Added AddParticipant and DeleteParticipant

internal/contests/delivery.go

@@ -12,4 +12,6 @@ type ContestHandlers interface {
 	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)
+	AddParticipant(ctx context.Context, req *contestv1.AddParticipantRequest) (*contestv1.AddParticipantResponse, error)
+	DeleteParticipant(ctx context.Context, req *contestv1.DeleteParticipantRequest) (*emptypb.Empty, error)
 }

internal/contests/delivery/grpc/handlers.go

@@ -65,3 +65,19 @@ func (h *ContestHandlers) DeleteTask(ctx context.Context, req *contestv1.DeleteT
 	}
 	return &emptypb.Empty{}, nil
 }
+
+func (h *ContestHandlers) AddParticipant(ctx context.Context, req *contestv1.AddParticipantRequest) (*contestv1.AddParticipantResponse, error) {
+	id, err := h.contestUC.AddParticipant(ctx, req.GetContestId(), req.GetUserId())
+	if err != nil {
+		return nil, err
+	}
+	return &contestv1.AddParticipantResponse{Id: id}, nil
+}
+
+func (h *ContestHandlers) DeleteParticipant(ctx context.Context, req *contestv1.DeleteParticipantRequest) (*emptypb.Empty, error) {
+	err := h.contestUC.DeleteParticipant(ctx, req.GetParticipantId())
+	if err != nil {
+		return nil, err
+	}
+	return &emptypb.Empty{}, nil
+}

internal/contests/pg_repository.go

@@ -11,4 +11,6 @@ type ContestRepository interface {
 	DeleteContest(ctx context.Context, id int32) error
 	AddTask(ctx context.Context, contestId int32, taskId int32) (int32, error)
 	DeleteTask(ctx context.Context, taskId int32) error
+	AddParticipant(ctx context.Context, contestId int32, userId int32) (int32, error)
+	DeleteParticipant(ctx context.Context, participantId int32) error
 }

internal/contests/repository/pg_repository.go

@@ -68,7 +68,7 @@ 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"
+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)
@@ -97,6 +97,35 @@ func (r *ContestRepository) DeleteTask(ctx context.Context, taskId int32) error
 	return nil
 }
 
+const addParticipantQuery = "INSERT INTO participant (user_id ,contest_id, name) VALUES (?, ?, ?) RETURNING id"
+
+func (r *ContestRepository) AddParticipant(ctx context.Context, contestId int32, userId int32) (int32, error) {
+	query := r.db.Rebind(addParticipantQuery)
+	name := ""
+	rows, err := r.db.QueryxContext(ctx, query, contestId, userId, name)
+	if err != nil {
+		return 0, handlePgErr(err)
+	}
+	defer rows.Close()
+	var id int32
+	err = rows.Scan(&id)
+	if err != nil {
+		return 0, err
+	}
+	return id, nil
+}
+
+const deleteParticipantQuery = "DELETE FROM participant WHERE id=?"
+
+func (r *ContestRepository) DeleteParticipant(ctx context.Context, participantId int32) error {
+	query := r.db.Rebind(deleteParticipantQuery)
+	_, err := r.db.ExecContext(ctx, query, participantId)
+	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

@@ -11,4 +11,6 @@ type ContestUseCase interface {
 	DeleteContest(ctx context.Context, id int32) error
 	AddTask(ctx context.Context, contestId int32, taskId int32) (int32, error)
 	DeleteTask(ctx context.Context, taskId int32) error
+	AddParticipant(ctx context.Context, contestId int32, userId int32) (int32, error)
+	DeleteParticipant(ctx context.Context, participantId int32) error
 }

internal/contests/usecase/usecase.go

@@ -37,3 +37,11 @@ func (uc *ContestUseCase) AddTask(ctx context.Context, contestId int32, taskId i
 func (uc *ContestUseCase) DeleteTask(ctx context.Context, taskId int32) error {
 	return uc.contestRepo.DeleteTask(ctx, taskId)
 }
+
+func (uc *ContestUseCase) AddParticipant(ctx context.Context, contestId int32, userId int32) (id int32, err error) {
+	return uc.contestRepo.AddParticipant(ctx, contestId, userId)
+}
+
+func (uc *ContestUseCase) DeleteParticipant(ctx context.Context, participantId int32) error {
+	return uc.contestRepo.DeleteParticipant(ctx, participantId)
+}