"""Raster-only resources; PDF bypasses export quotas but retains path/format validation.""" import base64 import hashlib import threading from io import BytesIO from PIL import Image from app.errors import ApiError _math_lock = threading.Lock() def enrich_document(document, file_path=None, unlimited=False, options=None, preserve_alpha=False): """Embed Vault images and MathText, with format-specific quotas and palette.""" from app.config import get_settings from urllib.parse import unquote, urlsplit vault = get_settings().vault_path.resolve() base = (vault / (file_path or '')).parent if file_path else vault from app.export.themes import pdf_palette palette = pdf_palette(options, []) if unlimited and options else None warnings = [] count = total = pixels = 0 def visit(node): nonlocal count, total, pixels if node.type in {'image','math_block','math_inline'} or node.attributes.get('static_png'): count += 1 try: if not unlimited and count > 64: raise ValueError('resource count') if node.attributes.get('static_png'): raw = node.attributes['static_png'] elif node.type == 'image': src = str(node.attributes.get('src','')) if urlsplit(src).scheme or src.startswith('//'): raise ValueError('remote image') path = (base / unquote(src)).resolve() if not path.is_relative_to(vault) or path.suffix.lower() not in {'.png','.jpg','.jpeg','.webp'} or (not unlimited and path.stat().st_size > 2_000_000): raise ValueError('image path or budget') raw = path.read_bytes() else: source = node.text depth = 0 for char in source: depth += (char == '{') - (char == '}') if not unlimited and depth > 20: raise ValueError('math depth') if (not unlimited and len(source) > 512) or depth != 0: raise ValueError('math budget') from matplotlib.mathtext import math_to_image from matplotlib import rc_context with _math_lock, rc_context({'savefig.transparent': bool(palette)}): out = BytesIO() math_to_image('$'+source+'$', out, dpi=180, format='png', color=palette['text'] if palette else 'black') raw = out.getvalue() with Image.open(BytesIO(raw)) as image: pixels += image.width * image.height if not unlimited and pixels > 16_000_000: raise ValueError('document pixels') if not unlimited and image.width * image.height > 4_000_000: raise ValueError('image dimensions') out = BytesIO() # Composite transparency over the PDF theme or the print/Word white surface. rgba=image.convert('RGBA'); background=Image.new('RGBA',rgba.size,palette['surface'] if palette else 'white') background.alpha_composite(rgba); (rgba if preserve_alpha else background.convert('RGB')).save(out,'PNG') png=out.getvalue();total += len(png) if not unlimited and total > 8_000_000: raise ValueError('resource bytes') node.attributes['static_png']=png except Exception: node.attributes.pop('static_png', None) warnings.append('图片无法内嵌（仅支持 Vault 内 PNG/JPEG/WebP），已保留替代文字' if node.type=='image' else '公式超出 MathText 语法或资源预算，已保留源码' if node.type.startswith('math') else '静态图表超过文档资源预算，已保留源码') for child in node.children: visit(child) for child in document.children: visit(child) return warnings def source_hash(source): return hashlib.sha256(source.strip().encode()).hexdigest() def validate_assets(assets, unlimited=False): result = {} total = pixels = 0 for asset in assets: try: raw = base64.b64decode(asset.png_base64, validate=True) total += len(raw) if not unlimited and total > 8 * 1024 * 1024: raise ValueError('asset budget') with Image.open(BytesIO(raw)) as image: pixels += image.width * image.height if not unlimited and pixels > 16_000_000: raise ValueError('document pixel budget') if image.format != 'PNG' or (not unlimited and image.width * image.height > 4_000_000): raise ValueError('image budget') image.load() out = BytesIO() rgba = image.convert('RGBA') background = Image.new('RGBA', rgba.size, 'white') background.alpha_composite(rgba) (rgba if unlimited else background.convert('RGB')).save(out, 'PNG') key = (asset.kind, asset.source_hash) if key in result: raise ValueError('duplicate asset') result[key] = out.getvalue() except Exception as exc: raise ApiError(422, 'EXPORT_ASSET_INVALID', 'Invalid PNG or resource budget exceeded.') from exc return result def attach_assets(document, assets): def visit(node): source = node.attributes.get('src', '') if node.type == 'image' else node.text key = (node.type, source_hash(source)) if key in assets: node.attributes['static_png'] = assets[key] for child in node.children: visit(child) for child in document.children: visit(child) def plot_png(plot): """DOCX consumes the same clipped geometry as SVG/PDF, rendered at 2x.""" from app.plot.render import compute_geometry, _sx, _sy, _fmt_num from PIL import ImageDraw, ImageFont geo = compute_geometry(plot) image = Image.new('RGB', (geo.width * 2, (geo.height + ((len(plot.expressions)+1)//2)*24) * 2), 'white') draw = ImageDraw.Draw(image) from app.export.fonts import FONT_PATH font = ImageFont.truetype(str(FONT_PATH), 20) if FONT_PATH else ImageFont.load_default(size=20) def line(points, color, width=2): draw.line([(x * 2, y * 2) for x, y in points], fill=color, width=width) sx = lambda x: _sx(x, geo.xmin, geo.xmax) sy = lambda y: _sy(y, geo.ymin, geo.ymax) for x in geo.xticks: if geo.grid: line([(sx(x),52),(sx(x),428)], '#d0d7de') draw.text((sx(x)*2, sy(geo.x_axis_y)*2+8), _fmt_num(x), fill='#57606a', font=font) for y in geo.yticks: if geo.grid: line([(52,sy(y)),(588,sy(y))], '#d0d7de') draw.text((max(0,sx(geo.y_axis_x)*2-75),sy(y)*2), _fmt_num(y), fill='#57606a', font=font) line([(52,sy(geo.x_axis_y)),(588,sy(geo.x_axis_y))], '#57606a') line([(sx(geo.y_axis_x),52),(sx(geo.y_axis_x),428)], '#57606a') for segments, color in zip(geo.polylines,geo.colors): for segment in segments: if len(segment)>1: line(segment,color,3) if geo.xlabel: draw.text((geo.width, (geo.height - 18)*2), geo.xlabel, fill='#1f2328', font=font, anchor='mm') if geo.ylabel: # Horizontal at the upper-left margin keeps CJK labels readable in Word. draw.text((24, 24), geo.ylabel, fill='#1f2328', font=font) for index, expression in enumerate(plot.expressions): draw.text((48+(index%2)*620,geo.height*2+index//2*48),expression.label or 'y = '+expression.expression,fill=geo.colors[index],font=font) out=BytesIO(); image.save(out,'PNG') return out.getvalue(), geo.warnings