blog: also rewrite image links

2024-07-30/01-first-impressions-fpgbc.md

@@ -31,11 +31,9 @@ Cable](https://en.wikipedia.org/wiki/Game_Link_Cable) (I don't have another
 Game Boy to test). Sadly it is missing the infrared sensor, but the usage of
 that was pretty limited anyway.
 
-<!-- PXL_20240729_175245569 -->
-[![FPGBC running Tetris.](https://capivaras.dev/images/1545d11f.jpeg)](https://capivaras.dev/images/1545d11f.jpeg)
+[![FPGBC running Tetris.](/2024-07-30/PXL_20240729_175245569.jpg)](/2024-07-30/PXL_20240729_175245569.jpg)
 
-<!-- PXL_20240729_175131157 -->
-[![Back of FPGBC. It includes even reproduction stickers of the original.](https://capivaras.dev/images/6746624f.jpeg)](https://capivaras.dev/images/6746624f.jpeg)
+[![Back of FPGBC. It includes even reproduction stickers of the original.](/2024-07-30/PXL_20240729_175131157.jpg)](/2024-07-30/PXL_20240729_175131157.jpg)
 
 So how well does it work? I can't say for sure. I don't have any original games
 with me, so I am relying in backups and a
@@ -72,8 +70,7 @@ came back to life.
 About the features of the device: if you press the volume button (yes, you can
 press it now), it opens the following menu:
 
-<!-- PXL_20240729_210604830 -->
-[![FPGBC menu.](https://capivaras.dev/images/4391c351.jpeg)](https://capivaras.dev/images/4391c351.jpeg)
+[![FPGBC menu.](/2024-07-30/PXL_20240729_210604830.jpg)](/2024-07-30/PXL_20240729_210604830.jpg)
 
 The first 2 features are the LCD backlight and volume. I didn't talk about
 those, but the LCD screen seems to be IPS, and the quality is really good, and
@@ -147,5 +144,4 @@ gift, and I will buy another one soon. Can't wait to play [Pokémon
 Gold](https://en.wikipedia.org/wiki/Pok%C3%A9mon_Gold_and_Silver) in (almost)
 original hardware again.
 
-<!-- PXL_20240729_123847458 -->
-[![The kit before assemble.](https://capivaras.dev/images/7f34caba.jpeg)](https://capivaras.dev/images/7f34caba.jpeg)
+[![The kit before assemble.](/2024-07-30/PXL_20240729_123847458.jpg)](/2024-07-30/PXL_20240729_123847458.jpg)

blog.go

@@ -32,7 +32,9 @@ import (
 	"github.com/yuin/goldmark"
 )
 
-const blogBaseUrl = "https://github.com/thiagokokada/blog/blob/main"
+const blogBaseUrl= "https://github.com/thiagokokada/blog"
+const blogMainUrl = blogBaseUrl + "/blob/main"
+const blogRawUrl = blogBaseUrl + "/raw/main"
 const readmeTemplate = `# Blog
 
 Mirror of my blog in https://kokada.capivaras.dev/.
@@ -147,12 +149,12 @@ func genRss(posts posts) string {
 		Title:       "kokada's blog",
 		Description: "# dd if=/dev/urandom of=/dev/brain0",
 	}
-	md := goldmark.New(goldmark.WithExtensions(NewLinkRewriter(blogBaseUrl, nil)))
+	md := goldmark.New(goldmark.WithExtensions(NewLinkRewriter(blogMainUrl, nil)))
 
 	var items []*feeds.Item
 	for el := posts.Back(); el != nil; el = el.Prev() {
 		post := el.Value
-		link := must1(url.JoinPath(blogBaseUrl, el.Key))
+		link := must1(url.JoinPath(blogMainUrl, el.Key))
 		var buf bytes.Buffer
 		must(md.Convert(post.contents, &buf))
 		items = append(items, &feeds.Item{

link_rewriter.go

@@ -51,6 +51,9 @@ func (e *linkRewriter) Transform(node *ast.Document, reader text.Reader, pc pars
 		if link, ok := n.(*ast.Link); ok {
 			e.rewriteLink(link)
 		}
+		if image, ok := n.(*ast.Image); ok {
+			e.rewriteImage(image)
+		}
 		return ast.WalkContinue, nil
 	})
 }
@@ -81,3 +84,17 @@ func (e *linkRewriter) rewriteLink(l *ast.Link) {
 		}
 	}
 }
+
+// rewriteImage modifies the image URL
+func (e *linkRewriter) rewriteImage(i *ast.Image) {
+	image := string(i.Destination)
+
+	if strings.HasPrefix(image, ".") {
+		log.Printf("[WARN]: relative image link reference found: %s\n", image)
+	}
+
+	if strings.HasPrefix(image, "/") {
+		dest := must1(url.JoinPath(blogRawUrl, image))
+		i.Destination = []byte(dest)
+	}
+}