first-commit

skills/pptx-html-fidelity-audit/scripts/extract_pptx.py

@@ -0,0 +1,134 @@
+#!/usr/bin/env python3
+"""
+Extract every shape on every slide of a .pptx into a JSON dump.
+
+Usage:
+    python extract_pptx.py <path/to/deck.pptx>            # prints to stdout
+    python extract_pptx.py <path/to/deck.pptx> -o dump.json
+
+The dump captures the *actual* state of the export — text content, position,
+size, and per-run typography (font name, size, bold, italic, color). Use this
+as the ground truth for the fidelity audit; do not trust the export script's
+intent.
+
+Coordinates are reported in inches (rounded to 3 decimals) so they're
+human-readable when comparing against rails like CONTENT_MAX_Y = 6.70".
+"""
+from __future__ import annotations
+
+import argparse
+import json
+import sys
+from pathlib import Path
+
+try:
+    from pptx import Presentation
+    from pptx.util import Emu
+except ImportError:
+    sys.stderr.write(
+        "python-pptx is required. Install with: pip install python-pptx\n"
+    )
+    sys.exit(2)
+
+
+def emu_to_in(emu: int | None) -> float | None:
+    if emu is None:
+        return None
+    return round(emu / 914400, 3)
+
+
+def color_repr(color) -> str | None:
+    """Best-effort color extraction. Returns hex string or None."""
+    if color is None:
+        return None
+    try:
+        # ColorFormat.type may be None when no explicit color is set.
+        if color.type is None:
+            return None
+        rgb = color.rgb
+        if rgb is None:
+            return None
+        return f"#{str(rgb).lower()}"
+    except (AttributeError, ValueError, TypeError):
+        return None
+
+
+def extract_runs(text_frame) -> list[dict]:
+    runs = []
+    for para in text_frame.paragraphs:
+        for run in para.runs:
+            font = run.font
+            runs.append({
+                "text": run.text,
+                "font": font.name,
+                "size_pt": float(font.size.pt) if font.size is not None else None,
+                "bold": bool(font.bold) if font.bold is not None else None,
+                "italic": bool(font.italic) if font.italic is not None else None,
+                # Color is independent of font name/size: a run can inherit
+                # font from the theme yet set its own color. Color drift is
+                # one of the things this audit needs to catch, so don't gate
+                # the extraction on unrelated font attributes.
+                "color": color_repr(font.color),
+            })
+    return runs
+
+
+def extract_shape(shape) -> dict:
+    data = {
+        "name": shape.name,
+        "shape_type": str(shape.shape_type) if shape.shape_type is not None else None,
+        "left_in": emu_to_in(shape.left),
+        "top_in": emu_to_in(shape.top),
+        "width_in": emu_to_in(shape.width),
+        "height_in": emu_to_in(shape.height),
+    }
+    if shape.left is not None and shape.height is not None and shape.top is not None:
+        data["bottom_in"] = emu_to_in(shape.top + shape.height)
+        data["right_in"] = emu_to_in(shape.left + shape.width)
+    if shape.has_text_frame:
+        tf = shape.text_frame
+        data["text"] = tf.text
+        data["runs"] = extract_runs(tf)
+    return data
+
+
+def extract_pptx(path: Path) -> dict:
+    prs = Presentation(str(path))
+    canvas = {
+        "width_in": emu_to_in(prs.slide_width),
+        "height_in": emu_to_in(prs.slide_height),
+    }
+    slides = []
+    for i, slide in enumerate(prs.slides, 1):
+        shapes = [extract_shape(s) for s in slide.shapes]
+        slides.append({"index": i, "shapes": shapes})
+    return {
+        "source": str(path),
+        "canvas": canvas,
+        "slide_count": len(slides),
+        "slides": slides,
+    }
+
+
+def main() -> int:
+    ap = argparse.ArgumentParser(description=__doc__.split("\n\n")[0])
+    ap.add_argument("path", type=Path, help=".pptx file to extract")
+    ap.add_argument("-o", "--output", type=Path, help="write JSON to this path; default stdout")
+    args = ap.parse_args()
+
+    if not args.path.exists():
+        ap.error(f"file not found: {args.path}")
+
+    data = extract_pptx(args.path)
+    payload = json.dumps(data, ensure_ascii=False, indent=2)
+    if args.output:
+        args.output.write_text(payload, encoding="utf-8")
+        sys.stderr.write(f"wrote {args.output} ({len(payload)} bytes, {data['slide_count']} slides)\n")
+    else:
+        sys.stdout.write(payload)
+        sys.stdout.write("\n")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())