Folder sync left too much to the user's sync tool: platform file access
(the Android SAF plugin), choosing the document, merging conflict copies —
and its merge base could fall out of step with the document (absorbing
conflict copies, "forget", picking a new Android folder), reading every
difference as a deletion.
The new mtgc-server crate stores one versioned library per user and accepts
a write only when it names the version it replaces. It never merges: devices
still do that with merge3, through a new sync cycle over a `Remote` trait in
mtgc-core. The base advances only on knowledge — to what was read, or to a
write the server confirmed — and is stored with the server and account it
belongs to, so a different account starts from an empty ancestor instead of
deleting. The working copy is only rewritten under the app-state lock, and
sync commands now run off the main thread.
Sign-in happens in the browser on the server's pages, via the owner's OIDC
provider and/or local username/password accounts (Argon2id, managed with
`mtgc-server user ...`), and returns a per-device revocable token to the app
by PKCE-protected code: a loopback port on desktop, the mtgc:// scheme on
Android.
The Info tab gains sign-in, the first-sync combine/replace choice, the
account's devices, and JSON export/import; the top bar shows sync state.
Includes a Dockerfile, Compose/Caddy example, and scripts to build and push
${DOCKER_REGISTRY}/mtgc/sync-server.
Android grants a *folder* through SAF, not a file, and the document name was
hardcoded to "library.json". A library named anything else was therefore never
found: the phone created an empty second library beside it and the two devices
silently never synced, while appearing to work.
The Info tab now lists the .json files in the granted folder and lets you choose
one. Picking an existing file adopts it — the working copy is dropped and
rebuilt from it, matching what desktop does when opening a document — while a
name that isn't there yet keeps the current library and publishes it, matching
New Library. The name is validated as a plain filename, since a path would
escape the granted folder that the SAF grant exists to bound.
Two bugs found while testing this on-device:
load_config decided whether a config was the pre-document format by testing
whether document_path or legacy_library_path were set. An Android install has
neither — its folder is a grant, not a path, and there is no legacy library —
so a valid config's document_name was discarded on every launch and the chosen
library file silently reverted to the default. It no longer infers the format
from which fields happen to be populated; every field defaults, and the legacy
library_path is picked up as a separate additive step. Covered by tests,
including one built from the exact Android config shape, because a setting that
quietly resets itself is not something a careful read catches.
The Info tab's sync refresh fired at mount when the app relaunched onto that
tab — the active tab is persisted — which is before setup() calls manage(),
producing "state not managed for field db". Gated on statusLoaded like the
startup refresh already was; get_status retries until the backend is ready, so
waiting on it is what guarantees the state exists.
Sync
The previous design put the merge inside SQL: timestamp-stamping triggers,
a tombstone table, per-device SQLite snapshots, a device id in the database,
and row merges written as correlated-subquery UPDATEs. All of that schema
was inherited by desktop, and the merge was very hard to verify.
Replace it with a single JSON document plus a three-way merge in plain Rust.
Storing the last-read remote document as the merge base makes "who changed
what" and "what was deleted" derivable, which removes the tombstone table,
the updated_at columns and all eight triggers. It also makes a single shared
file safe: if a publish is lost the remote is unchanged, so the next merge
re-detects the local edits and republishes rather than reading their absence
as a deletion. That removes the need for per-device files and for device
identity entirely. Schema impact drops to one column, decks.uuid.
Conflicts resolve to "theirs", which is required for convergence rather than
chosen for taste — preferring ours has each device re-asserting its own value
forever. Every such choice is reported to the user.
SQLite becomes invisible: the working copy lives in the app data dir and the
user only ever names a .json file. There is always a document, defaulting to
private storage, so edits are never stranded with nowhere to be saved.
Pointing at a file that doesn't exist yet moves the current library there;
pointing at one that does adopts it. A converter brings a pre-document
library.db across.
Android reaches the folder through the Storage Access Framework rather than
MANAGE_EXTERNAL_STORAGE, so no storage permission is declared at all.
Filters
Track card origin in reference.db: Universes Beyond, digital-only and
Un-set cards, plus numeric power/toughness. Each origin flag is derived as
"every printing", not "any printing" — ordinary cards get reprinted into
those sets, and Lightning Bolt appearing in Marvel Commander must not hide
it. Non-numeric power ("*", "1+*") stays NULL so it drops out of range
filters instead of being compared as zero.
Also wire up filters over data already present: price range, format legality
(restricted counts as legal) and "can be a commander". All of these degrade
silently against an older reference.db rather than failing every query.
The shared criteria live in one component used by both filter panels, as a
compact row of icon toggles.
Card Search gains the Library tab's bulk selection: checkboxes in both views,
select-all, and a bulk add-to-deck with a single undo for the whole batch.
