Files
J621/backend/apps/library/services.py
T
JakeBreath ebac3ac922 Keep e621 metadata on downloaded posts; clear up account roles
Roles:
- JakeBreathild is now staff + superuser (the real account); the 'jake'
  smoke-test account was demoted to a regular user
- /me exposes is_superuser and the account page shows an admin badge

e621 metadata:
- MediaItem gains e621_post_id and e621_data (trimmed post payload:
  tags by category, rating, score, favourites, comments, sources,
  description, pools, relationships, file info, uploader)
- Download to Library accepts the post payload from the SPA and stores
  it; the item's custom rating is seeded from the e621 rating when empty
- Library detail shows an e621 metadata card: link to the in-app post,
  score/favourites/comments, taxonomy-coloured tags, DText description,
  sources and pools; grid cards get an e621 badge and fall back to the
  e621 rating for their colour (display_rating)
- Guest visibility now also considers e621 tags, so downloaded explicit
  content is hidden from anonymous visitors
2026-09-17 10:27:06 -05:00

258 lines
7.9 KiB
Python

import hashlib
import json
import mimetypes
import os
import re
import shutil
import subprocess
from pathlib import Path
from django.conf import settings
from django.http import FileResponse, Http404, HttpResponse
from django.utils.text import get_valid_filename
from .models import MediaItem, MediaLocation
ALLOWED_EXTENSIONS = {".jpg", ".jpeg", ".png", ".gif", ".apng", ".mp4", ".webm"}
VIDEO_EXTENSIONS = {".mp4", ".webm"}
CHUNK_SIZE = 1024 * 1024
RANGE_RE = re.compile(r"bytes=(\d*)-(\d*)$")
def compute_md5(path):
digest = hashlib.md5()
with open(path, "rb") as handle:
for chunk in iter(lambda: handle.read(CHUNK_SIZE), b""):
digest.update(chunk)
return digest.hexdigest()
def index_file(path, folder):
"""Index one file into MediaItem/MediaLocation.
Returns (item, created_item, created_location).
"""
path = Path(path)
folder = Path(folder)
stat = path.stat()
md5 = compute_md5(path)
item, created_item = MediaItem.objects.get_or_create(
md5=md5, defaults={"size": stat.st_size}
)
if not created_item and item.size != stat.st_size:
item.size = stat.st_size
item.save(update_fields=["size", "updated_at"])
location, created_location = MediaLocation.objects.update_or_create(
item=item,
path=str(path),
defaults={
"rel_path": str(path.relative_to(folder)),
"mtime": stat.st_mtime,
},
)
return item, created_item, created_location
def parse_tags(raw):
"""Normalize a comma-separated string or JSON list into a list of tags."""
if raw is None:
return None
if isinstance(raw, (list, tuple)):
values = raw
else:
text = str(raw).strip()
if not text:
return None
if text.startswith("["):
try:
values = json.loads(text)
except json.JSONDecodeError:
values = text.split(",")
else:
values = text.split(",")
cleaned = []
for value in values:
tag = str(value).strip()
if tag and tag not in cleaned:
cleaned.append(tag[:100])
return cleaned
def unique_destination(folder, filename):
"""Return a non-existing path inside folder for the given filename."""
folder = Path(folder)
folder.mkdir(parents=True, exist_ok=True)
filename = get_valid_filename(Path(filename).name) or "upload"
candidate = folder / filename
stem, suffix = candidate.stem, candidate.suffix
counter = 1
while candidate.exists():
candidate = folder / f"{stem}-{counter}{suffix}"
counter += 1
return candidate
class RangeFileWrapper:
"""Iterate over a limited byte range of an open file."""
def __init__(self, file, length, chunk_size=64 * 1024):
self.file = file
self.remaining = length
self.chunk_size = chunk_size
def __iter__(self):
return self
def __next__(self):
if self.remaining <= 0:
raise StopIteration
data = self.file.read(min(self.chunk_size, self.remaining))
if not data:
raise StopIteration
self.remaining -= len(data)
return data
def close(self):
self.file.close()
def serve_file(request, path, download=False):
"""Serve a file with HTTP range support (needed for video seeking)."""
path = Path(path)
if not path.is_file():
raise Http404
size = path.stat().st_size
content_type = mimetypes.guess_type(str(path))[0] or "application/octet-stream"
range_header = request.headers.get("Range", "").strip()
if range_header:
match = RANGE_RE.match(range_header)
if match:
start_raw, end_raw = match.groups()
if start_raw == "" and end_raw:
length = min(int(end_raw), size)
start, end = size - length, size - 1
else:
start = int(start_raw or 0)
end = min(int(end_raw) if end_raw else size - 1, size - 1)
if start >= size or start > end:
response = HttpResponse(status=416)
response["Content-Range"] = f"bytes */{size}"
return response
length = end - start + 1
handle = open(path, "rb")
handle.seek(start)
response = FileResponse(
RangeFileWrapper(handle, length),
status=206,
content_type=content_type,
)
response["Content-Length"] = str(length)
response["Content-Range"] = f"bytes {start}-{end}/{size}"
response["Accept-Ranges"] = "bytes"
return response
response = FileResponse(
open(path, "rb"),
content_type=content_type,
as_attachment=download,
filename=path.name,
)
response["Accept-Ranges"] = "bytes"
return response
def download_file(url, destination):
"""Stream a remote file into destination (used by Download to Library)."""
import requests
headers = {"User-Agent": settings.USER_AGENT}
with requests.get(url, headers=headers, stream=True, timeout=120) as response:
response.raise_for_status()
with open(destination, "wb") as handle:
for chunk in response.iter_content(chunk_size=CHUNK_SIZE):
if chunk:
handle.write(chunk)
E621_DESCRIPTION_LIMIT = 20000
def trim_e621_post(post):
"""Keep a compact, size-bounded copy of an e621 post payload."""
if not isinstance(post, dict):
return None
file_data = post.get("file") or {}
relationships = post.get("relationships") or {}
score = post.get("score") or {}
categories = post.get("tags") or {}
return {
"id": post.get("id"),
"created_at": post.get("created_at"),
"rating": post.get("rating"),
"tags": {
str(category): [str(tag)[:200] for tag in tags][:500]
for category, tags in categories.items()
if isinstance(tags, list)
},
"score": {
"up": score.get("up"),
"down": score.get("down"),
"total": score.get("total"),
},
"fav_count": post.get("fav_count"),
"comment_count": post.get("comment_count"),
"sources": [
str(source)[:500]
for source in (post.get("sources") or [])
if source
][:20],
"description": str(post.get("description") or "")[:E621_DESCRIPTION_LIMIT],
"pools": [
int(pool)
for pool in (post.get("pools") or [])
if str(pool).isdigit()
][:50],
"relationships": {
"parent_id": relationships.get("parent_id"),
"has_children": relationships.get("has_children"),
},
"file": {
"md5": file_data.get("md5"),
"ext": file_data.get("ext"),
"size": file_data.get("size"),
"width": file_data.get("width"),
"height": file_data.get("height"),
},
"uploader_name": post.get("uploader_name"),
}
def generate_video_thumbnail(md5, path):
"""Extract a JPEG thumbnail from a video, cached under MEDIA_ROOT/thumbs."""
if not shutil.which("ffmpeg"):
return None
thumbs_dir = Path(settings.MEDIA_ROOT) / "thumbs"
thumbs_dir.mkdir(parents=True, exist_ok=True)
target = thumbs_dir / f"{md5}.jpg"
if target.exists() and target.stat().st_mtime >= os.path.getmtime(path):
return target
command = [
"ffmpeg",
"-y",
"-ss",
"0.5",
"-i",
str(path),
"-frames:v",
"1",
"-vf",
"scale=480:-2",
"-loglevel",
"error",
str(target),
]
try:
subprocess.run(command, check=True, capture_output=True, timeout=60)
except (subprocess.SubprocessError, OSError):
return None
return target if target.exists() else None