Added endpoints and logic for user following system.

gymboard-api/src/main/java/nl/andrewlalis/gymboard_api/domains/auth/controller/AuthController.java

@@ -1,12 +1,10 @@
 package nl.andrewlalis.gymboard_api.domains.auth.controller;
 
 import nl.andrewlalis.gymboard_api.domains.auth.dto.*;
-import nl.andrewlalis.gymboard_api.domains.auth.model.User;
 import nl.andrewlalis.gymboard_api.domains.auth.service.TokenService;
 import nl.andrewlalis.gymboard_api.domains.auth.service.UserService;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.core.Authentication;
-import org.springframework.security.core.annotation.AuthenticationPrincipal;
 import org.springframework.web.bind.annotation.*;
 
 @RestController

gymboard-api/src/main/java/nl/andrewlalis/gymboard_api/domains/auth/controller/UserController.java

@@ -3,12 +3,11 @@ package nl.andrewlalis.gymboard_api.domains.auth.controller;
 import nl.andrewlalis.gymboard_api.domains.auth.dto.*;
 import nl.andrewlalis.gymboard_api.domains.auth.model.User;
 import nl.andrewlalis.gymboard_api.domains.auth.service.UserService;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.core.annotation.AuthenticationPrincipal;
-import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.*;
-import org.springframework.web.bind.annotation.PostMapping;
-import org.springframework.web.bind.annotation.RequestBody;
-import org.springframework.web.bind.annotation.RestController;
 
 @RestController
 public class UserController {
@@ -66,4 +65,26 @@ public class UserController {
 	) {
 		return userService.updatePreferences(user.getId(), payload);
 	}
+
+	@PostMapping(path = "/auth/users/{userId}/followers")
+	public ResponseEntity<Void> followUser(@AuthenticationPrincipal User myUser, @PathVariable String userId) {
+		userService.followUser(myUser.getId(), userId);
+		return ResponseEntity.ok().build();
+	}
+
+	@DeleteMapping(path = "/auth/users/{userId}/followers")
+	public ResponseEntity<Void> unfollowUser(@AuthenticationPrincipal User myUser, @PathVariable String userId) {
+		userService.unfollowUser(myUser.getId(), userId);
+		return ResponseEntity.ok().build();
+	}
+
+	@GetMapping(path = "/auth/me/followers")
+	public Page<UserResponse> getFollowers(@AuthenticationPrincipal User user, Pageable pageable) {
+		return userService.getFollowers(user.getId(), pageable);
+	}
+
+	@GetMapping(path = "/auth/me/following")
+	public Page<UserResponse> getFollowing(@AuthenticationPrincipal User user, Pageable pageable) {
+		return userService.getFollowing(user.getId(), pageable);
+	}
 }

gymboard-api/src/main/java/nl/andrewlalis/gymboard_api/domains/auth/dao/UserFollowingRepository.java

@@ -0,0 +1,20 @@
+package nl.andrewlalis.gymboard_api.domains.auth.dao;
+
+import nl.andrewlalis.gymboard_api.domains.auth.model.User;
+import nl.andrewlalis.gymboard_api.domains.auth.model.UserFollowing;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface UserFollowingRepository extends JpaRepository<UserFollowing, Long> {
+	boolean existsByFollowedUserAndFollowingUser(User followedUser, User followingUser);
+
+	@Modifying
+	void deleteByFollowedUserAndFollowingUser(User followedUser, User followingUser);
+
+	Page<UserFollowing> findAllByFollowedUserOrderByCreatedAtDesc(User followedUser, Pageable pageable);
+	Page<UserFollowing> findAllByFollowingUserOrderByCreatedAtDesc(User followingUser, Pageable pageable);
+}

gymboard-api/src/main/java/nl/andrewlalis/gymboard_api/domains/auth/model/UserFollowing.java

@@ -10,7 +10,10 @@ import java.time.LocalDateTime;
  * have impacts on the notifications that a user can receive.
  */
 @Entity
-@Table(name = "auth_user_following")
+@Table(
+		name = "auth_user_following",
+		uniqueConstraints = @UniqueConstraint(columnNames = {"followed_user_id", "following_user_id"})
+)
 public class UserFollowing {
 	@Id
 	@GeneratedValue(strategy = GenerationType.IDENTITY)

gymboard-api/src/main/java/nl/andrewlalis/gymboard_api/domains/auth/service/UserService.java

@@ -5,15 +5,14 @@ import jakarta.mail.internet.MimeMessage;
 import nl.andrewlalis.gymboard_api.domains.api.model.WeightUnit;
 import nl.andrewlalis.gymboard_api.domains.auth.dao.*;
 import nl.andrewlalis.gymboard_api.domains.auth.dto.*;
-import nl.andrewlalis.gymboard_api.domains.auth.model.PasswordResetCode;
+import nl.andrewlalis.gymboard_api.domains.auth.model.*;
-import nl.andrewlalis.gymboard_api.domains.auth.model.User;
-import nl.andrewlalis.gymboard_api.domains.auth.model.UserActivationCode;
-import nl.andrewlalis.gymboard_api.domains.auth.model.UserPersonalDetails;
 import nl.andrewlalis.gymboard_api.util.StringGenerator;
 import nl.andrewlalis.gymboard_api.util.ULID;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Value;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
 import org.springframework.http.HttpStatus;
 import org.springframework.mail.javamail.JavaMailSender;
 import org.springframework.mail.javamail.MimeMessageHelper;
@@ -38,6 +37,7 @@ public class UserService {
 	private final UserPreferencesRepository userPreferencesRepository;
 	private final UserActivationCodeRepository activationCodeRepository;
 	private final PasswordResetCodeRepository passwordResetCodeRepository;
+	private final UserFollowingRepository userFollowingRepository;
 	private final ULID ulid;
 	private final PasswordEncoder passwordEncoder;
 	private final JavaMailSender mailSender;
@@ -51,7 +51,7 @@ public class UserService {
 			UserPreferencesRepository userPreferencesRepository,
 			UserActivationCodeRepository activationCodeRepository,
 			PasswordResetCodeRepository passwordResetCodeRepository,
-			ULID ulid,
+			UserFollowingRepository userFollowingRepository, ULID ulid,
 			PasswordEncoder passwordEncoder,
 			JavaMailSender mailSender
 	) {
@@ -60,6 +60,7 @@ public class UserService {
 		this.userPreferencesRepository = userPreferencesRepository;
 		this.activationCodeRepository = activationCodeRepository;
 		this.passwordResetCodeRepository = passwordResetCodeRepository;
+		this.userFollowingRepository = userFollowingRepository;
 		this.ulid = ulid;
 		this.passwordEncoder = passwordEncoder;
 		this.mailSender = mailSender;
@@ -276,4 +277,40 @@ public class UserService {
 		p = userPreferencesRepository.save(p);
 		return new UserPreferencesResponse(p);
 	}
+
+	@Transactional
+	public void followUser(String followerId, String followedId) {
+		User follower = userRepository.findById(followerId).orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
+		User followed = userRepository.findById(followedId).orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
+
+		if (!userFollowingRepository.existsByFollowedUserAndFollowingUser(followed, follower)) {
+			userFollowingRepository.save(new UserFollowing(followed, follower));
+		}
+	}
+
+	@Transactional
+	public void unfollowUser(String followerId, String followedId) {
+		User follower = userRepository.findById(followerId).orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
+		User followed = userRepository.findById(followedId).orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
+
+		userFollowingRepository.deleteByFollowedUserAndFollowingUser(followed, follower);
+	}
+
+	@Transactional(readOnly = true)
+	public Page<UserResponse> getFollowers(String userId, Pageable pageable) {
+		User user = userRepository.findById(userId)
+				.orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
+		return userFollowingRepository.findAllByFollowedUserOrderByCreatedAtDesc(user, pageable)
+				.map(UserFollowing::getFollowingUser)
+				.map(UserResponse::new);
+	}
+
+	@Transactional(readOnly = true)
+	public Page<UserResponse> getFollowing(String userId, Pageable pageable) {
+		User user = userRepository.findById(userId)
+				.orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
+		return userFollowingRepository.findAllByFollowingUserOrderByCreatedAtDesc(user, pageable)
+				.map(UserFollowing::getFollowedUser)
+				.map(UserResponse::new);
+	}
 }