Driven by a retail FIFA 17 capture: the client sends the WHOLE squad on
every save (~2KB, every slot/item/kit number), and a user swapping two
players produced nine changed slots across two saves. Slot deltas
therefore do not describe intent, so the only honest semantic operation
is "this is the squad now".
replace_squad, and why save_squad no longer has its own write path
------------------------------------------------------------------
save_squad UPDATEd the squad, DELETEd every squad_players row, then
INSERTed the new ones one at a time -- all outside a transaction. A
failure part-way through left a squad with some old players deleted and
only some new ones written: a state nobody asked for and no client can
detect. It also never checked that the cards being placed belonged to the
club, and accepted the same card in two slots.
replace_squad validates BEFORE any write (so a rejection leaves the
stored squad untouched) and performs every write in one transaction:
- card must exist AND belong to this club
- a card may occupy at most one slot
- a slot may hold at most one card
- slot indices must not be negative
- the squad being replaced must belong to this club
save_squad is now a thin wrapper over it. That deliberately tightens the
existing Core REST route -- it now validates ownership and rejects
duplicates. Those were bugs, and two write paths with different
guarantees is how the stricter one gets bypassed.
A cross-club card is reported as NotFound, not Forbidden: whether a card
exists in someone else's club is not the caller's business.
Game-rules boundary
-------------------
Core contained calculate_chemistry -- a full FUT-style link-scoring
formula. Chemistry is game-specific and changed between FIFA
generations, so a formula compiled into generic Core quietly makes Core a
FIFA-something server.
It now sits behind SquadRules, with the existing implementation preserved
byte-for-byte in behaviour as DefaultSquadRules ("openfut-default-v2").
Rules take a resolved SquadSnapshot of pure data rather than a pool and a
card database, so they are synchronous, testable without fixtures, and
cannot reach Core's storage. Fifa17SquadRules is deliberately NOT
written: the algorithm is unproven and inventing one is worse than having
none.
Client-reported values
----------------------
FIFA sends its own chemistry/rating/starRating. ClientReportedEvaluation
is a DIFFERENT TYPE from SquadEvaluation, so assigning one where the
other belongs does not compile. Disagreement is reported through
EvaluationComparison and never reconciled in either direction -- the
server's value stands and the mismatch is surfaced for investigation
against the exact squad that produced it.
Evidence
--------
17 unit tests, 113 in the crate, 7/7 mutations killed including
"ownership check removed", "replacement becomes a merge" and
"client-reported chemistry becomes the server value".
Scope note: `cargo fmt` without -p reformatted ~27 unrelated files; those
were reverted so this commit touches only the squad path.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
- GET /chemistry-styles — lists 18 FUT-style chemistry styles with stat boost breakdowns
- POST /collection/:id/chemistry-style — apply a style (Shadow, Hunter, Anchor, etc.)
- POST /collection/:id/position — override a player's position for 500 coins
- POST /collection/:id/training — add +1/+2/+3 OVR training bonus (max +3 total)
- GET /collection now includes chemistry_style, position_override, training_bonus,
effective_overall and effective_position fields per owned card
- Migration 0007 adds three columns to owned_cards with safe defaults
- 10 new integration tests — all 55 pass, clippy clean
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- Chemistry v2: FUT-style link scoring with per-player breakdown
(club +3/link cap 6, league +1/link cap 4, nation +1/link cap 3;
player cap 10, team cap 100); chemistry response now includes
per-player breakdown with club/league/nation link counts and pts
- Card pool: 34 new cards across Premier League, La Liga, Bundesliga
with overlapping clubs/nations for meaningful chemistry testing
- Card search: extended GET /cards with nation, league, club,
min_overall, max_overall, limit query params; results sorted by
overall descending
- Match opponent: added "ultimate" difficulty band (85+ OVR);
random formation selection from 6 tactical formations; falls back
to lower OVR pool when not enough cards at the requested band
- Tests: 9 new integration tests (28 total, all passing)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Chemistry & squads:
- Chemistry calculation on GET /squad (club/league/nation links, max 100)
- Formation validation on POST /squad (exactly 11 starters, exactly 1 GK)
Objectives:
- Weekly objectives JSON (4 objectives: warrior, goals, dedicated, SBC)
- Daily objectives auto-reset at midnight UTC (background task)
SBC validation expanded:
- max_overall per-player enforcement
- required_clubs validation
- min_players_from_same_nation validation
- min_players_from_same_club validation
Market:
- GET /market?min_overall=X&position=Y filtering
- Expiry cleanup runs before every NPC refresh
- NPC market auto-refresh every 24h (background task, runs at startup)
Matches:
- GET /matches/opponent?difficulty=beginner|professional|world_class|legendary
generates a random AI opponent squad from the card pool
Statistics:
- win_streak and best_win_streak tracking (migration 0002)
- GET /statistics/history?limit=N — last N matches with summary stats
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
funman300