Update project structure and build process

recovery_tool/utils/logger.go

@@ -0,0 +1,78 @@
+package utils
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"time"
+)
+
+// DebugMode is true when the `DEBUG` environment variable is set to "true".
+var DebugMode bool = os.Getenv("DEBUG") == "true"
+var outputStream io.Writer = io.Discard
+
+// SetOutputStream set a writer to record all logs (except Tracef).
+func SetOutputStream(s io.Writer) {
+	outputStream = s
+}
+
+// Logger provides logging methods. Logs are written to the stream set by
+// SetOutputStream. If `DebugMode` is true, we also print to stdout/stderr.
+// This allows callers to log detailed information without displaying it to
+// users during normal execution.
+type Logger struct {
+	tag string
+}
+
+// NewLogger returns an initialized Logger instance.
+func NewLogger(tag string) *Logger {
+	return &Logger{tag}
+}
+
+// SetTag updates the tag of this Logger.
+func (l *Logger) SetTag(newTag string) {
+	l.tag = newTag
+}
+
+// Tracef works like fmt.Printf, but only prints when `DebugMode` is true. These logs
+// are *not* recorded to the output stream.
+func (l *Logger) Tracef(format string, v ...interface{}) {
+	if !DebugMode {
+		return
+	}
+
+	message := strings.TrimSpace(fmt.Sprintf(format, v...))
+
+	fmt.Printf("%s %s %s\n", time.Now().Format(time.RFC3339Nano), l.getPrefix(), message)
+}
+
+// Printf works like fmt.Printf, but only prints when `DebugMode` is true. These logs
+// are recorded to the output stream, so they should not include sensitive information.
+func (l *Logger) Printf(format string, v ...interface{}) {
+	message := strings.TrimSpace(fmt.Sprintf(format, v...))
+
+	log := fmt.Sprintf("%s %s %s\n", time.Now().Format(time.RFC3339Nano), l.getPrefix(), message)
+	_, _ = outputStream.Write([]byte(log))
+	if DebugMode {
+		print(log)
+	}
+}
+
+// Errorf works like fmt.Errorf, but prints the error to the console if `DebugMode` is true.
+// These logs are recorded to the output stream, so they should not include sensitive information.
+func (l *Logger) Errorf(format string, v ...interface{}) error {
+	err := fmt.Errorf(format, v...)
+
+	log := fmt.Sprintf("ERROR: %s %s %v\n", time.Now().Format(time.RFC3339Nano), l.getPrefix(), err)
+	_, _ = outputStream.Write([]byte(log))
+	if DebugMode {
+		print(log)
+	}
+
+	return err
+}
+
+func (l *Logger) getPrefix() string {
+	return fmt.Sprintf("[%s]", l.tag)
+}