M2 Task 2.6 (media downloader) + Task 2.8 (media serve API).
Downloader (app/scraper/media.py):
- download_url(client, url): fetches bytes via the YunkeClient's underlying
httpx client (carries session cookies; respx-mockable; follows redirects).
- download_message_media(client, msg, store, session): URL-driven fetcher that
picks the best http(s) URL (file_url -> file_hd_url -> file_th_url), dedups
by md5 (skips the network when a Media row with local file already exists),
falls back to sha256(bytes) when no md5, stores via ObjectStore.put_by_hash,
and upserts a Media row. Skips type-10 system messages (non-media per
phase0-findings §2) and type-3 opaque-id / text (no http url). Resilient:
download errors are logged and return None (no raise).
- media_type_from_message / guess_mime_type helpers.
Repo (app/storage/repos.py): upsert_media — idempotent Core upsert into Media by
media_hash. Volatile download artifacts (local_path/size_bytes/mime_type) use
COALESCE(incoming, existing) on conflict so a re-scrape that did not re-download
does not clobber previously stored values. Exported from app.storage.
Serve API (app/api/routers/media.py): GET /api/media/{media_hash} streams the
local file via FileResponse (handles HTTP Range / 206). 404 when the row is
absent, has no local file, or the file is missing on disk. Content-type from the
row's mime_type, falling back to ext-derived guess.
Tests (+19, suite 130 -> 149, all green; ruff clean):
- test_media_downloader.py: image/video download + upsert; md5 dedup skips
second network hit; sha256 fallback when no md5; type-3/text/system -> None;
download failure -> None (no raise); upsert_media idempotency +
null-local_path preservation + 3x-same-key-one-row.
- test_api_media.py: 200 + content-type + bytes; 404 unknown hash; 404 missing
file on disk; Range -> 206 partial; ext-derived content-type when mime NULL.
Co-Authored-By: Claude <noreply@anthropic.com>
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