Import ClientFlow production v4928.1.5.132.4

app/pdf_format_guard.py

@@ -0,0 +1,113 @@
+"""PDF format guardrails for customer-facing document delivery.
+
+ClientFlow normally receives Jasmin PDFs as opaque bytes.  For customer-facing
+invoice sends we still need one cheap safety check: invoices should be printable
+A4, not a narrow receipt-like page returned by a wrong Jasmin print layout.
+
+The parser is deliberately dependency-free.  It reads common uncompressed page
+boxes such as /MediaBox and /CropBox, which are present in PDFs returned by the
+Jasmin print endpoints observed in production.
+"""
+from __future__ import annotations
+
+import hashlib
+import re
+from typing import Any, Dict, List
+
+A4_PORTRAIT_PT = (595.0, 842.0)
+POINT_TO_MM = 25.4 / 72.0
+
+
+def _looks_a4(width_pt: float, height_pt: float, tolerance_pt: float = 20.0) -> bool:
+    pairs = [(width_pt, height_pt), (height_pt, width_pt)]
+    return any(
+        abs(w - A4_PORTRAIT_PT[0]) <= tolerance_pt and abs(h - A4_PORTRAIT_PT[1]) <= tolerance_pt
+        for w, h in pairs
+    )
+
+
+def extract_pdf_boxes(data: bytes) -> List[Dict[str, Any]]:
+    latin = data.decode("latin-1", errors="ignore")
+    pattern = re.compile(
+        r"/(MediaBox|CropBox)\s*\[\s*([-+0-9.]+)\s+([-+0-9.]+)\s+([-+0-9.]+)\s+([-+0-9.]+)\s*\]",
+        re.I,
+    )
+    boxes: List[Dict[str, Any]] = []
+    seen: set[tuple[str, float, float, float, float]] = set()
+    for m in pattern.finditer(latin):
+        kind = m.group(1)
+        x0, y0, x1, y1 = (float(m.group(i)) for i in range(2, 6))
+        key = (kind.lower(), x0, y0, x1, y1)
+        if key in seen:
+            continue
+        seen.add(key)
+        w = abs(x1 - x0)
+        h = abs(y1 - y0)
+        boxes.append({
+            "kind": kind,
+            "width_pt": round(w, 2),
+            "height_pt": round(h, 2),
+            "width_mm": round(w * POINT_TO_MM, 1),
+            "height_mm": round(h * POINT_TO_MM, 1),
+            "orientation": "landscape" if w > h else "portrait",
+            "looks_a4": _looks_a4(w, h),
+        })
+    return boxes
+
+
+def analyze_pdf_format(data: bytes, content_type: str = "application/pdf") -> Dict[str, Any]:
+    info: Dict[str, Any] = {
+        "content_type": content_type,
+        "bytes": len(data or b""),
+        "sha256_12": hashlib.sha256(data or b"").hexdigest()[:12] if data else "",
+        "is_pdf_header": bool(data and data[:5] == b"%PDF-"),
+        "page_count_hint": None,
+        "boxes": [],
+        "format_warning": "",
+    }
+    if not data:
+        info["format_warning"] = "empty_response"
+        return info
+    if not info["is_pdf_header"]:
+        info["format_warning"] = "not_pdf_header"
+        return info
+    latin = data.decode("latin-1", errors="ignore")
+    page_count = len(re.findall(r"/Type\s*/Page(?!s)\b", latin))
+    info["page_count_hint"] = page_count or None
+    boxes = extract_pdf_boxes(data)
+    info["boxes"] = boxes
+    media_boxes = [b for b in boxes if str(b.get("kind") or "").lower() == "mediabox"]
+    if media_boxes and not any(bool(b.get("looks_a4")) for b in media_boxes):
+        info["format_warning"] = "non_a4_or_unexpected_mediabox"
+    elif len(data) < 15_000:
+        info["format_warning"] = "very_small_pdf"
+    elif len(data) > 2_500_000:
+        info["format_warning"] = "very_large_pdf"
+    return info
+
+
+def first_box_label(info: Dict[str, Any]) -> str:
+    boxes = info.get("boxes") if isinstance(info, dict) else []
+    if not boxes:
+        return "sem MediaBox/CropBox legível"
+    b = boxes[0]
+    return f"{b.get('kind') or 'Box'} {b.get('width_mm')}x{b.get('height_mm')}mm a4={b.get('looks_a4')}"
+
+
+def is_customer_send_blocking_pdf_warning(info: Dict[str, Any]) -> bool:
+    return str((info or {}).get("format_warning") or "") in {"not_pdf_header", "empty_response", "non_a4_or_unexpected_mediabox"}
+
+
+def invoice_pdf_block_message(document_number: str, info: Dict[str, Any]) -> str:
+    warning = str((info or {}).get("format_warning") or "")
+    box = first_box_label(info)
+    if warning == "non_a4_or_unexpected_mediabox":
+        return (
+            f"PDF da fatura {document_number or ''} bloqueado: o Jasmin devolveu formato não-A4 "
+            f"({box}). Verificar layout/template de impressão da série/tipo FA no Jasmin antes de enviar ao cliente."
+        ).strip()
+    if warning == "not_pdf_header":
+        return f"PDF da fatura {document_number or ''} bloqueado: o endpoint Jasmin não devolveu um PDF válido.".strip()
+    if warning == "empty_response":
+        return f"PDF da fatura {document_number or ''} bloqueado: resposta vazia do Jasmin.".strip()
+    return f"PDF da fatura {document_number or ''} bloqueado: {warning or 'formato inesperado'}.".strip()