From 24a2f472ec8593b4734e91ac15ee5503d16ae63a Mon Sep 17 00:00:00 2001
From: Rogier Lommers <rogier@lommers.org>
Date: Tue, 30 Jan 2018 05:34:00 +0100
Subject: [PATCH] Add flag to enable debug logging

---
 cli/cli.go       |  8 ++++++
 logger/logger.go | 63 ++++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 64 insertions(+), 7 deletions(-)

diff --git a/cli/cli.go b/cli/cli.go
index 3385ab82..80231bfd 100644
--- a/cli/cli.go
+++ b/cli/cli.go
@@ -8,6 +8,8 @@ import (
 	"flag"
 	"fmt"
 
+	"github.com/miniflux/miniflux/logger"
+
 	"github.com/miniflux/miniflux/config"
 	"github.com/miniflux/miniflux/daemon"
 	"github.com/miniflux/miniflux/storage"
@@ -22,6 +24,7 @@ func Parse() {
 	flagFlushSessions := flag.Bool("flush-sessions", false, "Flush all sessions (disconnect users)")
 	flagCreateAdmin := flag.Bool("create-admin", false, "Create admin user")
 	flagResetPassword := flag.Bool("reset-password", false, "Reset user password")
+	flagDebugMode := flag.Bool("debug", false, "Enable debug mode (more verbose output)")
 	flag.Parse()
 
 	cfg := config.NewConfig()
@@ -60,5 +63,10 @@ func Parse() {
 		return
 	}
 
+	if *flagDebugMode {
+		logger.EnableDebug()
+	}
+
+	// start daemon
 	daemon.Run(cfg, store)
 }
diff --git a/logger/logger.go b/logger/logger.go
index e6085034..01d041c9 100644
--- a/logger/logger.go
+++ b/logger/logger.go
@@ -10,28 +10,77 @@ import (
 	"time"
 )
 
+var requestedLevel = InfoLevel
+
+// LogLevel type
+type LogLevel uint32
+
+const (
+	// FatalLevel should be used in fatal situations, the app will exit
+	FatalLevel LogLevel = iota
+
+	// ErrorLevel should be used when someone should really look at the error
+	ErrorLevel
+
+	// InfoLevel should be used during normal operations
+	InfoLevel
+
+	// DebugLevel should be used only during development
+	DebugLevel
+)
+
+// Convert the Level to a string.
+func (level LogLevel) String() string {
+	switch level {
+	case DebugLevel:
+		return "DEBUG"
+	case InfoLevel:
+		return "INFO"
+	case ErrorLevel:
+		return "ERROR"
+	case FatalLevel:
+		return "FATAL"
+	}
+
+	return "UNKNOWN"
+}
+
+// EnableDebug increases logging, more verbose (debug)
+func EnableDebug() {
+	requestedLevel = DebugLevel
+	formatMessage(InfoLevel, "Debug mode enabled")
+}
+
 // Debug sends a debug log message.
 func Debug(format string, v ...interface{}) {
-	formatMessage("DEBUG", format, v...)
+	if requestedLevel >= DebugLevel {
+		formatMessage(DebugLevel, format, v...)
+	}
 }
 
 // Info sends an info log message.
 func Info(format string, v ...interface{}) {
-	formatMessage("INFO", format, v...)
+	if requestedLevel >= InfoLevel {
+		formatMessage(InfoLevel, format, v...)
+	}
 }
 
 // Error sends an error log message.
 func Error(format string, v ...interface{}) {
-	formatMessage("ERROR", format, v...)
+	if requestedLevel >= ErrorLevel {
+		formatMessage(ErrorLevel, format, v...)
+	}
 }
 
 // Fatal sends a fatal log message and stop the execution of the program.
 func Fatal(format string, v ...interface{}) {
-	formatMessage("FATAL", format, v...)
-	os.Exit(1)
+	if requestedLevel >= FatalLevel {
+		formatMessage(FatalLevel, format, v...)
+		os.Exit(1)
+	}
 }
 
-func formatMessage(level, format string, v ...interface{}) {
-	prefix := fmt.Sprintf("[%s] [%s] ", time.Now().Format("2006-01-02T15:04:05"), level)
+func formatMessage(level LogLevel, format string, v ...interface{}) {
+	prefix := fmt.Sprintf("[%s] [%s] ", time.Now().Format("2006-01-02T15:04:05"), level.String())
 	fmt.Fprintf(os.Stderr, prefix+format+"\n", v...)
 }