271 lines
7.7 KiB
Python
271 lines
7.7 KiB
Python
import re
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from pypdf import PdfReader, PdfWriter
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from reportlab.pdfgen import canvas
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from reportlab.lib.pagesizes import LETTER
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from io import BytesIO
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# ================= CONFIG =================
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PDF_INPUTS = [
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{"file": "pdfcreator/input.pdf", "sections": ["1.3", "2.1", "@111-114"]},
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{"file": "pdfcreator/input2.pdf", "sections": ["3.2"]},
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]
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OUTPUT_PDF = "pdfcreator/extracted_sections.pdf"
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HEADER_CROP = 0.12 # top of first page of section
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FOOTER_CROP = 0.06 # bottom of all pages
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# =========================================
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def strip_numbering(title):
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"""
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Remove leading numbering from a string like '1.3 Background'
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Returns 'Background'.
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"""
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return re.sub(r'^\d+(\.\d+)*\s+', '', title)
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# ---------- Outline utilities ------------
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def parse_page_range(entry):
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"""
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Returns a list of zero-based page indices if entry is a page range.
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Page ranges must be prefixed with '@', e.g., "@1-10".
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Otherwise returns None (treated as section prefix).
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"""
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if entry.startswith("@"):
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s = entry[1:] # remove the @
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try:
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start, end = s.split("-")
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start = int(start) - 1 # zero-based
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end = int(end) # inclusive in range
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return list(range(start, end))
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except ValueError:
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print(f"[WARN] Invalid page range: {entry}")
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return None
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return None # not a page range
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def build_outline_tree(reader):
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def _build(outline):
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tree = []
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for item in outline:
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if isinstance(item, list):
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tree[-1]["children"] = _build(item)
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else:
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tree.append({
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"title": item.title.strip(),
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"page": reader.get_destination_page_number(item),
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"children": []
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})
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return tree
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return _build(reader.outline)
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def find_section_with_level(nodes, prefix, level=0):
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for node in nodes:
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if node["title"].startswith(prefix):
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return node, level
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found = find_section_with_level(node["children"], prefix, level + 1)
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if found[0]:
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return found
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return None, None
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def collect_subtree_pages(node, pages=None):
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if pages is None:
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pages = []
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pages.append(node["page"])
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for child in node["children"]:
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collect_subtree_pages(child, pages)
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return pages
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def flatten_outline_pages(nodes, pages=None):
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if pages is None:
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pages = []
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for node in nodes:
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pages.append(node["page"])
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flatten_outline_pages(node["children"], pages)
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return pages
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def find_end_page(target_node, outline_tree, total_pages):
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subtree_pages = collect_subtree_pages(target_node)
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last_page = max(subtree_pages)
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all_pages = sorted(set(flatten_outline_pages(outline_tree)))
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for p in all_pages:
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if p > last_page:
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return p
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return total_pages
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# ---------- Page manipulation ------------
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def crop_page(page, top_ratio=0.0, bottom_ratio=0.0):
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llx, lly, urx, ury = page.mediabox
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height = ury - lly
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new_lly = lly + height * bottom_ratio
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new_ury = ury - height * top_ratio
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page.cropbox.lower_left = (llx, new_lly)
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page.cropbox.upper_right = (urx, new_ury)
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# ---------- TOC generation ---------------
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def create_toc_pdf(toc_entries, heading):
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buffer = BytesIO()
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c = canvas.Canvas(buffer, pagesize=LETTER)
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c.setFont("Helvetica-Bold", 16)
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c.drawString(50, 750, heading)
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c.setFont("Helvetica", 12)
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y = 720
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for entry in toc_entries:
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line = f"{strip_numbering(entry['title'])} ........................ {entry['page']}"
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c.drawString(50, y, line) # flat: no indentation
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y -= 18
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if y < 50:
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c.showPage()
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c.setFont("Helvetica", 12)
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y = 750
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c.save()
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buffer.seek(0)
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return PdfReader(buffer)
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# ================= MAIN ===================
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content_writer = PdfWriter()
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toc_entries = []
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current_page = 0
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REFERENCE_BOX = None
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for pdf_info in PDF_INPUTS:
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reader = PdfReader(pdf_info["file"])
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outline_tree = build_outline_tree(reader)
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total_pages = len(reader.pages)
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for entry in pdf_info["sections"]:
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page_indices = parse_page_range(entry)
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if page_indices:
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# --- Explicit page range ---
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toc_entries.append({
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"title": f"Pages {entry[1:]}", # remove '@' for display
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"page": current_page + 1,
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"level": 0
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})
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for i, p in enumerate(page_indices):
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if p < 0 or p >= total_pages:
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print(
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f"[WARN] Page {p+1} out of range in {pdf_info['file']}")
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continue
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page = reader.pages[p]
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crop_page(page, top_ratio=HEADER_CROP,
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bottom_ratio=FOOTER_CROP)
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if REFERENCE_BOX is None:
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REFERENCE_BOX = (
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page.cropbox.lower_left,
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page.cropbox.upper_right
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)
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page.mediabox.lower_left = REFERENCE_BOX[0]
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page.mediabox.upper_right = REFERENCE_BOX[1]
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page.cropbox.lower_left = REFERENCE_BOX[0]
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page.cropbox.upper_right = REFERENCE_BOX[1]
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content_writer.add_page(page)
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current_page += 1
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else:
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target, level = find_section_with_level(
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outline_tree, entry)
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if not target:
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print(
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f"[WARN] Section {entry} not found in {pdf_info['file']}")
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continue
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start_page = target["page"]
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end_page = find_end_page(target, outline_tree, total_pages)
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toc_entries.append({
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"title": target["title"], # EXACT heading text
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"page": current_page + 1, # 1-based
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"level": level
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})
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for i, p in enumerate(range(start_page, end_page)):
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page = reader.pages[p]
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if i == 0:
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crop_page(page, HEADER_CROP, FOOTER_CROP)
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else:
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crop_page(page, bottom_ratio=FOOTER_CROP)
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# Capture reference AFTER cropping
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if REFERENCE_BOX is None:
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REFERENCE_BOX = (
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page.cropbox.lower_left,
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page.cropbox.upper_right
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)
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# Normalize page size
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page.mediabox.lower_left = REFERENCE_BOX[0]
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page.mediabox.upper_right = REFERENCE_BOX[1]
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page.cropbox.lower_left = REFERENCE_BOX[0]
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page.cropbox.upper_right = REFERENCE_BOX[1]
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content_writer.add_page(page)
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current_page += 1
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# ---------- Build final PDF ---------------
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final_writer = PdfWriter()
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# Derive TOC heading from first source document
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first_reader = PdfReader(PDF_INPUTS[0]["file"])
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toc_heading = "Contents" if first_reader.outline else "Table of Contents"
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# Visible TOC pages
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toc_pdf = create_toc_pdf(toc_entries, toc_heading)
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toc_page_count = len(toc_pdf.pages)
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for page in toc_pdf.pages:
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final_writer.add_page(page)
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# Content pages
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for page in content_writer.pages:
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final_writer.add_page(page)
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bookmark_stack = {}
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for entry in toc_entries:
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parent = bookmark_stack.get(entry["level"] - 1)
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bm = final_writer.add_outline_item(
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title=entry["title"], # exact heading text
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page_number=(entry["page"] - 1) + toc_page_count,
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parent=parent
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)
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bookmark_stack[entry["level"]] = bm
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# ---------- Write output ------------------
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with open(OUTPUT_PDF, "wb") as f:
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final_writer.write(f)
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print(f"[OK] Created {OUTPUT_PDF}")
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