feat: ExchangeController & tests

src/main/java/eu/ztsh/wymiana/exception/UserNotFoundException.java

@@ -0,0 +1,11 @@
+package eu.ztsh.wymiana.exception;
+
+import eu.ztsh.wymiana.web.model.CurrencyExchangeRequest;
+
+public class UserNotFoundException extends RuntimeException {
+
+    public UserNotFoundException(CurrencyExchangeRequest entity) {
+        super("User with PESEL %s not found".formatted(entity.pesel()));
+    }
+
+}

src/main/java/eu/ztsh/wymiana/service/CurrencyService.java

@@ -2,6 +2,7 @@ package eu.ztsh.wymiana.service;
 
 import eu.ztsh.wymiana.exception.ExchangeFailedException;
 import eu.ztsh.wymiana.exception.InsufficientFundsException;
+import eu.ztsh.wymiana.exception.UserNotFoundException;
 import eu.ztsh.wymiana.model.Currency;
 import eu.ztsh.wymiana.model.User;
 import eu.ztsh.wymiana.validation.InstanceValidator;
@@ -49,7 +50,7 @@ public class CurrencyService {
                 user.currencies().putAll(exchanged);
                 return userService.update(user);
             })
-            .orElseThrow(ExchangeFailedException::new);
+            .orElseThrow(() -> new UserNotFoundException(request));
     }
 
     private Currency create(String symbol) {

src/main/java/eu/ztsh/wymiana/service/UserService.java

@@ -9,9 +9,11 @@ import eu.ztsh.wymiana.web.model.UserCreateRequest;
 import lombok.RequiredArgsConstructor;
 import org.hibernate.validator.constraints.pl.PESEL;
 import org.springframework.stereotype.Service;
+import org.springframework.validation.annotation.Validated;
 
 import java.util.Optional;
 
+@Validated
 @RequiredArgsConstructor
 @Service
 public class UserService {

src/main/java/eu/ztsh/wymiana/web/controller/ExchangeController.java

@@ -0,0 +1,42 @@
+package eu.ztsh.wymiana.web.controller;
+
+import eu.ztsh.wymiana.exception.InsufficientFundsException;
+import eu.ztsh.wymiana.exception.UserAlreadyExistsException;
+import eu.ztsh.wymiana.exception.UserNotFoundException;
+import eu.ztsh.wymiana.service.CurrencyService;
+import eu.ztsh.wymiana.validation.ValidationFailedException;
+import eu.ztsh.wymiana.web.model.CurrencyExchangeRequest;
+import jakarta.validation.Valid;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.validation.annotation.Validated;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RequiredArgsConstructor
+@Validated
+@RestController
+@RequestMapping(path = "/api/exchange", produces = "application/json")
+public class ExchangeController {
+
+    private final CurrencyService currencyService;
+
+    @PostMapping
+    public ResponseEntity<Object> exchange(@Valid @RequestBody CurrencyExchangeRequest request) {
+        try {
+            return ResponseEntity.status(200).body(currencyService.exchange(request));
+        } catch (Exception e) {
+            var status = switch (e) {
+                case InsufficientFundsException ignored -> HttpStatus.BAD_REQUEST;
+                case UserNotFoundException ignored -> HttpStatus.NOT_FOUND;
+                default -> HttpStatus.INTERNAL_SERVER_ERROR;
+            };
+            return ResponseEntity.status(status).body(e.getMessage());
+        }
+    }
+
+}

src/main/java/eu/ztsh/wymiana/web/controller/UserController.java

@@ -6,6 +6,7 @@ import eu.ztsh.wymiana.service.UserService;
 import eu.ztsh.wymiana.validation.ValidationFailedException;
 import eu.ztsh.wymiana.web.model.UserCreateRequest;
 import jakarta.validation.Valid;
+import jakarta.validation.ValidationException;
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
@@ -27,7 +28,13 @@ public class UserController {
 
     @GetMapping("{pesel}")
     public ResponseEntity<User> get(@PathVariable("pesel") String pesel) {
-        return ResponseEntity.of(userService.get(pesel));
+        try {
+            return userService.get(pesel)
+                .map(ResponseEntity::ok)
+                .orElse(ResponseEntity.notFound().build());
+        } catch (ValidationException e) {
+            return ResponseEntity.badRequest().build();
+        }
     }
 
     @PostMapping