Refactored coverart logic to engine layer

engine/cover.go

@@ -0,0 +1,59 @@
+package engine
+
+import (
+	"io"
+	"io/ioutil"
+	"os"
+
+	"github.com/deluan/gosonic/domain"
+	"github.com/dhowden/tag"
+)
+
+type Cover interface {
+	GetCover(id string, size int, out io.Writer) error
+}
+
+type cover struct {
+	mfileRepo domain.MediaFileRepository
+}
+
+func NewCover(mr domain.MediaFileRepository) Cover {
+	return cover{mr}
+}
+
+func (c cover) GetCover(id string, size int, out io.Writer) error {
+	mf, err := c.mfileRepo.Get(id)
+	if err != nil {
+		return err
+	}
+
+	var img []byte
+
+	if mf != nil && mf.HasCoverArt {
+		img, err = readFromTag(mf.Path)
+	} else {
+		img, err = ioutil.ReadFile("static/default_cover.jpg")
+	}
+
+	if err != nil {
+		return DataNotFound
+	}
+
+	_, err = out.Write(img)
+	return err
+}
+
+func readFromTag(path string) ([]byte, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	m, err := tag.ReadFrom(f)
+	if err != nil {
+		return nil, err
+	}
+
+	return m.Picture().Data, nil
+}