Update app.py

app.py

@@ -179,6 +179,8 @@ def markdown_to_pdf_content(markdown_text, add_space_before_numbered, headings_t
     return pdf_content, total_lines
 
 def create_pdf(markdown_text, base_font_size, num_columns, add_space_before_numbered, headings_to_fonts, doc_title, longest_line_words, total_lines):
+    if not markdown_text.strip():
+        return None  # Handle empty markdown gracefully
     buffer = io.BytesIO()
     page_width = A4[0] * 2
     page_height = A4[1]
@@ -198,14 +200,14 @@ def create_pdf(markdown_text, base_font_size, num_columns, add_space_before_numb
         available_font_files = glob.glob("*.ttf")
         if not available_font_files:
             st.error("No .ttf font files found.")
-            return
+            return None
         selected_font_path = next((f for f in available_font_files if "NotoEmoji-Bold" in f), None)
         if selected_font_path:
             pdfmetrics.registerFont(TTFont("NotoEmoji-Bold", selected_font_path))
         pdfmetrics.registerFont(TTFont("DejaVuSans", "DejaVuSans.ttf"))
     except Exception as e:
         st.error(f"Font registration error: {e}")
-        return
+        return None
     total_chars = sum(len(line) for line in pdf_content)
     hierarchy_weight = sum(1.5 if line.startswith("<b>") else 1 for line in pdf_content)
     content_density = total_lines * hierarchy_weight + total_chars / 50
@@ -216,7 +218,7 @@ def create_pdf(markdown_text, base_font_size, num_columns, add_space_before_numb
     suggested_columns = max(2, min(4, int(total_lines / ideal_lines_per_col) + 1))
     num_columns = num_columns if num_columns != 0 else suggested_columns
     col_width = usable_width / num_columns
-    min_font_size = 6
+    min_font_size = 5  # Reduced to allow tighter fit
     max_font_size = 16
     lines_per_col = total_lines / num_columns if num_columns > 0 else total_lines
     target_height_per_line = usable_height / lines_per_col if lines_per_col > 0 else usable_height
@@ -226,10 +228,10 @@ def create_pdf(markdown_text, base_font_size, num_columns, add_space_before_numb
         adjusted_font_size = int(col_width / (avg_line_chars / 10))
         adjusted_font_size = max(min_font_size, adjusted_font_size)
     
-    # Adjust font size to fit one page based on longest line
-    if longest_line_words > 17:
-        font_scale = 17 / longest_line_words  # Scale down from reference (17 words)
-        adjusted_font_size = max(min_font_size, int(adjusted_font_size * font_scale))
+    # Enhanced font size scaling for one-page fit
+    if longest_line_words > 17 or lines_per_col > 20:
+        font_scale = min(17 / max(longest_line_words, 17), 60 / max(lines_per_col, 20))
+        adjusted_font_size = max(min_font_size, int(base_font_size * font_scale))
     
     item_style = ParagraphStyle(
         'ItemStyle', parent=styles['Normal'], fontName="DejaVuSans",
@@ -309,6 +311,8 @@ def create_pdf(markdown_text, base_font_size, num_columns, add_space_before_numb
     return buffer.getvalue()
 
 def pdf_to_image(pdf_bytes):
+    if pdf_bytes is None:
+        return None
     try:
         doc = fitz.open(stream=pdf_bytes, filetype="pdf")
         images = []
@@ -325,7 +329,8 @@ def pdf_to_image(pdf_bytes):
 # PDF creation and linking functions
 WORDS_12 = ["one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "eleven", "twelve"]
 WORDS_24 = ["one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten",
-            "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen", "twenty", "twenty one", "twenty two", "twenty three", "twenty four"]
+            "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen", "twenty",
+            "twenty-one", "twenty-two", "twenty-three", "twenty-four"]
 
 def create_crossfile_pdfs(source_pdf="TestSource.pdf", target_pdf="TestTarget.pdf"):
     """Create two PDFs with cross-file linking."""
@@ -405,7 +410,7 @@ def create_crossfile_pdfs(source_pdf="TestSource.pdf", target_pdf="TestTarget.pd
     return source_pdf, target_pdf
 
 def create_selflinking_pdf(pdf_file="SelfLinking.pdf"):
-    """Create a PDF with a TOC on page 1 linking to a 1-20 list starting on page 2."""
+    """Create a PDF with a TOC on page 1 linking to a 1-24 list starting on page 2."""
     buffer = io.BytesIO()
     c = canvas.Canvas(buffer)
     
@@ -420,7 +425,7 @@ def create_selflinking_pdf(pdf_file="SelfLinking.pdf"):
         toc_y_positions.append(y)
     c.showPage()
     
-    # Page 2: Numbered list 1-20
+    # Page 2: Numbered list 1-24
     c.setFont("Helvetica", 12)
     list_y_positions = []
     for i, word in enumerate(WORDS_24, 1):
@@ -490,10 +495,10 @@ with st.sidebar:
     )
     base_font_size = st.slider("Font Size (points)", min_value=6, max_value=16, value=8, step=1)
     
-    add_space_before_numbered = st.checkbox("Add Space Ahead of Numbered Lines", value=False)
+    add_space_before_numbered = st.checkbox("Add Space Ahead of Numbered Lines", value=True)
     headings_to_fonts = st.checkbox(
         "Headings to Fonts",
-        value=False,
+        value=True,
         help="Convert Markdown headings (# Heading) to styled fonts"
     )
     auto_columns = st.checkbox("AutoColumns", value=True)
@@ -502,7 +507,7 @@ with st.sidebar:
     longest_line_words = 0
     total_lines = 0
     adjusted_font_size_display = base_font_size
-    if 'markdown_content' in st.session_state:
+    if 'markdown_content' in st.session_state and st.session_state.markdown_content.strip():
         current_markdown = st.session_state.markdown_content
         lines = current_markdown.strip().split('\n')
         total_lines = len([line for line in lines if line.strip()])
@@ -520,20 +525,26 @@ with st.sidebar:
         else:
             recommended_columns = 3
         # Adjust font size for one-page fit
-        if longest_line_words > 17:
-            font_scale = 17 / longest_line_words
-            adjusted_font_size_display = max(6, int(base_font_size * font_scale))
+        if longest_line_words > 17 or total_lines / max(num_columns, 1) > 20:
+            font_scale = min(17 / max(longest_line_words, 17), 60 / max(total_lines / max(num_columns, 1), 20))
+            adjusted_font_size_display = max(5, int(base_font_size * font_scale))
         st.markdown("**Document Stats**")
         st.write(f"- Longest Line: {longest_line_words} words")
         st.write(f"- Total Lines: {total_lines}")
         st.write(f"- Recommended Columns: {recommended_columns}")
         st.write(f"- Adjusted Font Size: {adjusted_font_size_display} points")
+    else:
+        st.markdown("**Document Stats**")
+        st.write("- Longest Line: 0 words")
+        st.write("- Total Lines: 0")
+        st.write("- Recommended Columns: 3")
+        st.write(f"- Adjusted Font Size: {base_font_size} points")
     
     column_options = [2, 3, 4]
     num_columns = st.selectbox(
         "Number of Columns",
         options=column_options,
-        index=column_options.index(recommended_columns)
+        index=column_options.index(recommended_columns) if recommended_columns in column_options else 0
     )
     st.info("Font size and columns adjust to fit one page.")
     
@@ -645,7 +656,8 @@ with st.container():
 with st.sidebar:
     st.download_button(
         label="💾 Save PDF",
-        data=pdf_bytes,
+        data=pdf_bytes if pdf_bytes else "",
         file_name=f"{prefix} {selected_md}.pdf" if selected_md else f"{prefix} output.pdf",
-        mime="application/pdf"
+        mime="application/pdf",
+        disabled=pdf_bytes is None
     )