first commit

backend/app/services/media.py

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+import io
+import re
+import uuid
+from pathlib import Path
+
+from fastapi import UploadFile
+from PIL import Image
+
+from app.storage import get_storage
+
+ALLOWED_EXTENSIONS = {".jpg", ".jpeg", ".png", ".webp"}
+MAX_BYTES = 8 * 1024 * 1024
+
+VARIANTS = {
+    "lg": 2400,
+    "md": 1200,
+    "thumb": 400,
+}
+
+
+def public_url_for_path(file_path: str) -> str:
+    normalized = file_path.replace("\\", "/").lstrip("/")
+    return get_storage().public_url(normalized)
+
+
+def thumb_path_for(file_path: str) -> str | None:
+    normalized = file_path.replace("\\", "/")
+    if "_lg." in normalized:
+        return re.sub(r"_lg\.(\w+)$", r"_thumb.\1", normalized)
+    base, ext = normalized.rsplit(".", 1) if "." in normalized else (normalized, "webp")
+    return f"{base}_thumb.{ext}"
+
+
+def thumb_url_for_path(file_path: str) -> str | None:
+    thumb = thumb_path_for(file_path)
+    if not thumb:
+        return None
+    return get_storage().public_url(thumb)
+
+
+def _encode_variant(img: Image.Image, max_edge: int) -> bytes:
+    work = img.convert("RGB") if img.mode in ("RGBA", "P") else img
+    w, h = work.size
+    if max(w, h) > max_edge:
+        ratio = max_edge / max(w, h)
+        work = work.resize((int(w * ratio), int(h * ratio)), Image.Resampling.LANCZOS)
+    buf = io.BytesIO()
+    work.save(buf, format="WEBP", quality=85 if max_edge >= 1200 else 80)
+    return buf.getvalue()
+
+
+def save_image(upload: UploadFile) -> str:
+    suffix = Path(upload.filename or "").suffix.lower()
+    if suffix not in ALLOWED_EXTENSIONS:
+        raise ValueError("Only JPG, PNG, and WebP images are allowed")
+
+    raw = upload.file.read()
+    if len(raw) > MAX_BYTES:
+        raise ValueError("Image must be under 8 MB")
+
+    storage = get_storage()
+    base = uuid.uuid4().hex
+    primary_key = f"{base}_lg.webp"
+
+    with Image.open(io.BytesIO(raw)) as img:
+        for variant, edge in VARIANTS.items():
+            key = f"{base}_{variant}.webp"
+            storage.save(key, _encode_variant(img, edge), "image/webp")
+
+    return primary_key