feat: implement PDF generation and update Dockerfile

- Add PDF generation using go-pdf/fpdf (Pure Go library)
- Walk markdown AST and render directly to PDF
- Update Dockerfile to include themes directory and config
- Fix ENTRYPOINT format for serve mode

Co-Authored-By: Claude (glm-5) <noreply@anthropic.com>

PLAN.md

@@ -11,19 +11,22 @@
 - [x] Project backbone exists (HTTP server, graceful shutdown, config reading).
 - [x] Markdown parsing logic implemented (using goldmark).
 - [x] HTML Template engine integrated (Hugo-like theme selection).
-- [ ] PDF Generation implemented (Pure Go library selected and integrated).
+- [x] PDF Generation implemented (using go-pdf/fpdf - Pure Go library).
 - [x] CLI Mode (`gocv`) generates static files to `./output` and exits.
-- [ ] Serve Mode (`gocv serve`) hosts HTML and serves PDF on demand.
-- [ ] File Watcher implemented for live reload in Serve Mode.
+- [x] Serve Mode (`gocv serve`) hosts HTML and serves PDF on demand.
+- [x] File Watcher implemented for live reload in Serve Mode (using fsnotify).
 - [ ] Dockerfile created for multi-stage build.
 
 ## Active Task
 - [x] Analyze existing backbone code and integrate Markdown parsing.
 - [x] Integrate HTML template engine with theme selection.
-- [ ] Implement Serve Mode with file watching for live reload.
+- [x] Implement Serve Mode with file watching for live reload.
+- [ ] Create Dockerfile for multi-stage build.
 
 ## Known Issues / Blockers
-- [ ] Identify best Pure Go PDF library that supports HTML/CSS (or define CSS subset).
+- [x] Identify best Pure Go PDF library that supports HTML/CSS (or define CSS subset).
+  - Selected go-pdf/fpdf - generates PDFs programmatically from markdown AST.
+  - Note: Not HTML-to-PDF conversion; walks goldmark AST and renders directly.
 - [x] Current output is raw HTML fragments without full HTML document structure.
 
 ## Completed Log

content.go

@@ -82,6 +82,11 @@ func generateOutput() error {
 			return fmt.Errorf("failed to write %s: %w", outputFile, err)
 		}
 		fmt.Printf("  -> Written: %s\n", outputFile)
+
+		// Generate PDF
+		if err := generatePDF(file.Content, file.Name); err != nil {
+			fmt.Printf("  -> PDF generation failed: %s\n", err)
+		}
 	}
 
 	return nil

dockerfile

@@ -19,7 +19,7 @@ RUN CGO_ENABLED=0 GOOS=${GO_OS} GOARCH=${GO_ARCH} \
     go build \
     -installsuffix cgo \
     -ldflags="-w -s -X 'main.APP_VERSION=${APP_VERSION}' -X 'main.COMMIT_ID=$(git log HEAD --oneline | awk '{print $1}' | head -n1)'" \
-    --o /gocv
+    -o /gocv
 
 # Stage 2 · scratch image
 FROM scratch
@@ -28,6 +28,13 @@ FROM scratch
 COPY --from=build /gocv /gocv
 # Copy the certificates - in case of fetches
 COPY --from=build /etc/ssl/certs/ca-certificates.crt /etc/ssl/cert.pem
+# Copy themes for templates
+COPY --from=build $GOPATH/src/${GIT_HOST}/${REPO_ORG}/${REPO_NAME}/themes /themes
+# Copy default config
+COPY --from=build $GOPATH/src/${GIT_HOST}/${REPO_ORG}/${REPO_NAME}/config.yaml /config.yaml
+
+# Create content and output directories
+# Note: In scratch image, we need to mount these at runtime
 
 # Execute the binary
-ENTRYPOINT ["/gocv serve"]
+ENTRYPOINT ["/gocv", "serve"]

go.mod

@@ -9,6 +9,7 @@ require (
 
 require (
 	github.com/fsnotify/fsnotify v1.9.0 // indirect
+	github.com/go-pdf/fpdf v0.9.0 // indirect
 	github.com/yuin/goldmark v1.7.16 // indirect
 	golang.org/x/sys v0.13.0 // indirect
 )

go.sum

@@ -1,5 +1,7 @@
 github.com/fsnotify/fsnotify v1.9.0 h1:2Ml+OJNzbYCTzsxtv8vKSFD9PbJjmhYF14k/jKC7S9k=
 github.com/fsnotify/fsnotify v1.9.0/go.mod h1:8jBTzvmWwFyi3Pb8djgCCO5IBqzKJ/Jwo8TRcHyHii0=
+github.com/go-pdf/fpdf v0.9.0 h1:PPvSaUuo1iMi9KkaAn90NuKi+P4gwMedWPHhj8YlJQw=
+github.com/go-pdf/fpdf v0.9.0/go.mod h1:oO8N111TkmKb9D7VvWGLvLJlaZUQVPM+6V42pp3iV4Y=
 github.com/gorilla/mux v1.8.1 h1:TuBL49tXwgrFYWhqrNgrUNEY92u81SPhu7sTdzQEiWY=
 github.com/gorilla/mux v1.8.1/go.mod h1:AKf9I4AEqPTmMytcMc0KkNouC66V3BtZ4qD5fmWSiMQ=
 github.com/yuin/goldmark v1.7.16 h1:n+CJdUxaFMiDUNnWC3dMWCIQJSkxH4uz3ZwQBkAlVNE=

pdf.go

@@ -0,0 +1,156 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/go-pdf/fpdf"
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/text"
+)
+
+// generatePDF generates a PDF file from markdown content
+func generatePDF(markdownContent, name string) error {
+	pdf := fpdf.New("P", "mm", "A4", "")
+	pdf.AddPage()
+	pdf.SetAutoPageBreak(true, 10)
+	pdf.SetMargins(15, 15, 15)
+
+	// Parse markdown to AST
+	reader := text.NewReader([]byte(markdownContent))
+	doc := goldmark.DefaultParser().Parse(reader)
+
+	// Walk the AST and render to PDF
+	err := ast.Walk(doc, func(n ast.Node, entering bool) (ast.WalkStatus, error) {
+		if !entering {
+			return ast.WalkContinue, nil
+		}
+
+		switch node := n.(type) {
+		case *ast.Heading:
+			renderHeading(pdf, node, reader)
+		case *ast.Paragraph:
+			renderParagraph(pdf, node, reader)
+		case *ast.List:
+			// Lists are handled by their items
+			return ast.WalkContinue, nil
+		case *ast.ListItem:
+			renderListItem(pdf, node, reader)
+		case *ast.CodeBlock:
+			renderCodeBlock(pdf, node, reader)
+		case *ast.CodeSpan:
+			renderCodeSpan(pdf, node, reader)
+		}
+
+		return ast.WalkContinue, nil
+	})
+
+	if err != nil {
+		return fmt.Errorf("failed to render PDF: %w", err)
+	}
+
+	// Ensure output directory exists
+	if err := os.MkdirAll(outputPath, 0755); err != nil {
+		return fmt.Errorf("failed to create output directory: %w", err)
+	}
+
+	// Write PDF to file
+	outputFile := filepath.Join(outputPath, name+".pdf")
+	if err := pdf.OutputFileAndClose(outputFile); err != nil {
+		return fmt.Errorf("failed to write PDF: %w", err)
+	}
+
+	fmt.Printf("  -> Written: %s\n", outputFile)
+	return nil
+}
+
+// getNodeText extracts text content from a node
+func getNodeText(n ast.Node, reader text.Reader) string {
+	var sb strings.Builder
+	for c := n.FirstChild(); c != nil; c = c.NextSibling() {
+		if textNode, ok := c.(*ast.Text); ok {
+			segment := textNode.Segment
+			sb.Write(reader.Value(segment))
+		} else {
+			sb.WriteString(getNodeText(c, reader))
+		}
+	}
+	return sb.String()
+}
+
+// renderHeading renders a heading to the PDF
+func renderHeading(pdf *fpdf.Fpdf, node *ast.Heading, reader text.Reader) {
+	txt := getNodeText(node, reader)
+	switch node.Level {
+	case 1:
+		pdf.SetFont("Helvetica", "B", 24)
+		pdf.Ln(5)
+	case 2:
+		pdf.SetFont("Helvetica", "B", 18)
+		pdf.Ln(3)
+	case 3:
+		pdf.SetFont("Helvetica", "B", 14)
+		pdf.Ln(2)
+	default:
+		pdf.SetFont("Helvetica", "B", 12)
+		pdf.Ln(1)
+	}
+	pdf.MultiCell(0, 8, txt, "", "", false)
+	pdf.Ln(2)
+}
+
+// renderParagraph renders a paragraph to the PDF
+func renderParagraph(pdf *fpdf.Fpdf, node *ast.Paragraph, reader text.Reader) {
+	txt := getNodeText(node, reader)
+	if txt == "" {
+		return
+	}
+	pdf.SetFont("Helvetica", "", 12)
+	pdf.MultiCell(0, 6, txt, "", "", false)
+	pdf.Ln(2)
+}
+
+// renderListItem renders a list item to the PDF
+func renderListItem(pdf *fpdf.Fpdf, node *ast.ListItem, reader text.Reader) {
+	txt := getNodeText(node, reader)
+	if txt == "" {
+		return
+	}
+	pdf.SetFont("Helvetica", "", 12)
+	pdf.Cell(5, 6, "- ")
+	pdf.MultiCell(0, 6, txt, "", "", false)
+}
+
+// renderCodeBlock renders a code block to the PDF
+func renderCodeBlock(pdf *fpdf.Fpdf, node *ast.CodeBlock, reader text.Reader) {
+	segments := node.Lines()
+	if segments.Len() == 0 {
+		return
+	}
+
+	pdf.SetFont("Courier", "", 10)
+	pdf.SetFillColor(240, 240, 240)
+	pdf.Ln(2)
+
+	for i := 0; i < segments.Len(); i++ {
+		segment := segments.At(i)
+		line := string(reader.Value(segment))
+		line = strings.TrimRight(line, "\n\r")
+		pdf.Cell(0, 5, "  "+line)
+		pdf.Ln(-1)
+	}
+
+	pdf.Ln(2)
+	pdf.SetFont("Helvetica", "", 12)
+}
+
+// renderCodeSpan renders inline code to the PDF
+func renderCodeSpan(pdf *fpdf.Fpdf, node *ast.CodeSpan, reader text.Reader) {
+	txt := getNodeText(node, reader)
+	pdf.SetFont("Courier", "", 12)
+	pdf.Cell(0, 6, txt)
+	pdf.SetFont("Helvetica", "", 12)
+}