initial import: random background api

build.py

@@ -0,0 +1,161 @@
+#!/usr/bin/env python3
+from __future__ import annotations
+
+import json
+import os
+import re
+import subprocess
+import sys
+import venv
+from datetime import datetime, timezone
+from pathlib import Path
+
+BASE_DIR = Path(__file__).resolve().parent
+MANIFEST_PATH = BASE_DIR / "manifest.json"
+
+VARIANTS = {
+    "mobile": [BASE_DIR / "mobile-image"],
+    "desktop": [BASE_DIR / "desketop-image"],
+}
+
+INPUT_EXTENSIONS = {
+    ".jpg",
+    ".jpeg",
+    ".png",
+    ".bmp",
+    ".gif",
+    ".tif",
+    ".tiff",
+    ".webp",
+}
+
+GENERATED_NAME_RE = re.compile(r"^\d+\.webp$", re.IGNORECASE)
+VENV_DIR = BASE_DIR / ".build-venv"
+
+
+def ensure_pillow() -> None:
+    try:
+        from PIL import Image  # noqa: F401
+        return
+    except Exception:
+        pass
+
+    venv_python = VENV_DIR / "bin" / "python"
+    if not venv_python.exists():
+        print("Pillow not found, creating a local build venv...", file=sys.stderr)
+        builder = venv.EnvBuilder(with_pip=True)
+        builder.create(VENV_DIR)
+
+    has_pillow = subprocess.run(
+        [str(venv_python), "-c", "import PIL"],
+        stdout=subprocess.DEVNULL,
+        stderr=subprocess.DEVNULL,
+        check=False,
+    ).returncode == 0
+
+    if not has_pillow:
+        print("Installing Pillow into the local build venv...", file=sys.stderr)
+        subprocess.check_call([str(venv_python), "-m", "pip", "install", "--quiet", "Pillow"])
+    os.execv(str(venv_python), [str(venv_python), str(Path(__file__).resolve()), *sys.argv[1:]])
+
+
+def load_pillow():
+    ensure_pillow()
+    from PIL import Image, ImageOps
+
+    return Image, ImageOps
+
+
+def iter_source_files(directory: Path) -> list[Path]:
+    if not directory.exists():
+        return []
+    files: list[Path] = []
+    for path in sorted(directory.iterdir(), key=lambda item: item.name.lower()):
+        if not path.is_file():
+            continue
+        if GENERATED_NAME_RE.match(path.name):
+            continue
+        if path.suffix.lower() not in INPUT_EXTENSIONS:
+            continue
+        files.append(path)
+    return files
+
+
+def select_source_directory(candidates: list[Path]) -> Path:
+    for directory in candidates:
+        if iter_source_files(directory):
+            return directory
+    for directory in candidates:
+        if directory.exists():
+            return directory
+    return candidates[0]
+
+
+def clear_generated_files(directory: Path) -> None:
+    if not directory.exists():
+        directory.mkdir(parents=True, exist_ok=True)
+        return
+    for path in directory.iterdir():
+        if path.is_file() and GENERATED_NAME_RE.match(path.name):
+            path.unlink()
+
+
+def convert_to_webp(source: Path, target: Path, image_mod, image_ops) -> None:
+    with image_mod.open(source) as image:
+        image = image_ops.exif_transpose(image)
+        if image.mode not in {"RGB", "RGBA", "LA", "P"}:
+            image = image.convert("RGBA")
+        elif image.mode == "P":
+            image = image.convert("RGBA")
+        elif image.mode == "LA":
+            image = image.convert("RGBA")
+        elif image.mode == "RGB":
+            pass
+        image.save(target, format="WEBP", quality=92, method=6)
+
+
+def build_variant(name: str, directories: list[Path], image_mod, image_ops) -> dict:
+    directory = select_source_directory(directories)
+    directory.mkdir(parents=True, exist_ok=True)
+    clear_generated_files(directory)
+
+    sources = iter_source_files(directory)
+    images: list[str] = []
+    for index, source in enumerate(sources, start=1):
+        target = directory / f"{index}.webp"
+        try:
+            convert_to_webp(source, target, image_mod, image_ops)
+            images.append(target.name)
+            print(f"[{name}] {source.name} -> {target.name}")
+        except Exception as exc:
+            print(f"[{name}] skip {source.name}: {exc}", file=sys.stderr)
+
+    return {
+        "folder": directory.name,
+        "count": len(images),
+        "images": images,
+    }
+
+
+def write_manifest(manifest: dict) -> None:
+    MANIFEST_PATH.write_text(json.dumps(manifest, ensure_ascii=False, indent=2) + "\n", encoding="utf-8")
+
+
+def main() -> int:
+    image_mod, image_ops = load_pillow()
+
+    manifest = {
+        "generated_at": datetime.now(timezone.utc).isoformat(),
+        "variants": {},
+    }
+
+    for name, directories in VARIANTS.items():
+        manifest["variants"][name] = build_variant(name, directories, image_mod, image_ops)
+
+    write_manifest(manifest)
+    print(f"Wrote manifest: {MANIFEST_PATH}")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())