init

config/parser.go

@@ -0,0 +1,83 @@
+package config
+
+import (
+	"encoding/json"
+	"fmt"
+	"path/filepath"
+	"strings"
+
+	"gopkg.in/yaml.v3"
+)
+
+// Format represents a config file format.
+type Format int
+
+const (
+	FormatJSON Format = iota
+	FormatYAML
+)
+
+// DetectFormat returns the format based on file extension.
+func DetectFormat(path string) (Format, error) {
+	ext := strings.ToLower(filepath.Ext(path))
+	switch ext {
+	case ".json":
+		return FormatJSON, nil
+	case ".yaml", ".yml":
+		return FormatYAML, nil
+	default:
+		return 0, fmt.Errorf("unsupported format: %s", ext)
+	}
+}
+
+// Parse deserializes raw bytes into a map based on the given format.
+func Parse(data []byte, format Format) (map[string]any, error) {
+	var result map[string]any
+	switch format {
+	case FormatJSON:
+		if err := json.Unmarshal(data, &result); err != nil {
+			return nil, fmt.Errorf("invalid JSON: %w", err)
+		}
+	case FormatYAML:
+		if err := yaml.Unmarshal(data, &result); err != nil {
+			return nil, fmt.Errorf("invalid YAML: %w", err)
+		}
+	default:
+		return nil, fmt.Errorf("unknown format")
+	}
+	if result == nil {
+		result = make(map[string]any)
+	}
+	return result, nil
+}
+
+// Serialize converts a map back to bytes in the given format.
+func Serialize(data map[string]any, format Format) ([]byte, error) {
+	switch format {
+	case FormatJSON:
+		return json.MarshalIndent(data, "", "  ")
+	case FormatYAML:
+		return yaml.Marshal(data)
+	default:
+		return nil, fmt.Errorf("unknown format")
+	}
+}
+
+// DeepMerge merges src into dst recursively. Values in src override those in dst.
+// Nested maps are merged; all other types are replaced.
+func DeepMerge(dst, src map[string]any) map[string]any {
+	out := make(map[string]any, len(dst))
+	for k, v := range dst {
+		out[k] = v
+	}
+	for k, v := range src {
+		if srcMap, ok := v.(map[string]any); ok {
+			if dstMap, ok := out[k].(map[string]any); ok {
+				out[k] = DeepMerge(dstMap, srcMap)
+				continue
+			}
+		}
+		out[k] = v
+	}
+	return out
+}