from datetime import date, datetime, timedelta from pathlib import Path from PIL import Image, ImageDraw, ImageFont from app.core.config import settings from app.core.paths import data_path from app.models import Certificate, CertificateAccessToken, Learner, ProjectCourse def pdf_cache_path(certificate_no: str) -> Path: safe_name = certificate_no.replace("/", "_") year = safe_name[2:6] if len(safe_name) >= 6 else "misc" folder = data_path("pdf-cache") / year folder.mkdir(parents=True, exist_ok=True) return folder / f"{safe_name}.pdf" def cached_pdf_is_fresh(path: Path) -> bool: if not path.exists(): return False modified_at = datetime.fromtimestamp(path.stat().st_mtime) return modified_at >= datetime.now() - timedelta(days=settings.pdf_cache_days) def render_certificate_pdf( certificate: Certificate, learner: Learner, project: ProjectCourse | None, token: CertificateAccessToken, ) -> Path: output_path = pdf_cache_path(certificate.certificate_no) template_path = Path(__file__).resolve().parents[1] / "assets" / "certificate-template.jpg" latest_renderer_mtime = max(template_path.stat().st_mtime, Path(__file__).stat().st_mtime) if cached_pdf_is_fresh(output_path) and output_path.stat().st_mtime >= latest_renderer_mtime: return output_path image = render_certificate_image(certificate, learner, project) image.save(output_path, "PDF", resolution=150.0) certificate.pdf_status = "generated" certificate.pdf_file_path = str(output_path) return output_path def render_certificate_image(certificate: Certificate, learner: Learner, project: ProjectCourse | None) -> Image.Image: template = Path(__file__).resolve().parents[1] / "assets" / "certificate-template.jpg" image = Image.open(template).convert("RGB") base_image = image.copy() draw = ImageDraw.Draw(image) issue_year, issue_month, issue_day = date_parts(certificate.issue_date) course_name = certificate.course_name or certificate.certificate_name or (project.name if project else certificate.project_code) stage_name = certificate.stage_name or "\u521d\u7ea7\u8bfe\u7a0b\u7684\u4e13\u4e1a\u5b66\u4e60\u3002" for box in [(150, 442, 760, 132), (404, 675, 220, 38)]: paper_patch(image, box) draw.text((512, 414), learner.current_name, fill="#111111", font=font(32, "kai", True), anchor="mm") x = 185.0 y = 494 x = draw_inline(draw, x, y, "\u5728", 24, 18) x = draw_inline(draw, x, y, issue_year, 24, 8, "kai", True) x = draw_inline(draw, x, y, "\u5e74", 24, 12) x = draw_inline(draw, x, y, issue_month, 24, 6, "kai", True) x = draw_inline(draw, x, y, "\u6708", 24, 12) x = draw_inline(draw, x, y, issue_day, 24, 4, "kai", True) x = draw_inline(draw, x, y, "\u65e5\u81f3", 24, 12) x = draw_inline(draw, x, y, issue_year, 24, 8, "kai", True) x = draw_inline(draw, x, y, "\u5e74", 24, 12) x = draw_inline(draw, x, y, issue_month, 24, 6, "kai", True) x = draw_inline(draw, x, y, "\u6708", 24, 12) x = draw_inline(draw, x, y, issue_day, 24, 4, "kai", True) x = draw_inline(draw, x, y, "\u65e5\u5b8c\u6210\u4e86", 24, 8) draw_inline_flow(draw, [(f"\u201c{course_name}\u201d", "course", 0), (stage_name, "normal", 14)], x, y) draw.text((512, 704), f"\u53d1\u8bc1\u65e5\u671f\uff1a{issue_year} \u5e74 {issue_month} \u6708 {issue_day} \u65e5", fill="#43382f", font=font(13, "song", True), anchor="mm") draw.text((105, 76), f"\u8bc1\u4e66\u7f16\u53f7\uff1a{certificate.certificate_no}", fill="#111827", font=font(14, "hei", True)) image.paste(base_image.crop((720, 535, 950, 629)), (720, 535)) return image def font(size: int, kind: str = "song", bold: bool = False) -> ImageFont.FreeTypeFont | ImageFont.ImageFont: choices = { "kai": [r"C:\Windows\Fonts\simkai.ttf", r"C:\Windows\Fonts\msyh.ttc", r"C:\Windows\Fonts\simsun.ttc"], "hei": [r"C:\Windows\Fonts\simhei.ttf", r"C:\Windows\Fonts\msyhbd.ttc", r"C:\Windows\Fonts\msyh.ttc"], "song": [r"C:\Windows\Fonts\msyh.ttc", r"C:\Windows\Fonts\simsun.ttc"], } paths = choices.get(kind, choices["song"]) if bold and kind == "song": paths = [r"C:\Windows\Fonts\msyhbd.ttc", r"C:\Windows\Fonts\simhei.ttf"] + paths for item in paths: if Path(item).exists(): try: return ImageFont.truetype(item, size) except Exception: pass return ImageFont.load_default() def date_parts(value: date | str | None) -> tuple[str, str, str]: if isinstance(value, date): return str(value.year), str(value.month), str(value.day) raw = str(value or "").strip() for fmt in ("%Y-%m-%d", "%Y/%m/%d"): try: d = datetime.strptime(raw[:10], fmt) return str(d.year), str(d.month), str(d.day) except ValueError: pass today = date.today() return str(today.year), str(today.month), str(today.day) def paper_patch(image: Image.Image, box: tuple[int, int, int, int]) -> None: x, y, w, h = box patch = Image.new("RGB", (w, h), "#fbf7ef") source = image.crop((72, max(0, y), 160, max(0, y) + h)) for tx in range(0, w, source.width): patch.paste(source.crop((0, 0, min(source.width, w - tx), h)), (tx, 0)) cover = Image.new("RGB", (w, h), "#fbf7ef") image.paste(Image.blend(patch, cover, 0.38), (x, y)) def draw_inline(draw: ImageDraw.ImageDraw, x: float, y: int, value: str, size: int, gap: int, kind: str = "song", bold: bool = False) -> float: text_font = font(size, kind, bold) draw.text((x, y), value, fill="#111111", font=text_font, anchor="ls") if bold: draw.text((x + 0.45, y), value, fill="#111111", font=text_font, anchor="ls") return x + draw.textlength(value, font=text_font) + gap def draw_course_name(draw: ImageDraw.ImageDraw, value: str, x: float, y: int) -> int: max_width = 900 - x text_font = font(27, "kai", True) if draw.textlength(value, font=text_font) <= max_width: draw.text((x, y), value, fill="#111111", font=text_font) draw.text((x + 0.45, y), value, fill="#111111", font=text_font) return y start_y = y + 34 lines = split_by_width(draw, value, text_font, 690)[:2] for index, line in enumerate(lines): line_y = start_y + index * 34 draw.text((185, line_y), line, fill="#111111", font=text_font) draw.text((185.45, line_y), line, fill="#111111", font=text_font) return start_y + (len(lines) - 1) * 34 def draw_inline_flow(draw: ImageDraw.ImageDraw, segments: list[tuple[str, str, int]], start_x: float, start_y: int) -> None: x = start_x y = start_y line_start = 185 line_height = 42 for value, style, gap_before in segments: x += gap_before text_font = font(27, "kai", True) if style == "course" else font(24, "song", False) for char in value: max_right = 900 if y == start_y else 730 width = draw.textlength(char, font=text_font) if x + width > max_right and x > line_start: x = line_start y += line_height draw.text((x, y), char, fill="#111111", font=text_font, anchor="ls") if style == "course": draw.text((x + 0.45, y), char, fill="#111111", font=text_font, anchor="ls") x += width def split_by_width(draw: ImageDraw.ImageDraw, value: str, text_font: ImageFont.ImageFont, max_width: int) -> list[str]: lines: list[str] = [] line = "" for char in value: next_line = line + char if line and draw.textlength(next_line, font=text_font) > max_width: lines.append(line) line = char else: line = next_line if line: lines.append(line) return lines def draw_fit(draw: ImageDraw.ImageDraw, pos: tuple[int, int], value: str, text_font: ImageFont.ImageFont, fill: str, max_width: int) -> None: font_obj = text_font size = getattr(text_font, "size", 24) while draw.textlength(value, font=font_obj) > max_width and size > 12: size -= 1 font_obj = font(size, "song", True) draw.text(pos, value, fill=fill, font=font_obj)