Add build_pdf.py for legacy paper PDF generation

Author: rwnq8

scripts/build_pdf.py

@@ -0,0 +1,384 @@
+#!/usr/bin/env python3
+"""
+build_pdf.py -- Fully automated Markdown -> HTML -> PDF pipeline v3.0
+
+Reusable CLI tool for DeepChat agent threads. Converts any Markdown file
+(with optional YAML frontmatter) to a professional A4 PDF via HTML intermediate.
+
+Pipeline:
+  1. Parse YAML frontmatter -> styled author block
+  2. Markdown -> HTML (code highlighting, tables, lists, math)
+  3. MathJax 3 CDN for LaTeX rendering (unless --no-math)
+  4. Edge/Chrome headless -> PDF with rendered JavaScript/MathJax
+
+Usage:
+  python build_pdf.py --input paper.md
+  python build_pdf.py --input paper.md --output out.pdf
+  python build_pdf.py --input paper.md --css custom.css --html-only
+"""
+
+import argparse
+import datetime
+import os
+import re
+import subprocess
+import sys
+import tempfile
+
+
+# ---------------------------------------------------------------------------
+# Embedded default CSS -- self-contained, no external CSS dependency
+# Use --css to override with a custom stylesheet file.
+# ---------------------------------------------------------------------------
+EMBEDDED_CSS = r"""/* build_pdf.css v3.0 -- Embedded academic PDF stylesheet */
+@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');
+:root{--text:#1a1a1a;--muted:#555;--border:#d0d0d0;--bg:#fafafa;--accent:#007acc;--title:24pt;--h1:18pt;--h2:15pt;--body:10.5pt}
+*{box-sizing:border-box;margin:0;padding:0}
+body{font-family:"Inter","Segoe UI","Helvetica Neue",Arial,sans-serif;font-size:var(--body);line-height:1.6;color:var(--text);max-width:6.2in;margin:0 auto;padding:0;text-align:left;background:white}
+h1.title{font-size:var(--title);font-weight:700;text-align:left;margin:0.8in 0 0.1in 0;line-height:1.1;color:var(--text);border-bottom:3px solid #000;padding-bottom:0.1in}
+h1{font-size:var(--h1);font-weight:600;margin:0.6in 0 0.3in 0;line-height:1.2;color:var(--text);border-bottom:2px solid #333;padding-bottom:0.1in;page-break-before:always;page-break-after:avoid}
+h2{font-size:var(--h2);font-weight:600;margin:1em 0 0.5em 0;color:var(--text);border-bottom:1px solid #ccc;padding-bottom:0.2em}
+h3{font-size:13pt;font-weight:600;margin:0.9em 0 0.4em 0;color:#333}
+p{margin:0 0 0.8em 0;line-height:1.6}
+.author-block{margin:0.2in 0 0.3in 0;padding:0.15in 0.2in;background:#f9f9f9;border-left:3px solid #000;border-radius:0 4px 4px 0;font-size:9.5pt;line-height:1.5}
+.author-block p{margin:0}.author-block strong{font-weight:600;color:var(--text)}
+.author-block a{color:var(--accent);text-decoration:none;border-bottom:1px dotted var(--accent)}
+.author-block .abstract-label{font-weight:700;display:block;margin-top:0.3em;font-size:10pt}
+.author-block .abstract-text{margin-top:0.2em;font-style:normal;color:var(--muted)}
+ul,ol{margin:0.8em 0;padding-left:2em}li{margin-bottom:0.4em;line-height:1.5}
+ol{counter-reset:item;list-style-type:none}ol>li{counter-increment:item;position:relative;padding-left:2em}
+ol>li::before{content:counter(item)".";font-weight:600;position:absolute;left:0;width:1.5em;text-align:right}
+code{font-family:"JetBrains Mono",Consolas,monospace;font-size:0.85em;background:#f9f9f9;padding:0.1em 0.3em;border-radius:2px;border:1px solid #e0e0e0;color:#d63384}
+pre{font-family:"JetBrains Mono",Consolas,monospace;background:#f9f9f9;padding:0.8em;margin:0.9em 0;border-radius:3px;overflow-x:auto;border:1px solid #e0e0e0;font-size:0.8em;line-height:1.5;border-left:3px solid #000;white-space:pre-wrap;word-break:break-word}
+pre code{background:none;padding:0;border:none;color:inherit;font-size:inherit}
+table{width:100%;border-collapse:collapse;margin:1.2em 0;font-size:0.95em;box-shadow:0 2px 4px rgba(0,0,0,0.05);border-radius:4px;overflow:hidden}
+th{background:#f0f0f0;font-weight:600;padding:0.5em 0.6em;text-align:left;border:1px solid var(--border);border-top:2px solid #000}
+td{background:#fff;padding:0.5em 0.6em;text-align:left;border:1px solid var(--border)}
+tr:nth-child(even) td{background:#fafafa}tbody tr td:first-child{font-weight:600}
+blockquote{border-left:3px solid #000;margin:1.2em 0;padding:0.5em 0 0.5em 0.9em;background:var(--bg);color:var(--muted);border-radius:0 2px 2px 0}
+a{color:var(--accent);text-decoration:none;border-bottom:1px dotted var(--accent)}
+mjx-container{overflow-x:auto;max-width:100%}mjx-container[display="true"]{display:block;margin:0.8em 0;text-align:left}
+.c{color:#6a737d;font-style:italic}.k{color:#d73a49;font-weight:bold}.s{color:#032f62}.mi{color:#005cc5}.nf{color:#6f42c1}.nc{color:#6f42c1;font-weight:bold}
+@media print{@page{size:A4;margin:0.75in 0.8in 0.75in 1.2in;@bottom-right{content:"Page "counter(page);font-family:"Inter",sans-serif;font-size:8pt;color:#666;padding:0.2in 0.4in 0 0}}body{padding:0;max-width:100%}.author-block{border:1px solid #000;border-left:3px solid #000}}
+"""
+
+MATHJAX_SCRIPT = """MathJax={tex:{inlineMath:[['$','$']],displayMath:[['$$','$$']],processEscapes:true,tags:'ams'},startup:{ready(){MathJax.startup.defaultReady();const n=document.querySelectorAll('mjx-container').length;console.log('MathJax ready: '+n+' expressions rendered')}}}"""
+
+MATHJAX_CDN = '<script async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-chtml.js"></script>'
+
+
+# ---------------------------------------------------------------------------
+# Utility functions
+# ---------------------------------------------------------------------------
+
+def find_browser():
+    """Locate an installed Edge or Chrome browser for headless PDF rendering."""
+    for p in [
+        r"C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe",
+        r"C:\Program Files\Microsoft\Edge\Application\msedge.exe",
+        r"C:\Program Files\Google\Chrome\Application\chrome.exe",
+    ]:
+        if os.path.exists(p):
+            return p
+    return None
+
+
+# CSS preset directory (relative to this script)
+CSS_DIR = os.path.join(os.path.dirname(os.path.abspath(__file__)), "css")
+
+# Named style presets map to css/<name>.css files
+STYLE_PRESETS = {
+    "academic": os.path.join(CSS_DIR, "academic.css"),
+    "modern": os.path.join(CSS_DIR, "modern.css"),
+    "minimal": os.path.join(CSS_DIR, "minimal.css"),
+}
+
+
+def resolve_css(style=None, css_path=None):
+    """Resolve CSS content from style preset, CSS file, or embedded default.
+
+    Priority: --css overrides --style overrides embedded default.
+    Returns (css_content, source_label) tuple.
+    """
+    # 1. Explicit CSS file (highest priority)
+    if css_path:
+        if not os.path.exists(css_path):
+            raise FileNotFoundError(f"CSS file not found: {css_path}")
+        with open(css_path, "r", encoding="utf-8") as f:
+            return f.read(), css_path
+
+    # 2. Named style preset
+    if style and style in STYLE_PRESETS:
+        preset_path = STYLE_PRESETS[style]
+        if not os.path.exists(preset_path):
+            print(f"WARNING: Style preset '{style}' not found at {preset_path}, falling back to embedded.", file=sys.stderr)
+        else:
+            with open(preset_path, "r", encoding="utf-8") as f:
+                return f.read(), f"{style} (preset: {preset_path})"
+
+    # 3. Embedded default (fallback)
+    return EMBEDDED_CSS, "(embedded default)"
+
+
+def parse_frontmatter(text):
+    """Extract YAML frontmatter dict and body from markdown text."""
+    meta, body = {}, text
+    if not text.startswith("---"):
+        return meta, body
+    parts = text.split("---", 2)
+    if len(parts) < 3:
+        return meta, body
+    body = parts[2]
+    for line in parts[1].strip().split("\n"):
+        if ":" not in line:
+            continue
+        k, _, v = line.partition(":")
+        k = k.strip().strip('"')
+        v = v.strip().strip('"').strip("'").strip()
+        if v.startswith("[") and v.endswith("]"):
+            v = [x.strip().strip('"') for x in v[1:-1].split(",")]
+        meta[k] = v
+    return meta, body
+
+
+def build_author_block(meta):
+    """Build an HTML author+metadata block from frontmatter dict."""
+    a = meta.get("authors", meta.get("author", ""))
+    o = meta.get("orcid", "0009-0002-4317-5604")
+    d = meta.get("doi", "")
+    dt = meta.get("date", datetime.date.today().isoformat())
+    ab = meta.get("abstract", "")
+    lines = []
+    if a:
+        lines.append(f"<p><strong>Author:</strong> {a}</p>")
+    lines.append(
+        f'<p><strong>ORCID:</strong> <a href="https://orcid.org/{o}">{o}</a></p>'
+    )
+    if d and "zenodo" in d:
+        lines.append(
+            f'<p><strong>DOI:</strong> <a href="https://doi.org/{d}">{d}</a></p>'
+        )
+    lines.append(f"<p><strong>Date:</strong> {dt}</p>")
+    if ab:
+        lines.append(
+            f'<p class="abstract-label">Abstract</p><p class="abstract-text">{ab}</p>'
+        )
+    return f'<div class="author-block">\n{"".join(lines)}\n</div>'
+
+
+# ---------------------------------------------------------------------------
+# Pipeline steps
+# ---------------------------------------------------------------------------
+
+def build_html(input_path, output_html, css_content, use_math=True, title_override=None):
+    """Convert Markdown to standalone HTML with embedded CSS and MathJax.
+
+    Args:
+        input_path: Path to the Markdown (.md) source file.
+        output_html: Path to write the generated HTML file.
+        css_content: CSS string to embed (from file or default).
+        use_math: Include MathJax CDN and config (default True).
+        title_override: Override title from frontmatter (optional).
+
+    Returns:
+        (title, html_size) tuple.
+    """
+    import markdown
+
+    with open(input_path, "r", encoding="utf-8") as f:
+        raw = f.read()
+
+    meta, body = parse_frontmatter(raw)
+    author_html = build_author_block(meta)
+
+    md = markdown.Markdown(extensions=["extra", "codehilite", "tables", "fenced_code"])
+    html_body = md.convert(body)
+
+    # Strip internal metadata lines that should not appear in publication PDFs
+    html_body = re.sub(r"<p><strong>Version:</strong>.*?</p>", "", html_body)
+    html_body = re.sub(r"<p><strong>Status:</strong>.*?</p>", "", html_body)
+
+    title = title_override or meta.get("title", "Untitled")
+
+    # Build HTML -- use string concat to avoid JS/CSS brace conflicts with f-strings
+    parts = [
+        '<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>',
+        title,
+        "</title><style>",
+        css_content,
+        "</style>",
+    ]
+    if use_math:
+        parts.append("<script>")
+        parts.append(MATHJAX_SCRIPT)
+        parts.append("</script>")
+        parts.append(MATHJAX_CDN)
+    parts.append("</head><body>")
+    parts.append(f'<h1 class="title">{title}</h1>')
+    parts.append(author_html)
+    parts.append(html_body)
+    parts.append("</body></html>")
+
+    html = "".join(parts)
+
+    with open(output_html, "w", encoding="utf-8") as f:
+        f.write(html)
+
+    size = os.path.getsize(output_html)
+    return title, size
+
+
+def html_to_pdf(html_path, pdf_path, browser_path):
+    """Convert HTML to PDF via headless browser (Edge/Chrome).
+
+    Args:
+        html_path: Path to the HTML file to render.
+        pdf_path: Path for the output PDF.
+        browser_path: Full path to msedge.exe or chrome.exe.
+
+    Returns:
+        PDF file size in bytes, or None on failure.
+    """
+    abs_html = os.path.abspath(html_path).replace("\\", "/")
+    abs_pdf = os.path.abspath(pdf_path)
+
+    cmd = [
+        browser_path,
+        "--headless",
+        f"--print-to-pdf={abs_pdf}",
+        "--no-pdf-header-footer",
+        f"file:///{abs_html}",
+    ]
+    result = subprocess.run(cmd, capture_output=True, text=True, timeout=30)
+    if result.returncode == 0 and os.path.exists(abs_pdf):
+        return os.path.getsize(abs_pdf)
+    return None
+
+
+# ---------------------------------------------------------------------------
+# CLI entry point
+# ---------------------------------------------------------------------------
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Markdown -> HTML -> PDF pipeline (v3.0)",
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        epilog="""
+Examples:
+  python build_pdf.py --input paper.md
+  python build_pdf.py --input paper.md --output out.pdf
+  python build_pdf.py --input paper.md --style modern
+  python build_pdf.py --input paper.md --style minimal --no-math
+  python build_pdf.py --input paper.md --css custom.css
+  python build_pdf.py --input paper.md --html-only
+  python build_pdf.py --input paper.md --title "My Paper Title"
+        """,
+    )
+    parser.add_argument(
+        "--input", "-i", required=True, help="Input Markdown file (.md)"
+    )
+    parser.add_argument(
+        "--output", "-o", default=None, help="Output PDF path (default: input name + .pdf)"
+    )
+    parser.add_argument(
+        "--style", choices=["academic", "modern", "minimal"], default=None,
+        help="CSS style preset: academic (default), modern, or minimal"
+    )
+    parser.add_argument(
+        "--css", default=None, help="Custom CSS file (overrides --style)"
+    )
+    parser.add_argument(
+        "--title", default=None, help="Override title from YAML frontmatter"
+    )
+    parser.add_argument(
+        "--no-math", action="store_true", help="Skip MathJax/LaTeX rendering"
+    )
+    parser.add_argument(
+        "--html-only", action="store_true", help="Stop after HTML generation (no PDF)"
+    )
+    parser.add_argument(
+        "--working-dir", default=None,
+        help="Directory for intermediate HTML file (default: output file directory)"
+    )
+
+    args = parser.parse_args()
+
+    # Validate input exists
+    if not os.path.exists(args.input):
+        print(f"ERROR: Input file not found: {args.input}", file=sys.stderr)
+        sys.exit(1)
+
+    # Determine output path
+    if args.output:
+        pdf_path = args.output
+    else:
+        base = os.path.splitext(os.path.basename(args.input))[0]
+        pdf_path = os.path.join(os.path.dirname(args.input) or ".", f"{base}.pdf")
+
+    pdf_dir = os.path.dirname(os.path.abspath(pdf_path))
+    work_dir = args.working_dir or pdf_dir
+
+    # Intermediate HTML: alongside PDF with same base name
+    html_name = os.path.splitext(os.path.basename(pdf_path))[0] + ".html"
+    html_path = os.path.join(work_dir, html_name)
+
+    print("=" * 60)
+    print("  Markdown -> HTML -> PDF Pipeline v3.0")
+    print("=" * 60)
+    print(f"  Input:     {args.input}")
+    print(f"  Output:    {pdf_path}")
+
+    # Step 1: Load CSS (style preset, custom file, or embedded default)
+    try:
+        css_content, css_source = resolve_css(style=args.style, css_path=args.css)
+        print(f"  CSS:       {css_source}")
+    except FileNotFoundError as e:
+        print(f"ERROR: {e}", file=sys.stderr)
+        sys.exit(2)
+
+    # Step 2: Markdown -> HTML
+    try:
+        title, html_size = build_html(
+            args.input, html_path, css_content,
+            use_math=not args.no_math,
+            title_override=args.title,
+        )
+        print(f"  [1/2] HTML: {html_size:,} bytes -> {html_path}")
+    except ImportError:
+        print("ERROR: 'markdown' library not installed. Run: pip install markdown", file=sys.stderr)
+        sys.exit(3)
+    except Exception as e:
+        print(f"ERROR: HTML build failed: {e}", file=sys.stderr)
+        sys.exit(4)
+
+    if args.html_only:
+        print(f"  [DONE] HTML only (--html-only). No PDF generated.")
+        print(f"  Title: {title}")
+        return
+
+    # Step 3: HTML -> PDF via headless browser
+    browser = find_browser()
+    if not browser:
+        print("  [SKIP] No browser found for PDF step.")
+        print(f"  Open {html_path} manually -> Ctrl+P -> Save as PDF")
+        sys.exit(5)
+
+    try:
+        pdf_size = html_to_pdf(html_path, pdf_path, browser)
+        if pdf_size:
+            print(f"  [2/2] PDF:  {pdf_size:,} bytes -> {pdf_path}")
+        else:
+            print(f"  [FAIL] PDF step returned no output.")
+            sys.exit(6)
+    except subprocess.TimeoutExpired:
+        print(f"  [FAIL] Browser PDF conversion timed out (30s).", file=sys.stderr)
+        sys.exit(7)
+    except Exception as e:
+        print(f"  [FAIL] PDF conversion error: {e}", file=sys.stderr)
+        sys.exit(8)
+
+    print(f"  >> PIPELINE COMPLETE <<")
+
+
+if __name__ == "__main__":
+    main()