Add flag for debug logging

cmd/ledger-tui/ledger-tui.go

@@ -2,6 +2,8 @@ package main
 
 import (
 	"fmt"
+	"io"
+	"log"
 	"os"
 
 	tea "github.com/charmbracelet/bubbletea"
@@ -12,19 +14,38 @@ import (
 )
 
 var rootCmd = &cobra.Command{
-	Use:   "ledger-tui",
-	Short: "An interactive terminal UI for ledger",
+	Use:               "ledger-tui",
+	Short:             "An interactive terminal UI for ledger",
+	PersistentPreRun:  configureLogging,
+	PersistentPostRun: loggingCleanup,
 }
 
-func main() {
-	if len(os.Getenv("DEBUG")) > 0 {
-		f, err := tea.LogToFile("debug.log", "debug")
+var debugLogging bool
+var debugLoggingFile *os.File
+
+func configureLogging(_ *cobra.Command, _ []string) {
+	if debugLogging {
+		var err error
+		debugLoggingFile, err = tea.LogToFile("debug.log", "debug")
 		if err != nil {
 			fmt.Println("fatal:", err)
 			os.Exit(1)
 		}
-		defer f.Close()
+	} else {
+		log.SetOutput(io.Discard)
 	}
+}
+
+func loggingCleanup(_ *cobra.Command, _ []string) {
+	if debugLoggingFile != nil {
+		debugLoggingFile.Close()
+		debugLoggingFile = nil
+	}
+}
+
+func main() {
+	rootCmd.PersistentFlags().BoolVar(&debugLogging, "debug", false,
+		"Output debug logs to debug.log file")
 
 	rootCmd.AddCommand(add.AddCmd)
 	rootCmd.AddCommand(license.LicenseCmd)