceMaxButtons {
+		numButtons = VirtualDeviceMaxButtons
+		logger.Logf("Limiting virtual device buttons to %d", VirtualDeviceMaxButtons)
+	}
+
+	if len(buttonList) > 0 {
+		buttons := make([]evdev.EvCode, 0, len(buttonList))
+		for _, codeStr := range buttonList {
+			code, err := eventcodes.ParseCode(codeStr, "BTN")
+			if err != nil {
+				logger.LogError(err, "Failed to create button, skipping")
+				continue
+			}
+			buttons = append(buttons, code)
+		}
+		return buttons
+	}
+
+	buttons := make([]evdev.EvCode, numButtons)
+
+	for i := 0; i < numButtons; i++ {
+		buttons[i] = eventcodes.ButtonFromIndex[i]
+	}
+
+	return buttons
+}
+
+func makeAxes(numAxes int, axisList []string) []evdev.EvCode {
+	if numAxes > 0 && len(axisList) > 0 {
+		logger.Log("'num_axes' and 'axes' both specified, ignoring 'num_axes'")
+	}
+
+	if len(axisList) > 0 {
+		axes := make([]evdev.EvCode, 0, len(axisList))
+		for _, codeStr := range axisList {
+			code, err := eventcodes.ParseCode(codeStr, "ABS")
+			if err != nil {
+				logger.LogError(err, "Failed to create axis, skipping")
+				continue
+			}
+			axes = append(axes, code)
+		}
+		return axes
+	}
+
+	if numAxes > 8 {
+		numAxes = 8
+		logger.Log("Limiting virtual device axes to 8")
+	}
+
+	axes := make([]evdev.EvCode, numAxes)
+	for i := 0; i < numAxes; i++ {
+		axes[i] = evdev.EvCode(i)
+	}
+
+	return axes
+}
+
+func makeRelativeAxes(numAxes int, axisList []string) []evdev.EvCode {
+	if numAxes > 0 && len(axisList) > 0 {
+		logger.Log("'num_rel_axes' and 'rel_axes' both specified, ignoring 'num_rel_axes'")
+	}
+
+	if len(axisList) > 0 {
+		axes := make([]evdev.EvCode, 0, len(axisList))
+		for _, codeStr := range axisList {
+			code, err := eventcodes.ParseCode(codeStr, "REL")
+			if err != nil {
+				logger.LogError(err, "Failed to create axis, skipping")
+				continue
+			}
+			axes = append(axes, code)
+		}
+		return axes
+	}
+
+	if numAxes > 10 {
+		numAxes = 10
+		logger.Log("Limiting virtual device relative axes to 10")
+	}
+
+	axes := make([]evdev.EvCode, numAxes)
+	for i := 0; i < numAxes; i++ {
+		axes[i] = evdev.EvCode(i)
+	}
+
+	return axes
+}

internal/virtualdevice/init_test.go

@@ -1,4 +1,4 @@
-package config
+package virtualdevice
 
 import (
 	"testing"
@@ -7,15 +7,15 @@ import (
 	"github.com/stretchr/testify/suite"
 )
 
-type DevicesConfigTests struct {
+type InitTests struct {
 	suite.Suite
 }
 
-func TestRunnerDevicesConfig(t *testing.T) {
+func TestRunnerInit(t *testing.T) {
-	suite.Run(t, new(DevicesConfigTests))
+	suite.Run(t, new(InitTests))
 }
 
-func (t *DevicesConfigTests) TestMakeButtons() {
+func (t *InitTests) TestMakeButtons() {
 	t.Run("Maximum buttons", func() {
 		buttons := makeButtons(VirtualDeviceMaxButtons, []string{})
 		t.Equal(VirtualDeviceMaxButtons, len(buttons))
@@ -44,7 +44,7 @@ func (t *DevicesConfigTests) TestMakeButtons() {
 	})
 }
 
-func (t *DevicesConfigTests) TestMakeAxes() {
+func (t *InitTests) TestMakeAxes() {
 	t.Run("8 axes", func() {
 		axes := makeAxes(8, []string{})
 		t.Equal(8, len(axes))
@@ -81,7 +81,7 @@ func (t *DevicesConfigTests) TestMakeAxes() {
 	})
 }
 
-func (t *DevicesConfigTests) TestMakeRelativeAxes() {
+func (t *InitTests) TestMakeRelativeAxes() {
 	t.Run("10 axes", func() {
 		axes := makeRelativeAxes(10, []string{})
 		t.Equal(10, len(axes))

internal/virtualdevice/variables.go

@@ -1,114 +1,16 @@
-package config
+package virtualdevice
 
-import (
+import "github.com/holoplot/go-evdev"
-	"github.com/holoplot/go-evdev"
-)
 
 const (
-	DeviceTypePhysical = "physical"
-	DeviceTypeVirtual  = "virtual"
-
 	DevicePresetKeyboard = "keyboard"
 	DevicePresetGamepad  = "gamepad"
 	DevicePresetJoystick = "joystick"
 	DevicePresetMouse    = "mouse"
 
-	RuleTypeButton        = "button"
-	RuleTypeButtonCombo   = "button-combo"
-	RuleTypeButtonLatched = "button-latched"
-	RuleTypeAxis          = "axis"
-	RuleTypeAxisCombined  = "axis-combined"
-	RuleTypeAxisToButton  = "axis-to-button"
-	RuleTypeAxisToRelaxis = "axis-to-relaxis"
-	RuleTypeModeSelect    = "mode-select"
-
-	CodePrefixButton  = "BTN"
-	CodePrefixKey     = "KEY"
-	CodePrefixAxis    = "ABS"
-	CodePrefixRelaxis = "REL"
-
 	VirtualDeviceMaxButtons = 74
 )
 
-var (
-	ButtonFromIndex = []evdev.EvCode{
-		evdev.BTN_TRIGGER,
-		evdev.BTN_THUMB,
-		evdev.BTN_THUMB2,
-		evdev.BTN_TOP,
-		evdev.BTN_TOP2,
-		evdev.BTN_PINKIE,
-		evdev.BTN_BASE,
-		evdev.BTN_BASE2,
-		evdev.BTN_BASE3,
-		evdev.BTN_BASE4,
-		evdev.BTN_BASE5,
-		evdev.BTN_BASE6,
-		evdev.EvCode(0x12c), // decimal 300
-		evdev.EvCode(0x12d), // decimal 301
-		evdev.EvCode(0x12e), // decimal 302
-		evdev.BTN_DEAD,
-		evdev.BTN_TRIGGER_HAPPY1,
-		evdev.BTN_TRIGGER_HAPPY2,
-		evdev.BTN_TRIGGER_HAPPY3,
-		evdev.BTN_TRIGGER_HAPPY4,
-		evdev.BTN_TRIGGER_HAPPY5,
-		evdev.BTN_TRIGGER_HAPPY6,
-		evdev.BTN_TRIGGER_HAPPY7,
-		evdev.BTN_TRIGGER_HAPPY8,
-		evdev.BTN_TRIGGER_HAPPY9,
-		evdev.BTN_TRIGGER_HAPPY10,
-		evdev.BTN_TRIGGER_HAPPY11,
-		evdev.BTN_TRIGGER_HAPPY12,
-		evdev.BTN_TRIGGER_HAPPY13,
-		evdev.BTN_TRIGGER_HAPPY14,
-		evdev.BTN_TRIGGER_HAPPY15,
-		evdev.BTN_TRIGGER_HAPPY16,
-		evdev.BTN_TRIGGER_HAPPY17,
-		evdev.BTN_TRIGGER_HAPPY18,
-		evdev.BTN_TRIGGER_HAPPY19,
-		evdev.BTN_TRIGGER_HAPPY20,
-		evdev.BTN_TRIGGER_HAPPY21,
-		evdev.BTN_TRIGGER_HAPPY22,
-		evdev.BTN_TRIGGER_HAPPY23,
-		evdev.BTN_TRIGGER_HAPPY24,
-		evdev.BTN_TRIGGER_HAPPY25,
-		evdev.BTN_TRIGGER_HAPPY26,
-		evdev.BTN_TRIGGER_HAPPY27,
-		evdev.BTN_TRIGGER_HAPPY28,
-		evdev.BTN_TRIGGER_HAPPY29,
-		evdev.BTN_TRIGGER_HAPPY30,
-		evdev.BTN_TRIGGER_HAPPY31,
-		evdev.BTN_TRIGGER_HAPPY32,
-		evdev.BTN_TRIGGER_HAPPY33,
-		evdev.BTN_TRIGGER_HAPPY34,
-		evdev.BTN_TRIGGER_HAPPY35,
-		evdev.BTN_TRIGGER_HAPPY36,
-		evdev.BTN_TRIGGER_HAPPY37,
-		evdev.BTN_TRIGGER_HAPPY38,
-		evdev.BTN_TRIGGER_HAPPY39,
-		evdev.BTN_TRIGGER_HAPPY40,
-		evdev.EvCode(0x2e8),
-		evdev.EvCode(0x2e9),
-		evdev.EvCode(0x2f0),
-		evdev.EvCode(0x2f1),
-		evdev.EvCode(0x2f2),
-		evdev.EvCode(0x2f3),
-		evdev.EvCode(0x2f4),
-		evdev.EvCode(0x2f5),
-		evdev.EvCode(0x2f6),
-		evdev.EvCode(0x2f7),
-		evdev.EvCode(0x2f8),
-		evdev.EvCode(0x2f9),
-		evdev.EvCode(0x2fa),
-		evdev.EvCode(0x2fb),
-		evdev.EvCode(0x2fc),
-		evdev.EvCode(0x2fd),
-		evdev.EvCode(0x2fe),
-		evdev.EvCode(0x2ff),
-	}
-)
-
 // Device Presets
 var (
 	CapabilitiesPresetGamepad = map[evdev.EvType][]evdev.EvCode{