feat(dataset-groups): CRUD, latest-in-group, group SLD with dataset fallback, CreateRasterFromFile

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

internal/service/dataset_group.go

@@ -0,0 +1,185 @@
+package service
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"path"
+	"path/filepath"
+	"strings"
+
+	"gis/internal/domain"
+
+	"github.com/google/uuid"
+)
+
+// DatasetGroupRepository is the persistence behaviour DatasetGroupService needs.
+type DatasetGroupRepository interface {
+	Create(ctx context.Context, g domain.DatasetGroup) (domain.DatasetGroup, error)
+	GetByID(ctx context.Context, id uuid.UUID) (domain.DatasetGroup, error)
+	GetByCode(ctx context.Context, code string) (domain.DatasetGroup, error)
+	List(ctx context.Context, code *string, limit, offset int) ([]domain.DatasetGroup, error)
+	Count(ctx context.Context, code *string) (int, error)
+	Update(ctx context.Context, g domain.DatasetGroup) (domain.DatasetGroup, error)
+	Delete(ctx context.Context, id uuid.UUID) error
+	SetSLD(ctx context.Context, id uuid.UUID, key, filename, contentType string) (domain.DatasetGroup, error)
+}
+
+// DatasetGroupInput carries the mutable fields of a group.
+type DatasetGroupInput struct {
+	Code        string
+	Name        string
+	Description string
+}
+
+// DatasetGroupPage is a page of groups.
+type DatasetGroupPage struct {
+	Items    []domain.DatasetGroup
+	Page     int
+	PageSize int
+	Total    int
+}
+
+// DatasetGroupService implements dataset-group business rules.
+type DatasetGroupService struct {
+	repo     DatasetGroupRepository
+	datasets DatasetRepository
+	store    ObjectStore
+}
+
+// NewDatasetGroupService wires the group repository, the dataset repository
+// (for the "latest" lookup) and the object store (for the group SLD).
+func NewDatasetGroupService(repo DatasetGroupRepository, datasets DatasetRepository, store ObjectStore) *DatasetGroupService {
+	return &DatasetGroupService{repo: repo, datasets: datasets, store: store}
+}
+
+// errInvalidGroupCode is the validation error returned for a non-slug code.
+func errInvalidGroupCode() error {
+	return fmt.Errorf("%w: code must be a slug (lowercase latin letters, digits, and dashes)", domain.ErrValidation)
+}
+
+// Create persists a new group after validating its code.
+func (s *DatasetGroupService) Create(ctx context.Context, in DatasetGroupInput) (domain.DatasetGroup, error) {
+	if !domain.ValidSlug(in.Code) {
+		return domain.DatasetGroup{}, errInvalidGroupCode()
+	}
+	return s.repo.Create(ctx, domain.DatasetGroup{Code: in.Code, Name: in.Name, Description: in.Description})
+}
+
+// Get returns one group by id.
+func (s *DatasetGroupService) Get(ctx context.Context, id uuid.UUID) (domain.DatasetGroup, error) {
+	return s.repo.GetByID(ctx, id)
+}
+
+// List returns a page of groups; page/pageSize are clamped like datasets.
+func (s *DatasetGroupService) List(ctx context.Context, code *string, page, pageSize int) (DatasetGroupPage, error) {
+	if page < 1 {
+		page = 1
+	}
+	if pageSize < 1 {
+		pageSize = DefaultPageSize
+	}
+	if pageSize > MaxPageSize {
+		pageSize = MaxPageSize
+	}
+	items, err := s.repo.List(ctx, code, pageSize, (page-1)*pageSize)
+	if err != nil {
+		return DatasetGroupPage{}, err
+	}
+	total, err := s.repo.Count(ctx, code)
+	if err != nil {
+		return DatasetGroupPage{}, err
+	}
+	return DatasetGroupPage{Items: items, Page: page, PageSize: pageSize, Total: total}, nil
+}
+
+// Update replaces a group's editable fields.
+func (s *DatasetGroupService) Update(ctx context.Context, id uuid.UUID, in DatasetGroupInput) (domain.DatasetGroup, error) {
+	if !domain.ValidSlug(in.Code) {
+		return domain.DatasetGroup{}, errInvalidGroupCode()
+	}
+	return s.repo.Update(ctx, domain.DatasetGroup{ID: id, Code: in.Code, Name: in.Name, Description: in.Description})
+}
+
+// Delete removes a group (409 via ErrConflict while datasets reference it) and
+// then best-effort removes its SLD object.
+func (s *DatasetGroupService) Delete(ctx context.Context, id uuid.UUID) error {
+	g, err := s.repo.GetByID(ctx, id)
+	if err != nil {
+		return err
+	}
+	if err := s.repo.Delete(ctx, id); err != nil {
+		return err
+	}
+	if g.SldStorageKey != nil {
+		_ = s.store.Remove(ctx, *g.SldStorageKey) // best-effort: the row is gone
+	}
+	return nil
+}
+
+// Latest returns the freshest dataset of the group (greatest end_date, NULLs
+// last, then newest), optionally restricted by status and file type.
+func (s *DatasetGroupService) Latest(ctx context.Context, id uuid.UUID, status *string, fileType *domain.FileType) (domain.Dataset, error) {
+	if _, err := s.repo.GetByID(ctx, id); err != nil {
+		return domain.Dataset{}, err
+	}
+	return s.datasets.LatestInGroup(ctx, id, status, fileType)
+}
+
+// UploadSLD validates and stores the group's shared SLD, replacing any previous one.
+func (s *DatasetGroupService) UploadSLD(ctx context.Context, id uuid.UUID, in UploadSLDInput) (domain.DatasetGroup, error) {
+	g, err := s.repo.GetByID(ctx, id)
+	if err != nil {
+		return domain.DatasetGroup{}, err
+	}
+
+	ext := strings.ToLower(filepath.Ext(in.Filename))
+	if !domain.ExtensionAllowedForSLD(ext) {
+		return domain.DatasetGroup{}, fmt.Errorf("%w: sld file must have one of these extensions: %s",
+			domain.ErrValidation, strings.Join(domain.AllowedSLDExtensions, ", "))
+	}
+
+	head := make([]byte, 512)
+	n, err := io.ReadFull(in.Reader, head)
+	if err != nil && err != io.EOF && err != io.ErrUnexpectedEOF {
+		return domain.DatasetGroup{}, fmt.Errorf("read sld upload: %w", err)
+	}
+	head = head[:n]
+	if err := domain.ValidateFileContent(ext, head); err != nil {
+		return domain.DatasetGroup{}, fmt.Errorf("%w: %s", domain.ErrValidation, err)
+	}
+	content := io.MultiReader(bytes.NewReader(head), in.Reader)
+
+	key := path.Join("groups", g.ID.String(), "sld", in.Filename)
+	if err := s.store.Put(ctx, key, content, in.Size, in.ContentType); err != nil {
+		return domain.DatasetGroup{}, err
+	}
+	updated, err := s.repo.SetSLD(ctx, id, key, in.Filename, in.ContentType)
+	if err != nil {
+		// Compensate: the row was not updated, so the object would be orphaned.
+		_ = s.store.Remove(ctx, key)
+		return domain.DatasetGroup{}, err
+	}
+	if g.SldStorageKey != nil && *g.SldStorageKey != key {
+		_ = s.store.Remove(ctx, *g.SldStorageKey) // best-effort: drop the replaced file
+	}
+	return updated, nil
+}
+
+// DownloadSLD returns the group and a reader for its SLD; ErrSLDNotFound when
+// none has been uploaded. The caller must close the reader.
+func (s *DatasetGroupService) DownloadSLD(ctx context.Context, id uuid.UUID) (domain.DatasetGroup, io.ReadCloser, error) {
+	g, err := s.repo.GetByID(ctx, id)
+	if err != nil {
+		return domain.DatasetGroup{}, nil, err
+	}
+	if g.SldStorageKey == nil {
+		return domain.DatasetGroup{}, nil, ErrSLDNotFound
+	}
+	obj, err := s.store.Get(ctx, *g.SldStorageKey)
+	if err != nil {
+		return domain.DatasetGroup{}, nil, err
+	}
+	return g, obj, nil
+}