"""Export helpers for packaging assets."""
from __future__ import annotations

from io import BytesIO

from PIL import Image, ImageDraw
from reportlab.lib.pagesizes import A4
from reportlab.lib.utils import ImageReader
from reportlab.pdfgen import canvas

try:
    import cairosvg  # type: ignore
except Exception:  # pragma: no cover
    cairosvg = None


def svg_to_png_bytes(svg_content: str, width: int = 1400, height: int = 1000) -> bytes:
    """Convert SVG content to PNG bytes with a Pillow fallback."""
    if cairosvg is not None:
        return cairosvg.svg2png(bytestring=svg_content.encode("utf-8"))

    # Fallback when cairosvg is unavailable: branded placeholder raster.
    img = Image.new("RGB", (width, height), "#0b1220")
    draw = ImageDraw.Draw(img)
    draw.rectangle((24, 24, width - 24, height - 24), outline="#00e5ff", width=3)
    draw.text((48, 56), "Foodlinkk Packaging Preview", fill="#e2e8f0")
    draw.text((48, 92), "Install cairosvg for full SVG rendering.", fill="#94a3b8")
    stream = BytesIO()
    img.save(stream, format="PNG")
    return stream.getvalue()


def svg_to_pdf_bytes(svg_content: str) -> bytes:
    """Render SVG in a PDF by first rasterizing to PNG."""
    png_data = svg_to_png_bytes(svg_content, width=1800, height=1300)
    png_image = Image.open(BytesIO(png_data)).convert("RGB")

    output = BytesIO()
    pdf = canvas.Canvas(output, pagesize=A4)
    page_w, page_h = A4

    img_w, img_h = png_image.size
    scale = min((page_w - 64) / img_w, (page_h - 64) / img_h)
    draw_w = img_w * scale
    draw_h = img_h * scale
    x = (page_w - draw_w) / 2
    y = (page_h - draw_h) / 2

    pdf.drawImage(ImageReader(png_image), x, y, width=draw_w, height=draw_h, preserveAspectRatio=True, mask="auto")
    pdf.showPage()
    pdf.save()
    return output.getvalue()