initial import

app/logger/logger.go

@@ -0,0 +1,58 @@
+package logger
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"sync"
+	"time"
+)
+
+var (
+	mtx    sync.Mutex
+	output io.Writer = os.Stderr
+)
+
+type Logger struct {
+	subject string
+}
+
+func NewLogger(subj string) *Logger {
+	return &Logger{
+		subject: subj,
+	}
+}
+
+func SetWriter(newOut io.Writer) {
+	mtx.Lock()
+	output = newOut
+	mtx.Unlock()
+}
+
+func (logg *Logger) Debugf(message string, args ...any) {
+	logg.printf("debug", message, args...)
+}
+
+func (logg *Logger) Infof(message string, args ...any) {
+	logg.printf("info", message, args...)
+}
+
+func (logg *Logger) Warningf(message string, args ...any) {
+	logg.printf("warning", message, args...)
+}
+
+func (logg *Logger) Errorf(message string, args ...any) {
+	logg.printf("error", message, args...)
+}
+
+func (logg *Logger) printf(level, message string, args ...any) {
+	timestamp := time.Now().Format(time.RFC3339)
+	buffer := bytes.NewBuffer([]byte{})
+	fmt.Fprintf(buffer, "%s %s.%s: ", timestamp, logg.subject, level)
+	fmt.Fprintf(buffer, message, args...)
+	fmt.Fprintf(buffer, "\n")
+	mtx.Lock()
+	fmt.Fprint(output, buffer.String())
+	mtx.Unlock()
+}