Added an endpoint allowing file metadata to be requested by ID.

services/prototype.go

@@ -389,6 +389,57 @@ func (service *prototype) searchDatabaseWithSpecificParams(ctx context.Context,
 	return searchDatabase(ctx, &searchInput, body.Specific)
 }
 
+type FileMetadataOutput struct {
+	Body FileMetadataResponse `doc:"Metadata for files with the given IDs"`
+}
+
+// fetches file metadata given a list of file identifiers
+func (service *prototype) fetchFileMetadata(ctx context.Context,
+	input *struct {
+		Authorization string `header:"authorization" doc:"Authorization header with encoded access token"`
+		Database      string `json:"database" query:"database" example:"jdp" doc:"The ID of the database for which file metadata is fetched"`
+		Ids           string `json:"ids" query:"ids" example:"JDP:6101cc0f2b1f2eeea564c978" doc:"A comma-separated list of file IDs"`
+		Offset        int    `json:"offset" query:"offset" example:"100" doc:"Metadata records begin at the given offset"`
+		Limit         int    `json:"limit" query:"limit" example:"50" doc:"Limits the number of metadata records returned"`
+	}) (*FileMetadataOutput, error) {
+
+	orcid, err := authorize(input.Authorization)
+	if err != nil {
+		return nil, err
+	}
+
+	// is the database valid?
+	_, ok := config.Databases[input.Database]
+	if !ok {
+		return nil, fmt.Errorf("Database %s not found", input.Database)
+	}
+
+	// have we been given any IDs?
+	if strings.TrimSpace(input.Ids) == "" {
+		return nil, huma.Error400BadRequest("No file IDs were provided!")
+	}
+	ids := strings.Split(input.Ids, ",")
+
+	slog.Info(fmt.Sprintf("Fetching file metadata for %d files in database %s...",
+		len(ids), input.Database))
+	db, err := databases.NewDatabase(orcid, input.Database)
+	if err != nil {
+		return nil, err
+	}
+
+	results, err := db.Resources(ids)
+	if err != nil {
+		slog.Error(err.Error())
+		return nil, err
+	}
+	return &FileMetadataOutput{
+		Body: FileMetadataResponse{
+			Database:  input.Database,
+			Resources: results,
+		},
+	}, nil
+}
+
 type TransferOutput struct {
 	Body   TransferResponse `doc:"A UUID for the requested transfer"`
 	Status int
@@ -527,6 +578,7 @@ func NewDTSPrototype() (TransferService, error) {
 	huma.Get(api, "/api/v1/databases/{db}/search-parameters", service.getDatabaseSearchParameters)
 	huma.Get(api, "/api/v1/files", service.searchDatabase)
 	huma.Post(api, "/api/v1/files", service.searchDatabaseWithSpecificParams)
+	huma.Get(api, "/api/v1/files/by-id", service.fetchFileMetadata)
 	huma.Post(api, "/api/v1/transfers", service.createTransfer)
 	huma.Get(api, "/api/v1/transfers/{id}", service.getTransferStatus)
 	huma.Delete(api, "/api/v1/transfers/{id}", service.deleteTransfer)

services/prototype_test.go

@@ -416,6 +416,35 @@ func TestSearchDatabase(t *testing.T) {
 	assert.Equal("file1", results.Resources[0].Name)
 }
 
+// fetches file metadata from the JDP for some specific files
+func TestFetchJdpMetadata(t *testing.T) {
+	assert := assert.New(t)
+
+	// try omitting file IDs
+	resp, err := get(baseUrl + apiPrefix + "files/by-id?database=jdp")
+	assert.Nil(err)
+	assert.Equal(http.StatusBadRequest, resp.StatusCode)
+
+	// now let's fetch 3 records
+	resp, err = get(baseUrl + apiPrefix +
+		"files/by-id?database=jdp&ids=JDP:6101cc0f2b1f2eeea564c978,JDP:613a7baa72d3a08c9a54b32d,JDP:61412246cc4ff44f36c8913d")
+	assert.Nil(err)
+
+	respBody, err := io.ReadAll(resp.Body)
+	assert.Nil(err)
+	assert.Equal(http.StatusOK, resp.StatusCode)
+	defer resp.Body.Close()
+
+	var results SearchResultsResponse
+	err = json.Unmarshal(respBody, &results)
+	assert.Nil(err)
+	assert.Equal("jdp", results.Database)
+	assert.Equal(3, len(results.Resources))
+	assert.Equal("JDP:6101cc0f2b1f2eeea564c978", results.Resources[0].Id)
+	assert.Equal("JDP:613a7baa72d3a08c9a54b32d", results.Resources[1].Id)
+	assert.Equal("JDP:61412246cc4ff44f36c8913d", results.Resources[2].Id)
+}
+
 // creates a transfer from source -> destination1
 func TestCreateTransfer(t *testing.T) {
 	assert := assert.New(t)

services/transfer_service.go

@@ -2,24 +2,12 @@ package services
 
 import (
 	"context"
-	"encoding/json"
-	"net/http"
 
 	"github.com/google/uuid"
 
 	"github.com/kbase/dts/frictionless"
 )
 
-// This package-specific helper function writes a JSON payload to an
-// http.ResponseWriter.
-func writeJson(w http.ResponseWriter, data []byte, code int) {
-	w.WriteHeader(code)
-	if len(data) > 0 {
-		w.Header().Set("Content-Type", "application/json")
-		w.Write(data)
-	}
-}
-
 // this type encodes a JSON object for responding to root queries
 type ServiceInfoResponse struct {
 	Name          string `json:"name" example:"DTS" doc:"The name of the service API"`
@@ -37,17 +25,6 @@ type ErrorResponse struct {
 	Error string `json:"message"`
 }
 
-// This package-specific helper function writes an error to an
-// http.ResponseWriter, giving it the proper status code, and encoding an
-// ErrorResponse in the response body.
-func writeError(w http.ResponseWriter, message string, code int) {
-	w.Header().Set("Content-Type", "application/json")
-	w.WriteHeader(code)
-	e := ErrorResponse{Code: code, Error: message}
-	data, _ := json.Marshal(e)
-	w.Write(data)
-}
-
 // a response for a database-related query (GET)
 type DatabaseResponse struct {
 	Id           string `json:"id" example:"jdp" `
@@ -56,13 +33,21 @@ type DatabaseResponse struct {
 	URL          string `json:"url" example:"https://data.jgi.doe.gov"`
 }
 
-// a response for a query (GET)
+// a response for a file search query (GET)
 type SearchResultsResponse struct {
 	// name of organization database
 	Database string `json:"database" example:"jdp" doc:"the database searched"`
 	// ElasticSearch query string
 	Query string `json:"query" example:"prochlorococcus" doc:"the given query string"`
-	// Resources matching the query
+	// resources matching the query
+	Resources []frictionless.DataResource `json:"resources" doc:"an array of Frictionless DataResources"`
+}
+
+// a response for a file metadata query (GET)
+type FileMetadataResponse struct {
+	// name of organization database
+	Database string `json:"database" example:"jdp" doc:"the database searched"`
+	// resources corresponding to given file IDs
 	Resources []frictionless.DataResource `json:"resources" doc:"an array of Frictionless DataResources"`
 }