feat: description file for custom theme; use gjson (#433)

* feat: description file for custom theme; use gjson

* fix gosec

* remove outdated stuff

pkg/utils/gjson.go

@@ -0,0 +1,36 @@
+package utils
+
+import (
+	"errors"
+
+	"github.com/tidwall/gjson"
+)
+
+var (
+	ErrGjsonNotFound  = errors.New("specified path does not exist")
+	ErrGjsonWrongType = errors.New("wrong type")
+)
+
+func GjsonGet(json []byte, path string) (gjson.Result, error) {
+	result := gjson.GetBytes(json, path)
+	if !result.Exists() {
+		return result, ErrGjsonNotFound
+	}
+
+	return result, nil
+}
+
+func GjsonParseStringMap(jsonObject string) (map[string]string, error) {
+	result := gjson.Parse(jsonObject)
+	if !result.IsObject() {
+		return nil, ErrGjsonWrongType
+	}
+
+	ret := make(map[string]string)
+	result.ForEach(func(key, value gjson.Result) bool {
+		ret[key.String()] = value.String()
+		return true
+	})
+
+	return ret, nil
+}

pkg/utils/hfs.go

@@ -0,0 +1,33 @@
+package utils
+
+import (
+	"embed"
+	"io/fs"
+	"os"
+)
+
+// HybridFS combines embed.FS and os.DirFS.
+type HybridFS struct {
+	embedFS, dir fs.FS
+}
+
+func NewHybridFS(embed embed.FS, subDir string, localDir string) (*HybridFS, error) {
+	subFS, err := fs.Sub(embed, subDir)
+	if err != nil {
+		return nil, err
+	}
+
+	return &HybridFS{
+		embedFS: subFS,
+		dir:     os.DirFS(localDir),
+	}, nil
+}
+
+func (hfs *HybridFS) Open(name string) (fs.File, error) {
+	// Ensure embed files are not replaced
+	if file, err := hfs.embedFS.Open(name); err == nil {
+		return file, nil
+	}
+
+	return hfs.dir.Open(name)
+}