1 files changed, 68 insertions, 0 deletions
diff --git a/internal/processor/markdown.go b/internal/processor/markdown.go
new file mode 100644
index 0000000..8d69bfe
--- /dev/null
+++ b/internal/processor/markdown.go
@@ -0,0 +1,68 @@
+package processor
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/extension"
+	"github.com/yuin/goldmark/renderer/html"
+)
+
+// imageRefPattern matches Markdown image syntax: ![alt](filename)
+// We use it to discover local asset references that must be copied.
+var imageRefPattern = regexp.MustCompile(`!\[[^\]]*\]\(([^)]+)\)`)
+
+// processMd converts a Markdown file to an HTML snippet.
+// Returns the HTML and a list of local image filenames referenced in the document.
+// Referenced images that exist alongside the source file are returned so the
+// caller can copy them into the post asset directory.
+func processMd(path string) (htmlContent string, localImages []string, err error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return "", nil, fmt.Errorf("read markdown %s: %w", path, err)
+	}
+
+	// Collect local image references so the caller can copy them as assets.
+	localImages = findLocalImages(string(data), filepath.Dir(path))
+
+	md := goldmark.New(
+		goldmark.WithExtensions(extension.GFM),
+		goldmark.WithRendererOptions(
+			html.WithUnsafe(), // Allow raw HTML in markdown (user-controlled content).
+		),
+	)
+
+	var buf bytes.Buffer
+	if err := md.Convert(data, &buf); err != nil {
+		return "", nil, fmt.Errorf("convert markdown %s: %w", path, err)
+	}
+
+	return buf.String(), localImages, nil
+}
+
+// findLocalImages returns image filenames referenced in markdown that actually
+// exist in sourceDir. Remote URLs (http/https) are ignored.
+func findLocalImages(mdContent, sourceDir string) []string {
+	matches := imageRefPattern.FindAllStringSubmatch(mdContent, -1)
+	var locals []string
+
+	for _, m := range matches {
+		ref := m[1]
+		// Skip remote URLs.
+		if strings.HasPrefix(ref, "http://") || strings.HasPrefix(ref, "https://") {
+			continue
+		}
+
+		candidate := filepath.Join(sourceDir, ref)
+		if _, err := os.Stat(candidate); err == nil {
+			locals = append(locals, filepath.Base(ref))
+		}
+	}
+
+	return locals
+}