feat(fonts): add fonts storage

pkg/svg/storage.go

@@ -1,28 +1,40 @@
 package svg
 
 import (
+	"errors"
 	"io"
 	"log"
 	"os"
 	"path/filepath"
+	"strings"
+
+	"golang.org/x/image/font/sfnt"
 )
 
 type SvgStorage interface {
 	Create(id string, svg io.Reader) (string, error)
 	Get(id string) (io.Reader, error)
+	AddFont(reader io.Reader, format string) error
+	GetFonts() ([]string, error)
+	GetFontsDir() (string, error)
 }
 
 type FileSvgStorage struct {
-	basepath string
+	basepath     string
+	fontssubpath string
 }
 
-func NewFileStorage(path string) *FileSvgStorage {
+func NewFileStorage(path string, fontssubpath string) *FileSvgStorage {
 	err := os.MkdirAll(path, 0755)
 	if err != nil {
 		panic(err)
 	}
+	err = os.MkdirAll(filepath.Join(path, fontssubpath), 0755)
+	if err != nil {
+		panic(err)
+	}
 	log.Println("Initialized file storage handler")
-	return &FileSvgStorage{path}
+	return &FileSvgStorage{path, fontssubpath}
 }
 
 func (f FileSvgStorage) Create(id string, svg io.Reader) (string, error) {
@@ -49,3 +61,62 @@ func (f FileSvgStorage) Get(id string) (io.Reader, error) {
 	}
 	return file, nil
 }
+
+func (f FileSvgStorage) AddFont(fontreader io.Reader, format string) error {
+	fontblob, err := io.ReadAll(fontreader)
+	if err != nil {
+		return err
+	}
+	if format != "ttf" && format != "otf" {
+		return errors.New("Format not supported")
+	}
+	file, err := os.CreateTemp(filepath.Join(f.basepath, f.fontssubpath), "*."+format)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	file.Write(fontblob)
+	return nil
+}
+
+func (f FileSvgStorage) GetFonts() ([]string, error) {
+	path := filepath.Join(f.basepath, f.fontssubpath)
+	entries, err := os.ReadDir(path)
+	if err != nil {
+		return nil, err
+	}
+	fonts := make([]string, len(entries))
+	for i, entry := range entries {
+		if entry.IsDir() {
+			continue
+		}
+		if strings.HasSuffix(entry.Name(), ".ttf") || strings.HasSuffix(entry.Name(), ".otf") {
+			fontblob, err := os.ReadFile(filepath.Join(path, entry.Name()))
+			if err != nil {
+				return nil, err
+			}
+			fontname, err := getFontName(fontblob)
+			if err != nil {
+				return nil, err
+			}
+			fonts[i] = fontname
+		}
+	}
+	return fonts, nil
+}
+
+func (f FileSvgStorage) GetFontsDir() (string, error) {
+	return filepath.Join(f.basepath, f.fontssubpath), nil
+}
+
+func getFontName(svgblob []byte) (string, error) {
+	font, err := sfnt.Parse(svgblob)
+	if err != nil {
+		return "", err
+	}
+	name, err := font.Name(nil, sfnt.NameIDFull)
+	if err != nil {
+		return "", err
+	}
+	return name, nil
+}