Attachments support for the outbox

app/uploads.py

@@ -0,0 +1,100 @@
+import hashlib
+from shutil import COPY_BUFSIZE  # type: ignore
+
+import blurhash  # type: ignore
+from fastapi import UploadFile
+from loguru import logger
+from PIL import Image
+
+from app import activitypub as ap
+from app import models
+from app.config import BASE_URL
+from app.config import ROOT_DIR
+from app.database import Session
+
+UPLOAD_DIR = ROOT_DIR / "data" / "uploads"
+
+
+def save_upload(db: Session, f: UploadFile) -> models.Upload:
+    # Compute the hash
+    h = hashlib.blake2b(digest_size=32)
+    while True:
+        buf = f.file.read(COPY_BUFSIZE)
+        if not buf:
+            break
+        h.update(buf)
+
+    f.file.seek(0)
+    content_hash = h.hexdigest()
+
+    existing_upload = (
+        db.query(models.Upload)
+        .filter(models.Upload.content_hash == content_hash)
+        .one_or_none()
+    )
+    if existing_upload:
+        logger.info(f"Upload with {content_hash=} already exists")
+        return existing_upload
+
+    logger.info(f"Creating new Upload with {content_hash=}")
+    dest_filename = UPLOAD_DIR / content_hash
+    with open(dest_filename, "wb") as dest:
+        while True:
+            buf = f.file.read(COPY_BUFSIZE)
+            if not buf:
+                break
+            dest.write(buf)
+
+    has_thumbnail = False
+    image_blurhash = None
+    width = None
+    height = None
+
+    if f.content_type.startswith("image"):
+        with open(dest_filename, "rb") as df:
+            image_blurhash = blurhash.encode(df, x_components=4, y_components=3)
+
+        try:
+            with Image.open(dest_filename) as i:
+                width, height = i.size
+                i.thumbnail((740, 740))
+                i.save(UPLOAD_DIR / f"{content_hash}_resized", format=i.format)
+        except Exception:
+            logger.exception(
+                f"Failed to created thumbnail for {f.filename}/{content_hash}"
+            )
+        else:
+            has_thumbnail = True
+            logger.info("Thumbnail generated")
+
+    new_upload = models.Upload(
+        content_type=f.content_type,
+        content_hash=content_hash,
+        has_thumbnail=has_thumbnail,
+        blurhash=image_blurhash,
+        width=width,
+        height=height,
+    )
+    db.add(new_upload)
+    db.commit()
+
+    return new_upload
+
+
+def upload_to_attachment(upload: models.Upload, filename: str) -> ap.RawObject:
+    extra_attachment_fields = {}
+    if upload.blurhash:
+        extra_attachment_fields.update(
+            {
+                "blurhash": upload.blurhash,
+                "height": upload.height,
+                "width": upload.width,
+            }
+        )
+    return {
+        "type": "Document",
+        "mediaType": upload.content_type,
+        "name": filename,
+        "url": BASE_URL + f"/attachments/{upload.content_hash}",
+        **extra_attachment_fields,
+    }