add signals

keycard_context.go

@@ -9,6 +9,7 @@ import (
 	"github.com/status-im/keycard-go/globalplatform"
 	"github.com/status-im/keycard-go/io"
 	"github.com/status-im/keycard-go/types"
+	"github.com/status-im/nim-keycard-go/go/keycard/signal"
 )
 
 type keycardContext struct {
@@ -91,6 +92,7 @@ func (kc *keycardContext) run() {
 		return
 	}
 
+	signal.SendKeycardConnected("")
 	l("card found at index %d", index)
 	reader := kc.readers[index]
 

main.go

@@ -6,6 +6,9 @@ import (
 	"encoding/json"
 	"fmt"
 	"time"
+	"unsafe"
+
+	"github.com/status-im/nim-keycard-go/go/keycard/signal"
 )
 
 var kctx *keycardContext
@@ -15,6 +18,10 @@ func main() {
 }
 
 func example() {
+	signal.SetDefaultNodeNotificationHandler(func(jsonEvent string) {
+		fmt.Printf("SIGNAL %+v\n", jsonEvent)
+	})
+
 	fmt.Printf("RUNNING EXAMPLE \n")
 	res := Start()
 	fmt.Printf("*** start %+v\n", C.GoString(res))
@@ -399,3 +406,8 @@ func ChangePairingPassword(jsonParams *C.char) *C.char {
 
 	return retValue("ok", true)
 }
+
+//export SetSignalEventCallback
+func SetSignalEventCallback(cb unsafe.Pointer) {
+	signal.SetSignalEventCallback(cb)
+}

signal/events_keycard.go

@@ -0,0 +1,10 @@
+package signal
+
+const (
+	// EventSignRequestAdded is triggered when send transaction request is queued
+	EventKeycardConnected = "keycard.connected"
+)
+
+func SendKeycardConnected(event interface{}) {
+	send(EventKeycardConnected, event)
+}

signal/signals.c

@@ -0,0 +1,25 @@
+// ======================================================================================
+// cgo compilation (for desktop platforms and local tests)
+// ======================================================================================
+
+#include <stdio.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "_cgo_export.h"
+
+typedef void (*callback)(const char *jsonEvent);
+callback gCallback = 0;
+
+bool StatusServiceSignalEvent(const char *jsonEvent) {
+	if (gCallback) {
+		gCallback(jsonEvent);
+	} else {
+		NotifyNode((char *)jsonEvent); // re-send notification back to status node
+	}
+
+	return true;
+}
+
+void SetEventCallback(void *cb) {
+	gCallback = (callback)cb;
+}

signal/signals.go

@@ -0,0 +1,116 @@
+package signal
+
+/*
+#include <stddef.h>
+#include <stdbool.h>
+#include <stdlib.h>
+extern bool StatusServiceSignalEvent(const char *jsonEvent);
+extern void SetEventCallback(void *cb);
+*/
+import "C"
+import (
+	"encoding/json"
+	"unsafe"
+
+	"sync"
+
+	"github.com/ethereum/go-ethereum/log"
+)
+
+// MobileSignalHandler is a simple callback function that gets called when any signal is received
+type MobileSignalHandler func([]byte)
+
+// storing the current signal handler here
+var mobileSignalHandler MobileSignalHandler
+
+// All general log messages in this package should be routed through this logger.
+var logger = log.New("package", "status-go/signal")
+
+// Envelope is a general signal sent upward from node to RN app
+type Envelope struct {
+	Type  string      `json:"type"`
+	Event interface{} `json:"event"`
+}
+
+// NewEnvelope creates new envlope of given type and event payload.
+func NewEnvelope(typ string, event interface{}) *Envelope {
+	return &Envelope{
+		Type:  typ,
+		Event: event,
+	}
+}
+
+// send sends application signal (in JSON) upwards to application (via default notification handler)
+func send(typ string, event interface{}) {
+	signal := NewEnvelope(typ, event)
+	data, err := json.Marshal(&signal)
+	if err != nil {
+		logger.Error("Marshalling signal envelope", "error", err)
+		return
+	}
+	// If a Go implementation of signal handler is set, let's use it.
+	if mobileSignalHandler != nil {
+		mobileSignalHandler(data)
+	} else {
+		// ...and fallback to C implementation otherwise.
+		str := C.CString(string(data))
+		C.StatusServiceSignalEvent(str)
+		C.free(unsafe.Pointer(str))
+	}
+}
+
+// NodeNotificationHandler defines a handler able to process incoming node events.
+// Events are encoded as JSON strings.
+type NodeNotificationHandler func(jsonEvent string)
+
+var notificationHandler NodeNotificationHandler = TriggerDefaultNodeNotificationHandler
+
+// notificationHandlerMutex guards notificationHandler for concurrent calls
+var notificationHandlerMutex sync.RWMutex
+
+// SetDefaultNodeNotificationHandler sets notification handler to invoke on Send
+func SetDefaultNodeNotificationHandler(fn NodeNotificationHandler) {
+	notificationHandlerMutex.Lock()
+	notificationHandler = fn
+	notificationHandlerMutex.Unlock()
+}
+
+// ResetDefaultNodeNotificationHandler sets notification handler to default one
+func ResetDefaultNodeNotificationHandler() {
+	notificationHandlerMutex.Lock()
+	notificationHandler = TriggerDefaultNodeNotificationHandler
+	notificationHandlerMutex.Unlock()
+}
+
+// TriggerDefaultNodeNotificationHandler triggers default notification handler (helpful in tests)
+func TriggerDefaultNodeNotificationHandler(jsonEvent string) {
+	logger.Trace("Notification received", "event", jsonEvent)
+}
+
+//export NotifyNode
+//nolint: golint
+func NotifyNode(jsonEvent *C.char) {
+	notificationHandlerMutex.RLock()
+	defer notificationHandlerMutex.RUnlock()
+	notificationHandler(C.GoString(jsonEvent))
+}
+
+//export TriggerTestSignal
+//nolint: golint
+func TriggerTestSignal() {
+	str := C.CString(`{"answer": 42}`)
+	C.StatusServiceSignalEvent(str)
+	C.free(unsafe.Pointer(str))
+}
+
+// SetMobileSignalHandler sets new handler for geth events
+// this function uses pure go implementation
+func SetMobileSignalHandler(handler MobileSignalHandler) {
+	mobileSignalHandler = handler
+}
+
+// SetSignalEventCallback set callback
+// this function uses C implementation (see `signals.c` file)
+func SetSignalEventCallback(cb unsafe.Pointer) {
+	C.SetEventCallback(cb)
+}