diff options
Diffstat (limited to 'src/app.py')
| -rw-r--r-- | src/app.py | 82 |
1 files changed, 27 insertions, 55 deletions
@@ -4,10 +4,11 @@ # production-friendly flask app with weasyprint + reportlab fallback import logging +import io import os import secrets import time -from pathlib import Path, PurePosixPath +from pathlib import Path from flask import ( Flask, @@ -15,7 +16,6 @@ from flask import ( current_app, request, send_from_directory, - abort, ) from markupsafe import escape from markdown import markdown @@ -29,7 +29,6 @@ DEFAULT_MAX_CONTENT_LENGTH = 512 * 1024 * 1024 DEFAULT_MAX_FORM_MEMORY_SIZE = DEFAULT_MAX_CONTENT_LENGTH BASE_DIR = Path(__file__).resolve().parent -GENERATED_DIR = BASE_DIR / "generated" TEMPLATES_DIR = BASE_DIR / "templates" PARTIALS_DIR = TEMPLATES_DIR / "partials" STATIC_DIR = BASE_DIR / "static" @@ -130,25 +129,10 @@ def env_bool(name, default=False): return raw.strip().lower() in {"1", "true", "yes", "on"} -def ensure_runtime_dirs(): - GENERATED_DIR.mkdir(parents=True, exist_ok=True) - - -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 is_safe_relative_path(path_part): - if not path_part or "\\" in path_part: - return False - safe_path = PurePosixPath(path_part) - return not safe_path.is_absolute() and ".." not in safe_path.parts - - def read_partial(name, replacements=None): """read a partial html template and apply replacements""" content = (PARTIALS_DIR / name).read_text(encoding="utf-8") @@ -382,21 +366,20 @@ def build_full_html(body_html, css): </html>""" -def convert_with_weasyprint(full_html, output_path): - """render html to pdf via weasyprint. returns (ok, error_msg).""" +def convert_with_weasyprint(full_html): + """render html to pdf via weasyprint. returns (ok, pdf_bytes, error_msg).""" try: doc = HTML( string=full_html, base_url=str(BASE_DIR), ) - doc.write_pdf(output_path) - return True, "" + return True, doc.write_pdf(), "" except Exception as exc: - return False, str(exc) + return False, b"", str(exc) def convert_with_reportlab( - source_markdown, output_path, paper_size, margin, font_family, line_spacing + source_markdown, paper_size, margin, font_family, line_spacing ): """fallback: produce a basic text pdf with reportlab. not pretty, but guarantees a file is always created.""" @@ -466,8 +449,10 @@ def convert_with_reportlab( pagesize = size_map.get(paper_size, LETTER) m = margin_map.get(margin, 1.0 * inch) + buffer = io.BytesIO() + doc = SimpleDocTemplate( - output_path, + buffer, pagesize=pagesize, leftMargin=m, rightMargin=m, @@ -547,11 +532,11 @@ def convert_with_reportlab( story.append(Preformatted(code_text, code_style)) doc.build(story) + return buffer.getvalue() def generate_pdf( source_markdown, - output_path, paper_size, margin, font_family, @@ -572,31 +557,28 @@ def generate_pdf( ) full_html = build_full_html(body_html, css) - ok, err = convert_with_weasyprint(full_html, output_path) + ok, pdf_bytes, err = convert_with_weasyprint(full_html) if ok: - return True, "" + return True, pdf_bytes, "" # weasyprint failed — fall back to reportlab try: current_app.logger.warning( "weasyprint failed, using reportlab fallback: %s", err ) - convert_with_reportlab( + pdf_bytes = convert_with_reportlab( source_markdown, - output_path, paper_size, margin, font_family, line_spacing, ) - return True, f"(used fallback renderer) {err}" + return True, pdf_bytes, f"(used fallback renderer) {err}" except Exception as fallback_err: - return False, f"weasyprint: {err} | reportlab: {fallback_err}" + return False, b"", f"weasyprint: {err} | reportlab: {fallback_err}" def create_app(): - ensure_runtime_dirs() - app = Flask( __name__, template_folder=str(TEMPLATES_DIR), @@ -701,12 +683,12 @@ def create_app(): ) disable_backgrounds = request.form.get("disable_backgrounds") == "on" - output_name = f"{APP_NAME}_{int(time.time())}_{random_hex()}.pdf" - output_path = GENERATED_DIR / output_name + download_name = ( + f"{APP_NAME}_{int(time.time())}_{secrets.token_hex(20)}.pdf" + ) - ok, err = generate_pdf( + ok, pdf_bytes, err = generate_pdf( md, - str(output_path), paper_size, margin, font_family, @@ -728,25 +710,15 @@ def create_app(): 500, ) - return read_partial( - "result.html", - { - "{{ filename }}": str(escape(output_name)), - "{{ download_url }}": f"/download/{output_name}", - }, - ) + if err: + app.logger.warning("pdf generated with fallback renderer: %s", err) - @app.route("/download/<path:filename>") - def download(filename): - if not is_safe_relative_path(filename): - abort(400) - return send_from_directory( - str(GENERATED_DIR), - filename, - as_attachment=True, - download_name=filename, - conditional=True, + response = Response(pdf_bytes, mimetype="application/pdf") + response.headers["Content-Disposition"] = ( + f'attachment; filename="{download_name}"' ) + response.headers["Cache-Control"] = "no-store" + return response return app |