2 files changed, 106 insertions, 8 deletions

diff --git a/logger.go b/logger.go
new file mode 100644
index 0000000..1fcbfeb
--- /dev/null
+++ b/logger.go
@@ -0,0 +1,92 @@
+package main
+
+import (
+	"fmt"
+	"log"
+)
+
+type LevelEnum uint8
+
+const (
+	None LevelEnum = iota
+	Error
+	Warn
+	Info
+	Debug
+)
+
+type levelInfo struct {
+	abbrev string
+	color  string
+}
+
+var (
+	levelInfos = map[LevelEnum]levelInfo{
+		Error: {"ERR", ansiRed},
+		Warn:  {"WARN", ansiYellow},
+		Info:  {"INFO", ansiCyan},
+		Debug: {"DEBUG", ansiGreen},
+	}
+)
+
+func (s LevelEnum) Info() levelInfo {
+	info, ok := levelInfos[s]
+	if !ok {
+		return levelInfo{"UNK", ansiWhite}
+	}
+	return info
+}
+
+func (s LevelEnum) Format() string {
+	info := s.Info()
+	return colorize("["+info.abbrev+"]", info.color)
+}
+
+type Logger struct {
+	Level LevelEnum
+
+	ns string
+}
+
+func NewLogger(level LevelEnum) *Logger {
+	return &Logger{
+		Level: level,
+	}
+}
+
+func (l *Logger) WithNS(ns string) *Logger {
+	return &Logger{
+		Level: l.Level,
+		ns:    formatNS(ns),
+	}
+}
+
+func (l *Logger) Logf(level LevelEnum, format string, args ...any) {
+	if level > l.Level {
+		return
+	}
+	log.Printf("%s%s %s", l.ns, level.Format(), fmt.Sprintf(format, args...))
+}
+
+func (l *Logger) Errorf(format string, args ...any) { l.Logf(Error, format, args...) }
+func (l *Logger) Warnf(format string, args ...any)  { l.Logf(Warn, format, args...) }
+func (l *Logger) Infof(format string, args ...any)  { l.Logf(Info, format, args...) }
+func (l *Logger) Debugf(format string, args ...any) { l.Logf(Debug, format, args...) }
+
+func formatNS(ns string) string {
+	return colorize("["+ns+"]", ansiPurple)
+}
+
+var ansiReset = "\033[0m"
+var ansiRed = "\033[31m"
+var ansiGreen = "\033[32m"
+var ansiYellow = "\033[33m"
+var ansiBlue = "\033[34m"
+var ansiPurple = "\033[35m"
+var ansiCyan = "\033[36m"
+var ansiGray = "\033[37m"
+var ansiWhite = "\033[97m"
+
+func colorize(s string, color string) string {
+	return color + s + ansiReset
+}
diff --git a/main.go b/main.go
index a72bb5b..7340795 100644
--- a/main.go
+++ b/main.go
@@ -18,20 +18,29 @@ func main() {
 	flag.BoolVarP(&concatenate, "concatenate", "c", false, "concatenate tar archives")
 	flag.Parse()
 
-	if err := process(prefix, concatenate, verbose); err != nil {
+	logger := NewLogger(LevelEnum(verbose) + 2)
+	params := processParams{
+		prefix:      prefix,
+		concatenate: concatenate,
+	}
+	if err := process(params, logger); err != nil {
 		log.Fatal(err)
 	}
+}
 
+type processParams struct {
+	prefix      string
+	concatenate bool
 }
 
-func process(prefix string, concatenate bool, verbose int) error {
+func process(params processParams, logger *Logger) error {
 	tr := tar.NewReader(os.Stdin)
 	tw := tar.NewWriter(os.Stdout)
 	defer tw.Close()
 	for {
 		hdr, err := tr.Next()
 		if err == io.EOF {
-			if !concatenate {
+			if params.concatenate {
 				tr = tar.NewReader(os.Stdin)
 				hdr, err = tr.Next()
 				if err == io.EOF {
@@ -46,11 +55,8 @@ func process(prefix string, concatenate bool, verbose int) error {
 			return err
 		}
 
-		if verbose >= 1 {
-			log.Printf("file: %s", hdr.Name)
-		}
-
-		hdr.Name = prefix + hdr.Name
+		logger.Infof(`TarEntry.name = %s`, hdr.Name)
+		hdr.Name = params.prefix + hdr.Name
 
 		if err = tw.WriteHeader(hdr); err != nil {
 			return err