dev/codeforces/ Добавил мапперы для превращения модели в response

Author: AlexanderGarifullin

src/main/java/com/cf/cfteam/utils/codeforces/GroupMapper.java

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+package com.cf.cfteam.utils.codeforces;
+
+import com.cf.cfteam.transfer.responses.codeforces.PlayerResponse;
+
+import java.util.List;
+
+public class RatingCalculator {
+
+    public static double getWinProbability(double ra, double rb) {
+        return 1.0 / (1.0 + Math.pow(10.0, (rb - ra) / 400.0));
+    }
+
+    public static double aggregateRatings(List<PlayerResponse> players) {
+        double left = 1.0;
+        double right = 1E4;
+
+        for (int tt = 0; tt < 100; tt++) {
+            double r = (left + right) / 2.0;
+
+            double rWinsProbability = 1.0;
+            for (PlayerResponse player : players) {
+                rWinsProbability *= getWinProbability(r, player.rating());
+            }
+
+            double rating = Math.log10(1 / rWinsProbability - 1) * 400 + r;
+
+            if (rating > r) {
+                left = r;
+            } else {
+                right = r;
+            }
+        }
+
+        return (left + right) / 2.0;
+    }
+
+    private RatingCalculator() {
+        throw new UnsupportedOperationException("Utility class");
+    }
+}

src/main/java/com/cf/cfteam/utils/codeforces/RatingCalculator.java

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+package com.cf.cfteam.utils.codeforces.mappers;
+
+import com.cf.cfteam.models.entities.codeforces.Group;
+import com.cf.cfteam.models.entities.security.User;
+import com.cf.cfteam.transfer.payloads.codeforces.GroupPayload;
+import com.cf.cfteam.transfer.responses.codeforces.GroupResponse;
+import com.cf.cfteam.transfer.responses.codeforces.PlayerResponse;
+import com.cf.cfteam.transfer.responses.codeforces.TeamResponse;
+import lombok.NoArgsConstructor;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Component;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@Component
+@RequiredArgsConstructor
+public final class GroupMapper {
+
+    private final TeamMapper teamMapper;
+
+    public Group fromPayloadToEntity(GroupPayload payload, User user) {
+        return Group.builder()
+                .name(payload.name())
+                .description(payload.description())
+                .user(user)
+                .build();
+    }
+
+    public Group updateEntityFromPayload(Group group, GroupPayload payload) {
+        group.setName(payload.name());
+        group.setDescription(payload.description());
+        return group;
+    }
+
+    public GroupResponse fromEntityToResponse(Group group) {
+        List<TeamResponse> convertedTeams = new ArrayList<>();
+
+        if (group.getTeams() != null) {
+            convertedTeams = group.getTeams().stream()
+                    .map(teamMapper::fromEntityToResponse)
+                    .toList();
+        }
+
+        return GroupResponse.builder()
+                .id(group.getId())
+                .name(group.getName())
+                .description(group.getDescription())
+                .teams(convertedTeams)
+                .build();
+    }
+}

src/main/java/com/cf/cfteam/utils/codeforces/mappers/GroupMapper.java

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+package com.cf.cfteam.utils.codeforces.mappers;
+
+import com.cf.cfteam.models.entities.codeforces.Player;
+import com.cf.cfteam.transfer.responses.codeforces.PlayerResponse;
+import com.github.benmanes.caffeine.cache.Cache;
+import com.github.benmanes.caffeine.cache.LoadingCache;
+import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component
+@RequiredArgsConstructor
+public class PlayerMapper {
+
+    private final LoadingCache<String, Double> ratingCache;
+
+    public PlayerResponse fromEntityToResponse(Player player) {
+        return PlayerResponse.builder()
+                .id(player.getId())
+                .login(player.getLogin())
+                .rating(ratingCache.get(player.getLogin()))
+                .build();
+    }
+}

src/main/java/com/cf/cfteam/utils/codeforces/mappers/PlayerMapper.java

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+package com.cf.cfteam.utils.codeforces.mappers;
+
+import com.cf.cfteam.models.entities.codeforces.Team;
+import com.cf.cfteam.transfer.responses.codeforces.PlayerResponse;
+import com.cf.cfteam.transfer.responses.codeforces.TeamResponse;
+import com.cf.cfteam.utils.codeforces.RatingCalculator;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Component;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@Component
+@RequiredArgsConstructor
+public class TeamMapper {
+
+    private final PlayerMapper playerMapper;
+
+    public TeamResponse fromEntityToResponse(Team team) {
+        List<PlayerResponse> convertedPlayers = new ArrayList<>();
+        Double teamRating = 0.;
+
+        if (team.getPlayers() != null) {
+            convertedPlayers = team.getPlayers().stream()
+                    .map(playerMapper::fromEntityToResponse)
+                    .toList();
+
+            teamRating = RatingCalculator.aggregateRatings(convertedPlayers);
+        }
+
+        return TeamResponse.builder()
+                .id(team.getId())
+                .name(team.getName())
+                .description(team.getDescription())
+                .players(convertedPlayers)
+                .teamRating(teamRating)
+                .build();
+    }
+}