✨ feat: rewrite in Go

src/logger.go

@@ -0,0 +1,85 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+	"time"
+)
+
+type logLevel int
+
+const (
+	levelDebug logLevel = 10
+	levelInfo  logLevel = 20
+	levelWarn  logLevel = 30
+	levelError logLevel = 40
+)
+
+var logThreshold = resolveThreshold()
+
+func resolveThreshold() logLevel {
+	switch strings.ToLower(strings.TrimSpace(os.Getenv("LOG_LEVEL"))) {
+	case "debug":
+		return levelDebug
+	case "warn":
+		return levelWarn
+	case "error":
+		return levelError
+	default:
+		return levelInfo
+	}
+}
+
+func sanitize(value any) string {
+	return sanitizeN(value, 200)
+}
+
+func sanitizeN(value any, maxLength int) string {
+	var str string
+	switch v := value.(type) {
+	case nil:
+		str = ""
+	case string:
+		str = v
+	default:
+		str = fmt.Sprint(v)
+	}
+	var b strings.Builder
+	for _, r := range str {
+		if r < 0x20 || (r >= 0x7f && r <= 0x9f) {
+			b.WriteRune('�')
+		} else {
+			b.WriteRune(r)
+		}
+	}
+	out := []rune(b.String())
+	if len(out) > maxLength {
+		return string(out[:maxLength]) + "…"
+	}
+	return string(out)
+}
+
+func emit(level logLevel, name string, stream *os.File, args []any) {
+	if level < logThreshold {
+		return
+	}
+	parts := make([]string, len(args))
+	for i, a := range args {
+		if s, ok := a.(string); ok {
+			parts[i] = s
+		} else if b, err := json.Marshal(a); err == nil {
+			parts[i] = string(b)
+		} else {
+			parts[i] = fmt.Sprint(a)
+		}
+	}
+	ts := time.Now().UTC().Format("2006-01-02T15:04:05.000Z")
+	fmt.Fprintf(stream, "[%s] %-5s %s\n", ts, strings.ToUpper(name), strings.Join(parts, " "))
+}
+
+func logDebug(args ...any) { emit(levelDebug, "debug", os.Stdout, args) }
+func logInfo(args ...any)  { emit(levelInfo, "info", os.Stdout, args) }
+func logWarn(args ...any)  { emit(levelWarn, "warn", os.Stderr, args) }
+func logError(args ...any) { emit(levelError, "error", os.Stderr, args) }