feat(auth): create login endpoint and handle related exceptions

Author: felipemelozx

src/main/java/fun/trackmoney/auth/controller/AuthController.java

@@ -1,5 +1,7 @@
 package fun.trackmoney.auth.controller;
 
+import fun.trackmoney.auth.dto.LoginRequestDTO;
+import fun.trackmoney.auth.dto.LoginResponseDTO;
 import fun.trackmoney.auth.service.AuthService;
 import fun.trackmoney.user.dtos.UserRequestDTO;
 import fun.trackmoney.user.dtos.UserResponseDTO;
@@ -49,4 +51,16 @@ public ResponseEntity<ApiResponse<UserResponseDTO>> register(
         )
     );
   }
+
+  @PostMapping("login")
+  public ResponseEntity<ApiResponse<LoginResponseDTO>> login(@RequestBody LoginRequestDTO loginDto) {
+    return ResponseEntity.ok().body(
+        new ApiResponse<>(
+            true,
+            "Login successful!",
+            authService.login(loginDto),
+            null
+        )
+    );
+  }
 }

src/main/java/fun/trackmoney/auth/dto/LoginRequestDTO.java

@@ -0,0 +1,4 @@
+package fun.trackmoney.auth.dto;
+
+public record LoginRequestDTO(String email, String password){
+}

src/main/java/fun/trackmoney/auth/dto/LoginResponseDTO.java

@@ -0,0 +1,4 @@
+package fun.trackmoney.auth.dto;
+
+public record LoginResponseDTO (String Token){
+}

src/main/java/fun/trackmoney/auth/exception/LoginException.java

@@ -0,0 +1,25 @@
+package fun.trackmoney.auth.exception;
+
+import fun.trackmoney.utils.CustomFieldError;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class LoginException extends RuntimeException {
+  private final List<CustomFieldError> errors;
+
+  public LoginException(String message) {
+    super(message);
+    this.errors = new ArrayList<>();
+    this.errors.add(new CustomFieldError("Email: ", message));
+  }
+
+  public LoginException(List<CustomFieldError> errors) {
+    super("Email not found!");
+    this.errors = errors;
+  }
+
+  public List<CustomFieldError> getErrors() {
+    return errors;
+  }
+}

src/main/java/fun/trackmoney/auth/service/AuthService.java

@@ -1,34 +1,38 @@
 package fun.trackmoney.auth.service;
 
+import fun.trackmoney.auth.dto.LoginRequestDTO;
+import fun.trackmoney.auth.dto.LoginResponseDTO;
+import fun.trackmoney.auth.exception.LoginException;
+import fun.trackmoney.auth.infra.jwt.JwtService;
 import fun.trackmoney.user.dtos.UserRequestDTO;
 import fun.trackmoney.user.dtos.UserResponseDTO;
+import fun.trackmoney.user.entity.UserEntity;
 import fun.trackmoney.user.service.UserService;
+import org.springframework.security.crypto.password.PasswordEncoder;
 import org.springframework.stereotype.Service;
 
-/**
- * Provides authentication-related services, including user registration.
- */
 @Service
 public class AuthService {
 
   private final UserService userService;
+  private final PasswordEncoder passwordEncoder;
+  private final JwtService jwtservice;
 
-  /**
-   * Constructs an AuthService with the specified UserService.
-   *
-   * @param userService the service used to handle user-related operations
-   */
-  public AuthService(UserService userService) {
+  public AuthService(UserService userService, PasswordEncoder passwordEncoder, JwtService jwtservice) {
     this.userService = userService;
+    this.passwordEncoder = passwordEncoder;
+    this.jwtservice = jwtservice;
   }
 
-  /**
-   * Registers a new user based on the provided user data.
-   *
-   * @param userDto the data transfer object containing user registration details
-   * @return a data transfer object containing the registered user's details
-   */
   public UserResponseDTO register(UserRequestDTO userDto) {
     return userService.register(userDto);
   }
+
+  public LoginResponseDTO login(LoginRequestDTO loginDto) {
+    UserEntity user = userService.findUserByEmail(loginDto);
+    if(!passwordEncoder.matches(loginDto.password(), user.getPassword())){
+      throw new LoginException("Password is incorrect.");
+    }
+    return new LoginResponseDTO(jwtservice.generateToken(user.getEmail()));
+  }
 }

src/main/java/fun/trackmoney/config/exception/RestExceptionHandler.java

@@ -1,6 +1,8 @@
 package fun.trackmoney.config.exception;
 
+import fun.trackmoney.auth.exception.LoginException;
 import fun.trackmoney.user.exception.EmailAlreadyExistsException;
+import fun.trackmoney.user.exception.EmailNotFoundException;
 import fun.trackmoney.user.exception.PasswordNotValid;
 import fun.trackmoney.utils.CustomFieldError;
 import fun.trackmoney.utils.response.ApiResponse;
@@ -18,7 +20,7 @@ public class RestExceptionHandler {
   @ExceptionHandler(PasswordNotValid.class)
   public ResponseEntity<ApiResponse<List<String>>> passwordNotValid(PasswordNotValid ex) {
     return ResponseEntity.badRequest().body(
-        new ApiResponse<>(false, ex.getMessage(), null, ex.getErrors() )
+        new ApiResponse<>(false, ex.getMessage(), null, ex.getErrors())
     );
   }
 
@@ -49,4 +51,18 @@ public ResponseEntity<ApiResponse<Object>> handleEmailAlreadyExists(EmailAlready
         .body(new ApiResponse<>(false, ex.getMessage(), null,
             List.of(new CustomFieldError("Email", ex.getMessage()))));
   }
+
+  @ExceptionHandler(EmailNotFoundException.class)
+  public ResponseEntity<ApiResponse<List<String>>> emailNotFound(EmailNotFoundException ex) {
+    return ResponseEntity.badRequest().body(
+        new ApiResponse<>(false, ex.getMessage(), null, ex.getErrors())
+    );
+  }
+
+  @ExceptionHandler(LoginException.class)
+  public ResponseEntity<ApiResponse<List<CustomFieldError>>> loginException(LoginException ex) {
+    return ResponseEntity.badRequest().body(
+        new ApiResponse<>(false, ex.getMessage(), null, ex.getErrors())
+    );
+  }
 }

src/main/java/fun/trackmoney/user/exception/EmailNotFoundException.java

@@ -0,0 +1,25 @@
+package fun.trackmoney.user.exception;
+
+import fun.trackmoney.utils.CustomFieldError;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class EmailNotFoundException extends RuntimeException {
+  private final List<CustomFieldError> errors;
+
+  public EmailNotFoundException(String message) {
+    super(message);
+    this.errors = new ArrayList<>();
+    this.errors.add(new CustomFieldError("Email: ", message));
+  }
+
+  public EmailNotFoundException(List<CustomFieldError> errors) {
+    super("Email not found!");
+    this.errors = errors;
+  }
+
+  public List<CustomFieldError> getErrors() {
+    return errors;
+  }
+}

src/main/java/fun/trackmoney/user/service/UserService.java

@@ -1,9 +1,11 @@
 package fun.trackmoney.user.service;
 
+import fun.trackmoney.auth.dto.LoginRequestDTO;
 import fun.trackmoney.user.dtos.UserRequestDTO;
 import fun.trackmoney.user.dtos.UserResponseDTO;
 import fun.trackmoney.user.entity.UserEntity;
 import fun.trackmoney.user.exception.EmailAlreadyExistsException;
+import fun.trackmoney.user.exception.EmailNotFoundException;
 import fun.trackmoney.user.exception.PasswordNotValid;
 import fun.trackmoney.user.mapper.UserMapper;
 import fun.trackmoney.user.repository.UserRepository;
@@ -41,4 +43,11 @@ public UserResponseDTO register(UserRequestDTO userRequestDTO) {
       throw new EmailAlreadyExistsException("Email already registered.");
     }
   }
+
+  public UserEntity findUserByEmail(LoginRequestDTO loginDto) {
+    return userRepository.findByEmail(loginDto.email())
+        .orElseThrow(() -> {
+          throw new EmailNotFoundException("User not found");
+        });
+  }
 }