From d151ec91488f10134babae4d4a879d823b221b62 Mon Sep 17 00:00:00 2001 From: kj_sh604 Date: Wed, 11 Mar 2026 22:32:11 -0400 Subject: refactor: re-write in a fmailiar language to make it easier to maintain --- src/app.py | 568 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 568 insertions(+) create mode 100644 src/app.py (limited to 'src/app.py') diff --git a/src/app.py b/src/app.py new file mode 100644 index 0000000..88deef4 --- /dev/null +++ b/src/app.py @@ -0,0 +1,568 @@ +#!/usr/bin/env python3 + +# likha-pdf — markdown to pdf, no latex required +# converts markdown to html, then html to pdf via weasyprint +# falls back to reportlab if weasyprint chokes — a pdf is always produced + +import os +import re +import secrets +import time + +from flask import ( + Flask, + request, + send_from_directory, + render_template_string, + abort, +) +from markupsafe import escape +from markdown import markdown +from pygments.formatters import HtmlFormatter +from weasyprint import HTML + +APP_NAME = "likha-pdf" +PORT = 5001 + +BASE_DIR = os.path.dirname(os.path.abspath(__file__)) +GENERATED_DIR = os.path.join(BASE_DIR, "generated") +UPLOADS_DIR = os.path.join(BASE_DIR, "uploads") +TEMPLATES_DIR = os.path.join(BASE_DIR, "templates") +PARTIALS_DIR = os.path.join(TEMPLATES_DIR, "partials") +STATIC_DIR = os.path.join(BASE_DIR, "static") + +ALLOWED_IMAGE_EXTS = {"png", "jpg", "jpeg", "gif", "webp", "svg"} + +VALID_PAPER_SIZES = { + "a0paper", "a1paper", "a2paper", "a3paper", "a4paper", "a5paper", "a6paper", + "b0paper", "b1paper", "b2paper", "b3paper", "b4paper", "b5paper", "b6paper", + "c4paper", "c5paper", "c6paper", + "letterpaper", "legalpaper", "executivepaper", + "ledgerpaper", "tabloid", "statement", "flsa", +} + +VALID_MARGINS = {"0.25in", "0.5in", "0.75in", "1in", "1.25in", "1.5in", "1.75in"} + +VALID_LINE_SPACINGS = {"1", "1.5", "2"} + +# css page dimensions for each paper size +PAPER_CSS = { + "a0paper": "841mm 1189mm", + "a1paper": "594mm 841mm", + "a2paper": "420mm 594mm", + "a3paper": "297mm 420mm", + "a4paper": "210mm 297mm", + "a5paper": "148mm 210mm", + "a6paper": "105mm 148mm", + "b0paper": "1000mm 1414mm", + "b1paper": "707mm 1000mm", + "b2paper": "500mm 707mm", + "b3paper": "353mm 500mm", + "b4paper": "250mm 353mm", + "b5paper": "176mm 250mm", + "b6paper": "125mm 176mm", + "c4paper": "229mm 324mm", + "c5paper": "162mm 229mm", + "c6paper": "114mm 162mm", + "letterpaper": "8.5in 11in", + "legalpaper": "8.5in 14in", + "executivepaper": "7in 10in", + "ledgerpaper": "17in 11in", + "tabloid": "11in 17in", + "statement": "5.5in 8.5in", + "flsa": "8.5in 13in", +} + +MARKDOWN_EXTENSIONS = [ + "tables", + "fenced_code", + "codehilite", + "nl2br", + "sane_lists", + "smarty", + "toc", + "attr_list", + "md_in_html", +] + +MARKDOWN_EXT_CONFIG = { + "codehilite": { + "css_class": "highlight", + "guess_lang": True, + "noclasses": True, + }, +} + +app = Flask( + __name__, + template_folder=TEMPLATES_DIR, + static_folder=STATIC_DIR, + static_url_path="/static", +) +app.config["MAX_CONTENT_LENGTH"] = 64 * 1024 * 1024 # 64 MB + + +# helpers +def random_hex(length=32): + return secrets.token_hex(length // 2) + + +def pick_option(value, fallback, valid): + return value if value in valid else fallback + + +def sanitize_filename(name): + """keep only safe characters in a filename""" + name = os.path.basename(name.replace("\\", "/")) + out = [] + for ch in name: + if ch.isalnum() or ch in "-_.": + out.append(ch) + elif ch == " ": + out.append("_") + return "".join(out) + + +def is_allowed_image(filename): + dot = filename.rfind(".") + if dot < 1 or dot == len(filename) - 1: + return False + ext = filename[dot + 1:].lower() + return ext in ALLOWED_IMAGE_EXTS + + +def is_safe_relative_path(path_part): + return ( + bool(path_part) + and ".." not in path_part + and "\\" not in path_part + and not path_part.startswith("/") + ) + + +def read_partial(name, replacements=None): + """read a partial html template and apply replacements""" + path = os.path.join(PARTIALS_DIR, name) + with open(path, "r", encoding="utf-8") as f: + content = f.read() + if replacements: + for token, value in replacements.items(): + content = content.replace(token, value) + return content + + +def tail_text(value, max_len=1200): + if len(value) <= max_len: + return value + return value[-max_len:] + + +# pdf stylesheet generator +def build_pdf_css(paper_size, margin, font_family, line_spacing, show_page_numbers): + """build the css for weasyprint pdf rendering""" + page_dims = PAPER_CSS.get(paper_size, "8.5in 11in") + + if font_family == "sans": + font_stack = '"Helvetica Neue", Helvetica, Arial, "Noto Sans", sans-serif' + else: + font_stack = '"Georgia", "Noto Serif", "Times New Roman", serif' + + page_number_css = "" + if show_page_numbers: + page_number_css = """ + @bottom-center { + content: counter(page); + font-size: 9pt; + color: #666; + }""" + + return f""" +@page {{ + size: {page_dims}; + margin: {margin};{page_number_css} +}} + +body {{ + font-family: {font_stack}; + font-size: 11pt; + line-height: {line_spacing}; + color: #000; + word-wrap: break-word; + overflow-wrap: break-word; +}} + +h1, h2, h3, h4, h5, h6 {{ + margin-top: 1em; + margin-bottom: 0.4em; + page-break-after: avoid; +}} + +h1 {{ font-size: 20pt; }} +h2 {{ font-size: 16pt; }} +h3 {{ font-size: 13pt; }} +h4 {{ font-size: 11pt; }} + +p {{ + margin: 0 0 0.6em 0; +}} + +pre {{ + background: #f5f5f5; + border: 1px solid #ddd; + border-radius: 3px; + padding: 0.6em; + font-size: 9pt; + white-space: pre-wrap; + word-wrap: break-word; + overflow-wrap: break-word; + page-break-inside: avoid; +}} + +code {{ + font-family: "Courier New", Courier, "Liberation Mono", monospace; + font-size: 9pt; +}} + +p > code, li > code {{ + background: #f0f0f0; + padding: 0.1em 0.3em; + border-radius: 2px; +}} + +blockquote {{ + border-left: 3px solid #ccc; + margin: 0.6em 0; + padding: 0.3em 0.8em; + color: #555; +}} + +table {{ + border-collapse: collapse; + width: 100%; + margin: 0.6em 0; + page-break-inside: avoid; +}} + +th, td {{ + border: 1px solid #ccc; + padding: 0.4em 0.6em; + text-align: left; +}} + +th {{ + background: #f5f5f5; + font-weight: bold; +}} + +img {{ + max-width: 100%; + height: auto; +}} + +a {{ + color: #0066cc; + text-decoration: underline; +}} + +hr {{ + border: none; + border-top: 1px solid #ccc; + margin: 1em 0; +}} + +ul, ol {{ + margin: 0.4em 0; + padding-left: 1.5em; +}} + +li {{ + margin-bottom: 0.2em; +}} +""" + + +# pdf conversion +def markdown_to_html(source): + """convert markdown text to an html fragment""" + return markdown( + source, + extensions=MARKDOWN_EXTENSIONS, + extension_configs=MARKDOWN_EXT_CONFIG, + ) + + +def build_full_html(body_html, css): + """wrap the converted html body in a full document with styles""" + return f""" + + + + + + +{body_html} + +""" + + +def convert_with_weasyprint(full_html, output_path): + """render html to pdf via weasyprint. returns (ok, error_msg).""" + try: + doc = HTML( + string=full_html, + base_url=BASE_DIR, + ) + doc.write_pdf(output_path) + return True, "" + except Exception as exc: + return False, str(exc) + + +def convert_with_reportlab(source_markdown, output_path, paper_size, margin, + font_family, line_spacing): + """fallback: produce a basic text pdf with reportlab. + not pretty, but guarantees a file is always created.""" + from reportlab.lib.pagesizes import ( + A0, A1, A2, A3, A4, A5, A6, + B0, B1, B2, B3, B4, B5, B6, + LETTER, LEGAL, LEDGER, TABLOID, + ) + from reportlab.lib.units import inch, mm + from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, Preformatted + from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle + from reportlab.lib.enums import TA_LEFT + + size_map = { + "a0paper": A0, "a1paper": A1, "a2paper": A2, "a3paper": A3, + "a4paper": A4, "a5paper": A5, "a6paper": A6, + "b0paper": B0, "b1paper": B1, "b2paper": B2, "b3paper": B3, + "b4paper": B4, "b5paper": B5, "b6paper": B6, + "letterpaper": LETTER, "legalpaper": LEGAL, + "executivepaper": (7 * inch, 10 * inch), + "ledgerpaper": LEDGER, "tabloid": TABLOID, + "statement": (5.5 * inch, 8.5 * inch), + "flsa": (8.5 * inch, 13 * inch), + "c4paper": (229 * mm, 324 * mm), + "c5paper": (162 * mm, 229 * mm), + "c6paper": (114 * mm, 162 * mm), + } + + margin_map = { + "0.25in": 0.25 * inch, "0.5in": 0.5 * inch, "0.75in": 0.75 * inch, + "1in": 1.0 * inch, "1.25in": 1.25 * inch, "1.5in": 1.5 * inch, + "1.75in": 1.75 * inch, + } + + pagesize = size_map.get(paper_size, LETTER) + m = margin_map.get(margin, 1.0 * inch) + + doc = SimpleDocTemplate( + output_path, + pagesize=pagesize, + leftMargin=m, rightMargin=m, + topMargin=m, bottomMargin=m, + ) + + styles = getSampleStyleSheet() + font_name = "Helvetica" if font_family == "sans" else "Times-Roman" + spacing_val = float(line_spacing) if line_spacing else 1.0 + + body_style = ParagraphStyle( + "BodyCustom", + parent=styles["Normal"], + fontName=font_name, + fontSize=11, + leading=11 * spacing_val * 1.2, + alignment=TA_LEFT, + ) + + code_style = ParagraphStyle( + "CodeCustom", + parent=styles["Code"], + fontName="Courier", + fontSize=9, + leading=11, + leftIndent=12, + ) + + story = [] + in_code_block = False + code_lines = [] + + for line in source_markdown.splitlines(): + if line.startswith("```"): + if in_code_block: + # close code block + code_text = "\n".join(code_lines) + story.append(Preformatted(code_text, code_style)) + story.append(Spacer(1, 6)) + code_lines = [] + in_code_block = False + else: + in_code_block = True + continue + + if in_code_block: + code_lines.append(line) + continue + + stripped = line.strip() + + if not stripped: + story.append(Spacer(1, 6)) + continue + + # heading detection + if stripped.startswith("#"): + level = len(stripped) - len(stripped.lstrip("#")) + level = min(level, 6) + text = stripped.lstrip("#").strip() + heading_style = ParagraphStyle( + f"H{level}", + parent=styles["Heading1"], + fontName=font_name, + fontSize=max(20 - (level * 2), 11), + ) + story.append(Paragraph(text, heading_style)) + story.append(Spacer(1, 4)) + continue + + story.append(Paragraph(line, body_style)) + + # flush any unclosed code block + if code_lines: + code_text = "\n".join(code_lines) + story.append(Preformatted(code_text, code_style)) + + doc.build(story) + + +def generate_pdf(source_markdown, output_path, paper_size, margin, + font_family, line_spacing, show_page_numbers): + """convert markdown to pdf. always produces a file.""" + body_html = markdown_to_html(source_markdown) + css = build_pdf_css(paper_size, margin, font_family, line_spacing, show_page_numbers) + full_html = build_full_html(body_html, css) + + ok, err = convert_with_weasyprint(full_html, output_path) + if ok: + return True, "" + + # weasyprint failed — fall back to reportlab + try: + convert_with_reportlab( + source_markdown, output_path, + paper_size, margin, font_family, line_spacing, + ) + return True, f"(used fallback renderer) {err}" + except Exception as fallback_err: + return False, f"weasyprint: {err} | reportlab: {fallback_err}" + + +# routes +@app.route("/") +def index(): + index_path = os.path.join(TEMPLATES_DIR, "index.html") + with open(index_path, "r", encoding="utf-8") as f: + return f.read() + + +@app.route("/convert", methods=["POST"]) +def convert(): + md = request.form.get("markdown", "").strip() + if not md: + return read_partial("error.html", { + "{{ message }}": "Markdown content is required.", + }), 400 + + paper_size = pick_option( + request.form.get("paper_size", ""), "letterpaper", VALID_PAPER_SIZES, + ) + margin = pick_option( + request.form.get("margin", ""), "1in", VALID_MARGINS, + ) + + font_family = request.form.get("main_font", "serif") + if font_family not in ("serif", "sans"): + font_family = "serif" + + line_spacing = pick_option( + request.form.get("line_spacing", ""), "1", VALID_LINE_SPACINGS, + ) + show_page_numbers = request.form.get("page_numbers") == "on" + + epoch = int(time.time()) + output_name = f"{APP_NAME}_{epoch}_{random_hex()}.pdf" + output_path = os.path.join(GENERATED_DIR, output_name) + + ok, err = generate_pdf( + md, output_path, + paper_size, margin, font_family, line_spacing, show_page_numbers, + ) + + if not ok: + return read_partial("error.html", { + "{{ message }}": str(escape(tail_text(err))), + }), 500 + + return read_partial("result.html", { + "{{ filename }}": str(escape(output_name)), + "{{ download_url }}": f"/download/{output_name}", + }) + + +@app.route("/upload-image", methods=["POST"]) +def upload_image(): + uploaded = request.files.get("image") + if not uploaded or not uploaded.filename or not uploaded.filename.strip(): + return read_partial("upload_error.html", { + "{{ message }}": "image file is required.", + }), 400 + + original = sanitize_filename(uploaded.filename) + if not original or not is_allowed_image(original): + return read_partial("upload_error.html", { + "{{ message }}": "unsupported image type.", + }), 400 + + ext = original.rsplit(".", 1)[-1].lower() + epoch = int(time.time()) + stored_name = f"img_{epoch}_{random_hex()}.{ext}" + image_path = os.path.join(UPLOADS_DIR, stored_name) + uploaded.save(image_path) + + snippet = f"![](uploads/{stored_name})" + return read_partial("upload_result.html", { + "{{ filename }}": str(escape(stored_name)), + "{{ markdown_snippet }}": str(escape(snippet)), + "{{ preview_url }}": f"/uploads/{stored_name}", + }) + + +@app.route("/uploads/") +def serve_upload(filename): + if not is_safe_relative_path(filename): + abort(400) + return send_from_directory(UPLOADS_DIR, filename) + + +@app.route("/download/") +def download(filename): + if not is_safe_relative_path(filename): + abort(400) + return send_from_directory( + GENERATED_DIR, filename, + as_attachment=True, + download_name=filename, + ) + + +# main +if __name__ == "__main__": + os.makedirs(GENERATED_DIR, exist_ok=True) + os.makedirs(UPLOADS_DIR, exist_ok=True) + + print(f" {APP_NAME} listening on http://localhost:{PORT}") + app.run(host="0.0.0.0", port=PORT, debug=False) -- cgit v1.2.3