Modified QuestionEntity to have author property gotten from Principal

src/main/kotlin/com/serge/nsn/qahub/api/controller/QuestionController.kt

@@ -0,0 +1,27 @@
+package com.serge.nsn.qahub.api.controller
+
+import com.serge.nsn.qahub.api.dto.QuestionDto
+import com.serge.nsn.qahub.services.QuestionService
+import org.springframework.web.bind.annotation.*
+import java.security.Principal
+
+@RestController
+@RequestMapping("/api/question")
+class QuestionController(
+    private val questionService: QuestionService
+) {
+
+    @GetMapping("/all")
+    fun getAll() = questionService.getAllQuestions()
+
+    @GetMapping("/{id}")
+    fun get(@PathVariable id: Long) = questionService.getQuestionById(id)
+
+    @GetMapping("/user/{userId}")
+    fun getByUserId(@PathVariable userId: Long): List<QuestionDto> {
+        return questionService.getByUserId(userId)
+    }
+
+    @PostMapping("/ask")
+    fun ask(@RequestBody question: QuestionDto, principal: Principal) = questionService.askQuestion(question, principal)
+}

src/main/kotlin/com/serge/nsn/qahub/services/QuestionService.kt

@@ -0,0 +1,42 @@
+package com.serge.nsn.qahub.services
+
+import com.serge.nsn.qahub.api.dto.QuestionDto
+import com.serge.nsn.qahub.data.entities.QuestionEntity
+import com.serge.nsn.qahub.data.entities.UserEntity
+import com.serge.nsn.qahub.data.repositories.QuestionRepository
+import com.serge.nsn.qahub.data.repositories.UserRepository
+import org.springframework.http.HttpStatus
+import org.springframework.http.ResponseEntity
+import org.springframework.stereotype.Service
+import java.security.Principal
+
+@Service
+class QuestionService(
+    private val questionRepository: QuestionRepository,
+    private val userRepository: UserRepository
+) {
+    fun askQuestion(dto: QuestionDto, principal: Principal): ResponseEntity<QuestionDto> {
+        val questionAuthor: UserEntity = userRepository.findByEmail(principal.name).get()
+        val askedQuestion = questionRepository
+            .save(
+                QuestionEntity(
+                    id = dto.id,
+                    title = dto.title,
+                    content = dto.content,
+                    author = questionAuthor.name,
+                    user = questionAuthor
+                )
+
+            )
+
+        return ResponseEntity(QuestionDto(askedQuestion), HttpStatus.CREATED)
+    }
+
+    fun getAllQuestions() = questionRepository.findAll().map { QuestionDto(it) }
+    fun getQuestionById(id: Long) = questionRepository.findById(id).map { QuestionDto(it) }
+
+    fun getByUserId(userId: Long): List<QuestionDto> {
+        return questionRepository.findAllByUserId(userId).map { QuestionDto(it) }
+    }
+
+}