cmd/blog: copy static assets from appview during build

Signed-off-by: Anirudh Oppiliappan <[e-mail]>

.gitignore

···
 genjwks.out
 /nix/vm-data
 blog/build/
+build/
+.wrangler/

.tangled/workflows/deploy-blog.yml

···
       mkdir -p appview/pages/static
       touch appview/pages/static/x
 
-  - name: build blog cmd
-    command: |
-      go build -o blog.out ./cmd/blog
-
   - name: generate css
     command: |
       tailwindcss -i input.css -o appview/pages/static/tw.css
+
+  - name: build blog cmd
+    command: |
+      go build -o blog.out ./cmd/blog
 
   - name: build static site
     command: |

appview/pages/funcmap.go

···
 	}
 
 	secret := p.avatar.SharedSecret
+	if secret == "" {
+		return ""
+	}
 	h := hmac.New(sha256.New, []byte(secret))
 	h.Write([]byte(did))
 	signature := hex.EncodeToString(h.Sum(nil))

blog/templates/index.html

···
         <h2 class="font-bold text-gray-900 dark:text-white text-base leading-snug mb-1 group-hover:underline">{{ .Meta.Title }}</h2>
         <p class="text-sm text-gray-500 dark:text-gray-400 line-clamp-2 flex-1">{{ .Meta.Subtitle }}</p>
         <div class="flex items-center mt-4">
+          {{ $hasAvatar := false }}{{ range .Meta.Authors }}{{ if tinyAvatar .Handle }}{{ $hasAvatar = true }}{{ end }}{{ end }}
+          {{ if $hasAvatar }}
           <div class="inline-flex items-center -space-x-2">
             {{ range .Meta.Authors }}
-            <img src="{{ tinyAvatar .Handle }}" class="size-6 rounded-full border border-gray-300 dark:border-gray-700" alt="{{ .Name }}" title="{{ .Name }}" />
+            {{ $av := tinyAvatar .Handle }}{{ if $av }}<img src="{{ $av }}" class="size-6 rounded-full border border-gray-300 dark:border-gray-700" alt="{{ .Name }}" title="{{ .Name }}" />{{ end }}
             {{ end }}
           </div>
+          {{ end }}
         </div>
       </div>
     </a>

blog/templates/post.html

···
       <p class="italic mt-1 mb-3 text-lg text-gray-600 dark:text-gray-400">{{ .Post.Meta.Subtitle }}</p>
 
       <div class="flex items-center gap-3 not-prose">
+        {{ $hasAvatar := false }}{{ range $authors }}{{ if tinyAvatar .Handle }}{{ $hasAvatar = true }}{{ end }}{{ end }}
+        {{ if $hasAvatar }}
         <div class="inline-flex items-center -space-x-2">
           {{ range $authors }}
-          <img src="{{ tinyAvatar .Handle }}" class="size-7 rounded-full border border-gray-300 dark:border-gray-700" alt="{{ .Handle }}" title="{{ .Handle }}" />
+          {{ $av := tinyAvatar .Handle }}{{ if $av }}<img src="{{ $av }}" class="size-7 rounded-full border border-gray-300 dark:border-gray-700" alt="{{ .Handle }}" title="{{ .Handle }}" />{{ end }}
           {{ end }}
         </div>
+        {{ end }}
         <div class="flex items-center gap-1 text-sm text-gray-700 dark:text-gray-300">
           {{ range $i, $a := $authors }}
           {{ if gt $i 0 }}<span class="text-gray-400">&amp;</span>{{ end }}

cmd/blog/main.go

···
 	"context"
 	"fmt"
 	"io"
+	"io/fs"
 	"log/slog"
 	"net/http"
 	"os"
···
 		return fmt.Errorf("rendering index: %w", err)
 	}
 
-	// posts — each at build/<slug>/index.html directly (no /blog/ prefix)
 	for _, post := range posts {
-		post := post
 		postDir := filepath.Join(outDir, post.Meta.Slug)
 		if err := os.MkdirAll(postDir, 0755); err != nil {
 			return err
···
 		}
 	}
 
-	// atom feed — at build/feed.xml
+	// atom feed
 	baseURL := "https://blog.tangled.org"
 	atom, err := blog.AtomFeed(posts, baseURL)
 	if err != nil {
···
 		return fmt.Errorf("writing feed: %w", err)
 	}
 
+	// copy embedded static assets into build/static/ so Cloudflare Pages
+	// can serve them from the same origin as the built HTML
+	staticSrc, err := fs.Sub(pages.Files, "static")
+	if err != nil {
+		return fmt.Errorf("accessing embedded static dir: %w", err)
+	}
+	if err := copyFS(staticSrc, filepath.Join(outDir, "static")); err != nil {
+		return fmt.Errorf("copying static assets: %w", err)
+	}
+
 	logger.Info("build complete", "dir", outDir)
 	return nil
+}
+
+// copyFS copies all files from src into destDir, preserving directory structure.
+func copyFS(src fs.FS, destDir string) error {
+	return fs.WalkDir(src, ".", func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		dest := filepath.Join(destDir, path)
+		if d.IsDir() {
+			return os.MkdirAll(dest, 0755)
+		}
+		data, err := fs.ReadFile(src, path)
+		if err != nil {
+			return err
+		}
+		return os.WriteFile(dest, data, 0644)
+	})
 }
 
 func runServe(ctx context.Context, logger *slog.Logger, addr string) error {