Add the Auth controller to login and get the user token.

src/main/java/space/kklochko/spring_rest_example/controllers/AuthController.java

@@ -0,0 +1,54 @@
+package space.kklochko.spring_rest_example.controllers;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+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;
+import space.kklochko.spring_rest_example.db.repositories.TokenRepository;
+import space.kklochko.spring_rest_example.db.repositories.UserRepository;
+import space.kklochko.spring_rest_example.models.Token;
+import space.kklochko.spring_rest_example.models.User;
+import space.kklochko.spring_rest_example.models.factories.TokenFactory;
+import space.kklochko.spring_rest_example.security.hashes.Sha256Hash;
+
+@RestController
+@RequestMapping("/api/v1/auth")
+public class AuthController {
+    @Autowired
+    private UserRepository userRepository;
+
+    @Autowired
+    private TokenRepository tokenRepository;
+
+    @Autowired
+    private TokenFactory tokenFactory;
+
+    @PostMapping("/login")
+    public ResponseEntity<String> authenticateUser(@RequestBody User user){
+        if(user.getUsername() == null || user.getUsername().isEmpty())
+            return ResponseEntity.status(500).body("Failed to login, because no username!!!");
+
+        if(user.getPassword() == null || user.getPassword().isEmpty())
+            return ResponseEntity.status(500).body("Failed to login, because no password!!!");
+
+        User expected = userRepository.read(user.getUsername());
+
+        if(expected == null)
+            return ResponseEntity.status(500).body("Failed to login, because the user does not exist!!! Please, check your username!!!");
+
+        String hashedPassword = (new Sha256Hash()).hashOf(user.getPassword());
+
+        if(!expected.getPassword().equals(hashedPassword))
+            return ResponseEntity.status(500).body("Failed to login, because incorrect password!!! Please, check your password!!!");
+
+        Token token = tokenFactory.create(expected.getUsername(), expected.getRole());
+
+        tokenRepository.create(token);
+
+        return new ResponseEntity<>(String.format("token: %s", token.getToken()), HttpStatus.OK);
+    }
+}
+