chore: initial commit

internal/logger/logger.go

@@ -0,0 +1,89 @@
+package logger
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"strings"
+)
+
+type Level int
+
+const (
+	LevelDebug Level = iota
+	LevelInfo
+	LevelWarn
+	LevelError
+)
+
+type Logger struct {
+	base      *log.Logger
+	level     Level
+	component string
+}
+
+func New(level string) (*Logger, error) {
+	parsed, err := ParseLevel(level)
+	if err != nil {
+		return nil, err
+	}
+	return &Logger{
+		base:      log.New(os.Stdout, "", log.LstdFlags|log.Lmicroseconds),
+		level:     parsed,
+		component: "app",
+	}, nil
+}
+
+func ParseLevel(raw string) (Level, error) {
+	switch strings.ToLower(strings.TrimSpace(raw)) {
+	case "debug":
+		return LevelDebug, nil
+	case "info", "":
+		return LevelInfo, nil
+	case "warn", "warning":
+		return LevelWarn, nil
+	case "error":
+		return LevelError, nil
+	default:
+		return LevelInfo, fmt.Errorf("invalid LOG_LEVEL=%q, expected debug|info|warn|error", raw)
+	}
+}
+
+func (l *Logger) WithComponent(component string) *Logger {
+	if component == "" {
+		component = "app"
+	}
+	return &Logger{
+		base:      l.base,
+		level:     l.level,
+		component: component,
+	}
+}
+
+func (l *Logger) Level() Level {
+	return l.level
+}
+
+func (l *Logger) Debugf(format string, args ...any) {
+	l.logf(LevelDebug, "DEBUG", format, args...)
+}
+
+func (l *Logger) Infof(format string, args ...any) {
+	l.logf(LevelInfo, "INFO", format, args...)
+}
+
+func (l *Logger) Warnf(format string, args ...any) {
+	l.logf(LevelWarn, "WARN", format, args...)
+}
+
+func (l *Logger) Errorf(format string, args ...any) {
+	l.logf(LevelError, "ERROR", format, args...)
+}
+
+func (l *Logger) logf(level Level, label, format string, args ...any) {
+	if level < l.level {
+		return
+	}
+	msg := fmt.Sprintf(format, args...)
+	l.base.Printf("[%s] [%s] %s", label, l.component, msg)
+}