Puzzle improvements

internal/client/screens/puzzle.go

@@ -108,7 +108,6 @@ func (m *PuzzleModel) initGame() {
 	m.solutionIdx = 0
 	m.enginePending = false
 	m.input = NewLocalMoveInput(flipped)
-	m.submitted = false
 	m.state = puzzleStatePlaying
 	m.buildContextHistory()
 	m.viewIdx = m.totalViewPositions()
@@ -120,6 +119,15 @@ func (m *PuzzleModel) retry() {
 	m.initGame()
 }
 
+// resumeAfterFailure returns to the playing state at the current position without
+// resetting the puzzle. The wrong move was never applied, so game/solutionIdx are
+// already where the player needs to continue. ELO is unaffected (already recorded).
+func (m *PuzzleModel) resumeAfterFailure() {
+	m.state = puzzleStatePlaying
+	m.viewIdx = m.totalViewPositions()
+	m.syncBoardToView()
+}
+
 // showSolution resets the game to the puzzle FEN, applies all solution moves, and sets
 // viewIdx to the puzzle start so the user can step through with arrow keys.
 func (m *PuzzleModel) showSolution() {
@@ -393,8 +401,12 @@ func (m *PuzzleModel) navigateForward() {
 }
 
 func (m *PuzzleModel) handleRetryKey() tea.Cmd {
-	if m.state == puzzleStateFailure || m.state == puzzleStateSuccess || m.state == puzzleStateSolution {
+	switch m.state {
+	case puzzleStateFailure:
+		m.resumeAfterFailure()
+	case puzzleStateSuccess, puzzleStateSolution:
 		m.retry()
+	case puzzleStateLoading, puzzleStatePlaying:
 	}
 	return m.initCmd()
 }

internal/client/screens/puzzle_test.go

@@ -84,17 +84,122 @@ func TestPuzzleValidateInvalidSAN(t *testing.T) {
 	}
 }
 
-func TestPuzzleRetryResetsToPlaying(t *testing.T) {
+func TestRetryAfterFailureResumesPlaying(t *testing.T) {
 	m := setupPuzzleModel(t)
 	m.validateAndApply("e5") // wrong move → failure
-	m.retry()
+	m.handleRetryKey()
 	if m.state != puzzleStatePlaying {
 		t.Errorf("after retry state = %v, want puzzleStatePlaying", m.state)
 	}
-	// FEN position should be restored — e4 should still have a pawn
+	// Wrong move was never applied — e4 should still have a pawn.
 	pos := m.game.Position()
 	if pos.Board().Piece(chess.E4) == chess.NoPiece {
-		t.Error("after retry, e4 should still have a pawn (restored from FEN)")
+		t.Error("after retry, e4 should still have a pawn")
+	}
+}
+
+func TestRetryAfterFailureKeepsProgress(t *testing.T) {
+	m := setupMultiMovePuzzle(t)
+	ok, engineUCI := m.validateAndApply("d5") // correct first move
+	if !ok {
+		t.Fatal("correct first move d5 was rejected")
+	}
+	m.applyEngineResponse(engineUCI) // engine plays exd5 → solutionIdx 2, playing
+	if m.solutionIdx != 2 {
+		t.Fatalf("solutionIdx = %d before failure, want 2", m.solutionIdx)
+	}
+	ok, _ = m.validateAndApply("Nf6") // legal but wrong (solution is Qxd5)
+	if ok {
+		t.Fatal("wrong move Nf6 was accepted")
+	}
+	if m.state != puzzleStateFailure {
+		t.Fatalf("state = %v after wrong move, want puzzleStateFailure", m.state)
+	}
+	m.handleRetryKey()
+	if m.state != puzzleStatePlaying {
+		t.Errorf("state = %v after retry, want puzzleStatePlaying", m.state)
+	}
+	if m.solutionIdx != 2 {
+		t.Errorf("solutionIdx = %d after retry, want 2 (progress preserved)", m.solutionIdx)
+	}
+	if len(m.game.Moves()) != 2 {
+		t.Errorf("game has %d moves after retry, want 2 (not reset)", len(m.game.Moves()))
+	}
+}
+
+func TestRetryAfterSuccessResetsToStart(t *testing.T) {
+	m := setupPuzzleModel(t)
+	m.validateAndApply("d5") // correct single-move solution → success
+	if m.state != puzzleStateSuccess {
+		t.Fatalf("state = %v, want puzzleStateSuccess", m.state)
+	}
+	m.handleRetryKey()
+	if m.state != puzzleStatePlaying {
+		t.Errorf("state = %v after retry, want puzzleStatePlaying", m.state)
+	}
+	if m.solutionIdx != 0 {
+		t.Errorf("solutionIdx = %d after retry, want 0 (reset to start)", m.solutionIdx)
+	}
+	if len(m.game.Moves()) != 0 {
+		t.Errorf("game has %d moves after retry, want 0 (reset to start)", len(m.game.Moves()))
+	}
+}
+
+func TestSubmittedPersistsAcrossRetry(t *testing.T) {
+	// Failure path: submit fires once, guard survives the resume.
+	m := setupPuzzleModel(t)
+	m.validateAndApply("e5") // wrong → failure
+	if cmd := m.submitAttempt(false); cmd == nil {
+		t.Fatal("first submitAttempt returned nil, expected a command")
+	}
+	if !m.submitted {
+		t.Fatal("expected submitted=true after first submitAttempt")
+	}
+	m.handleRetryKey() // resume from failure
+	if !m.submitted {
+		t.Error("submitted should remain true after retry-from-failure")
+	}
+	if cmd := m.submitAttempt(true); cmd != nil {
+		t.Error("submitAttempt after retry should be a no-op (nil), guard not held")
+	}
+	// Success path: guard survives the reset-to-start replay.
+	m2 := setupPuzzleModel(t)
+	m2.validateAndApply("d5") // → success
+	m2.submitAttempt(true)
+	m2.handleRetryKey() // reset to start
+	if !m2.submitted {
+		t.Error("submitted should remain true after retry-from-success")
+	}
+	if cmd := m2.submitAttempt(true); cmd != nil {
+		t.Error("submitAttempt after success replay should be a no-op (nil)")
+	}
+}
+
+func TestNewPuzzleResetsSubmitted(t *testing.T) {
+	m := setupPuzzleModel(t)
+	m.submitAttempt(false)
+	if !m.submitted {
+		t.Fatal("expected submitted=true after submitAttempt")
+	}
+	m.SetPuzzle(shared.PuzzleRecord{
+		ID: "next1", FEN: openingFEN, Moves: "d7d5", Rating: 1500, UserPuzzleRating: 1500,
+	})
+	if m.submitted {
+		t.Error("submitted should reset to false for a new puzzle")
+	}
+}
+
+func TestDeltaPersistsAcrossRetry(t *testing.T) {
+	m := setupPuzzleModel(t)
+	m.validateAndApply("e5") // wrong → failure
+	m.submitAttempt(false)
+	m.Update(PuzzleAttemptMsg{NewRating: 1484}) // initial rating 1500 → delta -16
+	if !m.hasDelta || m.lastDelta != -16 {
+		t.Fatalf("hasDelta=%v lastDelta=%d, want true/-16", m.hasDelta, m.lastDelta)
+	}
+	m.handleRetryKey() // resume from failure
+	if !m.hasDelta || m.lastDelta != -16 {
+		t.Errorf("after retry hasDelta=%v lastDelta=%d, want true/-16 (delta persists)", m.hasDelta, m.lastDelta)
 	}
 }
 
@@ -221,10 +326,13 @@ func TestRetryFromSolutionState(t *testing.T) {
 	m := setupPuzzleModel(t)
 	m.validateAndApply("e5")
 	m.showSolution()
-	m.retry()
+	m.handleRetryKey()
 	if m.state != puzzleStatePlaying {
 		t.Errorf("state = %v after retry from solution, want puzzleStatePlaying", m.state)
 	}
+	if m.solutionIdx != 0 {
+		t.Errorf("solutionIdx = %d after retry from solution, want 0 (reset to start)", m.solutionIdx)
+	}
 }
 
 func TestSKeyTriggersShowSolution(t *testing.T) {

internal/server/db.go

@@ -407,6 +407,17 @@ func (d *DB) RecordAttemptAndUpdateRating(ctx context.Context, username, puzzleI
 	return tx.Commit(ctx)
 }
 
+// HasAttempted reports whether the user already has any recorded attempt for the puzzle.
+func (d *DB) HasAttempted(ctx context.Context, username, puzzleID string) (bool, error) {
+	var exists bool
+	err := d.pool.QueryRow(
+		ctx,
+		`SELECT EXISTS(SELECT 1 FROM user_puzzle_attempts WHERE username = $1 AND puzzle_id = $2)`,
+		username, puzzleID,
+	).Scan(&exists)
+	return exists, err
+}
+
 // GetPuzzleRating returns the user's current puzzle rating. Returns 1500 if user not found.
 func (d *DB) GetPuzzleRating(ctx context.Context, username string) (int, error) {
 	var rating int

internal/server/db_test.go

@@ -406,6 +406,91 @@ func TestDB_RecordAttemptAndUpdateRating(t *testing.T) {
 	}
 }
 
+func TestDB_HasAttempted(t *testing.T) {
+	db := testDB(t)
+	truncateAll(t, db)
+	ctx := context.Background()
+	if err := db.CreateUser(ctx, "ha"); err != nil {
+		t.Fatal(err)
+	}
+	base := PuzzleRow{
+		ID: "ha1", Rating: 1500,
+		FEN:   "rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1",
+		Moves: "d7d5", PuzzleDate: time.Now().UTC().Truncate(24 * time.Hour),
+		Themes: []string{}, OpeningTags: []string{},
+	}
+	if err := db.SavePuzzle(ctx, base); err != nil {
+		t.Fatal(err)
+	}
+	attempted, err := db.HasAttempted(ctx, "ha", "ha1")
+	if err != nil {
+		t.Fatalf("HasAttempted: %v", err)
+	}
+	if attempted {
+		t.Fatal("expected HasAttempted=false before any attempt")
+	}
+	if err := db.RecordAttemptAndUpdateRating(ctx, "ha", "ha1", true, false, 1516); err != nil {
+		t.Fatalf("RecordAttemptAndUpdateRating: %v", err)
+	}
+	attempted, err = db.HasAttempted(ctx, "ha", "ha1")
+	if err != nil {
+		t.Fatalf("HasAttempted: %v", err)
+	}
+	if !attempted {
+		t.Fatal("expected HasAttempted=true after recording an attempt")
+	}
+}
+
+func TestRecordPuzzleAttempt_Idempotent(t *testing.T) {
+	db := testDB(t)
+	truncateAll(t, db)
+	ctx := context.Background()
+	if err := db.CreateUser(ctx, "idem"); err != nil {
+		t.Fatal(err)
+	}
+	base := PuzzleRow{
+		ID: "idem1", Rating: 1500,
+		FEN:   "rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq e3 0 1",
+		Moves: "d7d5", PuzzleDate: time.Now().UTC().Truncate(24 * time.Hour),
+		Themes: []string{}, OpeningTags: []string{},
+	}
+	if err := db.SavePuzzle(ctx, base); err != nil {
+		t.Fatal(err)
+	}
+	h := &Hub{db: db, clients: make(map[string]*Client), games: make(map[string]*Game)}
+	r1, err := h.RecordPuzzleAttempt(ctx, "idem", "idem1", false, false) // first try: failed
+	if err != nil {
+		t.Fatalf("first RecordPuzzleAttempt: %v", err)
+	}
+	if r1 >= 1500 {
+		t.Fatalf("expected rating to drop after a failed attempt, got %d", r1)
+	}
+	r2, err := h.RecordPuzzleAttempt(ctx, "idem", "idem1", true, false) // retry: must be a no-op
+	if err != nil {
+		t.Fatalf("second RecordPuzzleAttempt: %v", err)
+	}
+	if r2 != r1 {
+		t.Errorf("second attempt changed rating: r1=%d r2=%d, want unchanged", r1, r2)
+	}
+	stored, err := db.GetPuzzleRating(ctx, "idem")
+	if err != nil {
+		t.Fatalf("GetPuzzleRating: %v", err)
+	}
+	if stored != r1 {
+		t.Errorf("stored rating = %d, want %d (no second mutation)", stored, r1)
+	}
+	var count int
+	row := db.pool.QueryRow(ctx,
+		`SELECT COUNT(*) FROM user_puzzle_attempts WHERE username = $1 AND puzzle_id = $2`,
+		"idem", "idem1")
+	if err := row.Scan(&count); err != nil {
+		t.Fatalf("count attempts: %v", err)
+	}
+	if count != 1 {
+		t.Errorf("attempt rows = %d, want 1 (no duplicate)", count)
+	}
+}
+
 func TestDB_GetPuzzleRating_DefaultWhenNotFound(t *testing.T) {
 	db := testDB(t)
 	truncateAll(t, db)

internal/server/hub.go

@@ -218,6 +218,14 @@ func (h *Hub) RecordPuzzleAttempt(ctx context.Context, username, puzzleID string
 	if err != nil {
 		return 0, err
 	}
+	attempted, err := h.db.HasAttempted(ctx, username, puzzleID)
+	if err != nil {
+		return 0, err
+	}
+	if attempted {
+		slog.Info("Puzzle already attempted; rating unchanged", "username", username, "puzzle_id", puzzleID)
+		return currentRating, nil
+	}
 	newRating := currentRating
 	if !skipped {
 		newRating = PuzzleEloOutcome(currentRating, puzzle.Rating, solved)