Added AddTask and DeleteTask. Without db tests

internal/contests/delivery.go

@@ -10,4 +10,6 @@ type ContestHandlers interface {
 	CreateContest(ctx context.Context, req *contestv1.CreateContestRequest) (*contestv1.CreateContestResponse, error)
 	ReadContest(ctx context.Context, req *contestv1.ReadContestRequest) (*contestv1.ReadContestResponse, error)
 	DeleteContest(ctx context.Context, req *contestv1.DeleteContestRequest) (*emptypb.Empty, error)
+	AddTask(ctx context.Context, req *contestv1.AddTaskRequest) (*contestv1.AddTaskResponse, error)
+	DeleteTask(ctx context.Context, req *contestv1.DeleteTaskRequest) (*emptypb.Empty, error)
 }

internal/contests/delivery/grpc/handlers.go

@@ -49,3 +49,19 @@ func (h *ContestHandlers) DeleteContest(ctx context.Context, req *contestv1.Dele
 	}
 	return &emptypb.Empty{}, nil
 }
+
+func (h *ContestHandlers) AddTask(ctx context.Context, req *contestv1.AddTaskRequest) (*contestv1.AddTaskResponse, error) {
+	id, err := h.contestUC.AddTask(ctx, req.GetContestId(), req.GetProblemId())
+	if err != nil {
+		return nil, err
+	}
+	return &contestv1.AddTaskResponse{Id: id}, nil
+}
+
+func (h *ContestHandlers) DeleteTask(ctx context.Context, req *contestv1.DeleteTaskRequest) (*emptypb.Empty, error) {
+	err := h.contestUC.DeleteTask(ctx, req.GetTaskId())
+	if err != nil {
+		return nil, err
+	}
+	return &emptypb.Empty{}, nil
+}

internal/contests/pg_repository.go

@@ -9,4 +9,6 @@ type ContestRepository interface {
 	CreateContest(ctx context.Context, title string) (int32, error)
 	ReadContestById(ctx context.Context, id int32) (*models.Contest, error)
 	DeleteContest(ctx context.Context, id int32) error
+	AddTask(ctx context.Context, contestId int32, taskId int32) (int32, error)
+	DeleteTask(ctx context.Context, taskId int32) error
 }

internal/contests/repository/pg_repository.go

@@ -68,6 +68,35 @@ func (r *ContestRepository) DeleteContest(ctx context.Context, id int32) error {
 	return nil
 }
 
+const addTaskQuery = "INSERT INTO task (problem_id, contest_id,position) VALUES (?, ?,(SELECT COALESCE(MAX(position),0) + 1 FROM task)	) RETURNING id"
+
+func (r *ContestRepository) AddTask(ctx context.Context, contestId int32, taskId int32) (int32, error) {
+	query := r.db.Rebind(addTaskQuery)
+	rows, err := r.db.QueryxContext(ctx, query, taskId, contestId)
+	if err != nil {
+		return 0, handlePgErr(err)
+	}
+	defer rows.Close()
+	var id int32
+	rows.Next()
+	err = rows.Scan(&id)
+	if err != nil {
+		return 0, handlePgErr(err)
+	}
+	return id, nil
+}
+
+const deleteTaskQuery = "DELETE FROM task WHERE id=?"
+
+func (r *ContestRepository) DeleteTask(ctx context.Context, taskId int32) error {
+	query := r.db.Rebind(deleteTaskQuery)
+	_, err := r.db.ExecContext(ctx, query, taskId)
+	if err != nil {
+		return handlePgErr(err)
+	}
+	return nil
+}
+
 func handlePgErr(err error) error {
 	var pgErr *pgconn.PgError
 	if !errors.As(err, &pgErr) {

internal/contests/usecase.go

@@ -9,4 +9,6 @@ type ContestUseCase interface {
 	CreateContest(ctx context.Context, title string) (int32, error)
 	ReadContestById(ctx context.Context, id int32) (*models.Contest, error)
 	DeleteContest(ctx context.Context, id int32) error
+	AddTask(ctx context.Context, contestId int32, taskId int32) (int32, error)
+	DeleteTask(ctx context.Context, taskId int32) error
 }

internal/contests/usecase/usecase.go

@@ -29,3 +29,11 @@ func (uc *ContestUseCase) ReadContestById(ctx context.Context, id int32) (*model
 func (uc *ContestUseCase) DeleteContest(ctx context.Context, id int32) error {
 	return uc.contestRepo.DeleteContest(ctx, id)
 }
+
+func (uc *ContestUseCase) AddTask(ctx context.Context, contestId int32, taskId int32) (id int32, err error) {
+	return uc.contestRepo.AddTask(ctx, contestId, taskId)
+}
+
+func (uc *ContestUseCase) DeleteTask(ctx context.Context, taskId int32) error {
+	return uc.contestRepo.DeleteTask(ctx, taskId)
+}