feat(admin): add game lifecycle controls

src/main/java/games/dmg/spigottyrant/GameLifecycleService.java

@@ -0,0 +1,137 @@
+package games.dmg.spigottyrant;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.EnumMap;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.UUID;
+
+public final class GameLifecycleService {
+    public LifecycleState start(
+        PersistentState state,
+        UUID tyrantId,
+        Optional<UUID> vigilanteId,
+        Instant now
+    ) {
+        if (state.game().lifecycle() != GameLifecycle.UNSTARTED) {
+            throw new IllegalStateException("game has already been started");
+        }
+        if (vigilanteId.filter(tyrantId::equals).isPresent()) {
+            throw new IllegalArgumentException("Tyrant and Vigilante must be different players");
+        }
+        GameState game = new GameState(
+            GameLifecycle.RUNNING,
+            Optional.of(tyrantId),
+            vigilanteId,
+            Optional.empty(),
+            Optional.empty(),
+            Optional.empty(),
+            Duration.ZERO,
+            0,
+            1,
+            Set.of()
+        );
+        return new LifecycleState(game, state.players());
+    }
+
+    public LifecycleState pause(PersistentState state, Instant now) {
+        if (state.game().lifecycle() != GameLifecycle.RUNNING) {
+            throw new IllegalStateException("only a running game can be paused");
+        }
+        GameState current = state.game();
+        GameState paused = new GameState(
+            GameLifecycle.PAUSED,
+            current.tyrantId(),
+            current.vigilanteId(),
+            current.pendingTyrant(),
+            current.pendingVigilante(),
+            Optional.of(now),
+            current.accumulatedPausedTime(),
+            current.tyrantLevel(),
+            current.unspentChoices(),
+            current.purchases()
+        );
+        return new LifecycleState(paused, state.players());
+    }
+
+    public LifecycleState resume(PersistentState state, Instant now) {
+        GameState current = state.game();
+        if (current.lifecycle() != GameLifecycle.PAUSED || current.pausedAt().isEmpty()) {
+            throw new IllegalStateException("only a paused game can be resumed");
+        }
+        Instant pausedAt = current.pausedAt().orElseThrow();
+        Duration pausedFor = Duration.between(pausedAt, now);
+        if (pausedFor.isNegative()) {
+            throw new IllegalArgumentException("resume time must not precede pause time");
+        }
+        GameState resumed = new GameState(
+            GameLifecycle.RUNNING,
+            current.tyrantId(),
+            current.vigilanteId(),
+            shiftSelection(current.pendingTyrant(), pausedFor),
+            shiftSelection(current.pendingVigilante(), pausedFor),
+            Optional.empty(),
+            current.accumulatedPausedTime().plus(pausedFor),
+            current.tyrantLevel(),
+            current.unspentChoices(),
+            current.purchases()
+        );
+        Map<UUID, PlayerState> players = new HashMap<>();
+        for (PlayerState player : state.players().values()) {
+            players.put(player.playerId(), shift(player, pausedFor));
+        }
+        return new LifecycleState(resumed, players);
+    }
+
+    public LifecycleState reset(PersistentState state) {
+        Map<UUID, PlayerState> players = new HashMap<>();
+        for (PlayerState player : state.players().values()) {
+            players.put(player.playerId(), new PlayerState(
+                player.playerId(),
+                player.latestName(),
+                player.lastLogin(),
+                player.optedOutUntil(),
+                TyrantClass.NONE,
+                Optional.empty(),
+                Map.of(),
+                Set.of(),
+                player.capturedMobs()
+            ));
+        }
+        return new LifecycleState(GameState.empty(), players);
+    }
+
+    private static Optional<PendingSelection> shiftSelection(
+        Optional<PendingSelection> selection,
+        Duration pausedFor
+    ) {
+        return selection.map(value -> new PendingSelection(
+            value.candidateId(), value.expiresAt().plus(pausedFor)
+        ));
+    }
+
+    private static PlayerState shift(PlayerState player, Duration pausedFor) {
+        Map<Ability, Instant> cooldowns = new EnumMap<>(Ability.class);
+        player.cooldownEnds().forEach((ability, deadline) ->
+            cooldowns.put(ability, deadline.plus(pausedFor))
+        );
+        return new PlayerState(
+            player.playerId(),
+            player.latestName(),
+            shiftInstant(player.lastLogin(), pausedFor),
+            shiftInstant(player.optedOutUntil(), pausedFor),
+            player.tyrantClass(),
+            player.followerOf(),
+            cooldowns,
+            player.readyAbilityItems(),
+            player.capturedMobs()
+        );
+    }
+
+    private static Optional<Instant> shiftInstant(Optional<Instant> value, Duration duration) {
+        return value.map(instant -> instant.plus(duration));
+    }
+}