apps/backend/src/main/java/app/playmancala/game/GameSerialization.java

@@ -156,7 +156,8 @@ public final class GameSerialization {
                 publicSummary(game, mancalaGame.getPlayer2Id()), boxed(mancalaGame.getBoard().getStoneArray()),
                 getResult(game, ending), ending.endReason(),
                 ending.leftUserId() == null ? null : PublicIds.publicUserId(ending.leftUserId()), game.startedAt, endedAt,
-                moves.size(), game.peakSpectators, game.clock.initialMs(), moves, game.allSpectatorIds.size(), game.bot);
+                moves.size(), game.peakSpectators, game.clock.initialMs(), moves, game.allSpectatorIds.size(), game.bot,
+                game.series.id());
     }
 
     // The player with a public id, for anything saved or listed.

apps/backend/src/main/java/app/playmancala/history/Migrations.java

@@ -23,7 +23,7 @@ public final class Migrations {
     private static final long MIGRATION_LOCK_ID = 727274;
 
     // Applied in this order; never change a migration that has been released, add a new one instead.
-    public static final List<String> VERSIONS = List.of("001_games", "002_clock", "003_bot");
+    public static final List<String> VERSIONS = List.of("001_games", "002_clock", "003_bot", "004_series");
 
     private Migrations() {
     }

apps/backend/src/main/java/app/playmancala/history/PostgresGameHistoryRepository.java

@@ -59,9 +59,9 @@ public class PostgresGameHistoryRepository implements GameHistoryRepository {
             int inserted;
             try (PreparedStatement statement = connection.prepareStatement("""
                     INSERT INTO games (id, player1_id, player2_id, result, end_reason, left_user_id, started_at, ended_at,
-                        move_count, final_board, moves, peak_spectators, total_spectators, clock_initial_ms, bot)
+                        move_count, final_board, moves, peak_spectators, total_spectators, clock_initial_ms, bot, series_id)
                     VALUES (?::uuid, ?, ?, ?, ?, ?, to_timestamp(? / 1000.0), to_timestamp(? / 1000.0),
-                        ?, ?::jsonb, ?::jsonb, ?, ?, ?, ?::jsonb)
+                        ?, ?::jsonb, ?::jsonb, ?, ?, ?, ?::jsonb, ?::uuid)
                     ON CONFLICT (id) DO NOTHING""")) {
                 statement.setString(1, record.id());
                 statement.setString(2, record.player1().userId());
@@ -79,6 +79,7 @@ public class PostgresGameHistoryRepository implements GameHistoryRepository {
                 if (record.clockInitialMs() == null) statement.setNull(14, Types.INTEGER);
                 else statement.setInt(14, Math.toIntExact(record.clockInitialMs()));
                 statement.setString(15, record.bot() == null ? null : Json.write(record.bot()));
+                statement.setString(16, record.seriesId());
                 inserted = statement.executeUpdate();
             }
             if (inserted == 0) return null;
@@ -105,7 +106,7 @@ public class PostgresGameHistoryRepository implements GameHistoryRepository {
         if (!UUID_PATTERN.matcher(id).matches()) return null;
         return query(connection -> {
             try (PreparedStatement statement = connection.prepareStatement(
-                    "SELECT " + SUMMARY_COLUMNS + ", g.moves, g.total_spectators, g.bot " + FROM_GAMES + " WHERE g.id = ?::uuid")) {
+                    "SELECT " + SUMMARY_COLUMNS + ", g.moves, g.total_spectators, g.bot, g.series_id " + FROM_GAMES + " WHERE g.id = ?::uuid")) {
                 statement.setString(1, id);
                 try (ResultSet row = statement.executeQuery()) {
                     if (!row.next()) return null;
@@ -114,7 +115,8 @@ public class PostgresGameHistoryRepository implements GameHistoryRepository {
                             summary.result(), summary.endReason(), summary.leftUserId(), summary.startedAt(),
                             summary.endedAt(), summary.moveCount(), summary.peakSpectators(), summary.clockInitialMs(),
                             Json.MAPPER.readValue(row.getString("moves"), MOVES), row.getInt("total_spectators"),
-                            row.getString("bot") == null ? null : Json.MAPPER.readValue(row.getString("bot"), BotSettings.class));
+                            row.getString("bot") == null ? null : Json.MAPPER.readValue(row.getString("bot"), BotSettings.class),
+                            row.getString("series_id"));
                 }
             }
         });

apps/backend/src/main/java/app/playmancala/model/GameRecord.java

@@ -8,9 +8,10 @@ import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import app.playmancala.bot.BotSettings;
 
 // A saved, finished game: a FinishedGameSummary plus its moves and the number of distinct spectators. Every id in it
-// is a public id. `bot` is how the bot played, in games against the bot.
+// is a public id. `bot` is how the bot played, in games against the bot; `seriesId` is missing in games saved before
+// rematches.
 @JsonPropertyOrder({ "id", "player1", "player2", "board", "result", "endReason", "leftUserId", "startedAt", "endedAt",
-        "moveCount", "peakSpectators", "clockInitialMs", "moves", "totalSpectators", "bot" })
+        "moveCount", "peakSpectators", "clockInitialMs", "moves", "totalSpectators", "bot", "seriesId" })
 public record GameRecord(
         String id,
         PlayerSummary player1,
@@ -26,14 +27,15 @@ public record GameRecord(
         @JsonInclude(JsonInclude.Include.NON_NULL) Long clockInitialMs,
         List<MoveRecord> moves,
         int totalSpectators,
-        @JsonInclude(JsonInclude.Include.NON_NULL) BotSettings bot) {
+        @JsonInclude(JsonInclude.Include.NON_NULL) BotSettings bot,
+        @JsonInclude(JsonInclude.Include.NON_NULL) String seriesId) {
 
     // A game between people.
     public GameRecord(String id, PlayerSummary player1, PlayerSummary player2, List<Integer> board, GameResult result,
             EndReason endReason, String leftUserId, long startedAt, long endedAt, int moveCount, int peakSpectators,
             Long clockInitialMs, List<MoveRecord> moves, int totalSpectators) {
         this(id, player1, player2, board, result, endReason, leftUserId, startedAt, endedAt, moveCount, peakSpectators,
-                clockInitialMs, moves, totalSpectators, null);
+                clockInitialMs, moves, totalSpectators, null, null);
     }
 
     public FinishedGameSummary toSummary() {

apps/backend/src/main/resources/db/migrations/004_series.sql

@@ -0,0 +1,3 @@
+-- The series a game belongs to: a game and the rematches after it (docs/specs/rematch). NULL for games saved before.
+ALTER TABLE games ADD COLUMN series_id uuid;
+CREATE INDEX games_series_id ON games (series_id);

apps/backend/src/test/java/app/playmancala/game/GameManagerTest.java

@@ -668,6 +668,13 @@ class GameManagerTest {
             assertEquals(game.id, games.get(0).get("gameId").asText());
         }
 
+        @Test
+        void savesTheSeriesWithTheGame() {
+            BackendGame game = startGame();
+            rtmt.receive(ALICE.id(), Channels.LEAVE_GAME);
+            assertEquals(game.series.id(), repository.records.get(game.id).seriesId());
+        }
+
         @Test
         void restoresTheSeriesOfALiveGame() {
             Series series = new Series("series-1", List.of(new SeriesGame("game-1", Seat.PLAYER2, null,

apps/backend/src/test/java/app/playmancala/history/PostgresGameHistoryRepositoryTest.java

@@ -90,7 +90,7 @@ class PostgresGameHistoryRepositoryTest {
                 ResultSet rows = statement.executeQuery("SELECT version FROM schema_migrations ORDER BY version")) {
             while (rows.next()) versions.add(rows.getString(1));
         }
-        assertEquals(List.of("001_games", "002_clock", "003_bot"), versions);
+        assertEquals(List.of("001_games", "002_clock", "003_bot", "004_series"), versions);
     }
 
     @Test
@@ -122,7 +122,7 @@ class PostgresGameHistoryRepositoryTest {
         GameRecord game = record(ALICE, new PlayerSummary("bot:hard", "Bot", false));
         GameRecord botGame = new GameRecord(game.id(), game.player1(), game.player2(), game.board(), game.result(),
                 game.endReason(), null, game.startedAt(), game.endedAt(), game.moveCount(), game.peakSpectators(), null,
-                game.moves(), game.totalSpectators(), new BotSettings(BotLevel.HARD, 72, -5_123_456_789_012L));
+                game.moves(), game.totalSpectators(), new BotSettings(BotLevel.HARD, 72, -5_123_456_789_012L), null);
         repository.save(botGame);
         assertEquals(Json.tree(botGame), Json.tree(repository.get(game.id())));
         assertEquals("bot:hard", repository.getRecentForUser(ALICE.userId(), 1).getFirst().player2().userId());
@@ -131,6 +131,19 @@ class PostgresGameHistoryRepositoryTest {
         assertFalse(Json.tree(repository.get(betweenPeople.id())).has("bot"));
     }
 
+    @Test
+    void keepsTheSeriesAGameBelongsTo() {
+        GameRecord game = record();
+        GameRecord inSeries = new GameRecord(game.id(), game.player1(), game.player2(), game.board(), game.result(),
+                game.endReason(), null, game.startedAt(), game.endedAt(), game.moveCount(), game.peakSpectators(), null,
+                game.moves(), game.totalSpectators(), null, UUID.randomUUID().toString());
+        repository.save(inSeries);
+        assertEquals(Json.tree(inSeries), Json.tree(repository.get(game.id())));
+        GameRecord before = record();
+        repository.save(before);
+        assertFalse(Json.tree(repository.get(before.id())).has("seriesId"));
+    }
+
     @Test
     void keepsLeftUserIdForGamesAPlayerLeft() {
         GameRecord game = record(ALICE, BOB, GameResult.PLAYER2, EndReason.LEFT, ALICE.userId(), 0, 0, null, null);

docs/specs/rematch/tasks.md

@@ -8,7 +8,7 @@ Work through the tasks in order; each ends with its tests passing and a commit.
       the restore of old snapshots); unit and serialisation tests.
 - [x] 3. **Rematch requests**: `RematchOffers`, the four channels, the timers on the `Scheduler`, ending requests on
       `new_game`, `new_bot_game` and going offline, the bot accepting at once; unit tests.
-- [ ] 4. **Saving**: `seriesId` in `GameRecord`, migration `004_series`, the repository; integration tests.
+- [x] 4. **Saving**: `seriesId` in `GameRecord`, migration `004_series`, the repository; integration tests.
 - [ ] 5. **Core**: channel names, types, `getSeriesScore`, texts in English and Turkish; unit tests.
 - [ ] 6. **Web app, rematch**: the game page following `on_game_start` (`key={gameId}`), the game over card's rematch
       states, "Play again" as a rematch, the score in two columns.