pigway-frame-flow/pigway_frame_flow/renderers/photo_caption.py

"""Full-bleed photo with a compact, single-line camera-style watermark."""

from io import BytesIO

from PIL import Image, ImageDraw

from pigway_frame_flow.renderers.images import convert
from pigway_frame_flow.renderers.photo_layout import WatermarkLayout


def render_captioned_photo(
    data,
    caption,
    font_loader,
    fit="cover",
    profile="color",
    *,
    size=(1200, 1600),
    layout_provider=None,
):
    width, height = size
    layout = (layout_provider or WatermarkLayout()).layout(size, caption)
    if not (
        0 < layout.footer_height < height
        and 0 < layout.margin < width / 2
        and layout.font_size > 0
    ):
        raise ValueError("Invalid photo layout")
    photo_height = height - layout.footer_height
    # Legacy tasks used contain: watermark photos now fill the photo area,
    # keeping aspect ratio and cropping rather than stretching or letterboxing.
    photo_data = convert(
        data,
        "smart" if fit == "smart" else "cover",
        profile,
        size=(width, photo_height),
    )
    canvas = Image.new("RGB", size, "white")
    with Image.open(BytesIO(photo_data)) as photo:
        canvas.paste(photo, (0, 0))
    draw = ImageDraw.Draw(canvas)
    values = [
        " ".join(str(caption.get(key, "")).split())
        for key in ("title", "date", "place")
    ]
    text = " · ".join(value for value in values if value)
    font_size = layout.font_size
    font = font_loader(font_size)
    available = width - 2 * layout.margin
    while font_size > 24 and draw.textlength(text, font=font) > available:
        font_size -= 2
        font = font_loader(font_size)
    # Shorten the title before touching the date/location. Never wrap the band.
    while draw.textlength(text, font=font) > available and len(values[0]) > 2:
        values[0] = values[0].rstrip("…")[:-1] + "…"
        text = " · ".join(value for value in values if value)
    while draw.textlength(text, font=font) > available and len(text) > 2:
        text = text.rstrip("…")[:-1] + "…"
    draw.text(
        (width - layout.margin, photo_height + layout.footer_height / 2),
        text,
        font=font,
        fill="black",
        anchor="rm",
    )
    out = BytesIO()
    canvas.save(out, "JPEG", quality=93, optimize=True)
    return out.getvalue()