release nouri 0.6.0 polish backup and pwa

nouri/images.py

@@ -0,0 +1,163 @@
+from __future__ import annotations
+
+import os
+import uuid
+from pathlib import Path
+
+from PIL import Image, ImageOps, UnidentifiedImageError
+from werkzeug.datastructures import FileStorage
+from werkzeug.utils import secure_filename
+
+
+ALLOWED_IMAGE_EXTENSIONS = {"png", "jpg", "jpeg", "gif", "webp"}
+IMAGE_VARIANTS = {
+    "sm": {"width": 320, "quality": 76},
+    "md": {"width": 720, "quality": 82},
+    "lg": {"width": 1280, "quality": 86},
+}
+DEFAULT_RENDERED_FORMAT = "webp"
+ORIGINAL_MAX_WIDTH = 1600
+
+
+def allowed_image_file(filename: str) -> bool:
+    return "." in filename and filename.rsplit(".", 1)[1].lower() in ALLOWED_IMAGE_EXTENSIONS
+
+
+def ensure_upload_structure(upload_folder: str | Path) -> None:
+    upload_root = Path(upload_folder)
+    upload_root.mkdir(parents=True, exist_ok=True)
+    (upload_root / "variants").mkdir(parents=True, exist_ok=True)
+    for variant_name in IMAGE_VARIANTS:
+        (upload_root / "variants" / variant_name).mkdir(parents=True, exist_ok=True)
+
+
+def build_variant_filename(filename: str, variant_name: str) -> str:
+    source = Path(filename)
+    return f"{source.stem}__{variant_name}.webp"
+
+
+def build_variant_relative_path(filename: str, variant_name: str) -> str:
+    return f"variants/{variant_name}/{build_variant_filename(filename, variant_name)}"
+
+
+def remove_photo_assets(upload_folder: str | Path, filename: str | None) -> None:
+    if not filename:
+        return
+    upload_root = Path(upload_folder)
+    original_path = upload_root / filename
+    if original_path.exists():
+        original_path.unlink()
+    for variant_name in IMAGE_VARIANTS:
+        variant_path = upload_root / build_variant_relative_path(filename, variant_name)
+        if variant_path.exists():
+            variant_path.unlink()
+
+
+def _open_image(upload: FileStorage) -> Image.Image:
+    upload.stream.seek(0)
+    image = Image.open(upload.stream)
+    image.load()
+    return ImageOps.exif_transpose(image)
+
+
+def _prepare_image(image: Image.Image) -> Image.Image:
+    if image.mode not in {"RGB", "RGBA"}:
+        image = image.convert("RGBA" if "A" in image.getbands() else "RGB")
+    return image
+
+
+def _resize_copy(image: Image.Image, width: int) -> Image.Image:
+    resized = image.copy()
+    resized.thumbnail((width, width * 3), Image.Resampling.LANCZOS)
+    return resized
+
+
+def _save_image(image: Image.Image, destination: Path, quality: int) -> None:
+    destination.parent.mkdir(parents=True, exist_ok=True)
+    image.save(
+        destination,
+        format=DEFAULT_RENDERED_FORMAT.upper(),
+        quality=quality,
+        method=6,
+    )
+
+
+def save_photo_with_variants(
+    upload: FileStorage | None,
+    upload_folder: str | Path,
+    current_filename: str | None = None,
+) -> str | None:
+    if not upload or not upload.filename:
+        return current_filename
+
+    if not allowed_image_file(upload.filename):
+        raise ValueError("Bitte ein Bild als PNG, JPG, GIF oder WEBP hochladen.")
+
+    ensure_upload_structure(upload_folder)
+
+    original_name = secure_filename(upload.filename)
+    extension = original_name.rsplit(".", 1)[1].lower()
+
+    try:
+        image = _prepare_image(_open_image(upload))
+        filename = f"{uuid.uuid4().hex}.webp"
+        original_path = Path(upload_folder) / filename
+        optimized = _resize_copy(image, ORIGINAL_MAX_WIDTH)
+        _save_image(optimized, original_path, quality=88)
+        for variant_name, config in IMAGE_VARIANTS.items():
+            variant_image = _resize_copy(image, int(config["width"]))
+            variant_path = Path(upload_folder) / build_variant_relative_path(filename, variant_name)
+            _save_image(variant_image, variant_path, quality=int(config["quality"]))
+    except (UnidentifiedImageError, OSError, ValueError):
+        filename = f"{uuid.uuid4().hex}.{extension}"
+        original_path = Path(upload_folder) / filename
+        upload.stream.seek(0)
+        upload.save(original_path)
+
+    if current_filename and current_filename != filename:
+        remove_photo_assets(upload_folder, current_filename)
+
+    return filename
+
+
+def image_url(filename: str | None, url_builder, variant: str = "md", upload_folder: str | Path | None = None) -> str | None:
+    if not filename:
+        return None
+    if variant in IMAGE_VARIANTS:
+        if upload_folder is not None:
+            variant_path = Path(upload_folder) / build_variant_relative_path(filename, variant)
+            if variant_path.exists():
+                return url_builder("uploaded_file", filename=build_variant_relative_path(filename, variant))
+        else:
+            return url_builder("uploaded_file", filename=build_variant_relative_path(filename, variant))
+    return url_builder("uploaded_file", filename=filename)
+
+
+def image_srcset(filename: str | None, url_builder, upload_folder: str | Path | None = None) -> str:
+    if not filename:
+        return ""
+    parts = []
+    for variant_name, config in IMAGE_VARIANTS.items():
+        variant_url = image_url(filename, url_builder, variant_name, upload_folder=upload_folder)
+        if variant_url and (not upload_folder or variant_url != url_builder("uploaded_file", filename=filename)):
+            parts.append(f"{variant_url} {config['width']}w")
+    original_width = max(config["width"] for config in IMAGE_VARIANTS.values()) + 320
+    parts.append(f"{url_builder('uploaded_file', filename=filename)} {original_width}w")
+    return ", ".join(parts)
+
+
+def image_sizes(card: str = "grid") -> str:
+    if card == "detail":
+        return "(max-width: 720px) 100vw, 720px"
+    return "(max-width: 720px) 42vw, (max-width: 1080px) 28vw, 180px"
+
+
+def upload_file_size_ok(upload: FileStorage | None, max_bytes: int) -> bool:
+    if not upload or not upload.filename:
+        return True
+    stream = upload.stream
+    current_position = stream.tell()
+    stream.seek(0, os.SEEK_END)
+    size = stream.tell()
+    stream.seek(current_position)
+    return size <= max_bytes