Add API for changing tasks' order

Resolves #2

src/main/java/com/example/demo/controller/TasksController.java

@@ -30,11 +30,10 @@ import javax.validation.Valid;
 @RequestMapping(value = "/training-definitions/{definitionId}/phases/{phaseId}/tasks", produces = MediaType.APPLICATION_JSON_VALUE)
 @CrossOrigin(origins = "*", allowCredentials = "true", allowedHeaders = "*",
         methods = {RequestMethod.GET, RequestMethod.POST, RequestMethod.DELETE, RequestMethod.PUT})
-@Api(value = "/training-definitions/{definitionId}/phases",
+@Api(value = "/training-definitions/{definitionId}/tasks",
         tags = "Tasks",
         consumes = MediaType.APPLICATION_JSON_VALUE,
         authorizations = @Authorization(value = "bearerAuth"))
-
 public class TasksController {
 
     @Autowired
@@ -161,4 +160,23 @@ public class TasksController {
 
         return ResponseEntity.ok().build();
     }
+
+    @ApiOperation(httpMethod = "PUT",
+            value = "Move task to specified order",
+            nickname = "moveTaskToSpecifiedOrder",
+            produces = MediaType.APPLICATION_JSON_VALUE
+    )
+    @ApiResponses(value = {
+            @ApiResponse(code = 200, message = "Task moved to specified order"),
+            @ApiResponse(code = 500, message = "Unexpected application error")
+    })
+    @PutMapping(value = "/{taskIdFrom}/move-to/{newPosition}", produces = MediaType.APPLICATION_JSON_VALUE)
+    public ResponseEntity<Void> moveTaskToSpecifiedOrder(
+            @ApiParam(value = "Task ID - from", required = true) @PathVariable(name = "taskIdFrom") Long taskIdFrom,
+            @ApiParam(value = "Position (order) to which the task should be moved", required = true) @PathVariable(name = "newPosition") int newPosition) {
+
+        taskService.moveTaskToSpecifiedOrder(taskIdFrom, newPosition);
+
+        return ResponseEntity.ok().build();
+    }
 }

src/main/java/com/example/demo/repository/TaskRepository.java

@@ -12,6 +12,26 @@ public interface TaskRepository extends JpaRepository<Task, Long> {
     @Query("SELECT COALESCE(MAX(g.order), -1) FROM Task g WHERE g.trainingPhase.id = :phaseId")
     Integer getCurrentMaxOrder(@Param("phaseId") Long phaseId);
 
+    @Modifying
+    @Query("UPDATE Task t SET t.order = t.order - 1 " +
+            "WHERE t.trainingPhase.id = :trainingPhaseId " +
+            "AND t.order > :lowerBound " +
+            "AND t.order <= :upperBound ")
+    void decreaseOrderOfTasksOnInterval(@Param("trainingPhaseId") Long trainingPhaseId,
+                                         @Param("lowerBound") int lowerBound,
+                                         @Param("upperBound") int upperBound);
+
+
+    @Modifying
+    @Query("UPDATE Task t SET t.order = t.order + 1 " +
+            "WHERE t.trainingPhase.id = :trainingPhaseId " +
+            "AND t.order >= :lowerBound " +
+            "AND t.order < :upperBound ")
+    void increaseOrderOfTasksOnInterval(@Param("trainingPhaseId") Long trainingPhaseId,
+                                         @Param("lowerBound") int lowerBound,
+                                         @Param("upperBound") int upperBound);
+
+
     @Transactional
     @Modifying
     @Query("UPDATE Task t SET t.order = t.order - 1 " +

src/main/java/com/example/demo/service/TaskService.java

@@ -14,6 +14,7 @@ import org.slf4j.LoggerFactory;
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -133,4 +134,25 @@ public class TaskService {
 
         taskRepository.delete(task);
     }
+
+    @Transactional
+    public void moveTaskToSpecifiedOrder(Long taskIdFrom, int newPosition) {
+        Task task = taskRepository.findById(taskIdFrom)
+                .orElseThrow(() -> new RuntimeException("Task was not found"));
+        // TODO throw proper exception once kypo2-training is migrated
+
+        int fromOrder = task.getOrder();
+
+        if (fromOrder < newPosition) {
+            taskRepository.decreaseOrderOfTasksOnInterval(task.getTrainingPhase().getId(), fromOrder, newPosition);
+        } else if (fromOrder > newPosition) {
+            taskRepository.increaseOrderOfTasksOnInterval(task.getTrainingPhase().getId(), newPosition, fromOrder);
+        } else {
+            // nothing should be changed, no further actions needed
+            return;
+        }
+
+        task.setOrder(newPosition);
+        taskRepository.save(task);
+    }
 }