WIP: Logging

log/types.go

@@ -0,0 +1,111 @@
+package log
+
+import (
+	"encoding/json"
+	"strings"
+)
+
+// Level is a well-known log level, as defined below
+type Level int
+
+// Well known log levels
+const (
+	TraceLevel Level = iota
+	DebugLevel
+	InfoLevel
+	WarnLevel
+	ErrorLevel
+	FatalLevel
+)
+
+func (l Level) String() string {
+	switch l {
+	case TraceLevel:
+		return "TRACE"
+	case DebugLevel:
+		return "DEBUG"
+	case InfoLevel:
+		return "INFO"
+	case WarnLevel:
+		return "WARN"
+	case ErrorLevel:
+		return "ERROR"
+	case FatalLevel:
+		return "FATAL"
+	}
+	return "unknown"
+}
+
+func (l Level) MarshalJSON() ([]byte, error) {
+	return json.Marshal(l.String())
+}
+
+// ToLevel converts a string to a Level. It returns InfoLevel if the string
+// does not match any known log levels.
+func ToLevel(s string) Level {
+	switch strings.ToUpper(s) {
+	case "TRACE":
+		return TraceLevel
+	case "DEBUG":
+		return DebugLevel
+	case "INFO":
+		return InfoLevel
+	case "WARN", "WARNING":
+		return WarnLevel
+	case "ERROR":
+		return ErrorLevel
+	default:
+		return InfoLevel
+	}
+}
+
+// Format is a well-known log format
+type Format int
+
+// Log formats
+const (
+	TextFormat Format = iota
+	JSONFormat
+)
+
+func (f Format) String() string {
+	switch f {
+	case TextFormat:
+		return "text"
+	case JSONFormat:
+		return "json"
+	}
+	return "unknown"
+}
+
+// ToFormat converts a string to a Format. It returns TextFormat if the string
+// does not match any known log formats.
+func ToFormat(s string) Format {
+	switch strings.ToLower(s) {
+	case "text":
+		return TextFormat
+	case "json":
+		return JSONFormat
+	default:
+		return TextFormat
+	}
+}
+
+type Ctx interface {
+	Context() map[string]any
+}
+
+type fieldsCtx map[string]any
+
+func (f fieldsCtx) Context() map[string]any {
+	return f
+}
+
+func NewCtx(fields map[string]any) Ctx {
+	return fieldsCtx(fields)
+}
+
+type levelOverride struct {
+	value any
+	level Level
+}