evdev: add evdev monitor for caps lock state

core/internal/server/evdev/handlers.go

@@ -0,0 +1,27 @@
+package evdev
+
+import (
+	"net"
+
+	"github.com/AvengeMedia/DankMaterialShell/core/internal/server/models"
+)
+
+type Request struct {
+	ID     interface{}            `json:"id"`
+	Method string                 `json:"method"`
+	Params map[string]interface{} `json:"params"`
+}
+
+func HandleRequest(conn net.Conn, req Request, m *Manager) {
+	switch req.Method {
+	case "evdev.getState":
+		handleGetState(conn, req, m)
+	default:
+		models.RespondError(conn, req.ID.(int), "unknown method: "+req.Method)
+	}
+}
+
+func handleGetState(conn net.Conn, req Request, m *Manager) {
+	state := m.GetState()
+	models.Respond(conn, req.ID.(int), state)
+}

core/internal/server/evdev/handlers_test.go

@@ -0,0 +1,133 @@
+package evdev
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"net"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	mocks "github.com/AvengeMedia/DankMaterialShell/core/internal/mocks/evdev"
+	"github.com/AvengeMedia/DankMaterialShell/core/internal/server/models"
+)
+
+type mockNetConn struct {
+	net.Conn
+	readBuf  *bytes.Buffer
+	writeBuf *bytes.Buffer
+	closed   bool
+}
+
+func newMockNetConn() *mockNetConn {
+	return &mockNetConn{
+		readBuf:  &bytes.Buffer{},
+		writeBuf: &bytes.Buffer{},
+	}
+}
+
+func (m *mockNetConn) Read(b []byte) (n int, err error) {
+	return m.readBuf.Read(b)
+}
+
+func (m *mockNetConn) Write(b []byte) (n int, err error) {
+	return m.writeBuf.Write(b)
+}
+
+func (m *mockNetConn) Close() error {
+	m.closed = true
+	return nil
+}
+
+func TestHandleRequest(t *testing.T) {
+	t.Run("getState request", func(t *testing.T) {
+		mockDevice := mocks.NewMockEvdevDevice(t)
+		mockDevice.EXPECT().ReadOne().Return(nil, errors.New("test")).Maybe()
+
+		m := &Manager{
+			device:      mockDevice,
+			state:       State{Available: true, CapsLock: true},
+			subscribers: make(map[string]chan State),
+			closeChan:   make(chan struct{}),
+		}
+
+		conn := newMockNetConn()
+		req := Request{
+			ID:     123,
+			Method: "evdev.getState",
+			Params: map[string]interface{}{},
+		}
+
+		HandleRequest(conn, req, m)
+
+		var resp models.Response[State]
+		err := json.NewDecoder(conn.writeBuf).Decode(&resp)
+		require.NoError(t, err)
+
+		assert.Equal(t, 123, resp.ID)
+		assert.NotNil(t, resp.Result)
+		assert.True(t, resp.Result.Available)
+		assert.True(t, resp.Result.CapsLock)
+	})
+
+	t.Run("unknown method", func(t *testing.T) {
+		mockDevice := mocks.NewMockEvdevDevice(t)
+		mockDevice.EXPECT().ReadOne().Return(nil, errors.New("test")).Maybe()
+
+		m := &Manager{
+			device:      mockDevice,
+			state:       State{Available: true, CapsLock: false},
+			subscribers: make(map[string]chan State),
+			closeChan:   make(chan struct{}),
+		}
+
+		conn := newMockNetConn()
+		req := Request{
+			ID:     456,
+			Method: "evdev.unknownMethod",
+			Params: map[string]interface{}{},
+		}
+
+		HandleRequest(conn, req, m)
+
+		var resp models.Response[any]
+		err := json.NewDecoder(conn.writeBuf).Decode(&resp)
+		require.NoError(t, err)
+
+		assert.Equal(t, 456, resp.ID)
+		assert.NotEmpty(t, resp.Error)
+		assert.Contains(t, resp.Error, "unknown method")
+	})
+}
+
+func TestHandleGetState(t *testing.T) {
+	mockDevice := mocks.NewMockEvdevDevice(t)
+	mockDevice.EXPECT().ReadOne().Return(nil, errors.New("test")).Maybe()
+
+	m := &Manager{
+		device:      mockDevice,
+		state:       State{Available: true, CapsLock: false},
+		subscribers: make(map[string]chan State),
+		closeChan:   make(chan struct{}),
+	}
+
+	conn := newMockNetConn()
+	req := Request{
+		ID:     789,
+		Method: "evdev.getState",
+		Params: map[string]interface{}{},
+	}
+
+	handleGetState(conn, req, m)
+
+	var resp models.Response[State]
+	err := json.NewDecoder(conn.writeBuf).Decode(&resp)
+	require.NoError(t, err)
+
+	assert.Equal(t, 789, resp.ID)
+	assert.NotNil(t, resp.Result)
+	assert.True(t, resp.Result.Available)
+	assert.False(t, resp.Result.CapsLock)
+}

core/internal/server/evdev/manager.go

@@ -0,0 +1,256 @@
+package evdev
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/AvengeMedia/DankMaterialShell/core/internal/log"
+	evdev "github.com/holoplot/go-evdev"
+)
+
+const (
+	evKeyType      = 0x01
+	evLedType      = 0x11
+	keyCapslockKey = 58
+	ledCapslockKey = 1
+	keyStateOn     = 1
+)
+
+type EvdevDevice interface {
+	Name() (string, error)
+	Path() string
+	Close() error
+	ReadOne() (*evdev.InputEvent, error)
+	State(t evdev.EvType) (evdev.StateMap, error)
+}
+
+type Manager struct {
+	device      EvdevDevice
+	state       State
+	stateMutex  sync.RWMutex
+	subscribers map[string]chan State
+	subMutex    sync.RWMutex
+	closeChan   chan struct{}
+	closeOnce   sync.Once
+}
+
+func NewManager() (*Manager, error) {
+	device, err := findKeyboard()
+	if err != nil {
+		return nil, fmt.Errorf("failed to find keyboard: %w", err)
+	}
+
+	initialCapsLock := readInitialCapsLockState(device)
+
+	m := &Manager{
+		device:      device,
+		state:       State{Available: true, CapsLock: initialCapsLock},
+		subscribers: make(map[string]chan State),
+		closeChan:   make(chan struct{}),
+	}
+
+	go m.monitorCapsLock()
+
+	return m, nil
+}
+
+func readInitialCapsLockState(device EvdevDevice) bool {
+	ledStates, err := device.State(evLedType)
+	if err != nil {
+		log.Debugf("Could not read LED state: %v", err)
+		return false
+	}
+
+	return ledStates[ledCapslockKey]
+}
+
+func findKeyboard() (EvdevDevice, error) {
+	pattern := "/dev/input/event*"
+	matches, err := filepath.Glob(pattern)
+	if err != nil {
+		return nil, fmt.Errorf("failed to glob input devices: %w", err)
+	}
+
+	if len(matches) == 0 {
+		return nil, fmt.Errorf("no input devices found")
+	}
+
+	for _, path := range matches {
+		device, err := evdev.Open(path)
+		if err != nil {
+			continue
+		}
+
+		if isKeyboard(device) {
+			deviceName, _ := device.Name()
+			log.Debugf("Found keyboard: %s at %s", deviceName, path)
+			return device, nil
+		}
+
+		device.Close()
+	}
+
+	return nil, fmt.Errorf("no keyboard device found")
+}
+
+func isKeyboard(device EvdevDevice) bool {
+	deviceName, err := device.Name()
+	if err != nil {
+		return false
+	}
+
+	name := strings.ToLower(deviceName)
+
+	switch {
+	case strings.Contains(name, "keyboard"):
+		return true
+	case strings.Contains(name, "kbd"):
+		return true
+	case strings.Contains(name, "input") && strings.Contains(name, "key"):
+		return true
+	default:
+		return false
+	}
+}
+
+func (m *Manager) monitorCapsLock() {
+	defer func() {
+		if r := recover(); r != nil {
+			log.Errorf("Panic in evdev monitor: %v", r)
+		}
+	}()
+
+	for {
+		select {
+		case <-m.closeChan:
+			return
+		default:
+		}
+
+		event, err := m.device.ReadOne()
+		if err != nil {
+			if !isClosedError(err) {
+				log.Warnf("Failed to read evdev event: %v", err)
+			}
+			time.Sleep(100 * time.Millisecond)
+			continue
+		}
+
+		if event == nil {
+			continue
+		}
+
+		if event.Type == evKeyType && event.Code == keyCapslockKey && event.Value == keyStateOn {
+			m.toggleCapsLock()
+		}
+	}
+}
+
+func isClosedError(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	errStr := err.Error()
+	switch {
+	case strings.Contains(errStr, "closed"):
+		return true
+	case strings.Contains(errStr, "bad file descriptor"):
+		return true
+	default:
+		return false
+	}
+}
+
+func (m *Manager) toggleCapsLock() {
+	m.stateMutex.Lock()
+	m.state.CapsLock = !m.state.CapsLock
+	newState := m.state
+	m.stateMutex.Unlock()
+
+	log.Debugf("Caps lock toggled: %v", newState.CapsLock)
+	m.notifySubscribers(newState)
+}
+
+func (m *Manager) GetState() State {
+	m.stateMutex.RLock()
+	defer m.stateMutex.RUnlock()
+	return m.state
+}
+
+func (m *Manager) Subscribe(id string) chan State {
+	m.subMutex.Lock()
+	defer m.subMutex.Unlock()
+
+	ch := make(chan State, 16)
+	m.subscribers[id] = ch
+	return ch
+}
+
+func (m *Manager) Unsubscribe(id string) {
+	m.subMutex.Lock()
+	defer m.subMutex.Unlock()
+
+	if ch, ok := m.subscribers[id]; ok {
+		close(ch)
+		delete(m.subscribers, id)
+	}
+}
+
+func (m *Manager) notifySubscribers(state State) {
+	m.subMutex.RLock()
+	defer m.subMutex.RUnlock()
+
+	for _, ch := range m.subscribers {
+		select {
+		case ch <- state:
+		default:
+		}
+	}
+}
+
+func (m *Manager) Close() {
+	m.closeOnce.Do(func() {
+		close(m.closeChan)
+
+		if m.device != nil {
+			if err := m.device.Close(); err != nil && !isClosedError(err) {
+				log.Warnf("Error closing evdev device: %v", err)
+			}
+		}
+
+		m.subMutex.Lock()
+		for id, ch := range m.subscribers {
+			close(ch)
+			delete(m.subscribers, id)
+		}
+		m.subMutex.Unlock()
+	})
+}
+
+func InitializeManager() (*Manager, error) {
+	if os.Getuid() != 0 && !hasInputGroupAccess() {
+		return nil, fmt.Errorf("insufficient permissions to access input devices")
+	}
+
+	return NewManager()
+}
+
+func hasInputGroupAccess() bool {
+	pattern := "/dev/input/event*"
+	matches, err := filepath.Glob(pattern)
+	if err != nil || len(matches) == 0 {
+		return false
+	}
+
+	testFile, err := os.Open(matches[0])
+	if err != nil {
+		return false
+	}
+	testFile.Close()
+	return true
+}

core/internal/server/evdev/manager_test.go

@@ -0,0 +1,314 @@
+package evdev
+
+import (
+	"errors"
+	"testing"
+
+	evdev "github.com/holoplot/go-evdev"
+	"github.com/stretchr/testify/assert"
+
+	mocks "github.com/AvengeMedia/DankMaterialShell/core/internal/mocks/evdev"
+)
+
+func TestManager_Creation(t *testing.T) {
+	t.Run("manager created successfully with caps lock off", func(t *testing.T) {
+		mockDevice := mocks.NewMockEvdevDevice(t)
+		mockDevice.EXPECT().ReadOne().Return(nil, errors.New("test")).Maybe()
+
+		m := &Manager{
+			device:      mockDevice,
+			state:       State{Available: true, CapsLock: false},
+			subscribers: make(map[string]chan State),
+			closeChan:   make(chan struct{}),
+		}
+
+		assert.NotNil(t, m)
+		assert.True(t, m.state.Available)
+		assert.False(t, m.state.CapsLock)
+	})
+
+	t.Run("manager created successfully with caps lock on", func(t *testing.T) {
+		mockDevice := mocks.NewMockEvdevDevice(t)
+		mockDevice.EXPECT().ReadOne().Return(nil, errors.New("test")).Maybe()
+
+		m := &Manager{
+			device:      mockDevice,
+			state:       State{Available: true, CapsLock: true},
+			subscribers: make(map[string]chan State),
+			closeChan:   make(chan struct{}),
+		}
+
+		assert.NotNil(t, m)
+		assert.True(t, m.state.Available)
+		assert.True(t, m.state.CapsLock)
+	})
+}
+
+func TestManager_GetState(t *testing.T) {
+	mockDevice := mocks.NewMockEvdevDevice(t)
+	mockDevice.EXPECT().ReadOne().Return(nil, errors.New("test")).Maybe()
+
+	m := &Manager{
+		device:      mockDevice,
+		state:       State{Available: true, CapsLock: false},
+		subscribers: make(map[string]chan State),
+		closeChan:   make(chan struct{}),
+	}
+
+	state := m.GetState()
+	assert.True(t, state.Available)
+	assert.False(t, state.CapsLock)
+}
+
+func TestManager_Subscribe(t *testing.T) {
+	mockDevice := mocks.NewMockEvdevDevice(t)
+	mockDevice.EXPECT().ReadOne().Return(nil, errors.New("test")).Maybe()
+
+	m := &Manager{
+		device:      mockDevice,
+		state:       State{Available: true, CapsLock: false},
+		subscribers: make(map[string]chan State),
+		closeChan:   make(chan struct{}),
+	}
+
+	ch := m.Subscribe("test-client")
+	assert.NotNil(t, ch)
+	assert.Len(t, m.subscribers, 1)
+}
+
+func TestManager_Unsubscribe(t *testing.T) {
+	mockDevice := mocks.NewMockEvdevDevice(t)
+	mockDevice.EXPECT().ReadOne().Return(nil, errors.New("test")).Maybe()
+
+	m := &Manager{
+		device:      mockDevice,
+		state:       State{Available: true, CapsLock: false},
+		subscribers: make(map[string]chan State),
+		closeChan:   make(chan struct{}),
+	}
+
+	ch := m.Subscribe("test-client")
+	assert.Len(t, m.subscribers, 1)
+
+	m.Unsubscribe("test-client")
+	assert.Len(t, m.subscribers, 0)
+
+	select {
+	case _, ok := <-ch:
+		assert.False(t, ok, "channel should be closed")
+	default:
+		t.Error("channel should be closed")
+	}
+}
+
+func TestManager_ToggleCapsLock(t *testing.T) {
+	mockDevice := mocks.NewMockEvdevDevice(t)
+	mockDevice.EXPECT().ReadOne().Return(nil, errors.New("test")).Maybe()
+
+	m := &Manager{
+		device:      mockDevice,
+		state:       State{Available: true, CapsLock: false},
+		subscribers: make(map[string]chan State),
+		closeChan:   make(chan struct{}),
+	}
+
+	ch := m.Subscribe("test-client")
+
+	go func() {
+		m.toggleCapsLock()
+	}()
+
+	newState := <-ch
+	assert.True(t, newState.CapsLock)
+
+	go func() {
+		m.toggleCapsLock()
+	}()
+
+	newState = <-ch
+	assert.False(t, newState.CapsLock)
+}
+
+func TestManager_Close(t *testing.T) {
+	mockDevice := mocks.NewMockEvdevDevice(t)
+	mockDevice.EXPECT().Close().Return(nil).Once()
+	mockDevice.EXPECT().ReadOne().Return(nil, errors.New("test")).Maybe()
+
+	m := &Manager{
+		device:      mockDevice,
+		state:       State{Available: true, CapsLock: false},
+		subscribers: make(map[string]chan State),
+		closeChan:   make(chan struct{}),
+	}
+
+	ch1 := m.Subscribe("client1")
+	ch2 := m.Subscribe("client2")
+
+	m.Close()
+
+	select {
+	case _, ok := <-ch1:
+		assert.False(t, ok, "channel 1 should be closed")
+	default:
+		t.Error("channel 1 should be closed")
+	}
+
+	select {
+	case _, ok := <-ch2:
+		assert.False(t, ok, "channel 2 should be closed")
+	default:
+		t.Error("channel 2 should be closed")
+	}
+
+	assert.Len(t, m.subscribers, 0)
+
+	m.Close()
+}
+
+func TestIsKeyboard(t *testing.T) {
+	tests := []struct {
+		name     string
+		devName  string
+		expected bool
+	}{
+		{"keyboard in name", "AT Translated Set 2 keyboard", true},
+		{"kbd in name", "USB kbd", true},
+		{"input and key", "input key device", true},
+		{"random device", "Mouse", false},
+		{"empty name", "", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			mockDevice := mocks.NewMockEvdevDevice(t)
+			mockDevice.EXPECT().Name().Return(tt.devName, nil).Once()
+
+			result := isKeyboard(mockDevice)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}
+
+func TestIsKeyboard_ErrorHandling(t *testing.T) {
+	mockDevice := mocks.NewMockEvdevDevice(t)
+	mockDevice.EXPECT().Name().Return("", errors.New("device error")).Once()
+
+	result := isKeyboard(mockDevice)
+	assert.False(t, result)
+}
+
+func TestManager_MonitorCapsLock(t *testing.T) {
+	t.Run("caps lock key press toggles state", func(t *testing.T) {
+		mockDevice := mocks.NewMockEvdevDevice(t)
+
+		capsLockEvent := &evdev.InputEvent{
+			Type:  evKeyType,
+			Code:  keyCapslockKey,
+			Value: keyStateOn,
+		}
+
+		mockDevice.EXPECT().ReadOne().Return(capsLockEvent, nil).Once()
+		mockDevice.EXPECT().ReadOne().Return(nil, errors.New("stop")).Maybe()
+		mockDevice.EXPECT().Close().Return(nil).Maybe()
+
+		m := &Manager{
+			device:      mockDevice,
+			state:       State{Available: true, CapsLock: false},
+			subscribers: make(map[string]chan State),
+			closeChan:   make(chan struct{}),
+		}
+
+		ch := m.Subscribe("test")
+
+		go m.monitorCapsLock()
+
+		state := <-ch
+		assert.True(t, state.CapsLock)
+
+		m.Close()
+	})
+}
+
+func TestIsClosedError(t *testing.T) {
+	tests := []struct {
+		name     string
+		err      error
+		expected bool
+	}{
+		{"nil error", nil, false},
+		{"closed error", errors.New("device closed"), true},
+		{"bad file descriptor", errors.New("bad file descriptor"), true},
+		{"other error", errors.New("some other error"), false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := isClosedError(tt.err)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}
+
+func TestNotifySubscribers(t *testing.T) {
+	mockDevice := mocks.NewMockEvdevDevice(t)
+	mockDevice.EXPECT().ReadOne().Return(nil, errors.New("test")).Maybe()
+	mockDevice.EXPECT().Close().Return(nil).Maybe()
+
+	m := &Manager{
+		device:      mockDevice,
+		state:       State{Available: true, CapsLock: false},
+		subscribers: make(map[string]chan State),
+		closeChan:   make(chan struct{}),
+	}
+
+	ch1 := m.Subscribe("client1")
+	ch2 := m.Subscribe("client2")
+
+	newState := State{Available: true, CapsLock: true}
+	go m.notifySubscribers(newState)
+
+	state1 := <-ch1
+	state2 := <-ch2
+
+	assert.Equal(t, newState, state1)
+	assert.Equal(t, newState, state2)
+
+	m.Close()
+}
+
+func TestReadInitialCapsLockState(t *testing.T) {
+	t.Run("caps lock is on", func(t *testing.T) {
+		mockDevice := mocks.NewMockEvdevDevice(t)
+		ledState := evdev.StateMap{
+			ledCapslockKey: true,
+		}
+		mockDevice.EXPECT().State(evdev.EvType(evLedType)).Return(ledState, nil).Once()
+
+		result := readInitialCapsLockState(mockDevice)
+		assert.True(t, result)
+	})
+
+	t.Run("caps lock is off", func(t *testing.T) {
+		mockDevice := mocks.NewMockEvdevDevice(t)
+		ledState := evdev.StateMap{
+			ledCapslockKey: false,
+		}
+		mockDevice.EXPECT().State(evdev.EvType(evLedType)).Return(ledState, nil).Once()
+
+		result := readInitialCapsLockState(mockDevice)
+		assert.False(t, result)
+	})
+
+	t.Run("error reading LED state", func(t *testing.T) {
+		mockDevice := mocks.NewMockEvdevDevice(t)
+		mockDevice.EXPECT().State(evdev.EvType(evLedType)).Return(nil, errors.New("read error")).Once()
+
+		result := readInitialCapsLockState(mockDevice)
+		assert.False(t, result)
+	})
+}
+
+func TestHasInputGroupAccess(t *testing.T) {
+	result := hasInputGroupAccess()
+	t.Logf("hasInputGroupAccess: %v", result)
+}

core/internal/server/evdev/models.go

@@ -0,0 +1,6 @@
+package evdev
+
+type State struct {
+	Available bool `json:"available"`
+	CapsLock  bool `json:"capsLock"`
+}