pdf

1#!/usr/bin/env python32"""Create a PDF from a JSON spec using reportlab platypus.3 4Spec format (UTF-8 JSON):5{6  "title": "Example Report",7  "author": "example-author",8  "page_size": "A4",            // or "letter" (default: A4)9  "page_numbers": true,          // default true10  "elements": [11    {"type": "heading", "text": "Section 1", "level": 1},12    {"type": "paragraph", "text": "Body text..."},13    {"type": "table", "rows": [["H1", "H2"], ["a", "b"]], "header": true},14    {"type": "image", "path": "chart.png", "width": 400},15    {"type": "pagebreak"}16  ]17}18"""19from __future__ import annotations20 21import argparse22import json23import sys24 25 26def _reconfigure_stdio() -> None:27    for stream in (sys.stdout, sys.stderr):28        try:29            stream.reconfigure(encoding="utf-8")30        except Exception:31            pass32 33 34def build_pdf(spec: dict, out_path: str) -> int:35    try:36        from reportlab.lib import colors37        from reportlab.lib.pagesizes import A4, letter38        from reportlab.lib.styles import getSampleStyleSheet39        from reportlab.lib.units import inch40        from reportlab.platypus import (41            Image,42            PageBreak,43            Paragraph,44            SimpleDocTemplate,45            Spacer,46            Table,47            TableStyle,48        )49    except ImportError:50        print("Missing dependency: install with 'python3 -m pip install reportlab'", file=sys.stderr)51        return 252 53    page_size = letter if str(spec.get("page_size", "A4")).lower() == "letter" else A454    styles = getSampleStyleSheet()55    story = []56    for el in spec.get("elements", []):57        etype = el.get("type")58        if etype == "heading":59            level = min(max(int(el.get("level", 1)), 1), 3)60            story.append(Paragraph(el.get("text", ""), styles[f"Heading{level}"]))61        elif etype == "paragraph":62            story.append(Paragraph(el.get("text", ""), styles["BodyText"]))63            story.append(Spacer(1, 6))64        elif etype == "table":65            rows = el.get("rows", [])66            if not rows:67                continue68            table = Table(rows, repeatRows=1 if el.get("header", True) else 0)69            style = [70                ("GRID", (0, 0), (-1, -1), 0.5, colors.grey),71                ("VALIGN", (0, 0), (-1, -1), "TOP"),72            ]73            if el.get("header", True):74                style += [75                    ("BACKGROUND", (0, 0), (-1, 0), colors.lightgrey),76                    ("FONTNAME", (0, 0), (-1, 0), "Helvetica-Bold"),77                ]78            table.setStyle(TableStyle(style))79            story.append(table)80            story.append(Spacer(1, 10))81        elif etype == "image":82            kwargs = {}83            if el.get("width"):84                kwargs["width"] = float(el["width"])85            if el.get("height"):86                kwargs["height"] = float(el["height"])87            img = Image(el["path"], **kwargs)88            if "width" in kwargs and "height" not in kwargs:89                # keep aspect ratio90                ratio = img.imageHeight / img.imageWidth91                img.drawWidth = kwargs["width"]92                img.drawHeight = kwargs["width"] * ratio93            story.append(img)94            story.append(Spacer(1, 10))95        elif etype == "pagebreak":96            story.append(PageBreak())97        else:98            print(f"Warning: unknown element type {etype!r}, skipped", file=sys.stderr)99 100    def draw_page_number(canvas, doc):101        if spec.get("page_numbers", True):102            canvas.saveState()103            canvas.setFont("Helvetica", 9)104            canvas.drawCentredString(page_size[0] / 2.0, 0.5 * inch, f"Page {doc.page}")105            canvas.restoreState()106 107    doc = SimpleDocTemplate(108        out_path,109        pagesize=page_size,110        title=spec.get("title", ""),111        author=spec.get("author", ""),112    )113    doc.build(story, onFirstPage=draw_page_number, onLaterPages=draw_page_number)114    print(json.dumps({"output": out_path, "elements": len(spec.get("elements", []))}))115    return 0116 117 118def main() -> int:119    _reconfigure_stdio()120    parser = argparse.ArgumentParser(description="Create a PDF from a JSON spec (reportlab).")121    parser.add_argument("spec", help="Path to UTF-8 JSON spec file")122    parser.add_argument("-o", "--output", required=True, help="Output PDF path")123    args = parser.parse_args()124    with open(args.spec, encoding="utf-8") as fh:125        spec = json.load(fh)126    return build_pdf(spec, args.output)127 128 129if __name__ == "__main__":130    sys.exit(main())131