Merge pull request SaboStudios#218 from ogazboiz/feature/161-leave-game-endpoint

[BE] Implement leave game endpoint

Author: aji70

backend/package-lock.json

@@ -96,6 +96,39 @@ export class GamePlayersService {
     return player;
   }
 
+  async leaveGameForUser(gameId: number, userId: number): Promise<void> {
+    const game = await this.gameRepository.findOne({ where: { id: gameId } });
+    if (!game) {
+      throw new NotFoundException(`Game ${gameId} not found`);
+    }
+    if (game.status !== GameStatus.PENDING) {
+      throw new BadRequestException('Cannot leave game after it has started');
+    }
+
+    const player = await this.gamePlayerRepository.findOne({
+      where: { game_id: gameId, user_id: userId },
+    });
+    if (!player) {
+      throw new NotFoundException(
+        `User ${userId} is not a player in game ${gameId}`,
+      );
+    }
+
+    if (player.turn_order !== null) {
+      await this.gamePlayerRepository
+        .createQueryBuilder()
+        .update(GamePlayer)
+        .set({ turn_order: () => 'turn_order - 1' })
+        .where('game_id = :gameId', { gameId })
+        .andWhere('turn_order > :turnOrder', {
+          turnOrder: player.turn_order,
+        })
+        .execute();
+    }
+
+    await this.gamePlayerRepository.delete(player.id);
+  }
+
   private async isGameStarted(gameId: number): Promise<boolean> {
     const game = await this.gameRepository.findOne({ where: { id: gameId } });
     if (!game) return false;