Move ltml/server to cmd/serve-ltml; add cmd/render-ltml

cmd/render-ltml/main.go

@@ -0,0 +1,162 @@
+// Copyright 2026 Brent Rowland.
+// Use of this source code is governed the Apache License, Version 2.0, as described in the LICENSE file.
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+
+	"github.com/rowland/leadtype/ltml"
+	"github.com/rowland/leadtype/ltml/ltpdf"
+)
+
+type multiFlag []string
+
+func (m *multiFlag) String() string {
+	if m == nil || len(*m) == 0 {
+		return ""
+	}
+	return fmt.Sprintf("%v", []string(*m))
+}
+
+func (m *multiFlag) Set(v string) error {
+	*m = append(*m, v)
+	return nil
+}
+
+func main() {
+	var assetsDir string
+	var outputPath string
+	var extraFiles multiFlag
+
+	flag.StringVar(&assetsDir, "assets", "", "path to asset `directory`")
+	flag.StringVar(&assetsDir, "a", "", "path to asset `directory` (shorthand)")
+	flag.StringVar(&outputPath, "output", "", "output `file` (default: stdout)")
+	flag.StringVar(&outputPath, "o", "", "output `file` (shorthand)")
+	flag.Var(&extraFiles, "extra", "additional asset `file` (may be repeated)")
+	flag.Var(&extraFiles, "e", "additional asset `file` (shorthand)")
+	flag.Usage = func() {
+		fmt.Fprintf(os.Stderr, "Usage: render-ltml [flags] <file.ltml>\n\nFlags:\n")
+		flag.PrintDefaults()
+	}
+	flag.Parse()
+
+	if flag.NArg() != 1 {
+		flag.Usage()
+		os.Exit(2)
+	}
+
+	if err := run(flag.Arg(0), assetsDir, outputPath, []string(extraFiles)); err != nil {
+		fmt.Fprintf(os.Stderr, "render-ltml: %v\n", err)
+		os.Exit(1)
+	}
+}
+
+func run(inputFile, assetsDir, outputPath string, extraFiles []string) error {
+	// Resolve paths before potentially changing directory.
+	absInput, err := filepath.Abs(inputFile)
+	if err != nil {
+		return fmt.Errorf("resolving input: %w", err)
+	}
+
+	var absOutput string
+	if outputPath != "" {
+		absOutput, err = filepath.Abs(outputPath)
+		if err != nil {
+			return fmt.Errorf("resolving output: %w", err)
+		}
+	}
+
+	// Set up asset working directory when assets or extra files are provided.
+	if assetsDir != "" || len(extraFiles) > 0 {
+		workDir, cleanup, err := setupWorkDir(assetsDir, extraFiles)
+		if err != nil {
+			return err
+		}
+		defer cleanup()
+		if err := os.Chdir(workDir); err != nil {
+			return fmt.Errorf("chdir to work dir: %w", err)
+		}
+	}
+
+	// Parse LTML.
+	doc, err := ltml.ParseFile(absInput)
+	if err != nil {
+		return fmt.Errorf("parsing %s: %w", inputFile, err)
+	}
+
+	// Render to PDF.
+	w := ltpdf.NewDocWriter()
+	if err := doc.Print(w); err != nil {
+		return fmt.Errorf("rendering: %w", err)
+	}
+
+	// Write output.
+	var out io.Writer
+	if absOutput != "" {
+		f, err := os.Create(absOutput)
+		if err != nil {
+			return fmt.Errorf("creating output: %w", err)
+		}
+		defer f.Close()
+		out = f
+	} else {
+		out = os.Stdout
+	}
+
+	if _, err := w.WriteTo(out); err != nil {
+		return fmt.Errorf("writing output: %w", err)
+	}
+	return nil
+}
+
+// setupWorkDir creates a temporary directory populated with symlinks to the
+// contents of assetsDir and each file in extraFiles. The caller must invoke
+// the returned cleanup function when rendering is complete.
+func setupWorkDir(assetsDir string, extraFiles []string) (string, func(), error) {
+	tmpDir, err := os.MkdirTemp("", "render-ltml-*")
+	if err != nil {
+		return "", nil, fmt.Errorf("creating work dir: %w", err)
+	}
+	cleanup := func() { os.RemoveAll(tmpDir) }
+
+	if assetsDir != "" {
+		absAssets, err := filepath.Abs(assetsDir)
+		if err != nil {
+			cleanup()
+			return "", nil, fmt.Errorf("resolving assets dir: %w", err)
+		}
+		entries, err := os.ReadDir(absAssets)
+		if err != nil {
+			cleanup()
+			return "", nil, fmt.Errorf("reading assets dir: %w", err)
+		}
+		for _, entry := range entries {
+			src := filepath.Join(absAssets, entry.Name())
+			dst := filepath.Join(tmpDir, entry.Name())
+			if err := os.Symlink(src, dst); err != nil {
+				cleanup()
+				return "", nil, fmt.Errorf("linking asset %s: %w", entry.Name(), err)
+			}
+		}
+	}
+
+	for _, f := range extraFiles {
+		abs, err := filepath.Abs(f)
+		if err != nil {
+			cleanup()
+			return "", nil, fmt.Errorf("resolving extra file %s: %w", f, err)
+		}
+		dst := filepath.Join(tmpDir, filepath.Base(f))
+		if err := os.Symlink(abs, dst); err != nil {
+			cleanup()
+			return "", nil, fmt.Errorf("linking extra file %s: %w", filepath.Base(f), err)
+		}
+	}
+
+	return tmpDir, cleanup, nil
+}