support for cron based subscriptions management

server/subscription/service/service.go

@@ -0,0 +1,140 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"math"
+
+	"github.com/marcopiovanello/yt-dlp-web-ui/v3/server/subscription/data"
+	"github.com/marcopiovanello/yt-dlp-web-ui/v3/server/subscription/domain"
+	"github.com/marcopiovanello/yt-dlp-web-ui/v3/server/subscription/task"
+	"github.com/robfig/cron/v3"
+)
+
+type Service struct {
+	r      domain.Repository
+	runner task.TaskRunner
+}
+
+func New(r domain.Repository, runner task.TaskRunner) domain.Service {
+	s := &Service{
+		r:      r,
+		runner: runner,
+	}
+
+	// very crude recoverer
+	initial, _ := s.List(context.Background(), 0, math.MaxInt)
+	if initial != nil {
+		for _, v := range initial.Data {
+			s.runner.Submit(&v)
+		}
+	}
+
+	return s
+}
+
+func fromDB(model *data.Subscription) domain.Subscription {
+	return domain.Subscription{
+		Id:       model.Id,
+		URL:      model.URL,
+		Params:   model.Params,
+		CronExpr: model.CronExpr,
+	}
+}
+
+func toDB(dto *domain.Subscription) data.Subscription {
+	return data.Subscription{
+		Id:       dto.Id,
+		URL:      dto.URL,
+		Params:   dto.Params,
+		CronExpr: dto.CronExpr,
+	}
+}
+
+// Delete implements domain.Service.
+func (s *Service) Delete(ctx context.Context, id string) error {
+	return s.r.Delete(ctx, id)
+}
+
+// GetCursor implements domain.Service.
+func (s *Service) GetCursor(ctx context.Context, id string) (int64, error) {
+	return s.r.GetCursor(ctx, id)
+}
+
+// List implements domain.Service.
+func (s *Service) List(ctx context.Context, start int64, limit int) (
+	*domain.PaginatedResponse[[]domain.Subscription],
+	error,
+) {
+	dbSubs, err := s.r.List(ctx, start, limit)
+	if err != nil {
+		return nil, err
+	}
+
+	subs := make([]domain.Subscription, len(*dbSubs))
+
+	for i, v := range *dbSubs {
+		subs[i] = fromDB(&v)
+	}
+
+	var (
+		first int64
+		next  int64
+	)
+
+	if len(subs) > 0 {
+		first, err = s.r.GetCursor(ctx, subs[0].Id)
+		if err != nil {
+			return nil, err
+		}
+
+		next, err = s.r.GetCursor(ctx, subs[len(subs)-1].Id)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return &domain.PaginatedResponse[[]domain.Subscription]{
+		First: first,
+		Next:  next,
+		Data:  subs,
+	}, nil
+}
+
+// Submit implements domain.Service.
+func (s *Service) Submit(ctx context.Context, sub *domain.Subscription) (*domain.Subscription, error) {
+	if sub.CronExpr == "" {
+		sub.CronExpr = "*/5 * * * *"
+	}
+
+	_, err := cron.ParseStandard(sub.CronExpr)
+	if err != nil {
+		return nil, errors.Join(errors.New("failed parsing cron expression"), err)
+	}
+
+	subDB, err := s.r.Submit(ctx, &data.Subscription{
+		URL:      sub.URL,
+		Params:   sub.Params,
+		CronExpr: sub.CronExpr,
+	})
+
+	retval := fromDB(subDB)
+
+	if err := s.runner.Submit(sub); err != nil {
+		return nil, err
+	}
+
+	return &retval, err
+}
+
+// UpdateByExample implements domain.Service.
+func (s *Service) UpdateByExample(ctx context.Context, example *domain.Subscription) error {
+	_, err := cron.ParseStandard(example.CronExpr)
+	if err != nil {
+		return errors.Join(errors.New("failed parsing cron expression"), err)
+	}
+
+	e := toDB(example)
+
+	return s.r.UpdateByExample(ctx, &e)
+}