Add ability to clean up unused images

cmd/backend/images.go

@@ -1,10 +1,16 @@
 package backend
 
 import (
+	"bufio"
 	"fmt"
 	"image"
 	"io"
+	"io/fs"
+	"log"
 	"os"
+	"path/filepath"
+	"strings"
+	"time"
 
 	"github.com/chai2010/webp"
 	"github.com/disintegration/imaging"
@@ -30,7 +36,7 @@ func SaveImage(src io.Reader, maxHeight, maxWidth int, path string) (string, err
 	}
 
 	filename := fmt.Sprint(uuid.New(), ".webp")
-	file, err := os.Create(path + filename)
+	file, err := os.Create(filepath.Join(path, filename))
 	if err != nil {
 		return "", fmt.Errorf("error creating new image file: %v", err)
 	}
@@ -42,3 +48,59 @@ func SaveImage(src io.Reader, maxHeight, maxWidth int, path string) (string, err
 
 	return filename, nil
 }
+
+func CleanUpImages(c *Config) {
+	for {
+		if err := filepath.Walk(c.PicsDir, func(path string, info fs.FileInfo, err error) error {
+			if err != nil {
+				return err
+			}
+
+			if !info.IsDir() {
+				imageName := info.Name()
+				absImageName := path
+
+				if err = filepath.Walk(c.ArticleDir, func(path string, info fs.FileInfo, err error) error {
+					if err != nil {
+						return err
+					}
+
+					if !info.IsDir() {
+						mdFile, err := os.Open(path)
+						if err != nil {
+							return err
+						}
+						defer mdFile.Close()
+
+						scanner := bufio.NewScanner(mdFile)
+						imageWasFound := false
+
+						for scanner.Scan() {
+							if strings.Contains(scanner.Text(), imageName) {
+								imageWasFound = true
+							}
+						}
+
+						if !imageWasFound {
+							if err = os.Remove(absImageName); err != nil {
+								return err
+							}
+						}
+
+						return scanner.Err()
+					}
+
+					return nil
+				}); err != nil {
+					return err
+				}
+			}
+
+			return nil
+		}); err != nil {
+			log.Println(err)
+		}
+
+		time.Sleep(time.Hour)
+	}
+}