From 5bce7e793f835f5c14dcbe63d75ee992f7d81f04 Mon Sep 17 00:00:00 2001
From: Dmitry <yashulyak@gmail.com>
Date: Tue, 5 Mar 2019 11:03:06 +0200
Subject: [PATCH] Redirect log output to mobile system loggers

---
 logutils/override.go   | 29 +++++++++++++++++++----------
 logutils/stdhandler.go | 17 +++++++++++++++++
 params/config.go       |  3 +++
 3 files changed, 39 insertions(+), 10 deletions(-)
 create mode 100644 logutils/stdhandler.go

diff --git a/logutils/override.go b/logutils/override.go
index 70881937e..dd5283066 100644
--- a/logutils/override.go
+++ b/logutils/override.go
@@ -8,8 +8,19 @@ import (
 	"github.com/status-im/status-go/params"
 )
 
+// OverrideWithStdLogger overwrites ethereum's root logger with a logger from golang std lib.
+func OverrideWithStdLogger(config *params.NodeConfig) error {
+	return enableRootLog(config.LogLevel, NewStdHandler(log.LogfmtFormat()))
+}
+
 // OverrideRootLogWithConfig derives all configuration from params.NodeConfig and configures logger using it.
 func OverrideRootLogWithConfig(config *params.NodeConfig, colors bool) error {
+	if !config.LogEnabled {
+		return nil
+	}
+	if config.LogMobileSystem {
+		return OverrideWithStdLogger(config)
+	}
 	return OverrideRootLog(config.LogEnabled, config.LogLevel, FileOptions{
 		Filename:   config.LogFile,
 		MaxSize:    config.LogMaxSize,
@@ -26,18 +37,8 @@ func OverrideRootLog(enabled bool, levelStr string, fileOpts FileOptions, termin
 		disableRootLog()
 		return nil
 	}
-
-	return enableRootLog(levelStr, fileOpts, terminal)
-}
-
-func disableRootLog() {
-	log.Root().SetHandler(log.DiscardHandler())
-}
-
-func enableRootLog(levelStr string, fileOpts FileOptions, terminal bool) error {
 	var (
 		handler log.Handler
-		err     error
 	)
 	if fileOpts.Filename != "" {
 		handler = FileHandlerWithRotation(fileOpts, log.LogfmtFormat())
@@ -45,6 +46,14 @@ func enableRootLog(levelStr string, fileOpts FileOptions, terminal bool) error {
 		handler = log.StreamHandler(os.Stderr, log.TerminalFormat(terminal))
 	}
 
+	return enableRootLog(levelStr, handler)
+}
+
+func disableRootLog() {
+	log.Root().SetHandler(log.DiscardHandler())
+}
+
+func enableRootLog(levelStr string, handler log.Handler) error {
 	if levelStr == "" {
 		levelStr = "INFO"
 	}
diff --git a/logutils/stdhandler.go b/logutils/stdhandler.go
new file mode 100644
index 000000000..5f2c81eba
--- /dev/null
+++ b/logutils/stdhandler.go
@@ -0,0 +1,17 @@
+package logutils
+
+import (
+	stdlog "log"
+
+	"github.com/ethereum/go-ethereum/log"
+)
+
+// NewStdHandler returns handler that uses logger from golang std lib.
+func NewStdHandler(fmtr log.Format) log.Handler {
+	return log.FuncHandler(func(r *log.Record) error {
+		line := fmtr.Format(r)
+		// 8 is a number of frames that will be skipped when log is printed.
+		// this is needed to show the file (with line number) where call to a logger was made
+		return stdlog.Output(8, string(line))
+	})
+}
diff --git a/params/config.go b/params/config.go
index dc3bd127f..78269be3a 100644
--- a/params/config.go
+++ b/params/config.go
@@ -259,6 +259,9 @@ type NodeConfig struct {
 	// LogEnabled enables the logger
 	LogEnabled bool `json:"LogEnabled"`
 
+	// LogMobileSystem enables log redirection to android/ios system logger.
+	LogMobileSystem bool
+
 	// LogFile is filename where exposed logs get written to
 	LogFile string