Merge pull request #2 from exogen/feature/top-players-endpoint

Add accuracy leaderboard: players/top/accuracy endpoint

app/api/src/common/dto/top-players-query.dto.ts

@@ -0,0 +1,43 @@
+import { IsOptional, IsPositive, IsNotEmpty, IsIn, Max } from 'class-validator';
+
+const filterableGameTypes = [
+  'CTFGame',
+  'LakRabbitGame'
+] as const;
+
+type FilterableGameType = typeof filterableGameTypes[number];
+
+const hitStats = [
+	'discHitsTG',
+	'discDmgHitsTG',
+	'discMATG',
+	'laserHitsTG',
+	'laserMATG',
+	'cgHitsTG',
+	'shockHitsTG'
+] as const;
+
+type Stat = typeof hitStats[number];
+
+export class TopPlayersQueryDto {
+	@IsNotEmpty()
+	@IsIn(hitStats as any)
+	stat: Stat;
+
+	@IsOptional()
+	@IsIn(filterableGameTypes as any)
+	gameType: FilterableGameType;
+
+	@IsOptional()
+	@IsPositive()
+	minGames: number;
+
+	@IsOptional()
+	@IsPositive()
+	minShots: number;
+
+	@IsOptional()
+	@IsPositive()
+	@Max(100)
+	limit: number;
+}

app/api/src/players/players.controller.ts

@@ -3,6 +3,7 @@ import { ApiOperation } from '@nestjs/swagger';
 
 import { PlayersService } from './players.service';
 import { PaginationQueryDto } from '../common/dto/pagination-query.dto';
+import { TopPlayersQueryDto } from '../common/dto/top-players-query.dto';
 
 @Controller('players')
 export class PlayersController {
@@ -15,4 +16,26 @@ export class PlayersController {
 		const { limit = 10, offset = 0 } = paginationQuery;
 		return this.playerService.findAll({ limit, offset });
 	}
+
+	@Get('top/accuracy')
+	@ApiOperation({
+		tags: [ 'Player', 'Leaderboard' ],
+		summary: 'Return a leaderboard of players for a specific accuracy stat'
+	})
+	findTop(@Query() topPlayersQuery: TopPlayersQueryDto) {
+		const {
+			stat,
+			gameType,
+			minGames = 10,
+			minShots = 100,
+			limit = 10
+		} = topPlayersQuery;
+		return this.playerService.findTop({
+			stat,
+			gameType,
+			minGames,
+			minShots,
+			limit
+		});
+	}
 }

app/api/src/players/players.service.ts

@@ -6,6 +6,7 @@ import { Connection, Repository } from 'typeorm';
 import { Players } from './entities/Players';
 import { GameDetail } from '../game/entities/GameDetail';
 import { PaginationQueryDto } from '../common/dto/pagination-query.dto';
+import { TopPlayersQueryDto } from '../common/dto/top-players-query.dto';
 
 @Injectable()
 export class PlayersService {
@@ -42,4 +43,129 @@ export class PlayersService {
 		}
 		return player;
 	}
+
+	async findTop(topPlayersQuery: TopPlayersQueryDto) {
+		const { stat: hitsStat, gameType, minGames, minShots, limit } = topPlayersQuery;
+
+		const shotsStat = {
+			discDmgHitsTG: 'discShotsFiredTG',
+			discHitsTG: 'discShotsFiredTG',
+			discMATG: 'discShotsFiredTG',
+			laserHitsTG: 'laserShotsFiredTG',
+			laserMATG: 'laserShotsFiredTG',
+			cgHitsTG: 'cgShotsFiredTG',
+			shockHitsTG: 'shockShotsFiredTG'
+		}[hitsStat]
+
+		// Possibly make this a query param at some point?
+		const excludeDiscJumps = shotsStat === 'discShotsFiredTG';
+
+		const hitsValue = '(game.stats->:hitsStat->>0)::integer';
+		const shotsValue = '(game.stats->:shotsStat->>0)::integer';
+		const discJumpsValue = "(game.stats->'discJumpTG'->>0)::integer";
+		const killerDiscJumpsValue = "(game.stats->'killerDiscJumpTG'->>0)::integer";
+
+		// pgSQL doesn't let you reference aliased selections you've made in the
+		// same select statement, so unfortunately these computed JSON values are
+		// repeated in a couple places. Using template strings here to easily repeat
+		// the same expression instead of having multiple nested subqueries. Rest
+		// assured, no user-supplied values are ever interpolated, those are all
+		// parameterized instead.
+		const aggregatedHits = `SUM(${hitsValue})::integer`;
+		// Add sums of `discJumpTG` and `killerDiscJumpTG`.
+		const aggregatedDiscJumps =
+			`(SUM(${discJumpsValue})::integer + SUM(${killerDiscJumpsValue})::integer)`;
+
+		let aggregatedShots = `SUM(${shotsValue})::integer`;
+		if (excludeDiscJumps) {
+			// Since subtracting disc jumps could theoretically drop the shots count
+			// to 0, clamp it to at least the number of hits, otherwise it'd be
+			// possible to have >100% accuracy.
+			aggregatedShots = `GREATEST(${aggregatedHits}, ${aggregatedShots} - ${aggregatedDiscJumps})`
+		}
+
+		// Cast to float to avoid integer division truncating the result.
+		const aggregatedAccuracy = `(${aggregatedHits}::float / ${aggregatedShots}::float)`;
+
+		// TODO: This whole query could probably be turned into a `ViewEntity` at
+		// some point, but I couldn't get that to work.
+
+		let playersQuery = this.playersRepository.createQueryBuilder('player')
+			.setParameters({
+				hitsStat,
+				shotsStat,
+				minGames,
+				minShots,
+			})
+			.select([
+				'player.player_guid',
+				'player.player_name',
+				'stats.game_count',
+				'stats.hits',
+				'stats.shots',
+				'stats.accuracy'
+			])
+			.innerJoin(subQuery => {
+				let statsQuery = subQuery
+					.select(['game.player_guid'])
+					.from(GameDetail, 'game')
+					.addSelect('COUNT(game.id)::integer', 'game_count')
+					.addSelect(aggregatedHits, 'hits')
+					.addSelect(aggregatedShots, 'shots')
+					.addSelect(aggregatedAccuracy, 'accuracy')
+					.where(`${shotsValue} > 0`)
+					.groupBy('game.player_guid');
+
+				if (excludeDiscJumps) {
+					statsQuery = statsQuery.addSelect(aggregatedDiscJumps, 'disc_jumps');
+				}
+
+				if (gameType) {
+					statsQuery = statsQuery.andWhere('game.gametype = :gameType', { gameType })
+				}
+
+				return statsQuery;
+			}, 'stats', 'stats.player_guid = player.player_guid')
+			.where('stats.game_count >= :minGames')
+			.andWhere('stats.shots >= :minShots')
+			.orderBy('stats.accuracy', 'DESC')
+			.limit(limit);
+
+		if (excludeDiscJumps) {
+			playersQuery = playersQuery.addSelect('stats.disc_jumps');
+		}
+
+		// Uncomment to debug:
+		// console.log(query.getQueryAndParameters());
+
+		// typeorm doesn't let you select computed columns since they're not part
+		// of the entity definition. There are workarounds, but I'm not a fan of any
+		// and would rather use `getRawMany()` for now, which does include them.
+		// See: https://github.com/typeorm/typeorm/issues/296
+		const rows = await playersQuery.getRawMany();
+
+		// `getRawMany` was used, so manually snake_case -> camelCase.
+		const players = rows.map(row => ({
+			playerGuid: row.player_guid,
+			playerName: row.player_name,
+			gameCount: row.game_count,
+			hits: row.hits,
+			shots: row.shots,
+			discJumps: row.disc_jumps,
+			accuracy: row.accuracy
+		}));
+
+		return {
+			// Even though some of these parameters might have been supplied as input,
+			// it's still useful to know what values were actually used, in case
+			// defaults were used instead, values were clamped to min/max, etc.
+			hitsStat,
+			shotsStat,
+			excludeDiscJumps,
+			minGames,
+			minShots,
+			limit,
+			players
+		};
+	}
 }