refactoring: implement review feedback

pkg/thumbnails/imgsource/imgsource.go

@@ -1,33 +1,11 @@
 package imgsource
 
-import "image"
+import (
+	"context"
+	"image"
+)
 
 // Source defines the interface for image sources
 type Source interface {
-	Get(path string, ctx SourceContext) (image.Image, error)
-}
-
-// NewContext creates a new SourceContext instance
-func NewContext() SourceContext {
-	return SourceContext{
-		m: make(map[string]interface{}),
-	}
-}
-
-// SourceContext is used to pass source specific parameters
-type SourceContext struct {
-	m map[string]interface{}
-}
-
-// GetString tries to cast the value to a string
-func (s SourceContext) GetString(key string) string {
-	if s, ok := s.m[key].(string); ok {
-		return s
-	}
-	return ""
-}
-
-// Set sets a value
-func (s SourceContext) Set(key string, val interface{}) {
-	s.m[key] = val
+	Get(ctx context.Context, path string) (image.Image, error)
 }

pkg/thumbnails/imgsource/webdav.go

@@ -1,6 +1,7 @@
 package imgsource
 
 import (
+	"context"
 	"fmt"
 	"image"
 	"net/http"
@@ -28,7 +29,7 @@ const (
 )
 
 // Get downloads the file from a webdav service
-func (s WebDav) Get(file string, ctx SourceContext) (image.Image, error) {
+func (s WebDav) Get(ctx context.Context, file string) (image.Image, error) {
 	u, _ := url.Parse(s.baseURL)
 	u.Path = path.Join(u.Path, file)
 	req, err := http.NewRequest(http.MethodGet, u.String(), nil)
@@ -36,7 +37,10 @@ func (s WebDav) Get(file string, ctx SourceContext) (image.Image, error) {
 		return nil, fmt.Errorf("could not get the image \"%s\" error: %s", file, err.Error())
 	}
 
-	auth := ctx.GetString(WebDavAuth)
+	auth, ok := authorization(ctx)
+	if !ok {
+		return nil, fmt.Errorf("could not get image \"%s\" error: authorization is missing", file)
+	}
 	req.Header.Add("Authorization", auth)
 
 	client := &http.Client{}
@@ -55,3 +59,8 @@ func (s WebDav) Get(file string, ctx SourceContext) (image.Image, error) {
 	}
 	return img, nil
 }
+
+func authorization(ctx context.Context) (string, bool) {
+	auth, ok := ctx.Value(WebDavAuth).(string)
+	return auth, ok
+}