Make logger extensible

logger/writer.go

@@ -0,0 +1,54 @@
+package logger
+
+import (
+	"fmt"
+	"os"
+	"time"
+)
+
+// LogWriter is an interface for writing log messages
+// Implement this interface to create custom log backends (OS log, syslog, etc.)
+type LogWriter interface {
+	// Write writes a log message with the given level, timestamp, and formatted message
+	Write(level LogLevel, timestamp time.Time, message string)
+}
+
+// StandardWriter is the default log writer that writes to an io.Writer
+type StandardWriter struct {
+	output   *os.File
+	timezone *time.Location
+}
+
+// NewStandardWriter creates a new standard writer with the default configuration
+func NewStandardWriter() *StandardWriter {
+	// Get timezone from environment variable or use local timezone
+	timezone := os.Getenv("LOGGER_TIMEZONE")
+	var location *time.Location
+	var err error
+
+	if timezone != "" {
+		location, err = time.LoadLocation(timezone)
+		if err != nil {
+			// If invalid timezone, fall back to local
+			location = time.Local
+		}
+	} else {
+		location = time.Local
+	}
+
+	return &StandardWriter{
+		output:   os.Stdout,
+		timezone: location,
+	}
+}
+
+// SetOutput sets the output destination
+func (w *StandardWriter) SetOutput(output *os.File) {
+	w.output = output
+}
+
+// Write implements the LogWriter interface
+func (w *StandardWriter) Write(level LogLevel, timestamp time.Time, message string) {
+	formattedTime := timestamp.In(w.timezone).Format("2006/01/02 15:04:05")
+	fmt.Fprintf(w.output, "%s: %s %s\n", level.String(), formattedTime, message)
+}